Reinforced concrete(RC) columns are widely used as supporting structures for high-piled wharfs.The study of damage model of a RC column due to underwater explosion is a critical issue to assess the wharfs antiknock se...Reinforced concrete(RC) columns are widely used as supporting structures for high-piled wharfs.The study of damage model of a RC column due to underwater explosion is a critical issue to assess the wharfs antiknock security.In this study,the dynamic response and damage model of circular RC columns subjected to underwater explosions were investigated by means of scaled-down experiment models.Experiments were carried out in a 10.0 m diameter tank with the water depth of 2.25 m,under different explosive quantities(0.025 kg-1.6 kg),stand-off distances(0.0 m-7.0 m),and detonation depths(0.25 m-2.0 m).The shock wave load and dynamic response of experiment models were measured by configuring sensors of pressure,acceleration,strain,and displacement.Then,the load distribution characteristics,time history of test data,and damage models related to present conditions were obtained and discussed.Three damage models,including bending failure,bending-shear failure and punching failure,were identified.In addition,the experie nce model of shock wave loads on the surface of a RC column was proposed for engineering application.展开更多
AIM： To evaluate whether the effect of Gin dipeptideenriched total parenteral nutrition （TPN） on postoperative cytokine alteration depended on the disease severity of surgical patients. METHODS： Forty-eight patien...AIM： To evaluate whether the effect of Gin dipeptideenriched total parenteral nutrition （TPN） on postoperative cytokine alteration depended on the disease severity of surgical patients. METHODS： Forty-eight patients with major abdominal surgery were allocated to two groups to receive isonitrogenous （0.228 g nitrogen/kg per d） and isocaloric （30 kcal/kg per d） TPN for 6 d. Control group （Cony） using conventional TPN solution received 1.5 g amino acids/kg per day, whereas the test group received 0.972 g amino acids/kg per day and 0.417 g L-alanyI-L-glutamine （Ala-GIn）/kg per day. Blood samples were collected on d 1 and d 6 postoperatively for plasma interleukin （IL）-2, IL-6, IL-8, and interferon （IFN）-γ analysis. RESULTS： Plasma IL-2 and IFN-γ were not detectable. IL-6 concentrations were significantly lower on the 6^th postoperative day in the Ala-GIn group than those in the Cony group in patients with APACHE Ⅱ≤6, whereas no difference was noted in patients with APACHE Ⅱ〉6. There was no difference in IL-8 levels between the two groups. No difference in cumulative nitrogen balance was observed on d 2-5 after the operation between the two groups （Ala-GIn -3.2±1.6 g vs Cony -6.5±2.7 g）. A significant inverse correlation was noted between plasma IL-6 levels and cumulative nitrogen balance postoperatively in the Ala-GIn group, whereas no such correlation was observed in the Conv group. CONCLUSION： TPN supplemented with Gin dipeptide had no effect on plasma IL-8 levels after surgery. However, Gin supplementation had a beneficial effect on decreasing systemic IL-6 production after surgery in patients with low admission illness severity, and lower plasma IL-6 may improve nitrogen balance in patients with abdominal surgery when Gin was administered.展开更多
Low-velocity drop-weight impact experiments on individual and multiple Cyclotetramethylene tetranitramine (HMX) energetic particles were performed using a modified drop-weight machine equipped with high-speed photogra...Low-velocity drop-weight impact experiments on individual and multiple Cyclotetramethylene tetranitramine (HMX) energetic particles were performed using a modified drop-weight machine equipped with high-speed photography components. Multiple particles experienced more severe burning reactions than an individual particle. Comparisons between impacted salt and HMX particle show that jetting in HMX is mainly due to the motion of fragmented particles driven by gaseous reaction products. Velocity of jetting, flame propagation, and area expansion were measured via image processing, making it possible to quantify the chemical reaction or mechanical deformation violence at different stages.展开更多
The pseudorabies virus(PRV)is identified as a double-helical DNA virus responsible for causing Aujeszky's disease,which results in considerable economic impacts globally.The enzyme tryptophanyl-tRNA synthetase 2(W...The pseudorabies virus(PRV)is identified as a double-helical DNA virus responsible for causing Aujeszky's disease,which results in considerable economic impacts globally.The enzyme tryptophanyl-tRNA synthetase 2(WARS2),a mitochondrial protein involved in protein synthesis,is recognized for its broad expression and vital role in the translation process.The findings of our study showed an increase in both mRNA and protein levels of WARS2 following PRV infection in both cell cultures and animal models.Suppressing WARS2 expression via RNA interference in PK-15 cells led to a reduction in PRV infection rates,whereas enhancing WARS2 expression resulted in increased infection rates.Furthermore,the activation of WARS2 in response to PRV was found to be reliant on the cGAS/STING/TBK1/IRF3 signaling pathway and the interferon-alpha receptor-1,highlighting its regulation via the type I interferon signaling pathway.Further analysis revealed that reducing WARS2 levels hindered PRV's ability to promote protein and lipid synthesis.Our research provides novel evidence that WARS2 facilitates PRV infection through its management of protein and lipid levels,presenting new avenues for developing preventative and therapeutic measures against PRV infections.展开更多
