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Diastereoselective alkylation reactions employing a new camphor-based 2-phenylimino-2-oxazolidine chiral auxiliary

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Chinese Chemical Letters 2014年第11期25卷 1466-1468页

作者： Long-Duo zhang cui-fen lu zu-xing chen gui-chun yang Jun-Qi Nie Hubei Collaborative Innovation Center for Advanced Organochemical Materials & Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules Hubei University

A new camphor-based 2-phenylimino-2-oxazolidine chiral auxiliary was prepared and it was shown to be a particularly effective chiral auxiliary for asymmetric alkylations affording high yields and diastereoselectivities. The alkylation products were readily cleaved by simple alkaline hydrolysis to give a-alkylated carboxylic acids in good yield and in almost enatiomerically pure form.

关键词： Chiral auxiliaries Alkylation Asymmetric catalysis Camphor-based

Einstein Probe discovery of EP240408a: A peculiar X-ray transient with an intermediate timescale

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 222-240页

作者： Wenda zhang Weimin Yuan Zhixing ling Yong chen Nanda Rea Arne Rau Zhiming Cai Huaqing cheng Francesco Coti Zelati lixin Dai Jingwei Hu Shumei Jia Chichuan Jin Dongyue li Paul O’Brien Rongfeng Shen Xinwen Shu Shengli Sun Xiaojin Sun Xiaofeng Wang Lei yang Bing zhang chen zhang Shuang-Nan zhang Yonghe zhang Jie An David Buckley Alexis Coleiro Bertrand Cordier liming Dou Rob Eyles-Ferris Zhou Fan Hua feng Shaoyu Fu Johan P.U.Fynbo Lluis Galbany Saurabh W.Jha Shuaiqing Jiang Albert Kong Erik Kuulkers Weihua Lei Wenxiong li Bifang liu Mingjun liu xing liu Yuan liu Zhu liu Chandreyee Maitra Alessio Marino Itumeleng Monageng Kirpal Nandra Jeremy Sanders Roberto Soria lian Tao Junfeng Wang Song Wang Tinggui Wang Zhongxiang Wang Qingwen Wu Xuefeng Wu Dong Xu Yanjun Xu Suijian Xue Yongquan Xue Zijian zhang Zipei Zhu Hu Zou Congying Bao Fansheng chen Houlei chen Tianxiang chen Wei chen Yehai chen Yifan chen chenzhou cui Weiwei cui Yanfeng Dai Dongwei Fan Ju Guan Dawei Han Dongjie Hou Haibo Hu Maohai Huang Jia Huo Zhenqing Jia Bowen Jiang Ge Jin chengkui li Junfei li Longhui li Maoshun li Wei li Zhengda li Tianying lian Congzhan liu Heyang liu Huaqiu liu Fangjun lu Laidan luo Jia Ma Xuan Mao Haiwu Pan Xin Pan liming Song Hui Sun Yunyin Tan Qingjun Tang Yihan Tao Hao Wang Juan Wang Lei Wang Wenxin Wang Yilong Wang Yusa Wang Qinyu Wu Haitao Xu Jingjing Xu Xinpeng Xu Yunfei Xu Zhao Xu Changbin Xue Yulong Xue Ailiang Yan Haonan yang Xiongtao yang Yanji yang Juan zhang Mo zhang Wenjie zhang Zhen zhang Zhen zhang Ziliang zhang Donghua Zhao Haisheng Zhao Xiaofan Zhao Zijian Zhao Hongyan Zhou Yilin Zhou Yuxuan Zhu Zhencai Zhu National Astronomical Observatories Chinese Academy of Sciences School of Astronomy and Space Sciences University of Chinese Academy of Sciences Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Institute of Space Sciences (ICE) CSIC Institut d’Estudis Espacials de Catalunya (IEEC) Max Planck Institute for Extraterrestrial Physics Innovation Academy for Microsatellites Chinese Academy of Sciences Department of Physics University of Hong Kong School of Physics and Astronomy University of Leicester School of Physics and Astronomy Sun Yat-sen University Department of Physics Anhui Normal University Shanghai Institute of Technical Physics Chinese Academy of Sciences Physics Department Tsinghua University Nevada Center for Astrophysics University of Nevada Las Vegas Department of Physics and Astronomy University of Nevada Las Vegas South African Astronomical Observatory Department of Astronomy University of Cape Town Department of Physics University of the Free State Université Paris Cité CNRS Astroparticule et Cosmologie Université Paris Cité CEA Paris-Saclay IRFU/DAp-AIM Department of Astronomy Guangzhou University Cosmic Dawn Center (DAWN) Niels Bohr Institute University of Copenhagen Department of Physics and Astronomy Rutgers the State University of New Jersey Institute for Cosmic Ray Research The University of Tokyo ESA/ESTEC Department of Astronomy School of Physics Huazhong University of Science and Technology INAF-Osservatorio Astrofisico di Torino Sydney Institute for Astronomy School of Physics The University of Sydney Department of Astronomy Xiamen University Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University Department of Astronomy University of Science and Technology School of Astronomy and Space Sciences University of Science and Technology of China Institute of Deep Space Sciences Deep Space Exploration Laboratory Department of Astronomy School of Physics and Astronomy Yunnan University Shanghai Astronomical Observatory Chi

