On December 18, 2023, an M_(s) 6.2 earthquake jolted Jishishan County in the Linxia Hui Autonomous Prefecture in Northwest China's Gansu Province, causing substantial casualties and building collapses. The earthqu...On December 18, 2023, an M_(s) 6.2 earthquake jolted Jishishan County in the Linxia Hui Autonomous Prefecture in Northwest China's Gansu Province, causing substantial casualties and building collapses. The earthquake occurred in the Qilian Block on the northeastern border of the Qinghai-Tibet Plateau, where faults are highly active and the geological structure is complex. In this study, we utilized methods such as relocation, focal mechanism solutions, and earthquake rupture processes to describe seismogenic faults. The results indicated that the majority of aftershocks occurred at a depth of 12 km. The centroid depth of the main shock and the depth of the maximum rupture point during the rupture process were also 12 km. Various geophysical methods exhibited a high degree of consistency in depth exploration. Aftershocks were distributed mainly to the west and north of the main shock and extended in the NNW direction, primarily through unilateral rupture. The main shock was a reverse thrust event with a small dextral strike-slip component. In this study, more regional data, such as previous GPS observations, field geological observations, and the distributions of the primary stress states in the region, were also incorporated. We inferred that the main shock was triggered by the main fault at the northern margin of the Lajishan Fault and that the movement of the main fault also activated some secondary faults. The compressive forces on both sides of the Lajishan Fault Zone led to the uplift of mountain areas, accompanied by some landslides, leading to this catastrophic earthquake event. In this article, the activity relationships among the 2022 M_(s) 6.9 Menyuan earthquake, the 2019 M_(s) 5.7 Xiahe earthquake,and the Jishishan earthquake under the action of regional stress are also discussed. This study provides additional evidence and new ideas for exploring the seismogenic process of the Lajishan Fault Zone and has implications for future in-depth research on underground activity in this region.展开更多
Previous study showed that the Gle1 RNA export mediator-like (Gle1l) gene and the lymphocyte cytosolic protein 2 (Lcp2) gene were upregulated in response to influenza virus A/Puerto Rico/8/1934 (H1N1) in a mouse mode....Previous study showed that the Gle1 RNA export mediator-like (Gle1l) gene and the lymphocyte cytosolic protein 2 (Lcp2) gene were upregulated in response to influenza virus A/Puerto Rico/8/1934 (H1N1) in a mouse mode. To determine whether these two genes were upregulated in humans after influenza A virus infection, nasopharyngeal swabs were collected from eleven patients with flu-like symptoms for viral RNA extraction and PCR amplification. Sequencing analysis revealed that nucleoprotein (NP) gene fragments amplified from nasopharyngeal swabs of four patients shared the highest similarity with the NP gene from avian influenza A (H5N1) virus (A/ goose/Shantou/753/2002). Peripheral blood samples were then collected from four patients for quantitative analysis of GLE1 and LCP2 gene expression. Our results demonstrated that both GLE1 and LCP2 genes were upregulated in H5N1 influenza A virus infected patients, suggesting that upregulation of GLE1 and LCP2 genes may be important for the host defense against influenza A viruses.展开更多
High purity germanium detectors have important applications in many fields. Detector’s performance deteriorated significantly due to radiation of neutron. The annealing of damaged HPGe detector is expounded in this m...High purity germanium detectors have important applications in many fields. Detector’s performance deteriorated significantly due to radiation of neutron. The annealing of damaged HPGe detector is expounded in this monograph. The experiment results indicate that raising the temperature to 70°C for five days, the restoration efficiency can reach 90%.展开更多
The beam energy measurement system is significant and profit for both BES-III detector and BEPC-II accelerator. The detection of the high energy scattering photons is realized by virtue of the Compton backscattering p...The beam energy measurement system is significant and profit for both BES-III detector and BEPC-II accelerator. The detection of the high energy scattering photons is realized by virtue of the Compton backscattering principle. Many advanced techniques and precise instruments are employed to acquire the highly accurate measurement of positron/electron beam energy. During five years’ running period, in order to satisfy the requirement of data taking and enhance the capacity of measurement itself, the upgradation of system is continued, which involves the components reformation of laser and optics subsystem, replacement of view-port of the laser to vacuum insertion subsystem, the usage of electric cooling system for high purity germanium detector, and the refinement of data acquisition and processing subsystem. The upgrading of system guarantees the smooth and effective measuring of beam energy at BEPC-II and accommodates the accurate offline energy values for further physics analysis at BES-III.展开更多
Metal-organic frameworks(MOFs)have been intensely studied for the past few decades as an enormous family of highly tunable porous materials with promisingly applicable functionalities in adsorption,separation,catalysi...Metal-organic frameworks(MOFs)have been intensely studied for the past few decades as an enormous family of highly tunable porous materials with promisingly applicable functionalities in adsorption,separation,catalysis,sensing,electrochemistry,and a great number of emerging purposes.As a classic MOF,zeolitic imidazolate framework-8(ZIF-8)is conventionally one of the very few MOF members that has been commercialized with considerable production.展开更多
Two cryogenic systems of high purity germanium detector, liquid nitrogen and mechanical cooler, are expounded, to- gether with explanations of merits and demerits for each kind of cooling methods. The resolutions of d...Two cryogenic systems of high purity germanium detector, liquid nitrogen and mechanical cooler, are expounded, to- gether with explanations of merits and demerits for each kind of cooling methods. The resolutions of detector to the characteristic lines of 152Eu under different cooling conditions are studied. The laboratory results indicate that the me- chanical cooler (X-Cooler II) is an ideal replacement candidate for the liquid nitrogen cooling system that is being util- ized by BEMS at BEPC-II.展开更多
