The determination of source-side extracted heating parameters is of great significance to the economic operation of cogeneration systems.This paper investigated the coupling performance of a cogeneration heating and p...The determination of source-side extracted heating parameters is of great significance to the economic operation of cogeneration systems.This paper investigated the coupling performance of a cogeneration heating and power system multidimensionally based on the operating characteristics of the cogeneration units,the hydraulic and thermodynamic characteristics of the heating network,and the energy loads.Taking a steam network supported by a gas-steam combined cycle cogeneration system as the research case,the interaction effect among the source-side prime movers,the heating networks,and the terminal demand thermal parameters were investigated based on the designed values,the plant testing data,and the validated simulation.The operating maps of the gas-steam combined cycle cogeneration units were obtained using THERMOFLEX,and the minimum source-side steam parameters of the steam network were solved using an inverse solution procedure based on the hydro-thermodynamic coupling model.The cogeneration operating maps indicate that the available operating domain considerably narrows with the rise of the extraction steam pressure and flow rate.The heating network inverse solution demonstrates that the source-side steam pressure and temperature can be optimized from the originally designed 1.11 MPa and 238.8°C to 1.074 MPa and 191.15°C,respectively.Under the operating strategy with the minimum source-side heating parameters,the power peak regulation depth remarkably increases to 18.30%whereas the comprehensive thermal efficiency decreases.The operation under the minimum source-side heating steam parameters can be superior to the originally designed one in the economy at a higher price of the heating steam.At a fuel price of$0.38/kg and the power to fuel price of 0.18 kg/(kW·h),the critical price ratio of heating steam to fuel is 119.1 kg/t.The influence of the power-fuel price ratio on the economic deviation appears relatively weak.展开更多
The hazelnut weevil(Curculio dieckmanni Faust.)is a major pest of Asian hazel(Corylus heterophylla Fisch.)in China.Dead hazelnut weevil larvae were examined and the associated pathogenic bacterium was identifi ed as S...The hazelnut weevil(Curculio dieckmanni Faust.)is a major pest of Asian hazel(Corylus heterophylla Fisch.)in China.Dead hazelnut weevil larvae were examined and the associated pathogenic bacterium was identifi ed as Serratia marcescens Bizio.This signifi cantly shortened the lifespan of hazelnut weevil.Larval weight was reduced as a function of S.marcescens concentration and exposure time.The structure of infected midgut cells was altered,with necrosis of the wall tissues and many cells becoming dislodged,creating cavities.The S.marcencens strain inhibited digestive enzyme activity and protective enzymes in the midgut of adult hazelnut weevil.Inhibition on S.marcencens strain increased with treatment time.S.marcescens directly destroyed the midgut cells and interfered with digestive and protective enzymes.This decreased the food intake and increased mortality of hazelnut weevil.S.marcescens appears to be an eff ective bacterium for the control of hazelnut weevil but requires further study,including biological formulation development and fi eld application.展开更多
The bed material agglomeration and heating surface high-temperature Corrosion Problems of biomass-fired boiler in South China were studied in this work. The inner and outer surfaces of the corrosion sample were invest...The bed material agglomeration and heating surface high-temperature Corrosion Problems of biomass-fired boiler in South China were studied in this work. The inner and outer surfaces of the corrosion sample were investigated by scanning electron microscope (SEM) with Bruker EDX and XRD. Results showed that the outer side of the corrosion sample was mainly composed of alkali chloride deposited ash, sulphide and a small amount of eutectoid;while the inner side of the corrosion sample was still mainly made up of the composition of SUS316, but added with alkali metal, oxygen, chlorine and sulphur elements, appearing as the corrosion products and eutectoid. It was thought that alkali chloride deposit and the reaction with pipe metal to generate low melting point eutectoid on the outer surfaces, or the corrosion reaction through the alkali metal sulphatization process was the main reasons leading to the damage of metal surface oxide film. Chlorine plays a role as haptoreaction in the corrosion process, and transports metal material as the form of chloride from the inner side to the outer side of the pipe surfaces by diffusion, accelerating the corrosion process. Meanwhile, the slag was studied by scanning electron microscope (SEM) with Bruker EDX, and the transformation process of slage was computationally analyzed by FACTSAGE. Results showed that the amount of alkali metal in the agglomerates was little, however, caused a great impact on severe agglomerates. The increase of temperature enhanced the conversion process of alkali metal to molten oxide, especially when the temperature was higher than760℃, the amount of molten product increased sharply. Thus, the temperature control of fluidized bed plays an important role in solving the problem of alkali metal agglomerates;it also reliefs the volatile of alkali metal into gas phase, benefiting the control of heating surface corrosion.展开更多