We report the discovery of a peculiar X-ray transient,EP240408a,by Einstein Probe （EP） and follow-up studies made with EP,Swift,NICER,GROND,ATCA and other ground-based multiwavelength *** new transient was first detected with Wide-field X-ray Telescope （WXT） on board EP on April 8th,2024,manifested in an intense yet brief X-ray flare lasting for *** flare reached a peak flux of 3.9×10-9erg cm-2s-1in 0.5-4 ke V,～300 times brighter than the underlying X-ray emission detected throughout the *** and more precise follow-up observations by EP/FXT,Swift and NICER confirmed the finding of this new *** X-ray spectrum is non-thermal in 0.5-10 ke V,with a power-law photon index varying *** X-ray light curve shows a plateau lasting for ～4 d,followed by a steep decay till becoming undetectable ～10 d after the initial *** on its temporal property and constraints from previous EP observations,an unusual timescale in the range of 7-23 d is found for EP240408a,which is intermediate between the commonly found fast and long-term *** counterparts have been found in optical and near-infrared,with the earliest observation at 17 h after the initial X-ray detection,suggestive of intrinsically weak emission in these *** demonstrate that the remarkable properties of EP240408a are inconsistent with any of the transient types known so far,by comparison with,in particular,jetted tidal disruption events,gamma-ray bursts,X-ray binaries and fast blue optical *** nature of EP240408a thus remains an *** suggest that EP240408a may represent a new type of transients with intermediate timescales of the order of～10 *** detection and follow-ups of more of such objects are essential for revealing their origin.

关键词： X-ray transients ${\bm~{Einstein~~Probe}}$

Optimal timing of biliary drainage based on the severity of acute cholangitis:A single-center retrospective cohort study

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World Journal of Gastroenterology 2022年第29期28卷 3934-3945页

作者： Zhao-Qing lu Han-Yu zhang chen-fen Su Yue-Yan xing Guo-xing Wang chun-Sheng li Department of Emergency Medicine Beijing Friendship HospitalCapital Medical UniversityBeijing 100050China Emergency and Critical Care Center Beijing Friendship HospitalCapital Medical UniversityBeijing 100050China

BACKGROUND Biliary decompression is well known to greatly decrease the risks of mortality in acute cholangitis(AC).Although early biliary drainage is recommended by the treatment guidelines for AC,the best time for performing this procedure is yet to be ***,since the clinical outcomes of patients with severe AC vary dramatically,screening for patients that could benefit the most from early drainage would be more beneficial than the drainage performed based on the severity grade *** To investigate the optimal drainage timing for AC patients with each disease severity grade and organ *** In this retrospective monocenter cohort analysis,we reviewed 1305 patients who were diagnosed with AC according to the Tokyo guidelines 2018 at a Chinese tertiary hospital between July 2016 and December *** characteristics including age and sex,clinical and laboratory characteristics,and imaging findings of each patient were obtained from electronic medical *** investigated the all-cause in-hospital mortality(IHM),hospital length of stay(LOS),and hospitalization costs associated with the timing of biliary drainage according to the severity grading and different dysfunctioning organs and predictors[age,white blood cell(WBC)count,total bilirubin,albumin,lactate,malignant obstruction,and Charlton comorbidity index(CCI)].RESULTS Biliary drainage within 24 or 48 h in Grade Ⅲ AC patients could dramatically decrease IHM(3.9%vs 9.0%,P=0.041;4%vs 9.9%,P=0.018,respectively),while increasing LOS and hospitalization *** logistic analysis revealed that neurological,respiratory,renal,and cardiovascular dysfunctions,hypoalbuminemia,and malignant obstruction were significantly associated with IHM(odds ratio=5.32,2.541,6.356,4.021,5.655,and 7.522;Pliary decompression performed within 12 h of admission significantly decreased the IHM in AC patients with neur

