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An introduction to the novel vacuum plume effects experimental system

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Science China(Technological Sciences) 2016年第6期59卷 953-960页

作者： cai Guo Biao ling Gui Long HE Bi Jiao School of Astronautics Beihang University

This paper introduces a newly developed vacuum Plume effects Experimental System(PES) used for plume effect tests of rocket engines and vacuum heat tests of satellites. The design level, manufacturing technique, and testing capabilities of the PES have reached a highly advanced level at home and abroad. The PES mainly consists of a vacuum chamber, vacuum acquisition system, nitrogen system, helium system, and parameter measurement system. A breakthrough was obtained on the Large Scale Cryo-Pumping System, which was based on a combined liquid nitrogen and liquid helium heat sink. An internal cryopump with a limiting temperature of 4.2 K and an efficient absorption area of 305 m2 was developed. The absorption capability of the cryopump was above 7×107 L/s. Vacuum plume tests were performed in the temperature ranges of ambient temperature, liquid nitrogen, and liquid helium. The experimental results showed that the plume test capability of PES is higher than that of similar foreign equipment STG and CHAFF-4. For 2 g/s and 117 N rocket engines, the dynamic vacuum degree of environment was 8.0×10?4 Pa(approximately 137 km height) and 1.1×10?2 Pa(approximately 106 km height), respectively.

关键词： vacuum plume effect liquid nitrogen heat sink liquid helium heat sink plume absorption pump

Channel puncturing based low-complexity belief propagation detection for multi-user MIMO systems

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The Journal of China Universities of Posts and Telecommunications 2020年第6期27卷 8-16页

作者： cai Xingwei Ji Wei Qiu ling Liang Xiaowen Key Laboratory of Wireless-Optical Communications Chinese Academy of SciencesSchool of Information Science and TechnologyUniversity of Science and Technology of ChinaHefei 230026China

A low complexity punctured belief propagation(BP)detection utilizing channel puncturing for multi-user multiple-input multiple-output(MU-MIMO)systems is proposed in this *** paper constructs a cycle-free fator graph by puncturing certain non-zero entries in a transformed channel matrix,and proposes an adjusted BP algorithm with a more exact a posteriori message updating *** proposed algorithm converges rapidly in several iterations due to the cycle-free structure in the factor ***,puncturing brings distorted noise and thus leads to performance *** tackle this issue,this article further designs a layered detection with the help of maximum likelihood detector(MLD).Simulations demonstrate that the proposed detection algorithm achieves the identical performance to MLD with much lower complexity.

关键词： MU-MIMO rich scattering wireless environment BP layered detection algorithm

Research progresses on equipment technologies used in safety inspection,repair,and reinforcement for deepwater dams

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Science China(Technological Sciences) 2022年第5期65卷 1059-1071页

作者： XIANG yan SHENG JinBao WANG Lei cai YueBo MENG Ying cai Wei Dam Safety Management Department Nanjing Hydraulic Research InstituteNanjing210029China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing210029China Key Laboratory of Reservoir and Dam Safety Ministry of Water ResourcesNanjing210029China China Ship Scientific Research Center Wuxi214000China Hangzhou Hua-Neng Engineering Safety Technology Co. Ltd.Hangzhou310000China

China’s many dams are increasingly facing safety problems resulting from the natural aging of the dam hydraulic structure and geological disasters such as earthquakes under the operating condition of holding a vast amount of *** such as dam leakage and concrete cracking and erosion seriously affect the normal operation and effectiveness of a *** is impossible to empty a large reservoir with a high dam for many reasons,such as serious environmental consequences,and it is thus difficult to detect the working conditions of the underwater part of the *** is an increasingly urgent demand for detection and repair technologies that can be used in the deepwater ***,there are cutting-edge deepwater detection and processing technologies for hidden dangers in dam *** core technologies include underwater detection equipment,diving technologies,and underwater operation *** paper analyzes safety-oriented detection equipment recently used in unmanned detection,manned detection,and deepwater diver detection from the viewpoint of practical *** paper further reviews 100-m-depth-class technologies and applications of safety inspection,repair,and reinforcement equiment in the deepwater environment of reservoir *** outlook is provided on technology trends of deepwater detection,repair,and reinforcement and critical problems.

