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In situ modification of heavy oil catalyzed by nanosized metal-organic framework at mild temperature and its mechanism

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Chinese Journal of Chemical Engineering 2024年第3期67卷 166-173页

作者： Li Wang Ji-Xiang Guo Rui-Ying Xiong Chen-Hao Gao xiao-jun zhang Dan Luo The Unconventional Oil and Gas Institute China University of Petroleum-BeijingBeijing 102200China Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China

Two catalysts, nano-sized cobalt-metal-organic framework(Co-MOF) and nickel(Ni)-MOF, were successfully prepared by the modification method. Tetralin(C10H12) was used as the hydrogen donor for the catalytic cracking and hydrogenation modification study of the dehydrated crude oil from the Shengli Oilfield. The optimal reaction conditions were determined through orthogonal experiments, and the components of the crude oil and modified oil samples were analyzed. The results revealed that the nanoMOF catalysts were successfully prepared and exhibited high catalytic activity. They could catalyze the cracking of large molecules in heavy oil at mild temperatures(<300°C), leading to the decomposition of the hydrogen donor. When the mass fraction of the catalyst was 0.2%, the mass fraction of the hydrogen donor was 1%, and the reaction temperature was 280°C, the Ni-MOF showed the best catalytic viscosity reduction effect. It could reduce the viscosity of heavy oil at 50°C from 15761.9 m Pa.s to 1266.2 m Pa.s,with a viscosity reduction rate of 91.97%. The modification effect of Co-MOF was the next best, which could reduce the viscosity of heavy oil to 2500.1 m Pa.s with a viscosity reduction rate of 84.14%. Molecular dynamics simulations revealed a strong interaction force between the MOF surface and asphaltene molecules. In the process of heavy-oil catalytic hydrogenation, the nano-MOF catalyst exhibited high catalytic activity. On the one hand, the empty d orbitals outside the metal atoms in the catalyst could polarize the carbon atoms in the organic matter, accelerating the breaking of long chains. On the other hand, the metal atoms in the catalyst could bond with the carbon σ bonds, breaking the carbon-carbon bonds. This disrupted the structure of the recombined components in the crude oil, irreversibly reducing the viscosity of the heavy oil and improving its fluidity.

关键词： Nano-sized MOF Petroleum Viscosity reduction Catalyst Nanomaterials

Mechanisms of tumor immunosuppressive microenvironment formation in esophageal cancer

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World Journal of Gastroenterology 2024年第16期30卷 2195-2208页

作者： xiao-jun zhang Yan Yu He-Ping Zhao Lei Guo Kun Dai Jing Lv Department of Clinical Laboratory Honghui HospitalXi’an Jiaotong UniversityXi’an 710054Shaanxi ProvinceChina Department of Spinal Surgery Honghui HospitalXi’an Jiaotong UniversityXi’an 710054Shaanxi ProvinceChina Department of Clinical Laboratory Yanliang Railway Hospital of Xi’anXi’an 710089Shaanxi ProvinceChina

As a highly invasive malignancy,esophageal cancer(EC)is a global health issue,and was the eighth most prevalent cancer and the sixth leading cause of cancerrelated death worldwide in *** to its highly immunogenic nature,emerging immunotherapy approaches,such as immune checkpoint blockade,have demonstrated promising efficacy in treating EC;however,certain limitations and challenges still *** addition,tumors may exhibit primary or acquired resistance to immunotherapy in the tumor immune microenvironment(TIME);thus,understanding the TIME is urgent and crucial,especially given the importance of an immunosuppressive microenvironment in tumor *** aim of this review was to better elucidate the mechanisms of the suppressive TIME,including cell infiltration,immune cell subsets,cytokines and signaling pathways in the tumor microenvironment of EC patients,as well as the downregulated expression of major histocompatibility complex molecules in tumor cells,to obtain a better understanding of the differences in EC patient responses to immunotherapeutic strategies and accurately predict the efficacy of ***,personalized treatments could be developed to maximize the advantages of immunotherapy.

