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利格列汀多晶型研究

高等学校化学学报 2024年第1期45卷 33-42页

作者：刘奇刘沫毅董思雨王学重何运良北京石油化工学院新材料与化工学院恩泽生物质精细化工北京市重点实验室北京102617 华润双鹤药业股份有限公司北京100124 北京石油化工学院信息工程学院北京102617

研究了利格列汀复杂的晶型现象及其晶格中的构象变化.通过培养利格列汀的单晶并进行X射线单晶衍射分析,首次得到了包括晶型A在内的3种晶体结构;结合文献已报道的2种晶体结构,分析了各晶体结构的特点及其晶格中的分子构象.研究结果表明,... 详细信息

研究了利格列汀复杂的晶型现象及其晶格中的构象变化.通过培养利格列汀的单晶并进行X射线单晶衍射分析,首次得到了包括晶型A在内的3种晶体结构;结合文献已报道的2种晶体结构,分析了各晶体结构的特点及其晶格中的分子构象.研究结果表明,5种晶体里存在晶型A和晶型F两种晶型,其中晶型F为准多晶型,可以包含多种溶剂,形成通道型溶剂合物,其晶格参数随包含的溶剂略有变化.晶型A的构象与晶型F的构象存在较高能垒,导致2种晶型难以互相转化.晶型F不同溶剂合物之间的分子构象并不完全相同,在粉末X射线衍射(PXRD)谱图上也有显著差异.最后,通过混悬转晶和热分析等方法研究了晶型之间的转化关系.

关键词：利格列汀多晶型构象通道型溶剂合物

Deep learning-based on-line image analysis for continuous industrial crystallization processes

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Particuology 2023年第3期74卷 173-183页

作者： Shiliang Zong Guangzheng Zhou Meng Li xuezhong wang Beijing City Key Laboratory of Enze Biomass and Fine Chemicals College of New Materials and Chemical EngineeringBeijing Institute of Petrochemical TechnologyBeijing102617China

In situ microscopic imaging is a useful tool in monitoring crystallization processes,including crystal nucleation,growth,aggregation and breakage,as well as possible polymorphic *** convert the qualitative information to be quantitative for the purpose of process optimization and control,accurate analysis of crystal images is ***,the accuracy of image segmentation with traditional methods is largely affected by many factors,including solid concentration and image *** this study,the deep learning technique using mask region-based convolutional neural network(Mask R-CNN)is investigated for the analysis of on-line images from an industrial crystallizer of 10 m^(3) operated in continuous mode with high solid concentration and overlapped *** detailed label points for each crystal and transfer learning technique,two models trained with 70,908 and 7,709 crystals respectively are compared for the effect of training data *** former model effectively segments the aggregated and overlapped crystals even at high solid ***,it performs much better than the latter one and traditional multi-scale method both in terms of precision and recall,revealing the importance of large number of crystals in deep *** geometrical characteristics of segmented crystals are also analyzed,involving equivalent diameter,circularity,and aspect ratio.

关键词： Continuous crystallization Crystal shape Image analysis Deep learning Instance segmentation Process analytical technology

Long-chain alkanes in the atmosphere:A review

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Journal of Environmental Sciences 2022年第4期34卷 37-52页

作者： Junling Li Kun Li Hong Li xuezhong wang Weigang wang Ke wang Maofa Ge State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China Laboratory of Atmospheric Chemistry Paul Scherrer InstituteVilligen 5232Switzerland State Key Laboratory for Structural Chemistry of Unstable and Stable Species Beijing National Laboratory for Molecular SciencesCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China

As a representative species of intermediate volatile organic compounds(IVOCs),long-chain alkanes are considered to be important precursors of secondary organic aerosols(SOA)in the *** work reviews the previous studies on long-chain alkanes in the atmosphere:(1)the detection methods and filed observations of long-chain alkanes in both gas and particle phases are summarized briefly;(2)the laboratory studies of long chain alkanes are reviewed,the kinetic data,reaction mechanism,SOA yields,and physicochemical properties of SOA are included in detail;(3)the research progress related to model simulations of long-chain alkanes are also *** addition,based on available research results,several perspective contents are proposed that can be used as a guideline for future research plans.

关键词： Long-chain alkanes Detection methods Field observation Laboratory study Model simulation

Meta-analysis of the effect of low-level occupational benzene exposure on human peripheral blood leukocyte counts in China

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Journal of Environmental Sciences 2022年第4期34卷 204-210页

作者： Hao Zhang Hong Li Zhijian Peng Juan Cao Jiemeng Bao Lei Li xuezhong wang Yuanyuan Ji Zhuojiong Chen School of Science China University of GeosciencesBeijing 100083China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China Academy of Environmental Planning and Design Co.Ltd.Nanjing UniversityNanjing 210093China College of Earth Sciences Jilin UniversityChangchun 130061China