关键词： dam unmanned detection manned submersible detection deepwater detection deep water repair and reinforcement

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Decomposed Modeling of Controllable and Uncontrollable Components in Power Systems with High Penetration of Renewable Energies

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Journal of Modern Power Systems and Clean Energy 2022年第5期10卷 1164-1173页

作者： Hai Li Ning Zhang Yue Fan ling Dong Pengcheng cai State Key Laboratory of Power Systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China State Grid Qinghai Electric Power Co. Ltd.XiningChina State Grid Xinjiang Electric Power Co. Ltd.UrumqiChina

The high penetration of variable renewable energies requires the flexibility from both the generation and demand sides. This raises the necessity of modeling stochastic and flexible energy resources in power system operation. However,some distributed energy resources have both stochasticity and flexibility, e.g., prosumers with distributed photovoltaics and energy storage, and plug-in electric vehicles with stochastic charging behavior and demand response capability. Such partly controllable participants pose challenges to modeling the aggregate behavior of large numbers of entities in power system operation. This paper proposes a new perspective on the aggregate modeling of such energy resources in power system ***, a unified controllability-uncontrollability-decomposed model for various energy resources is established by modeling the controllable and uncontrollable parts of energy resources separately. Such decomposition enables the straightforward aggregate modeling of massive energy resources with different controllabilities by integrating their controllable components with linking constraints and uncontrollable components with dependent discrete convolution. Furthermore, a two-stage stochastic unit commitment model based on the proposed model for power system operation is established. The proposed model is tested using a three-bus system and real Qinghai provincial power grid of China. The result shows that this model is able to characterize at high accuracy the aggregate behavior of massive energy resources with different levels of controllability so that their flexibility can be fully explored.

关键词： Aggregation dependent discrete convolution flexibility stochastic unit commitment virtual power plant

Hierarchically 1D CdS decorated on 2D perovskite-type La_(2)Ti_(2)O_(7) nanosheet hybrids with enhanced photocatalytic performance

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Rare Metals 2021年第5期40卷 1067-1076页

作者： Liang Mao Xiao-yan cai Ming-Shan Zhu School of Materials Science and Physics China University of Mining and TechnologyXuzhou 221116China Jiangsu Province Engineering Laboratory of High Efficient Energy Storage Technology and Equipment China University of Mining and TechnologyXuzhou 221116China School of Environment Jinan UniversityGuangzhou 511443China

In this paper,a heterojunction of hierarchically one-dimensional(1D)cadmium sulfide(CdS)nanowires decorated on the two-dimensional(2D) La_(2)Ti_(2)O_(7) (LTO)has been fabricated by a simple two-step hydrothermal *** structure,morphology and surface chemical composition of CdS/LTO were studied by a variety of characterizations,in which the X-ray photoelectron spectroscopy(XPS)results showed a strong interaction between CdS and LTO through S-O *** typeⅡband alignment of CdS/LTO for favorable electron transfer from CdS to LTO and hole transfer from LTO to CdS was clarified by ultraviolet-visible(UV-Vis)diffuse reflectance spectroscopy and Mott-Schottky(M-S)plot *** the absence of any co-catalyst,H2 production from water splitting and Rhodamine B(RhB)decomposition in aqueous solution were carried out to evaluate the photocatalytic activities,showing that the photocatalytic performance of CdS/LTO was superior to that of pure LTO and CdS under visible light and simulated *** optimal CdS content in the CdS/LTO system was determined to be 7.5 wt%.The present results show an effective pathway to design a 1D/2D heterojunction photocatalyst in the face of overwhelming problems of energy crisis and environmental pollution.

关键词： Cadmium sulfide Lanthanum titanium oxide Heterojunction H_(2)production Dyes degradation

Simple Singular Whittaker Modules Over the Schrödinger Algebra

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Communications in Mathematics and Statistics 2019年第4期7卷 475-483页

作者： yan-an cai Xiufu Zhang Department of Mathematics Soochow UniversitySuzhou 215006JiangsuPeople’s Republic of China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190People’s Republic of China School of Mathematics and Statistics Jiangsu Normal UniversityXuzhou 221116People’s Republic of China

There are no simple singular Whittaker modules over most of important algebras,such as simple complex finite-dimensional Lie algebras,affine Kac-Moody Lie algebras,the Virasoro algebra,the Heisenberg-Virasoro algebra and the Schrödinger-Witt *** this paper,however,we construct simple singular Whittaker modules over the Schrödinger ***,simple singular Whittaker modules over the Schrödinger algebra are *** a result,simple modules for the Schrödinger algebrawhich are locally finite over the positive part are completely *** also give characterizations of simple highestweight modules and simple singular Whittaker modules.