This paper proposes the alternating direction method of multipliers-based infinity-norm(ADMIN) with threshold(ADMIN-T) and with percentage(ADMIN-P) detection algorithms,which make full use of the distribution of the s...This paper proposes the alternating direction method of multipliers-based infinity-norm(ADMIN) with threshold(ADMIN-T) and with percentage(ADMIN-P) detection algorithms,which make full use of the distribution of the signal to interference plus noise ratio(SINR) for an uplink massive MIMO system.The ADMIN-T and ADMIN-P detection algorithms are improved visions of the ADMIN detection algorithm,in which an appropriate SINR threshold in the ADMIN-T detection algorithm and a certain percentage in the ADMIN-P detection algorithm are designed to reduce the overall computational complexity.The detected symbols are divided into two parts by the SINR threshold which is based on the cumulative probability density function(CDF) of SINR and a percentage,respectively.The symbols in higher SINR part are detected by MMSE.The interference of these symbols is then cancelled by successive interference cancellation(SIC).Afterwards the remaining symbols with low SINR are iteratively detected by ADMIN.The simulation results show that the ADMIIN-T and the ADMIN-P detection algorithms provide a significant performance gain compared with some recently proposed detection algorithms.In addition,the computational complexity of ADMIN-T and ADMIN-P are significantly reduced.Furthermore,in the case of same number of transceiver antennas,the proposed algorithms have a higher performance compared with the case of asymmetric transceiver antennas.展开更多
The receiver function(RF) technique is an effective method for studying crustal structure. For a single station, the average 1-D crustal structure is usually derived by stacking the radial RFs from all back-azimuths, ...The receiver function(RF) technique is an effective method for studying crustal structure. For a single station, the average 1-D crustal structure is usually derived by stacking the radial RFs from all back-azimuths, whereas structural variations(such as dipping discontinuities or anisotropy) can be constrained through analysis of waveform dependence on the backazimuth of both the radial and tangential RFs. However, it is often difficult to directly extract information about structural variations from the waveform of RF, due to the common presence of noise in real data. In this study, we proposed a new method to derive structural variation information for individual stations by applying principal component analysis(PCA) to RFs sorted by back-azimuth. In this method(termed as RF-PCA), a set of principal components(PCs), which are uncorrelated with each other and reflect different characteristics of the RF data, were extracted and utilized separately to reconstruct new RFs. Synthetic tests show that the first PC of the radial RFs contains the average structural information of the crust beneath the corresponding station, and the second PC of the radial RFs and the first PC of the tangential RFs both reflect the variations of the crustal structure. Our synthetic modeling results indicate that the new RF-PCA method is valid for a variety of synthetic models with intra-crustal dipping discontinuities and/or anisotropy. We applied this method to the real data from a broadband temporary seismic station(s233) in the central part of the Sichuan Basin. The results suggest that the RF data can be best explained by the presence of two nearly parallel dipping discontinuities within the crust. Combining with previous logging data, seismic exploration and deep sounding observations, we interpret the shallow dipping discontinuity as the top boundary of the Precambrian crystalline basement of the Sichuan Basin and the deep one corresponding to the Conrad interface between the upper and lower crust, consistent with the geological feature of the study area. In this work, both synthetic tests and real data application results demonstrate the effectiveness of the RF-PCA method for studying crustal structures.展开更多
A new method is developed to constrain S-wave velocity structures of the shallow crust based on frequencydependent amplitudes of direct P-waves in P-wave receiver functions(P-RFs). This method involves the following t...A new method is developed to constrain S-wave velocity structures of the shallow crust based on frequencydependent amplitudes of direct P-waves in P-wave receiver functions(P-RFs). This method involves the following two steps:first, the high-frequency approximate amplitude formula of direct P-waves in P-RFs of individual stations is used to fit the observed amplitude distribution against the ray parameters at different frequencies, and second, the S-wave velocity depth profile beneath each station is constrained according to an empirical correlation between frequency and depth. Unlike traditional inversion techniques, the newly developed method is not dependent on initial velocity models, and the lateral and vertical resolutions of the results are controlled by the interstation distance and the data frequency, respectively. The effectiveness of the method is verified by synthetic tests on various models. The method is then applied to teleseismic P-RF data from a NW-SEtrending linear seismic array extending from the northeastern Tibetan Plateau to the central Sichuan Basin to construct an S-wave velocity image of the shallow crust along the array. The imaged velocity structure is further analysed and compared with the regional geology. In particular, the structural differences of sedimentary basins in the cratonic area of the stable Sichuan Basin and tectonically active belts in northeastern Tibet are investigated. By combining our results with previous observations, the relationship between the surficial geology and deep processes in the study region is also discussed.展开更多