关键词： Esophageal cancer Esophageal squamous cell carcinoma Esophageal adenocarcinoma Tumor immune microenvironment Immunosuppression Immunotherapy

Effect of Water Absorption on the Impact Properties of Carbon Fiber/Epoxy Composites

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Chinese Journal of Aeronautics 2006年第B12期19卷 14-18页

作者： LU xiao-jun zhang Qi School of Materials Science and Engineering Bejing University of Aeronautics and Astronautics Beijing 100083 China

In this paper, the effects of test temperatures and time on the impact damage behavior of unidirectional carbon fiber reinforced epoxy resin composites, immersed in pure water, on a pendulum impact tester, was studied. The results show that immersion in liquids has a significant effect on the impact resistance of the unidirectional composite material. It is obvious that after immersion, the mass of the material increases. The fracture initiation forces as well as the fracture initiation energy decrease as the immersion time lengthens. Moreover, the higher the temperature and the longer the time are, the more the crack propagation energy and the ductility index will be. Immersion makes the fracture mode change from the dominant fiber fracture into dominant delamination. All in all, immersion decreases the impact resistance of the composites and causes the fracture mode to change.

关键词： carbon fiber composites impact damage immersion fracture mechanisms

Visualization of Fiber Moving in Air Tunnel with Velocity Gradient

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Chinese Physics Letters 2020年第3期37卷 13-16页

作者： Yang Miao Xiang Guo xiao-jun zhang College of Mechanical Engineering and Applied Electronics Technology Beijing University of TechnologyBeijing 100124 Beijing Key Laboratory of Advanced Manufacturing Technology Beijing University of TechnologyBeijing 100124

To measure the parameters of fiber and to visualize the reshaping process of fiber in air tunnel,an experimental approach is developed in the present *** tunnel is designed with gradient flow velocity,and the fiber reshaping images as well as the fiber length value are obtained *** analytical expression of velocity distribution in the tunnel is theoretically derived and the simulated results are *** fiber reshaping including stretch and rotation is verified using the dynamical equation and the multi-spherical chain *** is shown that pull force by air flow makes a chain of balls become straight and Stokes moment makes the ball chain ***,reshaping criterion related with flow velocity is formulated.

关键词： fiber Velocity Tunnel

Competitive precipitation behavior of hybrid reinforcements in copper matrix composites fabricated by powder metallurgy

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International Journal of Minerals,Metallurgy and Materials 2021年第6期28卷 1090-1096页

作者： Tao Lan Yi-hui Jiang xiao-jun zhang Fei Cao Shu-hua Liang Shaanxi Province Key Laboratory for Electrical Materials and Infiltration Technology Xi’an University of TechnologyXi’an 710048China

Copper matrix composites reinforced by in situ-formed hybrid titanium boride whiskers(TiB_(w))and titanium diboride particles(TiB_(2p))were fabricated by powder *** observations showed competitive precipitation behavior between TiB_(w) and TiB_(2p),where the relative contents of the two reinforcements varied with sintering *** on thermodynamic and kinetic assessments,the precipitation mechanisms of the hybrid reinforcements were discussed,and the formation of both TiB_(w) and TiB_(2p) from the local melting zone was thermodynamically *** precipitation kinetics were mainly controlled by a solid-state diffusion of B *** forming a compact compound layer,in situ reactions were divided into two stages,where Zener growth and Dybkov growth prevailed,***,the competitive precipitation behavior was attributed to the transition of the growth model during the reaction process.

关键词： metal matrix composite hybrid reinforcement in situ reaction growth kinetics

Radiosynthesis of N-^(11) C-meisoindigotin as a novel PET agent for imaging of cyclin-dependent kinases and GSK-3β

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Chinese Chemical Letters 2012年第2期23卷 205-207页

作者： Jin Ming zhang xiao jun zhang Zhi Hong Xu Jia He Tian Department of Nuclear Medicine The PLA General HospitalBeijing 100853China Huayi Chemicals Co. Ltd.Changshu 215522China

Meisoindigotin has been demonstrated as a new type of cancer chemotherapeutic agent.N-^（11）C-meisoindigotin was synthesized by N-^（11）C-methyIation of the isoindigotin precursor with ^（11）C-labelled methyl *** decay corrected radiochemical yields were 15-25%,and the specific radioactivity was 1.0-1.2 Ci/μmol at the end of *** cellular uptake of[N-^（11）C]-meisoindigotin was evaluated in four different lung cancer cell *** results showed that the A549,GLC-82,95D cell lines exhibited higher uptake than 95C cell line after incubation for 60 min.N-^（11）-meisoindigotin was a promising candidate for further development as a novel PET radiotracer for imaging of cyclin-dependent kinases（CDKs） and GSK-3β.

