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Characteristic studies of heat sources and performance analysis of free-cooling assisted air conditioning and ventilation systems for working faces of mineral mines

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Building Simulation 2021年第6期14卷 1725-1736页

作者： Rang Tu Lijuan Huang Aibing Jin Mingfeng Zhang xiao hai School of Civil and Resources Engineering University of Science and Technology BeijingBeijing100083China Benxi Longxin Mining Co.Ltd BenxiLiaoning717000China

High temperature heat hazard at mineral mine becomes more and more serious as the increase of mining *** sources at working faces of mineral mines are complex and are of different characteristics,presenting new challenges for air conditioning *** this paper,heat sources at four types of working faces are summarized and their characteristics are *** on this,simplified equations,which are linear with length of working faces,are proposed to calculate heat dissipation *** that the main heat sources of different working faces can be found,and cooling load of air conditioning systems can be ***,considering main heat sources of coal mines,a typical working face is designed to investigate performances of different ventilation systems and air conditioning *** results show that segmented ventilation systems(SC)and heat shield assisted centralized ventilation systems(CCHS)can realize much better temperature distributions at working ***,cooling load can be greatly reduced for CCHS,when untreated air is supplied to the coal seam *** on this,free cooling assisted air conditioning systems are designed,and annual average energy efficiency ratio(EERann)of the systems are investigated and compared between direct evaporate cooling and indirect evaporate cooling(IEC).For SC,as compared with scenarios without free-cooling,IEC can increase EERann by 15%-23%and 22%-32%under Benxi and Datong ambient conditions,***,to ensure high EERann,CCHS is preferred and it is essential to increase thermal insulation of air ducts.

关键词： working face heat sources characteristics air ventilation system free cooling air conditioning energy efficiency

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聚丙烯酰胺对三峡库区紫色土分离能力的影响

武汉大学学报（理学版） 2024年第1期70卷 139-146页

作者：高峰夏振尧张伦王地向瑞刘德玉肖海三峡库区地质灾害教育部重点实验室湖北宜昌443002 三峡大学土木与建筑学院湖北宜昌443002 三峡大学三峡库区生态环境教育部工程研究中心湖北宜昌443002

以三峡库区紫色土为研究对象,设置6个聚丙烯酰胺(PAM)施加量(0、0.4、0.8、1.2、1.6、2.0 g/m^(2))和6个养护时长(1、3、7、15、30、60 d),采用冲刷实验,研究PAM施加量及养护时长对土壤分离能力的影响,并从表观黏聚力和水稳性团聚体稳... 详细信息

以三峡库区紫色土为研究对象,设置6个聚丙烯酰胺(PAM)施加量(0、0.4、0.8、1.2、1.6、2.0 g/m^(2))和6个养护时长(1、3、7、15、30、60 d),采用冲刷实验,研究PAM施加量及养护时长对土壤分离能力的影响,并从表观黏聚力和水稳性团聚体稳定性角度揭示土壤分离能力变化的原因。结果表明:同一PAM施加量条件下,土壤分离能力随着养护时长的增加而降低,同一养护时长条件下,随着PAM施加量增加,土壤分离能力先减小后增加,PAM施加量为0.8 g/m^(2)时,土壤分离能力最小;土壤分离能力与表观黏聚力、平均质量直径(MWD)和几何平均直径(GMD)之间均呈对数函数关系,表观黏聚力是描述土壤分离能力的最佳指标。

关键词：三峡库区紫色土聚丙烯酰胺土壤分离能力养护时长

Study of Cadmium-Doped Zinc Oxide Nanocrystals with Composition and Size Dependent Band Gaps

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Chinese Journal of Chemical Physics 2018年第2期31卷 197-202,246页

作者： hai-xiao Zhang Yue-tao Yang xiao-jun Liu Key Laboratory of Modern Acoustics Ministry of Education Institute of Acoustics Nanjing University Nanjing 210093 China

Cadrniurn-doped zinc oxide nanocrystals in the quantum confinement region have been firstly synthesized by a fast and facile sonochernical method. The alloyed structure of the nanocrystals is confirmed by X-ray diflraction, transmission electron rnicroscopy, and infrared analysis. With the increase of cadmium to zinc molar ratio from 0 to 2.0, the crystallite sizes of the samples decrease from 5.1 nrn to 2.6 nrn, and the band gaps of the samples show a red shift then a blue shift, and a red shift again. The variations of band gaps of the samples can be interpreted by the crystallite size and the composition. It is found that both the non-therrnal equilibrium environrnent established in the sonochernical reaction and the coordination ability of triethylene glycol solvent play crucial roles in the current preparation.