关键词： Acute cholangitis Endoscopic retrograde cholangiopancreatography Mortality Biliary drainage Organ dysfunction

Generation of mitochondrial replacement monkeys by female pronucleus transfer

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Zoological Research 2024年第2期45卷 292-298页

作者： chun-yang li xing-chen liu Yu-Zhuo li Yan Wang Yan-Hong Nie Yu-Ting Xu Xiao-Tong zhang Yong lu Qiang Sun Institute of Neuroscience Center for Excellence in Brain Science and Intelligence TechnologyState Key Laboratory of NeuroscienceChinese Academy of SciencesShanghai 200031China Key Laboratory of Genetic Evolution and Animal Models Chinese Academy of SciencesKunming 650201China University of Chinese Academy of Sciences Beijing 100049China

Mutations in mitochondrial DNA(mtDNA)are maternally inherited and have the potential to cause severe *** replacement therapies,including spindle,polar body,and pronuclear transfers,are promising strategies for preventing the hereditary transmission of mtDNA *** pronuclear transfer has been used to generate mitochondrial replacement mouse models and human embryos,its application in non-human primates has not been previously *** this study,we successfully generated four healthy cynomolgus monkeys(Macaca fascicularis)via female pronuclear *** individuals all survived for more than two years and exhibited minimal mtDNA carryover(3.8%–6.7%),as well as relatively stable mtDNA heteroplasmy dynamics during *** successful establishment of this nonhuman primate model highlights the considerable potential of pronuclear transfer in reducing the risk of inherited mtDNA diseases and provides a valuable preclinical research model for advancing mitochondrial replacement therapies in humans.

关键词： Non-human primates Mitochondrial replacement Female pronuclear transfer

Nanosized Rh grown on single-walled carbon nanohorns for efficient methanol oxidation reaction

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Rare Metals 2022年第6期41卷 2108-2117页

作者： Xiang-Jie Guo Qi zhang Ya-Nan li yang chen lu yang Hai-Yan He xing-Tao Xu Hua-Jie Huang Collegeof Mechanics and Materials Hohai University Nanjing 210098China International Center for Materials Nanoarchitectonics(WPI-MANA) National Institute for Materials ScienceIbaraki 305-0044Japan

Reasonable design and controllable synthesis of non-Pt catalysts with high methanol oxidation activity are regarded as a valid way to promote the large-scale com-mercial applications of direct methanol fuel cells(DMFCs).Herein,we develop a convenient and cost-ef-fective approach to the successful fabrication of nanosized Rh grown on single-walled carbon nanohorns(Rh/SWCNH)as anode catalysts for *** unique architectural configuration endows the as-obtained hybrids with a series of intriguing structural merits,including large specific surface areas,abundant opened holes,optimized electronic structures,homogeneous Rh dispersion,and good electrical *** a consequence,the resulting Rh/SWCNH catalysts exhibit exceptional elec-trocatalytic properties in terms of a large electrochemically active surface area of 102.5 m^(2)·g^(-1),a high mass activity of 784.0 mA·mg^(-1),as well as reliable long-term durability towards the methanol oxidation reaction in alkaline media,thereby holding great potential as alternatives for com-mercial Pt/carbon black and Pd/carbon black catalysts.