Background:Previous studies have demonstrated the preclinical pharmacological and toxicological consistency,and clinical pharmacokinetic equivalence of bevacizumab biosimilar LY01008 with reference bevacizumab(Avastin...Background:Previous studies have demonstrated the preclinical pharmacological and toxicological consistency,and clinical pharmacokinetic equivalence of bevacizumab biosimilar LY01008 with reference bevacizumab(Avastin).This randomized controlled trial aimed to compare the efficacy and safety of LY01008 with Avastin in first-line treatment of Chinese patients with advanced or recurrent non-squamous non-small cell lung cancer(NSCLC).Methods:StageⅢB-ⅣNSCLC patients with evaluable lesions,good physical status,and adequate organ functions from 67 centers across China were randomized in a ratio of 1:1 to receive LY01008 or Avastin 15 mg/kg intravenously in combination with paclitaxel/carboplatin(combined treatment)for 4-6 cycles,followed by maintenance monotherapy with LY01008 until disease progression,intolerable toxicity,or death.The primary endpoint was objective response rate(ORR)in accordance with Response Evaluation Criteria in Solid Tumors(RECIST)version 1.1 confirmed by independent radiological review committees(IRRC).Secondary endpoints included disease control rate(DCR),duration of response(DoR),progression-free survival(PFS),overall survival(OS),and safety.This study was registered in Clinical Trials.gov(NCT03533127).Results:Between December 15^(th),2017,and May 15^(th),2019,a total of 649 patients were randomized to the LY01008(n=324)or Avastin(n=325)group.As of September 25th,2019 for primary endpoint analysis,589 patients received ORR evaluation,with a median number of combined treatment cycles of 5(range 1-6)andmedian duration of treatment of 3.0(range 0.0-5.1)months.ORRof responseevaluable patients in the LY01008 and Avastin groups were 48.5% and 53.0%,respectively.The stratified ORR ratio was 0.91(90%CI 0.80-1.04,within the prespecified equivalence margin of 0.75-1.33).Up to May 15^(th),2020,with a median follow-up of 13.6(range 0.8-28.4)months,no notable differences in DCR,median DoR,median PFS,median OS,and 1-year OS rate were observed between the LY01008 and Avastin groups.There were no clinically meaningful differences in safety and immunogenicity across treatment groups.Conclusions:LY01008 demonstrated similarity to Avastin in terms of efficacy and safety in Chinese patients with advanced or recurrent non-squamous NSCLC.LY01008 combined with paclitaxel/carboplatin is expected to become a new treatment option for unresectable,metastatic,LY01008 and Avastin groups.There were no clinically meaningful differences in safety and immunogenicity across treatment groups.Conclusions:LY01008 demonstrated similarity to Avastin in terms of efficacy and safety in Chinese patients with advanced or recurrent non-squamous NSCLC.LY01008 combined with paclitaxel/carboplatin is expected to become a new treatment option for unresectable,metastatic,or recurrent non-squamous NSCLC patients in the first-line setting.展开更多
Homogenous charge compression ignition （HCCI） engines feature high thermal efficiency and ultralow emissions compared to gasoline engines. However, unlike SI engines, HCCI combustion does not have a direct way to tr...Homogenous charge compression ignition （HCCI） engines feature high thermal efficiency and ultralow emissions compared to gasoline engines. However, unlike SI engines, HCCI combustion does not have a direct way to trigger the in-cylinder combustion. Therefore, gasoline HCCI combustion is facing challenges in the control of ignition and, combustion, and operational range extension. In this paper, an active fuel design concept was proposed to explore a potential pathway to optimize the HCCI engine combustion and broaden its operational range. The active fuel design concept was realized by real time control of dual-fuel （gasoline and n-heptane） port injection, with exhaust gas recirculation （EGR） rate and intake temperature adjusted. It was found that the cylinder- to-cylinder variation in HCCI combustion could be effectively reduced by the optimization in fuel injection proportion, and that the rapid transition process from SI to HCCI could be realized. The active fuel design technology could significantly increase the adaptability of HCCI combustion to increased EGR rate and reduced intake temperature. Active fuel design was shown to broaden the operational HCCI load to 9.3 bar indicated mean effective pressure （IMEP）. HCCI operation was used by up to 70% of the SI mode load while reducing fuel consumption and nitrogen oxides emissions. Therefore, the active fuel design technology could manage the right fuel for clean engine combustion, and provide a potential pathway for engine fuel diversification and future engine concept.展开更多
The secretome secreted by stem cells and bioactive material has emerged as a promising therapeutic choice for traumatic brain injury(TBI).We aimed to determine the effect of 3D-printed collagen/chitosan/secretome deri...The secretome secreted by stem cells and bioactive material has emerged as a promising therapeutic choice for traumatic brain injury(TBI).We aimed to determine the effect of 3D-printed collagen/chitosan/secretome derived from human umbilical cord blood mesenchymal stem cells scaffolds(3D-CC-ST)on the injured tissue regeneration process.3D-CC-ST was performed using 3D printing technology at a low temperature(20C),and the physical properties and degeneration rate were measured.The utilization of low temperature contributed to a higher cytocompatibility of fabricating porous 3D architectures that provide a homogeneous distribution of cells.Immediately after the establishment of the canine TBI model,3D-CC-ST and 3D-CC(3D-printed collagen/chitosan scaffolds)were implanted into the cavity of TBI.Following implantation of scaffolds,neurological examination and motor evoked potential detection were performed to analyze locomotor function recovery.Histological and immunofluorescence staining were performed to evaluate neuro-regeneration.The group treated with 3D-CC-ST had good performance of behavior functions.Implanting 3D-CC-ST significantly reduced the cavity area,facilitated the regeneration of nerve fibers and vessel reconstruction,and promoted endogenous neuronal differentiation and synapse formation after TBI.The implantation of 3D-CC-ST also markedly reduced cell apoptosis and regulated the level of systemic inflammatory factors after TBI.展开更多