关键词： Alloyed nanocrystal Structure Spectroscopy Sonochemistry

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葫芦脲的特性及衍生化

广州化工 2024年第4期52卷 163-166页

作者：程芷琰张海波周晓海东莞职业技术学院卫生健康学院广东东莞523186 武汉大学化学与分子科学学院湖北武汉430072

葫芦脲是近年来发展迅速的新型大环主体分子之一,它是通过亚甲基桥连接不同数量的甘脲单元形成的一类桶状化合物。由于其结构特殊,近年来受到广泛关注和研究,其在分子开关、超分子催化反应器、药物载体等领域具有重要应用。然而葫芦脲... 详细信息

葫芦脲是近年来发展迅速的新型大环主体分子之一,它是通过亚甲基桥连接不同数量的甘脲单元形成的一类桶状化合物。由于其结构特殊,近年来受到广泛关注和研究,其在分子开关、超分子催化反应器、药物载体等领域具有重要应用。然而葫芦脲较差的溶解性和化学惰性阻碍了其发展和应用,将葫芦脲衍生化,可改变它的物化性质和识别能力,大大扩展其应用范围。介绍了葫芦脲的特性,包括结构、溶解性、稳定性、刚性及化学惰性。详细阐述了葫芦脲衍生化的两种途径,一是以取代甘脲为原料合成取代葫芦脲,二是将葫芦脲直接氧化引入羟基合成羟基葫芦脲。

关键词：葫芦脲特性葫芦脲衍生化

Global Convergence of a Modified Limited Memory BFGS Method for Non-convex Minimization

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Acta Mathematicae Applicatae Sinica 2013年第3期29卷 555-566页

作者： Yun-hai xiao Ting-feng Zeng-xin WEI Department of Mathematics Nanjing University Zhengzhou Technical College College of Mathematics and Information Science Guangxi University

In this paper, a modified limited memory BFGS method for solving large-scale unconstrained optimization problems is proposed. A remarkable feature of the proposed method is that it possesses global convergence property without convexity assumption on the objective function. Under some suitable conditions, the global convergence of the proposed method is proved. Some numerical results are reported which illustrate that the proposed method is efficient.

关键词： Non-convex minimization secant equation limited memory BFGS method global convergence

Sparse Estimation of High-Dimensional Inverse Covariance Matrices with Explicit Eigenvalue Constraints

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Journal of the Operations Research Society of China 2021年第3期9卷 543-568页

作者： Yun-hai xiao Pei-Li Li Sha Lu Institute of Applied Mathematics College of Mathematics and StatisticsHenan UniversityKaifeng 475000HenanChina School of Statistics Key Laboratory of Advanced Theory and Application in Statistics and Data Science-MOEEast China Normal UniversityShanghai 200062China Department of Mathematics Nanning Normal UniversityNanning 530299GuangxiChina

Firstly,this paper proposes a generalized log-determinant optimization model with the purpose of estimating the high-dimensional sparse inverse covariance *** the normality assumption,the zero components in the inverse covariance matrices represent the conditional independence between pairs of variables given all the other *** generalized model considered in this study,because of the setting of the eigenvalue bounded constraints,covers a large number of existing estimators as special ***,rather than directly tracking the challenging optimization problem,this paper uses a couple of alternating direction methods of multipliers(ADMM)to solve its dual model where 5 separable structures are *** first implemented algorithm is based on a single Gauss–Seidel iteration,but it does not necessarily converge *** contrast,the second algorithm employs the symmetric Gauss–Seidel(sGS)based ADMM which is equivalent to the 2-block iterative scheme from the latest sGS decomposition ***,we do numerical simulations using the synthetic data and the real data set which show that both algorithms are very effective in estimating high-dimensional sparse inverse covariance matrix.