In sharp contrast to the well researched and well developed aminocarbonylation of alkenes,the dearomative carbamoylation of abundant areneπ-systems has scarcely been studied despite its great potential to enrich the ...In sharp contrast to the well researched and well developed aminocarbonylation of alkenes,the dearomative carbamoylation of abundant areneπ-systems has scarcely been studied despite its great potential to enrich the diversity-oriented synthesis of high-value amides.The formidable challenges associated with such dearomatization include the low reactivity of stable aromaticπ-systems and intricate selectivity issues.Herein,we disclose a general approach toward highly selective dearomative carbamoylations of areneπ-bonds under CO-gas-free conditions.Its extraordinary versatility was demonstrated by tolerating a broad range of nucleophilic partners with high yields and excellent selectivities,thus providing modular access to the divergent synthesis ofβ-functionalized primary amides.In addition,diverse downstream derivatizations including a formal C–H 1,2-olefination/carbamoylation reaction were conducted,exhibiting great potential in synthetic and medicinal chemistry.展开更多
Catalysts and ligands possessing the great ability to tolerate over a wide range of mechanistically unrelated reactions are remarked as"privileged",which are rather scarce but extremely meaningful in asymmet...Catalysts and ligands possessing the great ability to tolerate over a wide range of mechanistically unrelated reactions are remarked as"privileged",which are rather scarce but extremely meaningful in asymmetric catalysis.Feng and co-workers have developed a library of conformationally flexible,C2-symmetric N,N'-dioxide amide compounds with original design and featured structure(named as Feng ligand now).They were initially reported as chiral organocatalysts in 2005 and have been further developed as a new class of privileged chiral ligands since 2006.Tremendous success,including versatile coordination chemistry with plenty of metal sources(main-group metals,transition metals,and rare-earth metals),a truly broad scope of asymmetric reactions(more than 50 types),diverse areas of catalysis(organocatalysis,Lewis-acid catalysis,bimetallic relay catalysis,and photocatalysis),numerous synthetic applications of bioactive compounds,has been achieved using Feng N,N'-dioxide.Besides,they demonstrate that chiral ligands with conformationally flexible property can offer excellent chiral environment as well,which challenges the conventional idea preferring rigid structures in the design of chiral ligands.Herein,we briefly introduced the discovery of Feng ligand and the millstones during the development.We also covered the successful applications of Feng ligand by other scientists as well as novel chiral ligands inspired by them.展开更多
The temperature control of the air-cooled proton exchange membrane fuel cell(PEMFC)is important for effective and safe operation.To develop a practical and precise controller,this study combines the Radial Basis Funct...The temperature control of the air-cooled proton exchange membrane fuel cell(PEMFC)is important for effective and safe operation.To develop a practical and precise controller,this study combines the Radial Basis Function(RBF)neural network with Back Propagation neural network adaptive Proportion Integration Differentiation(BP-PID),and then a metaheuristic algorithm is used to optimize the parameters of RBF-BP-PID for further improvement in temperature control.First,an air-cooled PEMFC system model is established.To match the simulation data with the experimental data,Teaching Learning Based Optimization-Differential Evolution(TLBO-DE)is proposed to identify the unknown parameters,and the maximum relative error is<3.5%.Second,RBF neural network is introduced to identify the stack temperature and provide the accurate∂y(k)/∂u(k)for BP-PID,which solves the problem of using sign function sgn(∂y(k)/∂u(k))to approximate the∂y(k)/∂u(k)in BP-PID.Regarding the temperature control of air-cooled PEMFC,several controllers are compared,including PID,Fuzzy-PID,BP-PID and RBF-BP-PID.The proposed RBF-BP-PID achieves the best control effect,which reduces the integrated time and absolute error(ITAE)by 3.4%and 15.8%based on BP-PID in the startup and steady phases,respectively.Since the∂y(k)/∂u(k)provided by RBF changes softly and continuously during the control process,the parameters selftuning ability of RBF-BP-PID is better than BP-PID.Third,to improve the control effect of RBF-BP-PID further,TLBO-DE is adopted to optimize the parameters of RBF neural network and BP neural network.展开更多
