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Journal of Thermal Science 2019年第3期28卷 585-595页

作者： ZHAI Xiaowei xu yu yu Zhijin College of Safety Science and Engineering Xi'an University of Science and Technology Shaanxi Key Laboratory of Prevention and Control of Coal Fire

LCO_2(liquid CO_2) can absorb heat and release latent heat via phase transition, which can provide considerable cooling energy and effectively solve the problem of thermal damage in deep coal mining processes. A LCO_2 cycle refrigeration system is designed to continuously cool down the working face in a mine, and CO_2 is cyclically utilized. Additionally, LCO_2 is used not only as a cold source but also to prevent spontaneous combustion of coal in the gob. COMSOL Multiphysics simulation software is used to characterize the thermal performance of the heat exchange system, where the heat transfers between the CO_2 and the airflow. For a LCO_2 consumption of 13.54 m^3/h, the temperature of the airflow in the tunnel decreases by 7.72°C, and the cooling volume of the system reaches 142.99 kW/h; the cooling volume provides a latent heat release of 46.68 k W/h. The main influencing factors of the refrigeration system, such as ventilation flux, LCO_2 flow, LCO_2 temperature and initial tunnel temperature, are also analyzed quantitatively through the software. The temperature of the steady airflow in the tunnel is proportional to the square of the local fan ventilation flux, and it decreases linearly with an increase in the LCO_2 flow but increases with both the temperature of the LCO_2 and the initial temperature in the tunnel. When the temperature difference between the LCO_2 and wind increases, the heat exchange between the CO_2 and wind intensifies, and the cooling volume increases.

关键词： LCO2 refrigeration working face cooling numerical simulation heat exchange

Issues influencing accuracy of hydrological modeling in a changing environment

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Water Science and Engineering 2021年第2期14卷 167-170页

作者： Chong-yu xu Department of Geosciences University of OsloOslo N-0316Norway

Hydrological models have undergone a long period of development and *** hydrological models of different temporal and spatial scales have been developed and applied in various fields of hydrological research and hydro-logical engineering,including hydrological forecasting,water resources estimation,river basin management,reservoir design and operation,and runoff simulation in ungauged *** have also been used in research on the impact of land use change and climate ***,hydrological models have taken on the most important problem-solving tasks in hydrology.

关键词： change. reservoir runoff

Morphology and phylogeny of Chrysogorgia pinniformis *** *** ***.,two golden corals from the Caroline seamounts in the tropical Western Pacific Ocean

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Journal of Oceanology and Limnology 2021年第5期39卷 1767-1789页

作者： yu xu Zifeng ZHAN Kuidong xu Laboratory of Marine Organism Taxonomy and Phylogeny Shandong Province Key Laboratory of Experimental Marine BiologyInstitute of OceanologyCenter for Ocean Mega-ScienceChinese Academy of SciencesQingdao 266071China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China University of Chinese Academy of Sciences Beijing 100049China

Two new species of Chrysogorgia Duchassaing&Michelotti,1864 collected from the Caroline seamounts in the tropical Western Pacific Ocean are *** pinniformis *** to Versluys’group C(Squamosae typicae)with only scales in polyp body wall and *** *** characterized by large branches pinnately branched and forming multiple fans with its small branches regularly and quasi-dichotomous branched,and scales and rods present in the polyp mouth *** is most similar to *** Cairns,2007 by the pinnate trait,but differs from the latter by its group C pattern(*** A,Spiculosae)and having sclerites present in the polyp mouth area(***).Chrysogorgia varians *** to the Chrysogorgia group A(Spiculosae)with rods distributed in the polyp body wall and *** is characterized by warty rods and elongated scales in the tentacles,many warts and ridges on the scales,conspicuously toothed margins at the rounded ends in the pinnules,and small rods with ridge-like warts in the polyp mouth *** species was frequent and abundant in the Caroline seamounts during our cruises and its morphological variability in growth period was *** phylogenetic analyses based on mtMutS and 28 S rDNA regions supported the assignment of the new species to the genus ***,the mtMutS marker showed very limited usefulness for species delimitation and inner relationship inference of *** contrast,the 28 S rDNA showed much higher level of genetic variation,and it may be a potential barcode for this *** the 28 S rDNA trees,the two new species clustered ***,compilation of our data showed that 42 of 78(ca.54%)Chrysogorgia species were found in the Indo-West Pacific convergent region,indicating that this area may be a hotspot of deep-water Chrysogorgia species.