Porous materials play an important role in chemical catalysis,separation and other industrial applications.High-efficiency preparation of porous materials has become an active research area.Conventional synthesis of p...Porous materials play an important role in chemical catalysis,separation and other industrial applications.High-efficiency preparation of porous materials has become an active research area.Conventional synthesis of porous materials has been dominated by one-pot solution processing conditions carried out by bulk mixing under conventional electric heating via hydrothermal,solvothermal or ionothermal reactions where high temperatures and pressures are the standard.Continuous flow synthesis has many key advantages in terms of efficient mass and heat transfer,precise control of residence times,improved opportunities for automation and feedback control of synthesis,scaling-up reactions and improved safety parameters compared to above mentioned conventional batch scale synthetic methods.In this review,continuous flow synthesis of various crystalline porous materials such as metal-organic frameworks(MOFs),covalent-organic frameworks(COFs),porous organic cages and zeolites is discussed.Combination of microfluidic methods with other techniques are also shown including various heating ways and various methods of substrate adding.展开更多
This paper experimentally and numerically studied the effects of fuel combination and intake valve opening(IVO)timing on combustion and emissions of an n-heptane and gasoline dual-flicl homogeneous charge compression ...This paper experimentally and numerically studied the effects of fuel combination and intake valve opening(IVO)timing on combustion and emissions of an n-heptane and gasoline dual-flicl homogeneous charge compression ignition(HCCI)engine.By changing the gasoline fraction(GF)from 0」to 0.5 and the IVO timing from-15°CA ATDC to 35°CA ATDC,the in-cylinder pressure traces,heat release behaviors,and HC and CO emissions were investigated.The results showed that both the increased GF and the retarded IVO timing delay the combustion phasing,lengthen the combustion duration,and decrease the peak heat release rate and the maximum average combustion temperature,whereas the IVO timing has a more obvious influence on combustion than GF.HC and CO emissions are decreased with reduced GF,advanced IVO timing and increased operational load.展开更多
Introduction HPGe detector is used widely,its property is affected by neutron.Annealing to the germanium crystal is a good approach to recover the detector.Purpose To raise the temperature of germanium crystal to reco...Introduction HPGe detector is used widely,its property is affected by neutron.Annealing to the germanium crystal is a good approach to recover the detector.Purpose To raise the temperature of germanium crystal to recover the resolution for the HPGe detector.Method A special copper ingot is designed and manufactured to increase the heating efficiency.Two temperature controlled power supplies are used to heat the germanium crystal and keep the temperature for cooling rod.Conclusion The experiment results indicate that raising temperature to 70℃for five days,the restoration efficiency is better than 90%.展开更多
Vigorous particle collisions and mechanical processes occurring during high-velocity pneumatic con- veying often lead to particle degradation. The resulting particle size reduction and particle number increase will im...Vigorous particle collisions and mechanical processes occurring during high-velocity pneumatic con- veying often lead to particle degradation. The resulting particle size reduction and particle number increase will impact on the flow characteristics, and subsequently affect the electrostatic type of flow measurements. This study investigates this phenomenon using both experimental and numerical meth- ods. Particle degradation was induced experimentally by recursively conveying the fillite material within a pneumatic pipeline. The associated particle size reduction was monitored. Three electrostatic sensors were embedded along the pipeline to monitor the flow. The results indicated a decreasing trend in the electrostatic sensor outputs with decreasing particle size, which suggested the attenuation of the flow velocity fluctuation. This trend was more apparent at higher conveying velocities, which suggested that more severe particle degradation occurred under these conditions. Coupled computational fluid dynamics and discrete element methods （CFD-DEM） analysis was used to qualitatively validate these experimental results. The numerical results suggested that smaller particles exhibited lower flow velocity fluctua- tions, which was consistent with the observed experimental results. These findings provide important information for the accurate aoolication of electrostatic measurement devices in oneumatic conveyors.展开更多
Incorporation of phosphine-Pd catalytic centers in gel network is an important strategy to develop highly active catalysts.In this contribution we show that catalytically active phosphine-Pd(II)gels can be readily obt...Incorporation of phosphine-Pd catalytic centers in gel network is an important strategy to develop highly active catalysts.In this contribution we show that catalytically active phosphine-Pd(II)gels can be readily obtained via re-action of rigid bridging terpyridyl phosphines and Pd(II).The terpyridyl phosphines,Py2P2 and Py2P,contain one 4,2':6',4"-terpyridyl group and two/one diphenylphosphino groups.Reactions of Py2P2/Py2P and Pd(II)in CHCl_(3)-MeOH afforded the corresponding phosphine-Pd(II)gels at room temperature or at elevated temperature(40℃).The gelation is driven by formation of metal-organic coordination.Mild heating is important in triggering the formation of Py2P-Pd(II)gel.The gels have a coherent,rigid spongy porous network of continuous nanome-ter-sized particles.The phosphine-Pd(II)gels showed high activity in the Suzuki-Miyaura reactions of aryl bro-mides under ambient conditions and could be recycled and reused.展开更多