Operating temperature is an important factor that affects the efficiency,durability,and safety of proton exchange membrane fuel cells(PEMFC).Thus,a thermal management system is necessary for controlling the appropriat...Operating temperature is an important factor that affects the efficiency,durability,and safety of proton exchange membrane fuel cells(PEMFC).Thus,a thermal management system is necessary for controlling the appropriate temperature.In this paper,a novel thermal management system based on two-stage utilization of cooling air is first established,whose core characteristic is utilizing the temperature difference between the cooling air leaving the main radiator and the auxiliary radiator.The novel thermal management system can reduce the parasitic power of the fan by 59.27%and improve the temperature control effect to a certain extent.The traditional feedforward decoupling control based on system identification is first adopted to control the temperature and surpasses dual-PID on all the 5 indexes,which are Integral Absolute Error Criterion(IAE)of temperature difference,IAE of inlet coolant temperature,parasitic power of fan,average overshoot of temperature difference and average overshoot of inlet coolant temperature.The multi-objective decoupling control based on multiobjective optimization is then proposed to further improve the temperature control effect on the basis of traditional feedforward decoupling control.The above 5 indexes are chosen as the optimization objectives,the decoupling coefficients are chosen as the decision variables,and the Pareto set is obtained by NSGAⅡand NSGAⅢ.The results show that the proposed multi-objective decoupling control has the main advantages as follows:(1)It can provide comprehensive optimization options for different design preferences;(2)It can significantly optimize a certain objective while other objectives are not too extreme;(3)It has the ability to surpass traditional feedforward decoupling control on all the 5 indexes;(4)It does not rely on the system identification.展开更多
基金funded by the National Natural Science Foundation of China(Grant Nos.51578543)。
文摘Reinforced concrete(RC) columns are widely used as supporting structures for high-piled wharfs.The study of damage model of a RC column due to underwater explosion is a critical issue to assess the wharfs antiknock security.In this study,the dynamic response and damage model of circular RC columns subjected to underwater explosions were investigated by means of scaled-down experiment models.Experiments were carried out in a 10.0 m diameter tank with the water depth of 2.25 m,under different explosive quantities(0.025 kg-1.6 kg),stand-off distances(0.0 m-7.0 m),and detonation depths(0.25 m-2.0 m).The shock wave load and dynamic response of experiment models were measured by configuring sensors of pressure,acceleration,strain,and displacement.Then,the load distribution characteristics,time history of test data,and damage models related to present conditions were obtained and discussed.Three damage models,including bending failure,bending-shear failure and punching failure,were identified.In addition,the experie nce model of shock wave loads on the surface of a RC column was proposed for engineering application.
基金Supported by a Research Grant from the National Science Council,Taipei, Taiwan, No. NSC91-2314-B002-245
文摘AIM： To evaluate whether the effect of Gin dipeptideenriched total parenteral nutrition （TPN） on postoperative cytokine alteration depended on the disease severity of surgical patients. METHODS： Forty-eight patients with major abdominal surgery were allocated to two groups to receive isonitrogenous （0.228 g nitrogen/kg per d） and isocaloric （30 kcal/kg per d） TPN for 6 d. Control group （Cony） using conventional TPN solution received 1.5 g amino acids/kg per day, whereas the test group received 0.972 g amino acids/kg per day and 0.417 g L-alanyI-L-glutamine （Ala-GIn）/kg per day. Blood samples were collected on d 1 and d 6 postoperatively for plasma interleukin （IL）-2, IL-6, IL-8, and interferon （IFN）-γ analysis. RESULTS： Plasma IL-2 and IFN-γ were not detectable. IL-6 concentrations were significantly lower on the 6^th postoperative day in the Ala-GIn group than those in the Cony group in patients with APACHE Ⅱ≤6, whereas no difference was noted in patients with APACHE Ⅱ〉6. There was no difference in IL-8 levels between the two groups. No difference in cumulative nitrogen balance was observed on d 2-5 after the operation between the two groups （Ala-GIn -3.2±1.6 g vs Cony -6.5±2.7 g）. A significant inverse correlation was noted between plasma IL-6 levels and cumulative nitrogen balance postoperatively in the Ala-GIn group, whereas no such correlation was observed in the Conv group. CONCLUSION： TPN supplemented with Gin dipeptide had no effect on plasma IL-8 levels after surgery. However, Gin supplementation had a beneficial effect on decreasing systemic IL-6 production after surgery in patients with low admission illness severity, and lower plasma IL-6 may improve nitrogen balance in patients with abdominal surgery when Gin was administered.