Gas turbine power units,as an effective way to cope with the severe challenge of renewable energy accommodation in power grids,arouse the interest of power enterprises in the deep peak-load regulation performance.Two ...Gas turbine power units,as an effective way to cope with the severe challenge of renewable energy accommodation in power grids,arouse the interest of power enterprises in the deep peak-load regulation performance.Two common alternative load-control strategies including constant turbine inlet temperature(TIT)and constant turbine exhaust temperature(TET)regulations were taken into consideration.To comparatively investigate the part-load performance under these strategies,both mathematical and physical models were set up successively to serve as a validation and complementary to each other.For the mathematical model of compressor with inlet guide vane(IGV),combustor and turbine,stage-stacking method based on blade average geometric parameter,energy conservation and turbine stage model were adopted respectively.For the physical model,design and off-design analysis were carried out based on GT PRO and THERMOFLEX respectively.The simulation result of mathematical model validated the reliability of the physical model.Based on this,the influence of ambient temperature and different load-regulating strategies on the off-design performance of gas turbine power units was studied in THERMOFLEX.The results in the case of a PG 9351FA gas turbine show that the ambient temperature has a great impact on system performance,i.e.,every 5℃ increase in the ambient temperature produces a reduction of 3.7%in the relative full-load output and 1.1%in the relative efficiency respectively;when the gas turbine operates under constant TIT strategy,TET starts to rise till it reaches the maximum allowable value with the load rate decreasing,and IGV keeps at the minimum angle with both TIT and TET decreasing when the load rate is lower than 65%;when the gas turbine operates under constant TET strategy,TIT drops slightly at load rate of above 60%while both TIT and TET evidently decrease below 60%load rate operating along the constant corrected speed line at the minimum allowable IGV opening;gas turbine effi-ciency is greatly affected by load rate and the performance degradation is more obvious especially in lower load rate regions;constant TET strategy is superior in the operating efficiency to constant TIT strategy under part-load conditions.展开更多
In this paper, a multiple population genetic algorithm (MPGA) is proposed to solve the problem of optimal load dispatch of gas turbine generation units. By introducing multiple populations on the basis of Standard Gen...In this paper, a multiple population genetic algorithm (MPGA) is proposed to solve the problem of optimal load dispatch of gas turbine generation units. By introducing multiple populations on the basis of Standard Genetic Algorithm (SGA), connecting each population through immigrant operator and preserving the best individuals of every generation through elite strategy, MPGA can enhance the efficiency in obtaining the global optimal solution. In this paper, MPGA is applied to optimize the load dispatch of 3×390MW gas turbine units. The results of MPGA calculation are compared with that of equal micro incremental method and AGC instruction. MPGA shows the best performance of optimization under different load conditions. The amount of saved gas consumption in the calculation is up to 2337.45m3N/h, which indicates that the load dispatch optimization of gas turbine units via MPGA approach can be effective.展开更多
The yield of rice is mostly affected by three factors,namely,panicle number,grain number and grain weight.Variation in panicle and grain numbers is mainly caused by tiller and panicle branches generated from axillary ...The yield of rice is mostly affected by three factors,namely,panicle number,grain number and grain weight.Variation in panicle and grain numbers is mainly caused by tiller and panicle branches generated from axillary meristems(AMs).MOC1 encodes a putative GRAS family nuclear protein that regulates AM formation.Although several alleles of MOC1 have been identified,its variation in germplasm resources remains unclear.In the present study we characterized a novel mocl allele named gnp6 which has a thymine insertion in the coding sequence of the SAW motif in the GRAS domain.This mutation causes arrested branch formation.The SAW motif is necessary for nuclear localization of GNP6/MOC1 where it functions as a transcription factor or co-regulator.Haplotype analysis showed that the coding region of GNP6/MOC1 was conserved without any non-synonymous mutations in 240 rice accessions.However,variation in the promoter region might affect the expression of it and its downstream genes.Joint haplotype analysis of GNP6/MOC1 and MOC3 showed that haplotype combinations H9,H10 and H11,namely MOC1-Hap1 in combination with MOC3-Hap3,MOC3-Hap4 or MOC3-Hap5 could be bred to promote branch formation.These findings will enrich the genetic resources available for rice breeders.展开更多
High-temperature pyrolysis technology can effectively solve the problem of municipal solid waste pollution.However,the pyrolysis gas contains a large amount of CO_(2),which would adversely affect the subsequent utiliz...High-temperature pyrolysis technology can effectively solve the problem of municipal solid waste pollution.However,the pyrolysis gas contains a large amount of CO_(2),which would adversely affect the subsequent utilization.To address this problem,a novel method of co-precipitation modification with Ca,Mg and Zr metals was proposed to improve the CO_(2)capture performance.X-ray diffraction(XRD)patterns and energy dispersive X-ray spectroscopy analysis showed that the two inert supports MgO and CaZrO_(3)were uniformly distributed in the modified calcium-based sorbents.In addition,the XRD results indicated that CaZrO_(3)was produced by the reaction of ZrO_(2)and CaO at high temperatures.The effects of doping ratios,adsorption temperature,calcination temperature,CO_(2)concentration and calcination atmosphere on the adsorption capacity and cycle stability of the modified calcium-based sorbent were studied.The modified calcium-based sorbent achieved the best CO_(2)capture performance when the doping ratio was 10:1:1 with carbonation at 700℃ under 20%CO_(2)/80%N_(2)atmosphere and calcination at 900℃ under100%N_(2)atmosphere.After ten cycles,the average carbonation conversion rate of Ca-10 sorbent was 72%.Finally,the modified calcium-based sorbents successfully reduced the CO_(2)concentration of the pyrolysis gas from 37%to 5%.展开更多