关键词： Non-smooth convex minimization Inverse covariance matrix Maximum likelihood estimation Augmented Lagrangian function Symmetric Gauss–Seidel iteration

BRIGHT:the three-dimensional X-ray crystal Bragg diffraction code

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Nuclear Science and Techniques 2019年第3期30卷 28-36页

作者： Nan-Shun Huang Kai Li hai-xiao Deng Shanghai Institute of Applied Physics Chinese Academy of Sciences University of Chinese Academy of Sciences Department of Physics The University of Chicago

In pursuit of a fully coherent X-ray free-electron laser(FEL), highly reflective Bragg crystals are used and will be used as a highly selective spectral filter in hard X-ray self-seeding FELs and X-ray FEL oscillators(XFELO), respectively. However, currently, when simulating self-seeding and XFELO, the three-dimensional effect of Bragg diffraction is not fully considered. In this paper, we derive a comprehensive solution for the response function of the crystal in Bragg diffraction. A three-dimensional X-ray crystal Bragg diffraction code, named BRIGHT, is introduced, which can be combined with other FEL-related codes, e.g., GENESIS and OPC. Performance and feasibility are assessed using two numerical examples,namely a self-seeding experiment for the linac coherent light source and XFELO options for Shanghai high repetition rate XFEL. The results indicate that BRIGHT provides a new and useful tool for three-dimensional modeling of FEL.

关键词： X-ray Bragg diffraction Self-seeding XFELO

Impacts of the upper-ocean salinity variations on the decadal sea level change in the Southeast Indian Ocean during the Argo era

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Acta Oceanologica Sinica 2020年第7期39卷 1-10页

作者： Jiamei Huang Wei Zhuang xiao-hai Yan Zelun Wu State Key Laboratory of Marine Environmental Science College of Ocean and Earth SciencesXiamen UniversityXiamen 361102China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China Joint Center for Ocean Remote Sensing University of Delaware-Xiamen UniversityNewarkDE 19716USA College of Earth Oceanand EnvironmentUniversity of DelawareNewarkDE 19716USA

In the past nearly two decades,the Argo Program has created an unprecedented global observing array with continuous in situ salinity observations,providing opportunities to extend our knowledge on the variability and effects of ocean *** this study,we utilize the Argo data during 2004–2017,together with the satellite observations and a newly released version of ECCO ocean reanalysis,to explore the decadal salinity variability in the Southeast Indian Ocean(SEIO)and its impacts on the regional sea level *** the observations and ECCO reanalysis show that during the Argo era,sea level in the SEIO and the tropical western Pacific experienced a rapid rise in 2005–2013 and a subsequent decline in 2013–*** a decadal phase reversal in sea level could be explained,to a large extent,by the steric sea level variability in the upper 300 *** data further show that,in the SEIO,both the temperature and salinity changes have significant positive contributions to the decadal sea level *** is different from much of the Indo-Pacific region,where the halosteric component often has minor or negative contributions to the regional sea level pattern on decadal *** salinity budget analyses based on the ECCO reanalysis indicate that the decadal salinity change in the upper 300 m of SEIO is mainly caused by the horizontal ocean *** detailed decomposition reveals that in the SEIO,there exists a strong meridional salinity front between the tropical low-salinity and subtropical high salinity *** meridional component of decadal circulation changes will induce strong cross-front salinity exchange and thus the significant regional salinity variations.

关键词： decadal sea level change southeast Indian Ocean halosteric effect salinity budget

Umbilical cord-derived mesenchymal stem cell transplantation combined with hyperbaric oxygen treatment for repair of traumatic brain injury

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Neural Regeneration Research 2016年第1期11卷 107-113页

作者： hai-xiao Zhou Zhi-gang Liu xiao-jiao Liu Qian-xue Chen Department of Plastic Surgery Renmin Hospital of Wuhan University Department of Anesthesiology Renmin Hospital of Wuhan University Department of Neurosurgery Renmin Hospital of Wuhan University

Transplantation of umbilical cord-derived mesenchymal stem cells（UC-MSCs） for repair of traumatic brain injury has been used in the clinic. Hyperbaric oxygen（HBO） treatment has long been widely used as an adjunctive therapy for treating traumatic brain injury. UC-MSC transplantation combined with HBO treatment is expected to yield better therapeutic effects on traumatic brain injury. In this study, we established rat models of severe traumatic brain injury by pressurized fluid（2.5–3.0 atm impact force）. The injured rats were then administered UC-MSC transplantation via the tail vein in combination with HBO treatment. Compared with monotherapy, aquaporin 4 expression decreased in the injured rat brain, but growth-associated protein-43 expression, calaxon-like structures, and CM-Dil-positive cell number increased. Following combination therapy, however, rat cognitive and neurological function significantly improved. UC-MSC transplantation combined with HBO therapyfor repair of traumatic brain injury shows better therapeutic effects than monotherapy and significantly promotes recovery of neurological functions.

关键词： nerve regeneration traumatic brain injury umbilical cord mesenchymal stem cells transplantation hyperbaric oxygen rats craniocerebral trauma neurological function neural regeneration