基金supported by the National Natural Science Foundation of China (Grants 11572045 and 11472051)the Defense Industrial Technology Development Program (Grant B1520132004)the General Project of the CAEP Safety and Ammunition Center (Grant RMC2015B03)
文摘Low-velocity drop-weight impact experiments on individual and multiple Cyclotetramethylene tetranitramine (HMX) energetic particles were performed using a modified drop-weight machine equipped with high-speed photography components. Multiple particles experienced more severe burning reactions than an individual particle. Comparisons between impacted salt and HMX particle show that jetting in HMX is mainly due to the motion of fragmented particles driven by gaseous reaction products. Velocity of jetting, flame propagation, and area expansion were measured via image processing, making it possible to quantify the chemical reaction or mechanical deformation violence at different stages.
基金supported by grants from the National Key R&D Program of China(2023YFD1801600 and 2021YFD1301200)Henan Province Higher Education Teaching Reform Research and Practice Project(2021SJGLX351).
文摘The pseudorabies virus(PRV)is identified as a double-helical DNA virus responsible for causing Aujeszky's disease,which results in considerable economic impacts globally.The enzyme tryptophanyl-tRNA synthetase 2(WARS2),a mitochondrial protein involved in protein synthesis,is recognized for its broad expression and vital role in the translation process.The findings of our study showed an increase in both mRNA and protein levels of WARS2 following PRV infection in both cell cultures and animal models.Suppressing WARS2 expression via RNA interference in PK-15 cells led to a reduction in PRV infection rates,whereas enhancing WARS2 expression resulted in increased infection rates.Furthermore,the activation of WARS2 in response to PRV was found to be reliant on the cGAS/STING/TBK1/IRF3 signaling pathway and the interferon-alpha receptor-1,highlighting its regulation via the type I interferon signaling pathway.Further analysis revealed that reducing WARS2 levels hindered PRV's ability to promote protein and lipid synthesis.Our research provides novel evidence that WARS2 facilitates PRV infection through its management of protein and lipid levels,presenting new avenues for developing preventative and therapeutic measures against PRV infections.
基金the National Natural Science Foundation of China(grant no.22271251)the Fundamental Research Funds for the Central Universities(grant nos.226-2023-00016,226-2023-00115,and 226-2022-00224).
文摘In sharp contrast to the well researched and well developed aminocarbonylation of alkenes,the dearomative carbamoylation of abundant areneπ-systems has scarcely been studied despite its great potential to enrich the diversity-oriented synthesis of high-value amides.The formidable challenges associated with such dearomatization include the low reactivity of stable aromaticπ-systems and intricate selectivity issues.Herein,we disclose a general approach toward highly selective dearomative carbamoylations of areneπ-bonds under CO-gas-free conditions.Its extraordinary versatility was demonstrated by tolerating a broad range of nucleophilic partners with high yields and excellent selectivities,thus providing modular access to the divergent synthesis ofβ-functionalized primary amides.In addition,diverse downstream derivatizations including a formal C–H 1,2-olefination/carbamoylation reaction were conducted,exhibiting great potential in synthetic and medicinal chemistry.
基金The authors acknowledge financial support from Zhejiang University,"1000-Youth Talents Plan"and the Fundamental Research Funds for the Central Universities(2020QNA3004).