With rapid growth of power demand, transmission capacity is also in urgent need of upgrading. In some cases, converting existing AC transmission lines to DC lines can Improve the transmission capacity and reduce the c...With rapid growth of power demand, transmission capacity is also in urgent need of upgrading. In some cases, converting existing AC transmission lines to DC lines can Improve the transmission capacity and reduce the construction investment. In this paper, the upstream finite element method was expanded to calculate the total electric field of same tower multi-circuit DC lines converted from double-circuit AC lines, and the validity of the algorithm was confirmed by experiments. Taking a DC line converted from a typical same tower 500 kV double-circuit AC transmission line as an example, the surface electric field and the ground total electric field in different pole conductor arrangement schemes were calculated and analyzed, and the critical height of pole conductors for DC lines in residential and non-residential area were determined. Then, the corridor width of DC and AC lines at critical height in residential and non-residential areas before and after AC-DC line transformation were compared. The results indicate that for DC lines converted from common 500 kV double-circuit AC lines, the ground total electric field can meet the requirements of corresponding standard with appropriate pole conductor arrangement schemes.展开更多
Background:Xenotransplantation is a potential way to reduce the shortage of the needed organ grafts for the end-stage disease.Immune rejection,physiological incompatibility and bio-safety are the most critical issues....Background:Xenotransplantation is a potential way to reduce the shortage of the needed organ grafts for the end-stage disease.Immune rejection,physiological incompatibility and bio-safety are the most critical issues.Methods:To ensure the safety and efficacy of gene editing,second-and thirdgeneration sequencing technologies have allowed us to obtain a clearer genetic background of donor pigs for xenotransplantation.Based on the Changsha Communiqué,the local DPF-excluded lists and DPF donor facility were established in Changsha,China.A pig-to-human islet clinical trial was conducted and overseen by the respective Chinese governmental agency.Results:The DPF standards for pig husbandry eliminated specific pathogens in donor pigs.We have established a PERV-C free,genetic information clean,DPF donor for xenotransplantation.A clinical trial of ten adult patients(9M:1F)with type 1 diabetes who received DPF porcine islet xenotransplantation via the portal vein were performed.Clinical accepted immunosuppressant drugs and autologous Treg were used for controlling immune rejection.No cross-species infection events occurred in this trial,and importantly,no cross-species transmission of PERV was found.Conclusions:Xenotransplantation is a pioneer study and safety is the most important issue.The fundamental principles for establishing xenotransplantation donor pigs should follow the Changsha Communiqué(2008),the second WHO consultation,and the 2018 Changsha Communiquéwhich would finally help reducing the risks of xenotransplantation.展开更多
Radiotherapy is an important treatment for cancer,but it is associated with major side effects due to the high dose of radiation(generally more than 50 Gy).Because radiation's low acute and late toxicity,many tumo...Radiotherapy is an important treatment for cancer,but it is associated with major side effects due to the high dose of radiation(generally more than 50 Gy).Because radiation's low acute and late toxicity,many tumors are treated with fractionated radiation in small doses(<2 Gy).Scintillator X-ray-induced photodynamic therapy is an efficient methodology for cancer management that employs small doses of X-ray irradiation(<2 Gy)in a complex process.Here we screened pharmaceutical drug intermediates that are derivatives of thioxanthone(TX)and investigated TX-derived organic pharmaceutical molecules that efficiently undergo X-ray-sensitization to populate triplet excitons(singlet oxygen)for cancer therapy when exposed to low-dose X-ray irradiation.By modifying alkoxy side chain substitutions at the 2-position to tune the molecular packing and intermolecular interactions,the fluorescence and room-temperature phosphorescence of a series of TX derivatives were assessed under X-ray irradiation.The ability of these derivatives to generate singlet oxygen and their potential for treating tumors provide new opportunities for developing organic molecules with simple chemical structures,in which large numbers of triplets can be populated directly under ultralow-dose X-ray irradiation.展开更多
Chemotherapy is an important adjuvant treatment of glioma,while the efficacy is far from satisfactory,due not only to the biological barriers of blood-brain barrier(BBB)and blood-tumor barrier(BTB)but also to the intr...Chemotherapy is an important adjuvant treatment of glioma,while the efficacy is far from satisfactory,due not only to the biological barriers of blood-brain barrier(BBB)and blood-tumor barrier(BTB)but also to the intrinsic resistance of glioma cells via multiple survival mechanisms such as upregulation of P-glycoprotein(P-gp).To address these limitations,we report a bacteria-based drug delivery strategy for BBB/BTB transportation,glioma targeting,and chemo-sensitization.Bacteria selectively colonized into hypoxic tumor region and modulated tumor microenvironment,including macrophages repolarization and neutrophils infiltration.Specifically,tumor migration of neutrophils was employed as hitchhiking delivery of doxorubicin(DOX)-loaded bacterial outer membrane vesicles(OMVs/DOX).By virtue of the surface pathogen-associated molecular patterns derived from native bacteria,OMVs/DOX could be selectively recognized by neutrophils,thus facilitating glioma targeted delivery of drug with significantly enhanced tumor accumulation by 18-fold as compared to the classical passive targeting effect.Moreover,the P-gp expression on tumor cells was silenced by bacteria typeⅢsecretion effector to sensitize the efficacy of DOX,resulting in complete tumor eradication with 100%survival of all treated mice.In addition,the colonized bacteria were finally cleared by anti-bacterial activity of DOX to minimize the potential infection risk,and cardiotoxicity of DOX was also avoided,achieving excellent compatibility.This work provides an efficient trans-BBB/BTB drug delivery strategy via cell hitchhiking for enhanced glioma therapy.展开更多