Hepatoid carcinoma of the pancreas(HCP)is an extremely rare pancreatic cancer resembling hepatocellular carcinoma,a type of liver cancer(1).Most reports have shown that it has an aggressive behavior and is associated ...Hepatoid carcinoma of the pancreas(HCP)is an extremely rare pancreatic cancer resembling hepatocellular carcinoma,a type of liver cancer(1).Most reports have shown that it has an aggressive behavior and is associated with early metastasis.There is no standardized treatment for HCP due to its rarity,and the limited number of cases reported in the literature(2,3).However,treatment options for this type of rare cancer include surgery,chemotherapy,and radiation therapy,depending on the stage of the cancer.Nevertheless,the prognosis of HCP is poor.展开更多
基金funded by the National Natural Science Foundation of China (Grant No. 42304072)。
文摘On December 18, 2023, an M_(s) 6.2 earthquake jolted Jishishan County in the Linxia Hui Autonomous Prefecture in Northwest China's Gansu Province, causing substantial casualties and building collapses. The earthquake occurred in the Qilian Block on the northeastern border of the Qinghai-Tibet Plateau, where faults are highly active and the geological structure is complex. In this study, we utilized methods such as relocation, focal mechanism solutions, and earthquake rupture processes to describe seismogenic faults. The results indicated that the majority of aftershocks occurred at a depth of 12 km. The centroid depth of the main shock and the depth of the maximum rupture point during the rupture process were also 12 km. Various geophysical methods exhibited a high degree of consistency in depth exploration. Aftershocks were distributed mainly to the west and north of the main shock and extended in the NNW direction, primarily through unilateral rupture. The main shock was a reverse thrust event with a small dextral strike-slip component. In this study, more regional data, such as previous GPS observations, field geological observations, and the distributions of the primary stress states in the region, were also incorporated. We inferred that the main shock was triggered by the main fault at the northern margin of the Lajishan Fault and that the movement of the main fault also activated some secondary faults. The compressive forces on both sides of the Lajishan Fault Zone led to the uplift of mountain areas, accompanied by some landslides, leading to this catastrophic earthquake event. In this article, the activity relationships among the 2022 M_(s) 6.9 Menyuan earthquake, the 2019 M_(s) 5.7 Xiahe earthquake,and the Jishishan earthquake under the action of regional stress are also discussed. This study provides additional evidence and new ideas for exploring the seismogenic process of the Lajishan Fault Zone and has implications for future in-depth research on underground activity in this region.
文摘Previous study showed that the Gle1 RNA export mediator-like (Gle1l) gene and the lymphocyte cytosolic protein 2 (Lcp2) gene were upregulated in response to influenza virus A/Puerto Rico/8/1934 (H1N1) in a mouse mode. To determine whether these two genes were upregulated in humans after influenza A virus infection, nasopharyngeal swabs were collected from eleven patients with flu-like symptoms for viral RNA extraction and PCR amplification. Sequencing analysis revealed that nucleoprotein (NP) gene fragments amplified from nasopharyngeal swabs of four patients shared the highest similarity with the NP gene from avian influenza A (H5N1) virus (A/ goose/Shantou/753/2002). Peripheral blood samples were then collected from four patients for quantitative analysis of GLE1 and LCP2 gene expression. Our results demonstrated that both GLE1 and LCP2 genes were upregulated in H5N1 influenza A virus infected patients, suggesting that upregulation of GLE1 and LCP2 genes may be important for the host defense against influenza A viruses.
文摘High purity germanium detectors have important applications in many fields. Detector’s performance deteriorated significantly due to radiation of neutron. The annealing of damaged HPGe detector is expounded in this monograph. The experiment results indicate that raising the temperature to 70°C for five days, the restoration efficiency can reach 90%.
文摘The beam energy measurement system is significant and profit for both BES-III detector and BEPC-II accelerator. The detection of the high energy scattering photons is realized by virtue of the Compton backscattering principle. Many advanced techniques and precise instruments are employed to acquire the highly accurate measurement of positron/electron beam energy. During five years’ running period, in order to satisfy the requirement of data taking and enhance the capacity of measurement itself, the upgradation of system is continued, which involves the components reformation of laser and optics subsystem, replacement of view-port of the laser to vacuum insertion subsystem, the usage of electric cooling system for high purity germanium detector, and the refinement of data acquisition and processing subsystem. The upgrading of system guarantees the smooth and effective measuring of beam energy at BEPC-II and accommodates the accurate offline energy values for further physics analysis at BES-III.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.51603052 and 51573216)the Fundamental Research Funds for the Central Universities(Grant Nos.18lgpy02 and 16lgjc66).
文摘Metal-organic frameworks(MOFs)have been intensely studied for the past few decades as an enormous family of highly tunable porous materials with promisingly applicable functionalities in adsorption,separation,catalysis,sensing,electrochemistry,and a great number of emerging purposes.As a classic MOF,zeolitic imidazolate framework-8(ZIF-8)is conventionally one of the very few MOF members that has been commercialized with considerable production.
文摘Two cryogenic systems of high purity germanium detector, liquid nitrogen and mechanical cooler, are expounded, to- gether with explanations of merits and demerits for each kind of cooling methods. The resolutions of detector to the characteristic lines of 152Eu under different cooling conditions are studied. The laboratory results indicate that the me- chanical cooler (X-Cooler II) is an ideal replacement candidate for the liquid nitrogen cooling system that is being util- ized by BEMS at BEPC-II.
基金This work was supported in part by the National Natural Science Foundation of China(NSFC)under grant numbers 61671047,61775015 and U2006217.