关键词： N-methylisoindigotin Tumor imaging agent Cyclin-dependent kinases

Expression change of TNF-αin myocardium and hepatic tissue of rats with compound stress of hyperthermia and Hpopolysaccharide

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Asian Pacific Journal of Tropical Medicine 2013年第4期6卷 300-304页

作者： xiao-jun zhang Ji Yue Ting-Bao Zhao Department of Spinal Cord Injury General Hospital of Jinan Millitary Command

Objective:To investigate the expression characteristics of TNF-αin myocardium and hepatic tissue of rats with compound stress of hyperthermia and lipopoiysaccharide(LPS).Methods: Male SPF Wistar rats were randomly divided into room temperature+physiological saline group (Croup C),hyperthermia+physiological saline group(Croup II),room temperature+LPS group(Croup L) and hyperthermia+LPS group(Croup HL).The rats were put in simulated climate *** HL and Croup H were exposed in the environment at a dry bulb temperature(TDB) of(35.0±0.5)℃,while Croup L and Croup C were exposed in the environment at a TDB of(26.0±0.5)℃. The rats in Croup HL and Croup L were given tail intravenous injection of LPS 10 mg/kg,while the rats in Croup H and Croup C were given tail intravenous injection of 9 g/L NaCl 10 ml/kg. After the stress,immunohistochemical SABC staining method was used to detect the expression characteristics of TNF-αin myocardium and hepatic tissue of rats,and those rats were given routine pathological ***:The expression of TNF-αin myocardium and hepatic tissue in Croup HL was enhanced remarkably,and the tissue damages of Croup HL were ***:The eardiotoxieity and hepatotoxicity caused by compound stress of hyperthermia and LPS is closely related to the expression of TNF-α.

关键词： Hyperthermia Lipopolysaccharide Systemic inflammatory response Syndrome Immunohistochemistry TNF-α

Research and design of the protection circuits in LD controller

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The Journal of China Universities of Posts and Telecommunications 2006年第4期13卷 73-76页

作者： SHAN Jiang-dong TIAN xiao-jian DENG jun zhang Shuang College of Electronic Science and Engineering Jilin University Changchun 130012 China

According to the parameters and applications of laser diode （LD）, three protection circuits were designed： the time-delay soft-start protection circuit, the power-on impulse protection circuit and the limit-current protection circuit. In this article, the structure and the principle of every protection circuit have been detailed. From several tests and feedbacks from customers, the expected goals have been completed.

关键词： LD protection circuits time-delay soft-start protection circuit power-on impulse protection circuit limit-current protection circuit

Multiple miscarriages in a female patient with two-chambered heart and situs inversus totalis:A case report

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World Journal of Clinical Cases 2022年第4期10卷 1333-1340页

作者： Hai-Zhen Duan Jia-Ji Liu xiao-jun zhang Ji zhang An-Yong Yu Department of Emergency Medicine Affiliated Hospital of Zunyi Medical UniversityZunyi 563000Guizhou ProvinceChina Department of Radiology the First People's Hospital of ZunyiZunyi 563000Guizhou ProvinceChina

BACKGROUND Single atrium with single ventricle,or a two-chambered heart,is an extremely rare congenital *** cases with two-chambered heart surviving to adulthood have been *** SUMMARY We reported an adult female patient with a two-chambered heart and situs inversus totalis accompanied by multiple pregnancies and *** resonance imaging detected a two-chambered heart.B-ultrasound-guided uterine aspiration was performed to absorb 8 g and 10 g of organized villus and decidual tissues,respectively,with a small amount of ***,cyanosis and fatigue-induced shortness of breath were gradually *** patient has currently outlived all similar cases reported so *** Hemodynamic changes in pregnant women with two-chambered heart impaired cardiac function,responsible for hypoperfusion and miscarriage.

关键词： Two-chambered heart Situs inversus totalis Abortion B-ultrasound Electrocardiography Case report