文摘Catalysts and ligands possessing the great ability to tolerate over a wide range of mechanistically unrelated reactions are remarked as"privileged",which are rather scarce but extremely meaningful in asymmetric catalysis.Feng and co-workers have developed a library of conformationally flexible,C2-symmetric N,N'-dioxide amide compounds with original design and featured structure(named as Feng ligand now).They were initially reported as chiral organocatalysts in 2005 and have been further developed as a new class of privileged chiral ligands since 2006.Tremendous success,including versatile coordination chemistry with plenty of metal sources(main-group metals,transition metals,and rare-earth metals),a truly broad scope of asymmetric reactions(more than 50 types),diverse areas of catalysis(organocatalysis,Lewis-acid catalysis,bimetallic relay catalysis,and photocatalysis),numerous synthetic applications of bioactive compounds,has been achieved using Feng N,N'-dioxide.Besides,they demonstrate that chiral ligands with conformationally flexible property can offer excellent chiral environment as well,which challenges the conventional idea preferring rigid structures in the design of chiral ligands.Herein,we briefly introduced the discovery of Feng ligand and the millstones during the development.We also covered the successful applications of Feng ligand by other scientists as well as novel chiral ligands inspired by them.
基金supported by the National key research and development project of China(Grant No.2023YFB4005803)the Youth Project of the National Natural Science Foundation of China(Grant No.52306113).
文摘The temperature control of the air-cooled proton exchange membrane fuel cell(PEMFC)is important for effective and safe operation.To develop a practical and precise controller,this study combines the Radial Basis Function(RBF)neural network with Back Propagation neural network adaptive Proportion Integration Differentiation(BP-PID),and then a metaheuristic algorithm is used to optimize the parameters of RBF-BP-PID for further improvement in temperature control.First,an air-cooled PEMFC system model is established.To match the simulation data with the experimental data,Teaching Learning Based Optimization-Differential Evolution(TLBO-DE)is proposed to identify the unknown parameters,and the maximum relative error is<3.5%.Second,RBF neural network is introduced to identify the stack temperature and provide the accurate∂y(k)/∂u(k)for BP-PID,which solves the problem of using sign function sgn(∂y(k)/∂u(k))to approximate the∂y(k)/∂u(k)in BP-PID.Regarding the temperature control of air-cooled PEMFC,several controllers are compared,including PID,Fuzzy-PID,BP-PID and RBF-BP-PID.The proposed RBF-BP-PID achieves the best control effect,which reduces the integrated time and absolute error(ITAE)by 3.4%and 15.8%based on BP-PID in the startup and steady phases,respectively.Since the∂y(k)/∂u(k)provided by RBF changes softly and continuously during the control process,the parameters selftuning ability of RBF-BP-PID is better than BP-PID.Third,to improve the control effect of RBF-BP-PID further,TLBO-DE is adopted to optimize the parameters of RBF neural network and BP neural network.
基金supported by the National key research and development project of China(Grant No.2023YFB4005803)the Youth Project of the National Natural Science Foundation of China(Grant No.52306113)the Project of Shaanxi Innovative Talent Promotion Plan-Technology Innovation Team(No.2024RS-CXTD-35).
文摘Operating temperature is an important factor that affects the efficiency,durability,and safety of proton exchange membrane fuel cells(PEMFC).Thus,a thermal management system is necessary for controlling the appropriate temperature.In this paper,a novel thermal management system based on two-stage utilization of cooling air is first established,whose core characteristic is utilizing the temperature difference between the cooling air leaving the main radiator and the auxiliary radiator.The novel thermal management system can reduce the parasitic power of the fan by 59.27%and improve the temperature control effect to a certain extent.The traditional feedforward decoupling control based on system identification is first adopted to control the temperature and surpasses dual-PID on all the 5 indexes,which are Integral Absolute Error Criterion(IAE)of temperature difference,IAE of inlet coolant temperature,parasitic power of fan,average overshoot of temperature difference and average overshoot of inlet coolant temperature.The multi-objective decoupling control based on multiobjective optimization is then proposed to further improve the temperature control effect on the basis of traditional feedforward decoupling control.The above 5 indexes are chosen as the optimization objectives,the decoupling coefficients are chosen as the decision variables,and the Pareto set is obtained by NSGAⅡand NSGAⅢ.The results show that the proposed multi-objective decoupling control has the main advantages as follows:(1)It can provide comprehensive optimization options for different design preferences;(2)It can significantly optimize a certain objective while other objectives are not too extreme;(3)It has the ability to surpass traditional feedforward decoupling control on all the 5 indexes;(4)It does not rely on the system identification.