This work is aimed to study the effects of component size and solubility on the surface composition of spray dried(SD)uniform two-component particles fabricated by micro-fluidic spray dryer.Various precursor liquid co...This work is aimed to study the effects of component size and solubility on the surface composition of spray dried(SD)uniform two-component particles fabricated by micro-fluidic spray dryer.Various precursor liquid consisting of small molecular of methionine(Met,33 g/L)or lysine(Lys,739 g/L)and large-sized silica(12 nm)were prepared by adjusting the mass ratio of components.X-ray energy disper-sive results showed that the respective enrichment degree(De)of Met and Lys on the surface of SD-M1S9 and-L1S9 prepared at 150 C were 182±9% and 125±14%.The De of hydrophobic Met for SD-M1S1 and-M9S1 were 46±9% and 4±2%,respectively,whereas relative hydrophilic Lys mainly distributed internal of the particle meanwhile the De of silica on the surface for SD-L1S1 and-L9S1 were 17±4%and 12±1%,respectively.Drying temperature(120 and 180℃)showed more apparent effect on the De of amino acid for the particles of less amino acid.The possible formation mechanism of surface composition and the surface composition impact on the wettability of particles were explored.These results provide new guidance for manufacturing functional SD powders with various components.展开更多
The ongoing large‐scale construction of ultra high voltage direct current projects in China makes the crossing of two high voltage direct current(HVDC)lines inevitable.It is critical to study the characteristics and ...The ongoing large‐scale construction of ultra high voltage direct current projects in China makes the crossing of two high voltage direct current(HVDC)lines inevitable.It is critical to study the characteristics and calculation method of 3‐D total electric fields of crossing HVDC lines.The problems encountered when applying the 3‐D upstream finite element method to calculate total electric field of crossing HVDC lines and the solutions are studied in this study.In view of the surface electric field varying greatly along longitudinal direction of conductors,the calculation method adopting the Davidon‐Fletcher‐Powell optimization algorithm is introduced to realize the fast computation of 3‐D space‐charge‐free field.Considering the distinct corona intensity at different positions of conductors,a new for-mula for initializing charge density is studied to ensure the convergence of calculation process.Considering the large computation amount of total electric field,an adaptive iteration strategy is put forward to effectively speed up the calculation.The measurement of ground total electric field underneath a crossing HVDC test line is conducted to verify the validity of the proposed calculation method.The distribution characteristics of electric fields of crossing HVDC lines are calculated and analysed.The research results will provide technical support for the design and environmental impact assessment of crossing HVDC transmission lines.展开更多
Ground total electric field(GTEF)is a vital parameter in the field of electromagnetic environment of high voltage direct current(HVDC)lines.Some experimental works re-ported that airborne suspended particles can be ch...Ground total electric field(GTEF)is a vital parameter in the field of electromagnetic environment of high voltage direct current(HVDC)lines.Some experimental works re-ported that airborne suspended particles can be charged in the corona ion flow of the lines and thus affect GTEF.This paper aims at studying the charging models for particles.Equivalent unipolar charging models(EUCMs)and bipolar charging models(BCMs)for describing field and diffusion charging mechanisms in bipolar ion environments are introduced and the Maxwell-Wagner relaxation is proposed to be incorporated.Besides,the EUCMs and BCMs are analysed and validated through comparisons with experimental data.The results show that BCMs are applicable to describing the particle charging in a bipolar ion environment,while EUCMs are not.The predictions made by BCM that takes into account the Maxwell-Wagner relaxation are in good agreement with experimental results.Moreover,the BCMs are proposed to analyse the experimental results about GTEF in the presence of particles,which are not understood before.It is demonstrated that the BCMs are able to qualitatively explain these results.Finally yet importantly,a new charging model combining field and diffusion charging mechanism is proposed for airborne suspended particles around HVDC lines and validated by experiments.The results show that the proposed hybrid field-diffusion charging model is able to give predictions consistent with experiments.展开更多
Background and Aims:This study was designed to uncov-er the mechanism for extracellular polysaccharide(EPS1-1)-mediated effects on hepatocellular carcinoma(HCC)devel-opment.Methods:HCC cells were treated with EPS1-1,m...Background and Aims:This study was designed to uncov-er the mechanism for extracellular polysaccharide(EPS1-1)-mediated effects on hepatocellular carcinoma(HCC)devel-opment.Methods:HCC cells were treated with EPS1-1,miR-494-3p mimic,sh-TRIM36,and pcDNA3.1-TRIM36.The levels of miR-494-3p and TRIM36 were measured in nor-mal hepatocytes,THLE-2,and HepG2 and HuH7HCC cell lines,along with the protein expression of cyclin D/E and p21.The proliferation,cell cycle,and apoptosis of HCC cells were assayed.The interactions between miR-494-3p and TRIM36,and between TRIM36 and cyclin E were assessed.Finally,the expression and localization of TRIM36 and cyclin E were monitored,and tumor apoptosis was detected,in tumor xenograft model.Results:EPS1-1 suppressed HCC cell proliferation and cyclin D/E expression and promoted apoptosis and p21 expression.miR-494-3p was upregulated and TRIM36 was downregulated in HCC cells.Transfection with miR-494-3p mimic or sh-TRIM36 facilitated HCC cell proliferation and the expression of cyclin D/E protein but they inhibited apoptosis and p21 expression in the pres-ence of EPS1-1.Overexpression of TRIM36 further con-solidated EPS1-1-mediated inhibition of HCC proliferation,cyclin D/E,and the promotion of apoptosis and p21 expres-sion.Those effects were reversed by miR-494-3p overex-pression.TRIM36 was a target gene of miR-494-3p,and TRIM36 induced cyclin E ubiquitination.EPS1-1 suppressed cyclin E expression,promoted TRIM36 expression and tu-mor apoptosis,all of which were abrogated by increasing the expression of miR-494-3p in vivo.Conclusions:EPS1-1 protected against HCC by limiting its proliferation and sur-vival through the miR-494-3p/TRIM36 axis and by inducing cyclin E ubiquitination.展开更多
基金Guangdong Province Key Laboratory of Efficient and Clean Energy Utilization(South China University of Technology)(2013A061401005)Research Fund(JMSWFW-2110-044)from Zhongshan Jiaming Electric Power Co.,Ltd.