文摘This paper proposes the alternating direction method of multipliers-based infinity-norm(ADMIN) with threshold(ADMIN-T) and with percentage(ADMIN-P) detection algorithms,which make full use of the distribution of the signal to interference plus noise ratio(SINR) for an uplink massive MIMO system.The ADMIN-T and ADMIN-P detection algorithms are improved visions of the ADMIN detection algorithm,in which an appropriate SINR threshold in the ADMIN-T detection algorithm and a certain percentage in the ADMIN-P detection algorithm are designed to reduce the overall computational complexity.The detected symbols are divided into two parts by the SINR threshold which is based on the cumulative probability density function(CDF) of SINR and a percentage,respectively.The symbols in higher SINR part are detected by MMSE.The interference of these symbols is then cancelled by successive interference cancellation(SIC).Afterwards the remaining symbols with low SINR are iteratively detected by ADMIN.The simulation results show that the ADMIIN-T and the ADMIN-P detection algorithms provide a significant performance gain compared with some recently proposed detection algorithms.In addition,the computational complexity of ADMIN-T and ADMIN-P are significantly reduced.Furthermore,in the case of same number of transceiver antennas,the proposed algorithms have a higher performance compared with the case of asymmetric transceiver antennas.
基金supported by the National Natural Science Foundation of China (Grant No. 41688103)the independent project of the State Key Laboratory of the Lithospheric Evolution, IGGCAS (Grant No. SKL-Z201704-11712180)
文摘The receiver function(RF) technique is an effective method for studying crustal structure. For a single station, the average 1-D crustal structure is usually derived by stacking the radial RFs from all back-azimuths, whereas structural variations(such as dipping discontinuities or anisotropy) can be constrained through analysis of waveform dependence on the backazimuth of both the radial and tangential RFs. However, it is often difficult to directly extract information about structural variations from the waveform of RF, due to the common presence of noise in real data. In this study, we proposed a new method to derive structural variation information for individual stations by applying principal component analysis(PCA) to RFs sorted by back-azimuth. In this method(termed as RF-PCA), a set of principal components(PCs), which are uncorrelated with each other and reflect different characteristics of the RF data, were extracted and utilized separately to reconstruct new RFs. Synthetic tests show that the first PC of the radial RFs contains the average structural information of the crust beneath the corresponding station, and the second PC of the radial RFs and the first PC of the tangential RFs both reflect the variations of the crustal structure. Our synthetic modeling results indicate that the new RF-PCA method is valid for a variety of synthetic models with intra-crustal dipping discontinuities and/or anisotropy. We applied this method to the real data from a broadband temporary seismic station(s233) in the central part of the Sichuan Basin. The results suggest that the RF data can be best explained by the presence of two nearly parallel dipping discontinuities within the crust. Combining with previous logging data, seismic exploration and deep sounding observations, we interpret the shallow dipping discontinuity as the top boundary of the Precambrian crystalline basement of the Sichuan Basin and the deep one corresponding to the Conrad interface between the upper and lower crust, consistent with the geological feature of the study area. In this work, both synthetic tests and real data application results demonstrate the effectiveness of the RF-PCA method for studying crustal structures.
基金supported by the National Natural Science Foundation of China (Grant No. 41688103)the Strategic Priority Research Program (A) of the Chinese Academy of Sciences (Grant No. XDA20070302)+1 种基金the Independent Project of the State Key Laboratory of the Lithospheric Evolution, IGGCAS (SKL-Z201704-11712180)The field work for seismic data collection was financially supported by the Projects (Grant Nos. SinoProbe-02-03, 2011ZX05008-001)
文摘A new method is developed to constrain S-wave velocity structures of the shallow crust based on frequencydependent amplitudes of direct P-waves in P-wave receiver functions(P-RFs). This method involves the following two steps:first, the high-frequency approximate amplitude formula of direct P-waves in P-RFs of individual stations is used to fit the observed amplitude distribution against the ray parameters at different frequencies, and second, the S-wave velocity depth profile beneath each station is constrained according to an empirical correlation between frequency and depth. Unlike traditional inversion techniques, the newly developed method is not dependent on initial velocity models, and the lateral and vertical resolutions of the results are controlled by the interstation distance and the data frequency, respectively. The effectiveness of the method is verified by synthetic tests on various models. The method is then applied to teleseismic P-RF data from a NW-SEtrending linear seismic array extending from the northeastern Tibetan Plateau to the central Sichuan Basin to construct an S-wave velocity image of the shallow crust along the array. The imaged velocity structure is further analysed and compared with the regional geology. In particular, the structural differences of sedimentary basins in the cratonic area of the stable Sichuan Basin and tectonically active belts in northeastern Tibet are investigated. By combining our results with previous observations, the relationship between the surficial geology and deep processes in the study region is also discussed.