关键词： Rhodium Carbon nanohorns Electrocatalysts Methanol oxidation Fuel cells

Solubilization of small molecules from coal and the resulting effects on the pore structure distribution

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Mining Science and Technology 2009年第6期19卷 761-768页

作者： QIN Zhi-hong JIANG chun HOU cui-li li xing-shun zhang li-ying chen Juan JIANG Bin School of Chemical Engineering and Technology China University of Mining ＆ Technology Xuzhou Jiangsu 221116 China lu＇an Mining Industry Group Changzhi Shanxi 046204 China

The solubilization of small molecules from coal by solvent extraction and the resulting effects on the pore distribution of a low rank coal were studied. Samples were extracted, in succession, with petroleum ether and with CS2. Extract and residue fractions collected during the solubilization process were analyzed by FTIR and by surface area and porosimetry. The results show that an obvious inflection point exists that allows separating the dissolution sequence into stages. Small molecules are first extracted from the free state, then molecules trapped in micropores are extracted and, finally, molecules trapped in the coal-matrix network are extracted. This is indicated from the extraction yield curves. Chain-like carbonyl compounds, -OH (or -NH) containing compounds that are hydrogen bonded and phenolics dominate the petroleum ether extracts. Chain-like carbonyl components and ether compounds (aliphatic ethers and aromatic ethers) dominate the CS2 extracts. A solvent dissolution mechanism and the effect of small molecule extraction on the pore structure are put forward. Diffusion, dissolution, pore opening, pore shrinking or even collapsing caused by swelling, creating of new micropores, pore opening and, finally, colloidallization of some micropores occurs. In the later stages of the extraction the internal structure of the coal is colloidallized due to swelling and the pore number or volume is greatly reduced.

关键词： coal fractional extraction FTIR distribution of pores

Enhanced thermoelectric performance of ternary compound Cu_(3)PSe_(4)by defect engineering

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Rare Metals 2020年第11期39卷 1256-1261页

作者： Yu-Meng zhang xing-chen Shen Yan-Ci Yan gui-Wen Wang Guo-Yu Wang Jiang-Yu li Xu lu Xiao-Yuan Zhou Chongqing Key Laboratory of Soft Condensed Matter Physics and Smart Materials College of PhysicsChongqing UniversityChongqing401331China Chongqing Institute of Green and Intelligent Technology Chinese Academy of ScienceChongqing400714China University of Chinese Academy of Sciences Beijing100044China Analytical and Testing Center of Chongqing University Chongqing401331China Shenzhen Key Laboratory of Nanobiomechanics Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen518055China

The diamond-like compound Cu_(3)PSe_(4)with low lattice thermal conductivity is deemed to be a promising thermoelectric material,which can directly convert waste heat into electricity or vice versa with no moving parts and greenhouse ***,its performance is limited by its low electrical *** this study,we report an effective method to enhance thermoelectric performance of Cu_(3)PSe_(4)by defect *** is found that the carrier concentrations of Cu_(3-x)PSe_(4)(x=0,0.03,0.06,0.09,0.12)compounds are increased by two orders of magnitude as x>0.03,from 1×10^(17)to 1×10^(19)cm^(-3).Combined with the intrinsically low lattice thermal conductivities and enhanced electrical transport performance,a maximum zT value of 0.62 is obtained at 727 K for x=0.12 sample,revealing that Cu defect regulation can be an effective method for enhancing thermoelectric performance of Cu_(3)PSe_(4).

关键词： Cu_(3)PSe_(4) Thermal conductivity Defect engineering Electrical conductivity Thermoelectric performance

Size-fractionated uranium isotopes in surface waters in the Jiulong Estuary in China

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Acta Oceanologica Sinica 2008年第1期27卷 29-41页

作者： lu E zhang Lei chen Min QIU Yusheng xing Na yang Weifeng li Yanping HUANG Yipu Department of Oceanography Xiamen University Xiamen 361005 China State Key Laboratory of Marine Environmental Science Xiamen University Xiamen 361005 China