文摘The determination of source-side extracted heating parameters is of great significance to the economic operation of cogeneration systems.This paper investigated the coupling performance of a cogeneration heating and power system multidimensionally based on the operating characteristics of the cogeneration units,the hydraulic and thermodynamic characteristics of the heating network,and the energy loads.Taking a steam network supported by a gas-steam combined cycle cogeneration system as the research case,the interaction effect among the source-side prime movers,the heating networks,and the terminal demand thermal parameters were investigated based on the designed values,the plant testing data,and the validated simulation.The operating maps of the gas-steam combined cycle cogeneration units were obtained using THERMOFLEX,and the minimum source-side steam parameters of the steam network were solved using an inverse solution procedure based on the hydro-thermodynamic coupling model.The cogeneration operating maps indicate that the available operating domain considerably narrows with the rise of the extraction steam pressure and flow rate.The heating network inverse solution demonstrates that the source-side steam pressure and temperature can be optimized from the originally designed 1.11 MPa and 238.8°C to 1.074 MPa and 191.15°C,respectively.Under the operating strategy with the minimum source-side heating parameters,the power peak regulation depth remarkably increases to 18.30%whereas the comprehensive thermal efficiency decreases.The operation under the minimum source-side heating steam parameters can be superior to the originally designed one in the economy at a higher price of the heating steam.At a fuel price of$0.38/kg and the power to fuel price of 0.18 kg/(kW·h),the critical price ratio of heating steam to fuel is 119.1 kg/t.The influence of the power-fuel price ratio on the economic deviation appears relatively weak.
基金the National Key Research and Development project of China(2016YFC0500308)Special Project for Double First-Class-Cultivation of Innovative Talents(000/41113102)+1 种基金the Natural Science Foundation of Heilongjiang Scientifi c Committee(C2018055)the Application Research Project of Heilongjiang Provincial Forest Industry Administration(sgzjY2014004).
文摘The hazelnut weevil(Curculio dieckmanni Faust.)is a major pest of Asian hazel(Corylus heterophylla Fisch.)in China.Dead hazelnut weevil larvae were examined and the associated pathogenic bacterium was identifi ed as Serratia marcescens Bizio.This signifi cantly shortened the lifespan of hazelnut weevil.Larval weight was reduced as a function of S.marcescens concentration and exposure time.The structure of infected midgut cells was altered,with necrosis of the wall tissues and many cells becoming dislodged,creating cavities.The S.marcencens strain inhibited digestive enzyme activity and protective enzymes in the midgut of adult hazelnut weevil.Inhibition on S.marcencens strain increased with treatment time.S.marcescens directly destroyed the midgut cells and interfered with digestive and protective enzymes.This decreased the food intake and increased mortality of hazelnut weevil.S.marcescens appears to be an eff ective bacterium for the control of hazelnut weevil but requires further study,including biological formulation development and fi eld application.
文摘The bed material agglomeration and heating surface high-temperature Corrosion Problems of biomass-fired boiler in South China were studied in this work. The inner and outer surfaces of the corrosion sample were investigated by scanning electron microscope (SEM) with Bruker EDX and XRD. Results showed that the outer side of the corrosion sample was mainly composed of alkali chloride deposited ash, sulphide and a small amount of eutectoid;while the inner side of the corrosion sample was still mainly made up of the composition of SUS316, but added with alkali metal, oxygen, chlorine and sulphur elements, appearing as the corrosion products and eutectoid. It was thought that alkali chloride deposit and the reaction with pipe metal to generate low melting point eutectoid on the outer surfaces, or the corrosion reaction through the alkali metal sulphatization process was the main reasons leading to the damage of metal surface oxide film. Chlorine plays a role as haptoreaction in the corrosion process, and transports metal material as the form of chloride from the inner side to the outer side of the pipe surfaces by diffusion, accelerating the corrosion process. Meanwhile, the slag was studied by scanning electron microscope (SEM) with Bruker EDX, and the transformation process of slage was computationally analyzed by FACTSAGE. Results showed that the amount of alkali metal in the agglomerates was little, however, caused a great impact on severe agglomerates. The increase of temperature enhanced the conversion process of alkali metal to molten oxide, especially when the temperature was higher than760℃, the amount of molten product increased sharply. Thus, the temperature control of fluidized bed plays an important role in solving the problem of alkali metal agglomerates;it also reliefs the volatile of alkali metal into gas phase, benefiting the control of heating surface corrosion.
基金This work was supported by Guangdong Province Key Laboratory of Efficient and Clean Energy Utilization(2013A061401005)by Guangdong Basic and Applied Basic Research Foundation(2020A1515011103)by research fund from Guangzhou Development Group Co.,Ltd.