To investigate the effect of low-level occupational benzene exposure on human peripheral blood leukocyte counts of the workers,domestic and foreign published research data on the change of human peripheral blood leukocyte counts under low-level occupational benzene exposure from January 1990 to December 2020 were collected and *** to the literature inclusion and exclusion criteria,18 independent studies from 12 publications were selected for meta-analysis to explore the effect of low-level occupational benzene exposure on human peripheral blood leukocyte *** results showed that the peripheral blood leukocyte counts abnormal rates of low-level occupational benzene exposure group were higher than those of the control group,and the difference was statistically ***-level occupational benzene exposure could result in a relatively higher abnormal rate of peripheral blood leukocyte counts in the exposed population,indicating that low-level occupational benzene exposure at workplaces specified by the current benzene occupational exposure limit in China would affect the peripheral blood leukocyte counts of the workers,thus benzene with concentrations under the limit in the ambient air of workplace could be still harmful to the health of the exposed *** results of this study could provide a scientific basis for future revision of the benzene occupational exposure limit in China,and could also be a reference for the formulation of environmental standard concerning benzene in China in the future.

关键词： Benzene at workplaces Low-level occupational exposure Peripheral blood Leukocyte Meta-analysis

H-tensors and nonsingular H-tensors

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Frontiers of Mathematics in China 2016年第3期11卷 557-575页

作者： xuezhong wang Yimin WEI School of Mathematical Sciences Fudan University Shanghai 200433 China School of Mathematics and Statistics Hexi University Zhangye 734000 China

The H-matrices are an important class in the matrix theory, and have many applications. Recently, this concept has been extended to higher order H-tensors. In this paper, we establish important properties of diagonally dominant tensors and H-tensors. Distributions of eigenvalues of nonsingular symmetricH-tensors are given. An J（t%-tensor is semi-positive, which enlarges the area of semi-positive tensor from H-tensor to H＋-tensor. The spectral radius of Jacobi tensor of a nonsingular （resp. singular） H-tensor is less than （resp. equal to） one. In particular, we show that a quasi-diagonally dominant tensor is a nonsingular H-tensor if and only if all of its principal sub-tensors are nonsingular H-tensors. An irreducible tensor H is an H-tensor if and only if it is quasi-diagonally dominant.

关键词： Diagonally dominant irreducible diagonally dominant H-tensor,nonsingular

左束支起搏在持续性心房颤动伴慢心室率患者中的临床疗效

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实用心电学杂志 2024年第1期33卷 44-48页

作者：张宇航王岳松杨达董学滨邵旭武王学忠安徽医科大学马鞍山临床学院(马鞍山市人民医院)心血管内科安徽医科大学第五临床医学院安徽马鞍山243000

目的观察左束支起搏(left bundle branch pacing,LBBP)治疗持续性心房颤动(简称房颤)合并慢心室率患者的临床有效性和安全性。方法选取因持续性房颤合并慢心室率行起搏治疗的患者56例,依据心室起搏电极植入部位将其分为右心室间隔部起搏... 详细信息

目的观察左束支起搏(left bundle branch pacing,LBBP)治疗持续性心房颤动(简称房颤)合并慢心室率患者的临床有效性和安全性。方法选取因持续性房颤合并慢心室率行起搏治疗的患者56例,依据心室起搏电极植入部位将其分为右心室间隔部起搏(right ventricular septal pacing,RVSP)组(29例)和LBBP组(27例),并根据临床症状及相关检查结果,将各组进一步分为心力衰竭(简称心衰)亚组和非心衰亚组,观察两组患者术中及术后12个月起搏参数(如阈值、感知和阻抗)、心电图、心脏超声和血浆脑钠肽前体(NT-proBNP)水平的变化,以及起搏相关并发症、心衰再住院率、新发脑梗死和全因死亡等情况。结果①两组间起搏参数比较差异均无统计学意义(P均>0.05),两组心衰患者术后12个月的NT-proBNP水平较术前均有下降,但RVSP组心衰亚组下降不明显(P>0.05)。②RVSP组与术前比较,术后12个月的LVEF、LVDd差异无统计学意义(P均>0.05);LAD显著增大(P0.05);心衰患者术后12个月LVEF升高,LVDd下降(P均0.05),再住院率RVSP组高于LBBP组(P<0.05)。结论LBBP在持续性房颤伴慢心室率患者中有助于延缓或逆转心衰患者左心室重构,改善心脏功能,降低心衰再住院率。LBBP应作为慢心室率房颤患者首选的起搏治疗方法。

关键词：心房颤动慢心室率心脏起搏器心功能心脏超声

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Interleukin-2 expression and glioma cell proliferation following Vaccinia vector gene transfection in vivo

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Neural Regeneration Research 2008年第4期3卷 415-417页

作者： Xiaogang wang xuezhong Wei Jiangqiu Liu Department of Neurosurgery General Hospital Shenyang Military Area Command of Chinese P~A Shenyang 110015 Liaoning ProvinceChina