基金China National Major Project for New Drug Innovation,Grant/Award Number:2017ZX09304015Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(CIFMS),Grant/Award Number:2016-I2M-1-001。
文摘Background:Previous studies have demonstrated the preclinical pharmacological and toxicological consistency,and clinical pharmacokinetic equivalence of bevacizumab biosimilar LY01008 with reference bevacizumab(Avastin).This randomized controlled trial aimed to compare the efficacy and safety of LY01008 with Avastin in first-line treatment of Chinese patients with advanced or recurrent non-squamous non-small cell lung cancer(NSCLC).Methods:StageⅢB-ⅣNSCLC patients with evaluable lesions,good physical status,and adequate organ functions from 67 centers across China were randomized in a ratio of 1:1 to receive LY01008 or Avastin 15 mg/kg intravenously in combination with paclitaxel/carboplatin(combined treatment)for 4-6 cycles,followed by maintenance monotherapy with LY01008 until disease progression,intolerable toxicity,or death.The primary endpoint was objective response rate(ORR)in accordance with Response Evaluation Criteria in Solid Tumors(RECIST)version 1.1 confirmed by independent radiological review committees(IRRC).Secondary endpoints included disease control rate(DCR),duration of response(DoR),progression-free survival(PFS),overall survival(OS),and safety.This study was registered in Clinical Trials.gov(NCT03533127).Results:Between December 15^(th),2017,and May 15^(th),2019,a total of 649 patients were randomized to the LY01008(n=324)or Avastin(n=325)group.As of September 25th,2019 for primary endpoint analysis,589 patients received ORR evaluation,with a median number of combined treatment cycles of 5(range 1-6)andmedian duration of treatment of 3.0(range 0.0-5.1)months.ORRof responseevaluable patients in the LY01008 and Avastin groups were 48.5% and 53.0%,respectively.The stratified ORR ratio was 0.91(90%CI 0.80-1.04,within the prespecified equivalence margin of 0.75-1.33).Up to May 15^(th),2020,with a median follow-up of 13.6(range 0.8-28.4)months,no notable differences in DCR,median DoR,median PFS,median OS,and 1-year OS rate were observed between the LY01008 and Avastin groups.There were no clinically meaningful differences in safety and immunogenicity across treatment groups.Conclusions:LY01008 demonstrated similarity to Avastin in terms of efficacy and safety in Chinese patients with advanced or recurrent non-squamous NSCLC.LY01008 combined with paclitaxel/carboplatin is expected to become a new treatment option for unresectable,metastatic,LY01008 and Avastin groups.There were no clinically meaningful differences in safety and immunogenicity across treatment groups.Conclusions:LY01008 demonstrated similarity to Avastin in terms of efficacy and safety in Chinese patients with advanced or recurrent non-squamous NSCLC.LY01008 combined with paclitaxel/carboplatin is expected to become a new treatment option for unresectable,metastatic,or recurrent non-squamous NSCLC patients in the first-line setting.
文摘Homogenous charge compression ignition （HCCI） engines feature high thermal efficiency and ultralow emissions compared to gasoline engines. However, unlike SI engines, HCCI combustion does not have a direct way to trigger the in-cylinder combustion. Therefore, gasoline HCCI combustion is facing challenges in the control of ignition and, combustion, and operational range extension. In this paper, an active fuel design concept was proposed to explore a potential pathway to optimize the HCCI engine combustion and broaden its operational range. The active fuel design concept was realized by real time control of dual-fuel （gasoline and n-heptane） port injection, with exhaust gas recirculation （EGR） rate and intake temperature adjusted. It was found that the cylinder- to-cylinder variation in HCCI combustion could be effectively reduced by the optimization in fuel injection proportion, and that the rapid transition process from SI to HCCI could be realized. The active fuel design technology could significantly increase the adaptability of HCCI combustion to increased EGR rate and reduced intake temperature. Active fuel design was shown to broaden the operational HCCI load to 9.3 bar indicated mean effective pressure （IMEP）. HCCI operation was used by up to 70% of the SI mode load while reducing fuel consumption and nitrogen oxides emissions. Therefore, the active fuel design technology could manage the right fuel for clean engine combustion, and provide a potential pathway for engine fuel diversification and future engine concept.
基金supported by the National Major Scientific and Technological Special Project for Significant New Drugs Development(2015ZX09102010).
文摘The secretome secreted by stem cells and bioactive material has emerged as a promising therapeutic choice for traumatic brain injury(TBI).We aimed to determine the effect of 3D-printed collagen/chitosan/secretome derived from human umbilical cord blood mesenchymal stem cells scaffolds(3D-CC-ST)on the injured tissue regeneration process.3D-CC-ST was performed using 3D printing technology at a low temperature(20C),and the physical properties and degeneration rate were measured.The utilization of low temperature contributed to a higher cytocompatibility of fabricating porous 3D architectures that provide a homogeneous distribution of cells.Immediately after the establishment of the canine TBI model,3D-CC-ST and 3D-CC(3D-printed collagen/chitosan scaffolds)were implanted into the cavity of TBI.Following implantation of scaffolds,neurological examination and motor evoked potential detection were performed to analyze locomotor function recovery.Histological and immunofluorescence staining were performed to evaluate neuro-regeneration.The group treated with 3D-CC-ST had good performance of behavior functions.Implanting 3D-CC-ST significantly reduced the cavity area,facilitated the regeneration of nerve fibers and vessel reconstruction,and promoted endogenous neuronal differentiation and synapse formation after TBI.The implantation of 3D-CC-ST also markedly reduced cell apoptosis and regulated the level of systemic inflammatory factors after TBI.
基金the National Natural Science Foundation of China(NSFC,No.51573216)the NSF of Guangdong Province for financial support。
文摘Porous materials play an important role in chemical catalysis,separation and other industrial applications.High-efficiency preparation of porous materials has become an active research area.Conventional synthesis of porous materials has been dominated by one-pot solution processing conditions carried out by bulk mixing under conventional electric heating via hydrothermal,solvothermal or ionothermal reactions where high temperatures and pressures are the standard.Continuous flow synthesis has many key advantages in terms of efficient mass and heat transfer,precise control of residence times,improved opportunities for automation and feedback control of synthesis,scaling-up reactions and improved safety parameters compared to above mentioned conventional batch scale synthetic methods.In this review,continuous flow synthesis of various crystalline porous materials such as metal-organic frameworks(MOFs),covalent-organic frameworks(COFs),porous organic cages and zeolites is discussed.Combination of microfluidic methods with other techniques are also shown including various heating ways and various methods of substrate adding.