文摘Gas turbine power units,as an effective way to cope with the severe challenge of renewable energy accommodation in power grids,arouse the interest of power enterprises in the deep peak-load regulation performance.Two common alternative load-control strategies including constant turbine inlet temperature(TIT)and constant turbine exhaust temperature(TET)regulations were taken into consideration.To comparatively investigate the part-load performance under these strategies,both mathematical and physical models were set up successively to serve as a validation and complementary to each other.For the mathematical model of compressor with inlet guide vane(IGV),combustor and turbine,stage-stacking method based on blade average geometric parameter,energy conservation and turbine stage model were adopted respectively.For the physical model,design and off-design analysis were carried out based on GT PRO and THERMOFLEX respectively.The simulation result of mathematical model validated the reliability of the physical model.Based on this,the influence of ambient temperature and different load-regulating strategies on the off-design performance of gas turbine power units was studied in THERMOFLEX.The results in the case of a PG 9351FA gas turbine show that the ambient temperature has a great impact on system performance,i.e.,every 5℃ increase in the ambient temperature produces a reduction of 3.7%in the relative full-load output and 1.1%in the relative efficiency respectively;when the gas turbine operates under constant TIT strategy,TET starts to rise till it reaches the maximum allowable value with the load rate decreasing,and IGV keeps at the minimum angle with both TIT and TET decreasing when the load rate is lower than 65%;when the gas turbine operates under constant TET strategy,TIT drops slightly at load rate of above 60%while both TIT and TET evidently decrease below 60%load rate operating along the constant corrected speed line at the minimum allowable IGV opening;gas turbine effi-ciency is greatly affected by load rate and the performance degradation is more obvious especially in lower load rate regions;constant TET strategy is superior in the operating efficiency to constant TIT strategy under part-load conditions.
文摘In this paper, a multiple population genetic algorithm (MPGA) is proposed to solve the problem of optimal load dispatch of gas turbine generation units. By introducing multiple populations on the basis of Standard Genetic Algorithm (SGA), connecting each population through immigrant operator and preserving the best individuals of every generation through elite strategy, MPGA can enhance the efficiency in obtaining the global optimal solution. In this paper, MPGA is applied to optimize the load dispatch of 3×390MW gas turbine units. The results of MPGA calculation are compared with that of equal micro incremental method and AGC instruction. MPGA shows the best performance of optimization under different load conditions. The amount of saved gas consumption in the calculation is up to 2337.45m3N/h, which indicates that the load dispatch optimization of gas turbine units via MPGA approach can be effective.
基金supported by the National Natural Science Foundation of China(31801324,31171521)the Open Project of Guangxi Key Laboratory of Rice Genetics and Breeding(2018-05-Z06-KF08)China Postdoctoral Science Foundation(2017T100117 and 2019M650902)。
文摘The yield of rice is mostly affected by three factors,namely,panicle number,grain number and grain weight.Variation in panicle and grain numbers is mainly caused by tiller and panicle branches generated from axillary meristems(AMs).MOC1 encodes a putative GRAS family nuclear protein that regulates AM formation.Although several alleles of MOC1 have been identified,its variation in germplasm resources remains unclear.In the present study we characterized a novel mocl allele named gnp6 which has a thymine insertion in the coding sequence of the SAW motif in the GRAS domain.This mutation causes arrested branch formation.The SAW motif is necessary for nuclear localization of GNP6/MOC1 where it functions as a transcription factor or co-regulator.Haplotype analysis showed that the coding region of GNP6/MOC1 was conserved without any non-synonymous mutations in 240 rice accessions.However,variation in the promoter region might affect the expression of it and its downstream genes.Joint haplotype analysis of GNP6/MOC1 and MOC3 showed that haplotype combinations H9,H10 and H11,namely MOC1-Hap1 in combination with MOC3-Hap3,MOC3-Hap4 or MOC3-Hap5 could be bred to promote branch formation.These findings will enrich the genetic resources available for rice breeders.
基金the support given by the National Key Research and Development Program of China(2018YFC1901203)Natural Science Foundation of Guangdong Province,China(2021A1515010497)+1 种基金Guangzhou Science and Technology Innovation Development Special FundFundamental Research Funds for the Central Universities(2019MS017)。
文摘High-temperature pyrolysis technology can effectively solve the problem of municipal solid waste pollution.However,the pyrolysis gas contains a large amount of CO_(2),which would adversely affect the subsequent utilization.To address this problem,a novel method of co-precipitation modification with Ca,Mg and Zr metals was proposed to improve the CO_(2)capture performance.X-ray diffraction(XRD)patterns and energy dispersive X-ray spectroscopy analysis showed that the two inert supports MgO and CaZrO_(3)were uniformly distributed in the modified calcium-based sorbents.In addition,the XRD results indicated that CaZrO_(3)was produced by the reaction of ZrO_(2)and CaO at high temperatures.The effects of doping ratios,adsorption temperature,calcination temperature,CO_(2)concentration and calcination atmosphere on the adsorption capacity and cycle stability of the modified calcium-based sorbent were studied.The modified calcium-based sorbent achieved the best CO_(2)capture performance when the doping ratio was 10:1:1 with carbonation at 700℃ under 20%CO_(2)/80%N_(2)atmosphere and calcination at 900℃ under100%N_(2)atmosphere.After ten cycles,the average carbonation conversion rate of Ca-10 sorbent was 72%.Finally,the modified calcium-based sorbents successfully reduced the CO_(2)concentration of the pyrolysis gas from 37%to 5%.
文摘With rapid growth of power demand, transmission capacity is also in urgent need of upgrading. In some cases, converting existing AC transmission lines to DC lines can Improve the transmission capacity and reduce the construction investment. In this paper, the upstream finite element method was expanded to calculate the total electric field of same tower multi-circuit DC lines converted from double-circuit AC lines, and the validity of the algorithm was confirmed by experiments. Taking a DC line converted from a typical same tower 500 kV double-circuit AC transmission line as an example, the surface electric field and the ground total electric field in different pole conductor arrangement schemes were calculated and analyzed, and the critical height of pole conductors for DC lines in residential and non-residential area were determined. Then, the corridor width of DC and AC lines at critical height in residential and non-residential areas before and after AC-DC line transformation were compared. The results indicate that for DC lines converted from common 500 kV double-circuit AC lines, the ground total electric field can meet the requirements of corresponding standard with appropriate pole conductor arrangement schemes.