关键词： Anthozoa Octocorallia Chrysogorgiidae deep sea taxonomy

Facile Access to Chiral Alcohols with Pharmaceutical Relevance Using a Ketoreductase Newly Mined from Pichia guilliermondi

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Chinese Journal of Chemistry 2013年第3期31卷 349-354页

作者： Guochao xu Huilei yu Jianhe xu Laboratory of Biocatalysis and Synthetic Biotechnology State Key Laboratory of Bioreactor Engineering East China University of Science and Technology Shanghai 200237 China

Chiral secondary alcohols with additional functional groups are frequently required as important and valuable synthons for pharmaceuticals, agricultural and other fine chemicals. With the advantages of environmentally benign reaction conditions, broad reaction scope, and high stereoselectivity, biocatalytic reduction of prochiral ketones of- fers significant potential in the synthesis of optically active alcohols. A CmCR homologous carbonyl reductase from Pichia guilliermondii NRRL Y-324 was successfully overexpressed. Substrate profile characterization revealed its broad substrate specificity, covering aryl ketones, aliphatic ketones and ketoesters. Furthermore, a variety of ketone substrates were asymmetrically reduced by the purified enzyme with an additionally NADPH regeneration system. The reduction system exhibited excellent enantioselectivity （~ 99% ee） in the reduction of all the aromatic ketones and ketoesters, except for 2-bromoacetophenone （93.5% ee）. Semi-preparative reduction of six ketones was achieved with high enantioselectivity （〉99% ee） and isolation yields （〉80%） within 12 h. This study provides a useful guidance for further application of this enzyme in the asymmetric synthesis of chiral alcohol enantiomers.

关键词： carbonyl reductase asymmetric reduction chiral alcohols Pichia guilliermondii biocatalysis

Antithetical impacts of deleterious LRP1B mutations in non-squamous and squamous NSCLCs on predicting benefits from immune checkpoint inhibitor alone or with chemotherapy over chemotherapy alone: retrospective analyses of the POPLAR/OAK and CHOICE-01 trial

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Science China Life Sciences 2025年第1期 249-262页

作者： Jinliang Wang Wenyong Zhou yu xu Jianchun Duan Qiaoxia Zhou Guoqiang Wang Leo Li Chunwei xu Wenxian Wang Shangli Cai Zhijie Wang Jie Wang Department of Oncology The Fifth Medical Center of Chinese PLA General Hospital Department of Thoracic Surgery Shanghai Chest HospitalSchool of MedicineShanghai Jiao Tong University Burning Rock Biotech CAMS Key Laboratory of Translational Research on Lung Cancer State Key Laboratory of Molecular OncologyDepartment of Medical OncologyNational Cancer Center/National Clinical Research Center for ancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical College Institute of Basic Medicine and Cancer (IBMC) Chinese Academy of Sciences Department of Clinical Trial The Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital)

