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COVID-19 mRNA vaccines

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Journal of Genetics and Genomics 2021年第2期48卷 107-114页

作者： Qingrui Huang Jiawei zeng Jinghua yan CAS Key Laboratory of Microbial Physiological and Metabolic Engineenng Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 101408China Check for updates

The ongoing COVID-19 pandemic and its unprecedented global societal and economic disruptive impact highlight the urgent need for safe and effective *** substantial advantages of versatility and rapid development,two m RNA vaccines against COVID-19 have completed late-stage clinical assessment at an unprecedented speed and reported positive *** this review,we outline keynotes in m RNA vaccine development,discuss recently published data on COVID-19 m RNA vaccine candidates,focusing on those in clinical trials and analyze future potential challenges.

关键词： vaccines vaccine clinical

高铁开通对工业技术效率的影响研究——基于市场可达性与集聚经济效应的分析

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山东财经大学学报 2025年第1期37卷 75-89页

作者：曾光宋安然路宇华中农业大学经济管理学院湖北武汉430070

中国高铁的快速发展降低了运输和交易成本,加速了要素流动,从而影响了地级及以上城市(以下简称地级市)的工业技术效率。基于2006—2020年259个地级市的面板数据,将市场可达性以及三种不同类型集聚外部性纳入同一框架,考察高铁开通对地... 详细信息

中国高铁的快速发展降低了运输和交易成本,加速了要素流动,从而影响了地级及以上城市(以下简称地级市)的工业技术效率。基于2006—2020年259个地级市的面板数据,将市场可达性以及三种不同类型集聚外部性纳入同一框架,考察高铁开通对地级市工业技术效率的直接、空间影响效应及其内在机制。研究发现:整体而言,尽管存在一定滞后效应,但地级市高铁开通可以显著提高其工业技术效率,且存在正向的空间溢出效应;高铁开通可以有效提高非区域中心城市工业技术效率,但对区域中心城市的提升效应不显著;机制分析结果表明,高铁开通能够有效提升地级市市场可达性、工业集聚专业化和竞争外部性,促进其技术效率的提升,但对多样化外部性具有显著负向影响,且结果具有较强的稳健性;与非区域中心城市相比,高铁开通对区域中心城市多样化外部性的影响不再显著。因此,各地应通过体制机制创新,优化要素配置,优化工业空间布局,引导、支持企业向工业园区等优势产地和市场区集聚,因地制宜地制定差异化的工业发展战略,放大高铁开通对地区工业技术效率的改善作用。

关键词：高铁开通集聚外部性市场可达性随机前沿方法工业技术效率

Engineering high-performance chemiluminescent probes via enzymatic pocket targeting: high-throughput screening for ultralong afterglow imaging of orthotopic hepatocellular carcinoma

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Science China Chemistry 2025年

作者： Shuai Huang Shuaige Bai Ting Luo Bin Feng Min Liu Fan Zheng Shuang Huang yanpeng Fang Dan Ding Wenbin zeng Xiangya School of Pharmaceutical Sciences Central South University College of Life Sciences Nankai University

Hepatocellular carcinoma （HCC） is a highly aggressive liver malignancy and the main form of liver cancer. Early diagnosis and treatment of HCC can effectively reduce mortality. Carboxylesterase （CE）-specific detection and imaging can be used for early diagnosis and image-guided surgical of HCC. However, traditional optical probes suffer from poor selectivity and low imaging signal-to-noise ratio. Here, we have constructed a series of chemiluminescent probes for carboxylesterase detection based on the strategy of enzymatic pocket-oriented steric tailoring techniques. The probes with different unique and excellent properties have been obtained through the structure-based steric hindrance adjustment on the recognition site. Here, CE-2 has been successfully used for high-throughput screening of rapid carboxylesterase inhibitors due to its extremely low detection limit (2.5×10-4U mL-1) and fast recognition ability. CE-3 has been successfully used for image-guided surgery of orthotopic hepatocellular carcinoma due to its ultra-long chemiluminescence imaging （over 12 h） of hepatocellular carcinoma. This study may promote advances in the rapid detection and screening of inhibitory drugs for CE and the field of surgical navigation in HCC.