基金supported by grants from the National Key Research and Development Program of China(Grant No.2019YFA0110703)the National Natural Science Foundation of China(Grant No.82272102)the Natural Science Foundation of Hunan Province,China(Grant No.2021JJ31018).
文摘Background:Xenotransplantation is a potential way to reduce the shortage of the needed organ grafts for the end-stage disease.Immune rejection,physiological incompatibility and bio-safety are the most critical issues.Methods:To ensure the safety and efficacy of gene editing,second-and thirdgeneration sequencing technologies have allowed us to obtain a clearer genetic background of donor pigs for xenotransplantation.Based on the Changsha Communiqué,the local DPF-excluded lists and DPF donor facility were established in Changsha,China.A pig-to-human islet clinical trial was conducted and overseen by the respective Chinese governmental agency.Results:The DPF standards for pig husbandry eliminated specific pathogens in donor pigs.We have established a PERV-C free,genetic information clean,DPF donor for xenotransplantation.A clinical trial of ten adult patients(9M:1F)with type 1 diabetes who received DPF porcine islet xenotransplantation via the portal vein were performed.Clinical accepted immunosuppressant drugs and autologous Treg were used for controlling immune rejection.No cross-species infection events occurred in this trial,and importantly,no cross-species transmission of PERV was found.Conclusions:Xenotransplantation is a pioneer study and safety is the most important issue.The fundamental principles for establishing xenotransplantation donor pigs should follow the Changsha Communiqué(2008),the second WHO consultation,and the 2018 Changsha Communiquéwhich would finally help reducing the risks of xenotransplantation.
基金supported by the National Natural Science Foundation of China(82172007,81771977,52103209,and 52373183)the Science Fund for Distinguished Young Scholars of Fujian Province(2021J06007)+2 种基金the Scientific Research Foundation of Xiang An Biomedicine Laboratory(2023XAKJ0101023)the Open Research Fund of the National Facility for Translational Medicine(Shanghai)(TMSK-2021-102)the Open Project of State Key Laboratory of Supramolecular Structure and Materials(sklssm2023026)。
文摘Radiotherapy is an important treatment for cancer,but it is associated with major side effects due to the high dose of radiation(generally more than 50 Gy).Because radiation's low acute and late toxicity,many tumors are treated with fractionated radiation in small doses(<2 Gy).Scintillator X-ray-induced photodynamic therapy is an efficient methodology for cancer management that employs small doses of X-ray irradiation(<2 Gy)in a complex process.Here we screened pharmaceutical drug intermediates that are derivatives of thioxanthone(TX)and investigated TX-derived organic pharmaceutical molecules that efficiently undergo X-ray-sensitization to populate triplet excitons(singlet oxygen)for cancer therapy when exposed to low-dose X-ray irradiation.By modifying alkoxy side chain substitutions at the 2-position to tune the molecular packing and intermolecular interactions,the fluorescence and room-temperature phosphorescence of a series of TX derivatives were assessed under X-ray irradiation.The ability of these derivatives to generate singlet oxygen and their potential for treating tumors provide new opportunities for developing organic molecules with simple chemical structures,in which large numbers of triplets can be populated directly under ultralow-dose X-ray irradiation.
基金supported by the National Natural Science Foundation of China(Nos.U1903125,82071986,82073799,and 81771827)Natural Science Foundation of Hunan province in China(2021JJ20084)+2 种基金the Science and Technology Project of Hunan Province(2021RC4017 and 2021RC3020,China)the Furong Scholars Programme of Hunan Provincethe Wisdom Accumulation and Talent Cultivation Project of the Third Xiangya Hospital of Central South University(China)。
文摘Chemotherapy is an important adjuvant treatment of glioma,while the efficacy is far from satisfactory,due not only to the biological barriers of blood-brain barrier(BBB)and blood-tumor barrier(BTB)but also to the intrinsic resistance of glioma cells via multiple survival mechanisms such as upregulation of P-glycoprotein(P-gp).To address these limitations,we report a bacteria-based drug delivery strategy for BBB/BTB transportation,glioma targeting,and chemo-sensitization.Bacteria selectively colonized into hypoxic tumor region and modulated tumor microenvironment,including macrophages repolarization and neutrophils infiltration.Specifically,tumor migration of neutrophils was employed as hitchhiking delivery of doxorubicin(DOX)-loaded bacterial outer membrane vesicles(OMVs/DOX).By virtue of the surface pathogen-associated molecular patterns derived from native bacteria,OMVs/DOX could be selectively recognized by neutrophils,thus facilitating glioma targeted delivery of drug with significantly enhanced tumor accumulation by 18-fold as compared to the classical passive targeting effect.Moreover,the P-gp expression on tumor cells was silenced by bacteria typeⅢsecretion effector to sensitize the efficacy of DOX,resulting in complete tumor eradication with 100%survival of all treated mice.In addition,the colonized bacteria were finally cleared by anti-bacterial activity of DOX to minimize the potential infection risk,and cardiotoxicity of DOX was also avoided,achieving excellent compatibility.This work provides an efficient trans-BBB/BTB drug delivery strategy via cell hitchhiking for enhanced glioma therapy.