BACKGROUND： The effectiveness of gene therapy is closely related to the efficiency of vector transfection and expression. OBJECTIVE： This study was designed to transfect a human brain glioma cell line with recombinant Vaccinia virus expressing the interleukin-2 （rVV-IL-2） gene, and to observe IL-2 expression and glioma cell proliferation potential after transfection. DESIGN： Experimental observation. SETTING： Department of Neurosurgery, Shenyang Military Area Command of Chinese PLA. MATERIALS： The rVV-IL-2 vectors were obtained through homologous recombination and screening in the Second Military Medical University of Chinese PLA. The human brain glioma cell line and IL-2-dependent cells were produced by the Second Military Medical University of Chinese PLA. Human IL-2 was produced by Genzyme Corporation. METHODS： At passage day l, Veto cells were amplified l ; 1 for virus and cells. A human brain glioma cell line was transfected using amplified Vaccinia viral vectors at varying multiplicities of infection （MOI）. At 2, 4, 6, 8, 12, and 24 hours post-transfection, superuatant was collected to determine by MTT assay IL-2 expression levels in IL-2 dependent cells. The transfected and non-transfected cells were divided into 4 groups, namely MOI1 ： 1, MOI 5 ： 1, MOI 10 ： 1, and control groups. MAIN OUTCOME MEASURES： IL-2 expression at different time points after transfection of human brain glioma cells with varying MOI of Vaccinia viral vectors; in vitro proliferation capacity of human brain glioma cells among the 4 groups. RESULTS： IL-2 expression was detectable 4 hours after Vaccinia viral vector transfection and reached 300 kU/L by 8 hours. There was no significant difference in the proliferating rate of human brain glioma cells among the 4 groups （P 〉 0.05）. CONCLUSION： Vaccinia viral vectors can transfect human brain glioma cells in vitro and express high levels of IL-2. Vaccinia virus and high IL-2 expression do not influence the proliferation rate of human brain g

关键词： Vaccinia virus vector glioma cell proliferation potential in vitro interleukin-2

High-efficiency simultaneous extraction of rare earth elements and iron from NdFeB waste by oxalic acid leaching

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Journal of Rare Earths 2021年第3期39卷 323-330,I0004页

作者： Qingsheng Liu Tao Tu Hao Guo Huajin Cheng xuezhong wang Faculty of Materials Metallurgy and Chemitry Jiangxi University of Science and TechnologyGanzhou 341000China Science School Jiangxi University of Science and TechnologyGanzhou 341000 China College of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China

Iron can not be recovered at high value because only rare earth elements are effectively recovered from NdFeB waste via oxidation roasting-hydrochloric acid leaching *** this study,a new method for leaching NdFeB waste with oxalic acid was *** high-efficiency,simultaneous and high-value recovery of rare earth elements and iron was realized to simplify the process and improve the economic *** of the oxalic acid leaching experiments show that under the optimum leaching conditions at 90℃ for 6 h in the aqueous solution of oxalic acid(2 mol/L) with a liquid-solid ratio of60 mL/g,the iron leaching efficiency and precipitation rate of rare earth oxalate reach 93.89% and 93.17%,*** earth oxalate and Fe(C_(2)O_(4))3^(3-) were left in the residue and the leaching solution,*** leaching mechanism was further analyzed by characterising the leach residues obtained through X-ray powder diffraction(XRD) and scanning electron microscopy-energy dispersive X-ray spectroscopy(SEM-EDS).Results of the leaching kinetics study indicate that the process of oxalic acid leaching follows the shrinking nucleus model,and the leaching kinetics model is controlled by the mixed factors of diffusion and chemical *** leaching residue was calcined at 850℃ for 3 h and then decomposed into rare earth oxide,which can be directly used to prepare rare earth alloy via molten salt *** the leaching solution,ferric oxalate solution was reduced using Fe powder to prepare the ferrous oxalate(FeC_(2)O_(4)-2H_(2)O).

关键词： NdFeB waste Oxalic acid Orthogonal experiment Leaching kinetics Reduction precipitation Rare earths

Optically levitated micro gyroscopes with an MHz rotational vaterite rotor

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Microsystems & Nanoengineering 2024年第3期10卷 219-227页

作者： Kai Zeng Xiangming Xu Yulie Wu xuezhong Wu Dingbang Xiao College of Intelligence Science and Technology National University of Defense TechnologyChangsha 410073China College of Information and Communication National University of Defense TechnologyWuhan 430000China Key Laboratory of Satellite Navigation Technology National University of Defense TechnologyChangsha 410073China

The field of levitated optomechanics has experienced significant advancements in manipulating the translational and rotational dynamics of optically levitated particles and exploring their sensing *** concept of using optically levitated particles as gyroscopes to measure angular motion has long been explored but has not yet been proven either theoretically or *** this study,we present the first rotor gyroscope based on optically levitated high-speed rotating *** gyroscope is composed of a micrometer-size ellipsoidal vaterite particle that is driven to rotate at MHz frequencies in a vacuum *** an external angular velocity is input,the optical axis deviates from its initial position,resulting in changes in the frequency and amplitude of the rotational *** analyzing these changes,the angular velocity of the input can be accurately detected,making it the smallest rotor gyroscope in the *** angular rate bias instability of the gyroscope is measured to be 0.08°/s and can be further improved to as low as 10^(−9)°/h theoretically by cooling the motion and increasing the angular moment of the levitated *** work opens a new application paradigm for levitated optomechanical systems and may pave the way for the development of quantum rotor gyroscopes.

关键词： particles. rotational angular