In non-small cell lung cancers,the non-squamous and squamous subtypes（nsqNSCLC and sqNSCLC） exhibit disparities in pathophysiology,tumor immunology,and potential genomic correlates affecting responses to immune checkpoint inhibitor（ICI）-based *** our inhouse training cohort（n=85）,the presence of the LRP1B deleterious mutation（LRP1B-del） was associated with longer and shorter progression-free survival（PFS） on ICIs alone in nsqNSCLCs and sqNSCLCs,respectively(Pinteraction=0.008).These results were validated using a larger public ICI cohort(n=208,Pinteraction<0.001).Multiplex immunofluorescence staining revealed an association between LRP1B-del and increased and decreased numbers of tumor-infiltrating CD8+T cells in nsqNSCLCs（P=0.040） and sqNSCLCs（P=0.014）,*** the POPLAR/OAK cohort,nsqNSCLCs with LRP1B-del demonstrated improved PFS benefits from atezolizumab over docetaxel(hazard ratio（HR）=0.70,P=0.046),whereas this benefit was negligible in those without LRP1B-del（HR=1.05,P=0.64）.Conversely,sqNSCLCs without LRP1B-del benefited more from atezolizumab（HR=0.60,P=0.002） than those with LRP1B-del（HR=1.30,P=0.31）.Consistent results were observed in the in-house CHOICE-01 cohort,in which nsqNSCLCs with LRP1B-del and sqNSCLCs without LRP1B-del benefited more from toripalimab plus chemotherapy than from chemotherapy alone(Pinteraction=0.008).This multi-cohort study delineates the antithetical impacts of LRP1B-del in nsqNSCLCs and sqNSCLCs on predicting the benefits from ICI alone or with chemotherapy over chemotherapy *** findings highlight the distinct clinical utility of LRP1B-del in guiding treatment choices for nsqNSCLCs and sqNSCLCs,emphasizing the necessity for a detailed analysis based on pathological subtypes when investigating biomarkers for cancer therapeutics.

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Compatibilization of PBT/PP Blends by Adding Side-chain Liquid Crystalline Ionomer with Quaternary Pyridinium Groups

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Chemical Research in Chinese Universities 2011年第1期27卷 140-144页

作者： xu Xin-yu Department of Polymer Materials and Engineering School of Chemistry and Materials Science Liaoning Shihua University Fushun 113001 P R. China

A side-chain liquid crystalline ionomer（SLCI） was synthesized by grafting copolymerization of 4-（4-ethoxybenzoyloxy）-4＇-allyloxybiphenyl and N-allyl-pyridium bromide on polymethylhydrosiloxane. The SLCI was blended with polypropylene（PP） and polybutylene terephthalate（PBT） by melt mixing. The thermal behavior, liquid crystalline properties, morphological structure, and mechanical properties of the blends were investigated by differential scanning calorimetry（DSC）, polarizing optical microscopy（POM）, scanning electron microscopy（SEM）, and tensile measurement. When a proper amount of SLCI was added, fine configurations were formed in the PBT/PP/SLCI blend system, and the mechanical properties were improved due to improved adhesion at the interface. When excess SLCI was added, an inhomogeneous structure resulted, which caused the mechanical properties to deteriorate.

关键词： Poly(butylent terephthalate) Poly(propylene) Liquid crystalline ionomer Compatibilization

Attitude Tracking Control for Rigid Spacecraft with Arbitrary Convergence Time

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Journal of Systems Science & Complexity 2024年第6期37卷 2579-2594页

作者： xu yu-Tian WU Ai-Guo Guangdong Provincial Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics Harbin Institute of Technology(Shenzhen)Shenzhen 518055China Key University Laboratory of Mechanism&Machine Theory and Intelligent Unmanned Systems of Guangdong Harbin Institute of Technology(Shenzhen)Shenzhen 518055China Department of Automation Harbin Institute of Technology(Shenzhen)Shenzhen 518055China HIT Wuhu Robot Technology Research Institute Wuhu 241060China

In this paper,attitude tracking control with arbitrary convergence time for rigid spacecraft is ***,a novel time-varying sliding function is proposed to achieve free-will arbitrary time convergence when the system states reside on the sliding *** such a sliding function,an attitude tracking controller is designed to guarantee that the states of the closed-loop system converge to the sliding surface within a predetermined time in the presence of external *** free-will arbitrary time convergences of the closed-loop system and sliding function are illustrated by numerical simulations.