基金supported by the National Natural Science Foundation of China(No.21878197)the Natural Science Foundation of Jjiangsu Province(No.BK20180096)+2 种基金Jiangsu Higher Education Iinstitutions(No.18KJA530004)the Suzhou Municipal Science and Technology Bureau(No.SYG201810)the Post-Doctoral Science Foundation ofjangsu(2021K356C)。
文摘This work is aimed to study the effects of component size and solubility on the surface composition of spray dried(SD)uniform two-component particles fabricated by micro-fluidic spray dryer.Various precursor liquid consisting of small molecular of methionine(Met,33 g/L)or lysine(Lys,739 g/L)and large-sized silica(12 nm)were prepared by adjusting the mass ratio of components.X-ray energy disper-sive results showed that the respective enrichment degree(De)of Met and Lys on the surface of SD-M1S9 and-L1S9 prepared at 150 C were 182±9% and 125±14%.The De of hydrophobic Met for SD-M1S1 and-M9S1 were 46±9% and 4±2%,respectively,whereas relative hydrophilic Lys mainly distributed internal of the particle meanwhile the De of silica on the surface for SD-L1S1 and-L9S1 were 17±4%and 12±1%,respectively.Drying temperature(120 and 180℃)showed more apparent effect on the De of amino acid for the particles of less amino acid.The possible formation mechanism of surface composition and the surface composition impact on the wettability of particles were explored.These results provide new guidance for manufacturing functional SD powders with various components.
基金State Grid Corporation of China,Grant/Award Number:GYB17201800203。
文摘The ongoing large‐scale construction of ultra high voltage direct current projects in China makes the crossing of two high voltage direct current(HVDC)lines inevitable.It is critical to study the characteristics and calculation method of 3‐D total electric fields of crossing HVDC lines.The problems encountered when applying the 3‐D upstream finite element method to calculate total electric field of crossing HVDC lines and the solutions are studied in this study.In view of the surface electric field varying greatly along longitudinal direction of conductors,the calculation method adopting the Davidon‐Fletcher‐Powell optimization algorithm is introduced to realize the fast computation of 3‐D space‐charge‐free field.Considering the distinct corona intensity at different positions of conductors,a new for-mula for initializing charge density is studied to ensure the convergence of calculation process.Considering the large computation amount of total electric field,an adaptive iteration strategy is put forward to effectively speed up the calculation.The measurement of ground total electric field underneath a crossing HVDC test line is conducted to verify the validity of the proposed calculation method.The distribution characteristics of electric fields of crossing HVDC lines are calculated and analysed.The research results will provide technical support for the design and environmental impact assessment of crossing HVDC transmission lines.
基金State Grid Corporation of China,Grant/Award Number:52010118001P。
文摘Ground total electric field(GTEF)is a vital parameter in the field of electromagnetic environment of high voltage direct current(HVDC)lines.Some experimental works re-ported that airborne suspended particles can be charged in the corona ion flow of the lines and thus affect GTEF.This paper aims at studying the charging models for particles.Equivalent unipolar charging models(EUCMs)and bipolar charging models(BCMs)for describing field and diffusion charging mechanisms in bipolar ion environments are introduced and the Maxwell-Wagner relaxation is proposed to be incorporated.Besides,the EUCMs and BCMs are analysed and validated through comparisons with experimental data.The results show that BCMs are applicable to describing the particle charging in a bipolar ion environment,while EUCMs are not.The predictions made by BCM that takes into account the Maxwell-Wagner relaxation are in good agreement with experimental results.Moreover,the BCMs are proposed to analyse the experimental results about GTEF in the presence of particles,which are not understood before.It is demonstrated that the BCMs are able to qualitatively explain these results.Finally yet importantly,a new charging model combining field and diffusion charging mechanism is proposed for airborne suspended particles around HVDC lines and validated by experiments.The results show that the proposed hybrid field-diffusion charging model is able to give predictions consistent with experiments.
文摘Background and Aims:This study was designed to uncov-er the mechanism for extracellular polysaccharide(EPS1-1)-mediated effects on hepatocellular carcinoma(HCC)devel-opment.Methods:HCC cells were treated with EPS1-1,miR-494-3p mimic,sh-TRIM36,and pcDNA3.1-TRIM36.The levels of miR-494-3p and TRIM36 were measured in nor-mal hepatocytes,THLE-2,and HepG2 and HuH7HCC cell lines,along with the protein expression of cyclin D/E and p21.The proliferation,cell cycle,and apoptosis of HCC cells were assayed.The interactions between miR-494-3p and TRIM36,and between TRIM36 and cyclin E were assessed.Finally,the expression and localization of TRIM36 and cyclin E were monitored,and tumor apoptosis was detected,in tumor xenograft model.Results:EPS1-1 suppressed HCC cell proliferation and cyclin D/E expression and promoted apoptosis and p21 expression.miR-494-3p was upregulated and TRIM36 was downregulated in HCC cells.Transfection with miR-494-3p mimic or sh-TRIM36 facilitated HCC cell proliferation and the expression of cyclin D/E protein but they inhibited apoptosis and p21 expression in the pres-ence of EPS1-1.Overexpression of TRIM36 further con-solidated EPS1-1-mediated inhibition of HCC proliferation,cyclin D/E,and the promotion of apoptosis and p21 expres-sion.Those effects were reversed by miR-494-3p overex-pression.TRIM36 was a target gene of miR-494-3p,and TRIM36 induced cyclin E ubiquitination.EPS1-1 suppressed cyclin E expression,promoted TRIM36 expression and tu-mor apoptosis,all of which were abrogated by increasing the expression of miR-494-3p in vivo.Conclusions:EPS1-1 protected against HCC by limiting its proliferation and sur-vival through the miR-494-3p/TRIM36 axis and by inducing cyclin E ubiquitination.