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Contrasting effects of N addition on the N and P status of understory vegetation in plantations of sapling and mature Larix principis-rupprechtii

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Journal of Plant Ecology 2018年第6期11卷 843-852页

作者： Tao yan Tiantian Qu Huanhuan song Philippe Ciais Shilong Piao Zhenzhong Sun Hui zeng Sino-French Institute for Earth System Science College of Urban and Environmental SciencesPeking University5 Yiheyuan RoadHaidian DistrictBeijing 100871China School of Urban Planning and Design Peking University2199 Lishui RoadNanshan DistrictShenzhen 518055China Institute of Applied Ecology Chinese Academy of Sciences72 Wenhua RoadShenhe DistrictShenyang 110016China Laboratoire des Sciences du Climat et de l’Environnement UMR 1572 CEA-CNRS-UVSQ91191 Gif-sur-YvetteFrance Key Laboratory of Alpine Ecology and Biodiversity Institute of Tibetan Plateau ResearchChinese Academy of Sciences16 Lincui RoadChaoyang DistrictBeijing 100085China Center for Excellence in Tibetan Earth Science Chinese Academy of Sciences16 Lincui RoadChaoyang DistrictBeijing 100085China

Aims The productivity of forest plantations in temperate areas is often lim-ited by nitrogen(N),but may shift towards phosphorus(P)limitation with increasing atmospheric N *** resorption is a nutrient conservation strategy in *** data on nutrient resorption are available for overstory trees,there are few data for understory *** We examined leaf N and P concentrations and N and P resorption efficiencies(NRE and PRE,respectively)in eight understory species in 11-and 45-year-old Larix principis-rupprechtii stands subjected to N supplementation over a 3-year *** findings Leaf N concentrations and N:P ratios increased and P concentrations decreased,with N input in species within the 45-year-old stand,but not in the 11-year-old *** and PRE were not altered by N input in any of the species in either stand,but N resorption pro-ficiency decreased and P resorption proficiency increased,in the species in the 45-year-old ***,the growth of understory species may be more P-limited in the 45-versus 11-year-old stand,and nutrient resorption proficiency was more sensitive to N add-ition than nutrient resorption *** results will improve the understanding of nutrient use strategies and their responses to N addition in understory *** contrasting effects of N addition on nutrient status between stand ages cannot be ignored when modeling ecosystem nutrient cycling under global N depos-ition conditions.

关键词： larch plantation N addition nutrient resorption stand age understory species

Aging Characteristics, Stress Corrosion Behaviour and Role of Mg Segregation at Grain Boundary in 7175High-strength Al Alloy

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Journal of Materials Science & Technology 1998年第3期14卷 259-264页

作者： song, Renguo Geng, Ping zeng, Meiguang Zhang, Baojin Northeastern Univ Coll Sci Dept Mat Sci Shenyang 110006 Peoples R China

The aging characteristics, stress corrosion behavior and chemical composition of grain boundary in 7175 high-strength Al alloy during long term aging process have been investigated by hardness measurement, constant elongation rate testing (CERT) and energy spectroscopy analysis. The results indicate that double peaks in aged state feature the hardness and strength of 7175 Al alloy. Although the intensity of double peaks is almost equal, the stress corrosion resistance in the second peak-aged state is better than that of the first peak-aged state. The effects of Mg segregation on the binding energy of grain boundary have been calculated by using free electron theory developed in this paper. The results showed that Mg segregation plays a significant role in controlling stress corrosion susceptibility, which is consistent with the experimental results. (Edited author abstract) 32 Refs.

关键词： Aluminum alloys

Prediction of velocity distribution in straight open-channel flow with partial vegetation by singular perturbation method

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Applied Mathematics and Mechanics(English Edition) 2016年第10期37卷 1315-1324页

作者： Wenxin HUAI Suwen song Jie HAN Yuhong zeng State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University

A numerical analysis model based on two-dimensional shallow water differential equations is presented for straight open-channel flow with partial vegetation across the channel. Both the drag force acting on vegetation and the momentum exchange between the vegetation and non-vegetation zones are considered. The depth-averaged streamwise velocity is solved by the singular perturbation method, while the Reynolds stress is calculated based on the results of the streamwise velocity. Comparisons with the experimental data indicate that the accuracy of prediction is significantly improved by introducing a term for the secondary current in the model. A sensitivity analysis shows that a sound choice of the secondary current intensity coefficient is important for an accurate prediction of the depth-averaged streamwise velocity near the vegetation and non-vegetation interfaces, and the drag force coefficient is crucial for predictions in the vegetation zone.