基金the National Natural Science Foundation of China(Grant Nos.51861135303 and 51776124)the Shanghai Science and Technology Committee,China(Grant No.19160745400).
文摘This paper experimentally and numerically studied the effects of fuel combination and intake valve opening(IVO)timing on combustion and emissions of an n-heptane and gasoline dual-flicl homogeneous charge compression ignition(HCCI)engine.By changing the gasoline fraction(GF)from 0」to 0.5 and the IVO timing from-15°CA ATDC to 35°CA ATDC,the in-cylinder pressure traces,heat release behaviors,and HC and CO emissions were investigated.The results showed that both the increased GF and the retarded IVO timing delay the combustion phasing,lengthen the combustion duration,and decrease the peak heat release rate and the maximum average combustion temperature,whereas the IVO timing has a more obvious influence on combustion than GF.HC and CO emissions are decreased with reduced GF,advanced IVO timing and increased operational load.
基金supported in part by National Natural Science Foundation of China(NSFC)under Contracts Nos.11375206,11811530073the Ministry of Science and Technology of China under Contract Nos.2015CB856700,2015CB856705+1 种基金State key laboratory of particle and detection and electronicsand the CAS Center for Excellence in Particle Physics(CCEPP)
文摘Introduction HPGe detector is used widely,its property is affected by neutron.Annealing to the germanium crystal is a good approach to recover the detector.Purpose To raise the temperature of germanium crystal to recover the resolution for the HPGe detector.Method A special copper ingot is designed and manufactured to increase the heating efficiency.Two temperature controlled power supplies are used to heat the germanium crystal and keep the temperature for cooling rod.Conclusion The experiment results indicate that raising temperature to 70℃for five days,the restoration efficiency is better than 90%.
文摘Vigorous particle collisions and mechanical processes occurring during high-velocity pneumatic con- veying often lead to particle degradation. The resulting particle size reduction and particle number increase will impact on the flow characteristics, and subsequently affect the electrostatic type of flow measurements. This study investigates this phenomenon using both experimental and numerical meth- ods. Particle degradation was induced experimentally by recursively conveying the fillite material within a pneumatic pipeline. The associated particle size reduction was monitored. Three electrostatic sensors were embedded along the pipeline to monitor the flow. The results indicated a decreasing trend in the electrostatic sensor outputs with decreasing particle size, which suggested the attenuation of the flow velocity fluctuation. This trend was more apparent at higher conveying velocities, which suggested that more severe particle degradation occurred under these conditions. Coupled computational fluid dynamics and discrete element methods （CFD-DEM） analysis was used to qualitatively validate these experimental results. The numerical results suggested that smaller particles exhibited lower flow velocity fluctua- tions, which was consistent with the observed experimental results. These findings provide important information for the accurate aoolication of electrostatic measurement devices in oneumatic conveyors.
基金supported by the National Key Research and Development Program of China(2020YFA0715000)the National Natural Science Foundation of China(521722315197225951832004)+3 种基金the Fundamental Research Funds for the Central Universities(WUT:2020Ⅲ043GX2020Ⅲ015GX)the support by MOE,Singapore Ministry of Education(Tier 1,A-8000186-01-00)the funding support from Singapore A*STAR CRF Awardthe scholarship support from China Scholarship Council(CSC)under No.202106950024。
基金National Natural Science Founda-tion of China (21273007 and 21350110212)Program for New Century Excellent Talents in University (NCET-13-0615)the Fundamental Research Funds for the Central Universities (14lgpy05)for support.
文摘Incorporation of phosphine-Pd catalytic centers in gel network is an important strategy to develop highly active catalysts.In this contribution we show that catalytically active phosphine-Pd(II)gels can be readily obtained via re-action of rigid bridging terpyridyl phosphines and Pd(II).The terpyridyl phosphines,Py2P2 and Py2P,contain one 4,2':6',4"-terpyridyl group and two/one diphenylphosphino groups.Reactions of Py2P2/Py2P and Pd(II)in CHCl_(3)-MeOH afforded the corresponding phosphine-Pd(II)gels at room temperature or at elevated temperature(40℃).The gelation is driven by formation of metal-organic coordination.Mild heating is important in triggering the formation of Py2P-Pd(II)gel.The gels have a coherent,rigid spongy porous network of continuous nanome-ter-sized particles.The phosphine-Pd(II)gels showed high activity in the Suzuki-Miyaura reactions of aryl bro-mides under ambient conditions and could be recycled and reused.
文摘Hepatoid carcinoma of the pancreas(HCP)is an extremely rare pancreatic cancer resembling hepatocellular carcinoma,a type of liver cancer(1).Most reports have shown that it has an aggressive behavior and is associated with early metastasis.There is no standardized treatment for HCP due to its rarity,and the limited number of cases reported in the literature(2,3).However,treatment options for this type of rare cancer include surgery,chemotherapy,and radiation therapy,depending on the stage of the cancer.Nevertheless,the prognosis of HCP is poor.