Surface water was collected from the Jiulong Estuary for determination of activity concentrations of uranium isotopes in different size fractions, namely, greater than 53, 10 -53, 2 - 10, 0.4 -2 μm, 10 000 u -0.4 μm and less than 10 000 u fractions by microfihration and cross-flow uhrafiltration technologies. Results indicated that most of the dissolved uranium （〈 0.4 μm） exis- ted in the low molecular mass fraction （〈 10 000 u）, and the colloidal uranium-238 （10 000 u -0.4 μm） only contributed less than 1% of the dissolved uranium-238. The fractions of colloidal uranium in the dissolved phases decreased with the increasing sa- linity. A positive linear relationship between uranium-238 activities and salinities was observed for the dissolved, colloidal and low molecular mass fractions, indicating a conservative behavior of uranium in the Jiulong Estuary. In the particulate phases （〉 0.4 μm）, the partitioning of uranium isotopes among different size fractions was controlled by the partitioning of particle concentrations. In the regions with salinities below 20, the partitioning of uranium-238 among different size fractions was as follows： 10 - 53 μm 〉 2 - 10 μm 〉 0.4 - 2 μm greater than above 53 μm. However, the order at the offshore station with salinities above 30 changed as follows ： 0.4 - 2 μm 〉 10 - 53 μm 〉 2 - 10 μm greater than above 53 μm. The fraction of the 0.4 - 2 μm particles increased at the offshore station, suggesting the increased contribution of the authigenic uranium. The activity ratio of uranium-234 to uranium-238 in the dissolved phases, including the low molecular mass fraction and the colloidal fraction, was larger than unity, showing the occurrence of excess uranium-234. In contrast, the activity ratio of uranium-234 to uranium-238 in all size fractions of the particulate phase was close to the equilibrium value （1.0）. The observed different values of the activity ratio of uranium-234 to uranium-238 in the dissolved phase and the particulat

关键词： uranium isotopes size fractionation Jiulong Estuary in China

Deep learning-based software engineering: progress,challenges, and opportunities

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Science China(Information Sciences) 2025年第1期 57-144页

作者： Xiangping chen xing HU Yuan HUANG He JIANG Weixing JI Yanjie JIANG Yanyan JIANG Bo liU Hui liU Xiaochen li Xiaoli liAN Guozhu MENG Xin PENG Hailong SUN lin SHI Bo WANG Chong WANG Jiayi WANG Tiantian WANG Jifeng XUAN Xin XIA Yibiao yang Yixin yang li zhang Yuming ZHOU lu zhang School of Journalism and Communication Sun Yat-sen University School of Software Technology Zhejiang University School of Software Engineering Sun Yat-sen University School of Software Dalian University of Technology School of Computer Science and Technology Beijing Institute of Technology Key Laboratory of High Confidence Software Technologies (Peking University) Ministry of EducationSchool of Computer Science Peking University State Key Laboratory for Novel Software Technology Nanjing University School of Computer Science and Engineering Beihang University Institute of Information Engineering Chinese Academy of Sciences School of Computer Science Fudan University State Key Laboratory of Complex & Critical Software Environment (CCSE) School of Software Beihang University School of Computer and Information Technology Beijing Jiaotong University School of Computer Science and Technology Harbin Institute of Technology School of Computer Science Wuhan University Huawei Technologies

Researchers have recently achieved significant advances in deep learning techniques, which in turn has substantially advanced other research disciplines, such as natural language processing, image processing, speech recognition, and software engineering. Various deep learning techniques have been successfully employed to facilitate software engineering tasks, including code generation, software refactoring, and fault localization. Many studies have also been presented in top conferences and journals, demonstrating the applications of deep learning techniques in resolving various software engineering tasks. However,although several surveys have provided overall pictures of the application of deep learning techniques in software engineering,they focus more on learning techniques, that is, what kind of deep learning techniques are employed and how deep models are trained or fine-tuned for software engineering tasks. We still lack surveys explaining the advances of subareas in software engineering driven by deep learning techniques, as well as challenges and opportunities in each subarea. To this end, in this study, we present the first task-oriented survey on deep learning-based software engineering. It covers twelve major software engineering subareas significantly impacted by deep learning techniques. Such subareas spread out through the whole lifecycle of software development and maintenance, including requirements engineering, software development, testing, maintenance, and developer collaboration. As we believe that deep learning may provide an opportunity to revolutionize the whole discipline of software engineering, providing one survey covering as many subareas as possible in software engineering can help future research push forward the frontier of deep learning-based software engineering more systematically. For each of the selected subareas,we highlight the major advances achieved by applying deep learning techniques with pointers to the available datasets i

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