关键词： Attitude tracking free-will arbitrary time stability rigid spacecraft sliding mode control

Training SVMs on a bound vectors set based on Fisher projection

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Frontiers of Computer Science 2014年第5期8卷 793-806页

作者： xu yu Jing YANG Zhiqiang XIE School of Information Science and Technology Qingdao University of Science and Technology Qingdao 266061 China College of Computer Science and Technology Harbin Engineering University Harbin 150001 China College of Computer Science and Technology Harbin University of Science and Technology Harbin 150080 China

Standard support vector machines （SVMs） train- ing algorithms have O（l3） computational and O（l2） space complexities, where l is the training set size. It is thus com- /putationally infeasible on very large data *** alleviate the Computational burden in SVM training, we propose an algo- rithm to train SVMs on a bound vectors set that is extracted based on Fisher projection. For linear separate problems, we use linear Fisher discriminant to compute the projection line, while for non-linear separate problems, we use kernel Fisher discriminant to compute the projection line. For each case, we select a certain ratio samples whose projections are adja- cent to those of the other class as bound vectors. Theoretical analysis shows that the proposed algorithm is with low com- putational and space *** experiments on several classification benchmarks demonstrate the effective- ness of our approach.

关键词： support vector machines bound vectors set,Fisher discriminant sequential minimal optimization

Experimental Investigation of Wave Load and Run-up on the Composite Bucket Foundation Influenced by Regular Waves

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Journal of Ocean University of China 2021年第2期20卷 271-284页

作者： yu Tongshun ZHAO Zishuai SHI Zhongyu xu yu College of Engineering Ocean University of ChinaQingdao 266100China Shandong Provincial Key Laboratory of Ocean Engineering Qingdao 266100China State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China

In the design of wind turbine foundations for offshore wind farms, the wave load and run-up slamming on the supporting structure are the quantities that need to be considered. Because of a special arc transition, the interaction between the wave field and the composite bucket foundation(CBF) becomes complicated. In this study, the hydrodynamic characteristics, including wave pressure, load, upwelling, and run-up, around the arc transition of a CBF influenced by regular waves are investigated through physical tests at Shandong Provincial Key Laboratory of Ocean Engineering, Ocean University of China. The distributions of the wave pressures and upwelling ratios around the CBF are described, and the relationship between the wave load and the wave parameters is discussed. New formulae based on the velocity stagnation head theory with linear wave theory and the second-order Stokes wave theory for wave kinematics are proposed to estimate the wave run-up. Moreover, the multiple regression method with nonlinear technology is employed to deduce an empirical formula for predicting run-up heights. Results show that the non-dimensional wave load increases with the increase in the values of the wave scattering parameter and relative wave height. The wave upwelling height is high in front of the CBF and has the lowest value at an angle of 135? with the incoming wave direction. The performance of the new formulae proposed in this study is compared using statistical indices to demonstrate that a good fit is obtained by the multiple regression method and the analytical model based on the velocity stagnation head theory is underdeveloped.

关键词： physical experiment composite bucket foundation wave load wave run-up regular waves

Joint task scheduling and multi-UAV deployment for aerial computing in emergency communication networks

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Science China(Information Sciences) 2023年第9期66卷 239-258页

作者： Tiankui ZHANG Chaobin CHEN yu xu Jonathan LOO Wenjun xu School of Information and Communication Engineering Beijing University of Posts and Telecommunications School of Computing and Engineering University of West London School of Artificial Intelligence Beijing University of Posts and Telecommunications

This article studies mobile edge computing technologies enabled by unmanned aerial vehicles(UAVs) in disasters. First, considering that the ground servers may be damaged in emergency scenarios, we proposed an air-ground cooperation architecture based on ad-hoc UAV networks. We defined the system cost as the weighted sum of task delay and energy consumption because of different delay sensitivity and energy sensitivity tasks in emergency communication networks. Then, we formulated the system cost-minimization problem of task scheduling and multi-UAV deployments. To solve the proposed mixed integer nonlinear programming problem, we decomposed it to two sub-problems that were solved by proposing a swap matchingbased task scheduling sub-algorithm and a successive convex approximation-based multi-UAV deployment sub-algorithm. Accordingly, we propose a joint optimization algorithm by iterating the two sub-algorithms to obtain a low complexity sub-optimal solution. Finally, the simulation results show that(i) the proposed algorithm converges in several iterations, and(ii) compared with the benchmark algorithms, the proposed algorithm has better performance of reducing task delay and energy consumption and achieves a good tradeoff between them for diverse tasks.

关键词： emergency communication mobile edge computing swap matching algorithm unmanned aerial vehicle