关键词： Schrödinger algebra Highest weight modules Singular Whittaker modules Simple modules Locally finite modules

Asymptotic Optimality of the Nonnegative Garrote Estimator Under Heteroscedastic Errors

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Journal of Systems Science & Complexity 2020年第2期33卷 545-562页

作者： CHEN Xiuping cai Guanghui GAO yan ZHAO Shangwei College of Statistics and Mathematics Zhejiang Gongshang UniversityHangzhou 310018China Department of Statistics College of ScienceMinzu University of ChinaBeijing 100081China

This paper proposes the Nonnegative Garrote(NG)estimator for linear model with heteroscedastic *** the other hand,under some regularity conditions,the authors show the asymptotic optimality of the NG estimator by referring to the idea of the asymptotic optimality of the model average *** results and a real data analysis are reported for testing the results obtained *** results provide a stronger theoretical basis for the use of NG estimator by strengthening existing findings.

关键词： Asymptotic optimality coefficient shrinkage heteroscedastic errors Nonnegative Garrote

Association of serum pepsinogen with degree of gastric mucosal atrophy in an asymptomatic population

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World Journal of Clinical Cases 2021年第31期9卷 9431-9439页

作者： Hao-Lei cai Yu-ling Tong Department of Surgery The Second Affiliated Hospital of Zhejiang University School of MedicineHangzhou 310009Zhejiang ProvinceChina International Healthcare Center The Second Affiliated Hospital of Zhejiang University School of MedicineHangzhou 310009Zhejiang ProvinceChina

BACKGROUND Atrophic gastritis is a precancerous lesion of the *** has been reported that pepsinogen(PG)can reflect the morphology and function of the gastric mucosa,and it is therefore used as a marker for the early diagnosis of atrophic *** To evaluate the diagnostic value of serum PG for degree of gastric mucosal atrophy in asymptomatic Chinese upon physical *** Medical data were collected from subjects who underwent transnasal gastroscopy between October 2016 and October *** each study subject,serum PG levels and presence of Helicobacter pylori(***)infection were *** was evaluated using the Operative Link for Gastritis Assessment(OLGA)classification and Operative Link on Gastric Intestinal Metaplasia Assessment(OLGIM)*** statistical analyses were carried out using SPSS statistical *** A total of 2256 subjects were enrolled and 1922 cases were finally included in the *** on the OLGA grading system,the levels of PGI were slightly decreased,while those of PGII were slightly *** PGI/PGII ratio(PGR)was reduced with increasing *** association between PG and OLGA grading was higher compared with that between PG and the OLGIM grading *** with the OLGA-0 group,a statistically significant difference was observed in the mean age of OLGA-Ⅰ,Ⅲ,and Ⅳ groups(P<0.05).In the ***-positive subjects,the PGR levels were notably lower in the OLGA-Ⅰ,Ⅱ,and Ⅲ groups compared with the OLGA-0 group(P<0.05).***-positive subjects exhibited significantly higher PGI and PGII serum levels and a significantly lower PGR compared with ***-negative patients in different OLGA groups(P<0.05).CONCLUSION Serum PG levels may represent a non-invasive screening marker for gastric mucosal atrophy in asymptomatic subjects.

关键词： Pepsinogen Helicobacter pylori Operative Link for Gastritis Assessment Atrophic gastritis Gastric mucosal atrophy Biomarker

The regulatory role of protein phosphorylation in human gammaherpesvirus associated cancers

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Virologica Sinica 2017年第5期32卷 357-368页

作者： Yuyan Wang Shuvomoy Banerjee ling Ding Cankun cai Fang Wei Qiliang cai MOH & MOE Key Laboratory of Medical Molecular Virology School of Basic Medical SciencesShanghai Medical College of Fudan University Shanghai 200032 China Amity Institute of Virology and Immunology Block-J3 Sector-125 Amity University Uttar Pradesh201303 India Sheng Yushou Center of Cell Biology and Immunology School of Life Sciences and BiotechnologyShanghai Jiao Tong University Shanghai 200240 China

Activation of specific sets of protein kinases by intracellular signal molecules has become more and more apparent in the past decade. Phosphorylation, one of key posttranslational modification events, is activated by kinase or regulatory protein and is vital for controlling many physiological functions of eukaryotic cells such as cell proliferation, differentiation, malignant transformation,and signal transduction mediated by external stimuli. Moreovers, the reversible modification of phosphorylation and dephosphorylation can result in different features of the target substrate molecules including DNA binding, protein-protein interaction, subcellular location and enzymatic activity, and is often hijacked by viral infection. Epstein-Barr virus(EBV) and Kaposi's sarcomaassociated herpesvirus(KSHV), two human oncogenic gamma-herpesviruses, are shown to tightly associate with many malignancies. In this review, we summarize the recent progresses on understanding of molecular properties and regulatory modes of cellular and viral proteins phosphorylation influenced by these two tumor viruses, and highlight the potential therapeutic targets and strategies against their related cancers.

关键词： Epstein-Barr Virus(EBV) Kaposi’s sarcoma-associated herpesvirus(KSHV) phosphorylation