关键词： depth-averaged velocity singular perturbation secondary flow

Design and analysis of a dual-stator brushless doubly-fed induction machine with a staggered dual-cage rotor

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Science China(Technological Sciences) 2022年第6期65卷 1318-1329页

作者： CHENG Ming zeng Yu yan XiaoMing ZHANG ChangGuo School of Electrical Engineering Southeast UniversityNanjing 210096China

In this paper,a new dual-stator brushless doubly-fed induction machine with a staggered dual cage rotor is proposed,with emphasis on the general interconnection rule of the conductor bars for the staggered dual cage *** the squirrel cage rotor offers the merits of robustness,reliable structure,high slot filling factor,and low rotor resistance comparing to the wound rotor,it is introduced to the dual-stator brushless doubly-fed induction machine to solve the problems of high copper loss and unreliable rotor structure for the dual-stator brushless doubly-fed induction machine with a wound *** originality of this article is to investigate the interconnection rule of conductor bars between the inner and outer *** constraint condition that is supposed to be satisfied is deduced by using the rotating magneto-motive force theory,based on which diverse slot/pole combinations are *** performance comparison between the existing and proposed machines is ***,a prototype is designed and *** experimental results verify the effectiveness of the proposed topology.

关键词： brushless doubly-fed machine dual cage rotor design wind power generation

Deep bedrock geothermal resources in the Maichen Sag,Beibuwan Basin and their potential for exploitation and utilization

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Energy Geoscience 2023年第4期4卷 188-197页

作者： yan zeng Ying Zhang Exploration and Production Research Institute SINOPECBeijing100083China

The Maichen Sag in the south-central part of the Beibuwan Basin is abundant in geothermal resources that have not been widely exploited and utilized due to inadequate research on *** study evaluated the geothermal resources in the Maichen Sag based on the regional geological setting and geothermal *** units for assessment and a geological model for areas with geothermal resources were established using spatial analysis *** spatial distribution models of the physical and thermophysical properties of the geothermal reservoirs were also built using the Kriging interpolation *** on the terrestrial heat flow distribution in the target areas,the spatial distribution of the geo-temperature field through the inversion under the constraints of the temperature data from boreholes were *** such as deep geo-temperature,thermophysical properties of rocks,and terrestrial heat flow values,were integrated into this quantitative evaluation of geothermal resources through the geological modeling-based volume method and the geothermal reservoir engineering-based numerical simulation *** results show that the Maichen Sag has favorable heat source conditions with intersected,deep-rooted faults and widely developed Upper Paleozoic fissured granite geothermal *** northern outer slope zone at a burial depth of 3‒5 km on the tectonic plane of the basement in the sag is suggested to be a potential target area,where,as calculated using the volume method,is likely to be the home to the total geothermal resources of 80.4×10^(9)GJ(i.e.,2.75×10^(9)tonnes of coal equivalent(tce))in the bedrock geothermal reservoirs at a burial depth of 3‒6 *** geotemperature of 172‒201℃at a formation depth of 5 km in the sag also indicates that the deep geothermal resources are of high value for exploitation.

关键词： Maichen sag Geothermal resource Resource evaluation Parameter estimation for geothermal resource exploitation Numerical simulation

A novel robust aerodynamic optimization technique coupled with adjoint solvers and polynomial chaos expansion

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Chinese Journal of Aeronautics 2022年第10期35卷 35-55页

作者： Wei ZHANG Qiang WANG Fanzhi zeng Chao yan National Key Laboratory of Computational Fluid Dynamics Beihang UniversityBeijing 100083China Aerospace Times Feipeng Company Limited China Academy of Aerospace Electronics TechnologyKunshan 215000China China Academy of Aerospace Aerodynamics Beijing 100074China

Uncertainty is common in the life cycle of an aircraft, and Robust Aerodynamic Optimization(RAO) that considers uncertainty is important in aircraft design. To avoid the curse of dimensionality in surrogate-based optimization, this study proposes an adjoint RAO technique called “R-Opt”. Polynomial Chaos Expansion(PCE) is coupled with the R-Opt technique to quantify uncertainty in the responses of the target(including its mean and standard deviation). Only one process of PCE model construction is required in each iteration, and the gradients of uncertainty can be inferred via chain rules. The proposed method is more efficient than prevalent methods,and avoids the problem of a disagreement over the best PCE basis from among a number of PCE models(especially in case of sparse PCE). It also supports the application of sparse *** benchmark tests and two airfoil cases were used to verify R-Opt, and the optimal solutions were deemed to be robust. It improved the mean aerodynamic performance and reduced the standard deviation of the target.

关键词： Adjoint technique Polynomial chaos expansion Robust design Uncertainty analysis Uncertainty gradient propagation