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Chinese Chemical Letters 2001年第7期12卷 579-580页

作者： Xue Qiang YIN guang zhong YANG Yuan Chao li Shanghai Institute of Materia Medica Chinese Academy of SciencesShanghai 200031

trans-3, 3b, 4, 9b, 10, 11-Hexahydro-6-methoxy-9b-methyl-7-(1-methylethyl) phenanthro {1,2-c[furan-1,5-dione]} was synthesized with good yield in two steps from triptophenolide methyl ether under mild conditions.

关键词： Tripterygium wilfordii triptolide triptophenolide methyl ether

Lattice Boltzmann method for simulating flows in open-channel with partial emergent rigid vegetation cover

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Journal of Hydrodynamics 2019年第4期31卷 717-724页

作者： zhong-hua Yang Feng-peng Bai Wen-xin Huai Cheng-guang li State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China Changjiang Water Resources Protection Institute Wuhan 430051 China Shandong Provincial Key Laboratory of Water Resources and Water Environment Water Resources Research Institute of Shandong Province Jinan 250013 China

Flows in open-channel with partial emergent rigid vegetation cover are simulated using the lattice Boltzmann method (LBM) described by the 2-D nonlinear shallow water equations. The effect of vegetation is represented with the vegetation roughness coefficient, which is related to the vegetation density, diameter of the vegetation elements and drag coefficient. The model is verified by three numerical tests: flow in a 180° curved open channel with partial vegetation cover at the outer bank, flow in a rectangular channel with a finite patch of vegetation and flow in a rectangular channel with a vegetated bank. Numerical results are compared with the experimental data, and the good agreement proved that the presented model can model the vegetated channel flows correctly.

关键词： Open-channel flow rigid vegetation lattice Boltzmann method (LBM) shallow water equations vegetation roughness coefficient

Super-high bed sintering for iron ores: inhomogeneous phenomena and its mechanism during mineralizing

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Journal of Iron and Steel Research International 2024年第8期31卷 1850-1860页

作者： Hui-bo liu liang-ping Xu Xi-duan Yang zhong-lin Dong Qiang zhong guang-hui li School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083HunanChina

The inhomogeneous sinter properties in super-high bed sintering have been reported in our previous *** inves-tigate the reasons for the inhomogeneous phenomena,detailed sampling and analysis of mixed material bed and sintered bed in super-high bed sintering plant were *** results indicated that the higher porosity and thinner dendrite of silico-ferrite of calcium and aluminum in the upper layer as well as dense structure and higher secondary hematite content in the lower layer led to the heterogeneities of mechanical strength and reduction properties exceeding 20%and 10%,*** the bed top downward,the basicity of mixed material decreased from 2.13 to 1.68 because the average particle size increased from 2.65 to 4.56 *** and fuels gathered in finer particles(-3 mm)of mixed material,and the-3 mm particles of mixed material generated more liquid phase than+3 mm *** heat input of super-high sintering bed was inhomogeneous due to the heat accumulation effect and unreasonable fuel *** inhomo-geneous sintering heat condition in sintering bed resulted in the different quantities and properties of liquid *** inhomogeneous quantities and properties of liquid phase that were influenced by inhomogeneous distribution of chemical composition,particle size,and heat input led to inhomogeneous mineralizing *** mineralizing condition is the key for homogeneous super-high bed sintering.

关键词： Iron ore Super-high bed sintering Mineralization Material segregation Heat accumulation

Interfacial Microstructure of Al-Sn-Pb Alloy/Steel During liquid-Solid Bonding Rolling

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Journal of Iron and Steel Research International 2006年第4期13卷 40-43页

作者： XU guang-ming li Bao-mian CUI Jian-zhong Key Laboratory of Electromagnetic Processing of Materials Northeastern UniversityShenyang 110004 Liaoning China

Studies were conducted on the interfacial microstructure of a steel/liquid aluminium and its evolution during the bonding rolling process. The effects of wetting time and deformation on the diffusion layer and on the bonding strength were examined. By means of electron microscopy and electron probe analysis, it was found that the diffusion layer is mainly composed of FeAI3. For a steel temperature of 250℃ and an aluminium temperature of 850 ~C, the diffusion layer was formed within 3 s, and the shear strength of the samples increased after 8 to 14 s. Although the interface was not damaged, it was deformed notably. For an aluminium temperature of 750℃ and a wetting time of 11 to 17 s, the shear strength of the interface remained high, but the interface was obviously broken during rolling, leading to reduced bonding strength.

关键词： liquid-solid bonding rolling wetness diffusion layers interracial strength

Characterization and Three-dimensional Structural Modeling of Humic Acid via Molecular Mechanics and Molecular Dynamic Simulation

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Chemical Research in Chinese Universities 2013年第6期29卷 1180-1184页

作者： ZHAO Nan L(U) Yi-zhong li guang-jun College of Resources and Environmental Sciences China Agricultural University Beijing 100193 P.R.China School of Chemistry and Environment Beijing University of Aeronautics and AstronauticsBeijing 100191 P.R.China

The humic acid（HA） sample obtained from the alluvial soil was characterized by elemental composition, pyrolysis gas chromatography-mass spectrometry（Py-GC-MS） and solid-state 13C nuclear magnetic resonance （13C NMR） spectroscopy. There is high fat content and a few nitrogen-containing functional groups in HA. Py-GC-MS demonstrates the characterization and structural identification of HA. One long list of identified pyrolysis products was proposed for the construction of conceptual model of HA. Solid-state 13C NMR data indicate there are higher values of alkyl-C, O-alkyl-C and aryl-C in HA. The elemental composition, structural carbon distribution and L3C NMR spectroscopy of simulated HA are consistent with those of experimental HA. HyperChem was used to simulate the three-dimensional molecular structure of the monomer, which was optimized by the molecular mechanics of the optimized potential for liquid simulations（OPLS） force field and molecular dynamics simulation to get the stable and balanced conformation. The deprotonation process study depicts that the degree of ionization of HA gets deeper, while the electronegativity of HA and the energy of van der Waals（vdW） increase. Moreover, the 3D structure of humic acid with -4 charges is the most stable. The deprotonation process is an endothermic process.

关键词： Alluvial soil Humic acid Conceptual model Elemental analysis Pyrolysis gas chromatography-mass spectrometry(Py-GC-MS) 13C nuclear magnetic resonance(13C NMR) Molecular simulation Three-dimensional structure Optimized potential for liquid simulatio

Microstructure and properties of coarse-grained WC-10Co cemented carbides with different carbon contents during heat treatments

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Rare Metals 2024年第4期43卷 1786-1792页

作者： Yuan-Feng Xie Xing-Cheng Xie zhong-Wu li Rui-Jun Cao zhong-Kun lin Qing li Chen-guang lin Powder Metallurgy and Special Materials Research Department General Research Institute for Nonferrous MetalsBeijing100088China

The effects of cryogenic treatment(CT)and tempering-cryogenic treatment(TCT)on the microstructure and properties of coarse-grained WC-10Co cemented carbides with different carbon contents were *** binder phase,WC mean grain sizes,W solubility in the binder,relative magnetic s aturation,densities,hardness,wear resistance and second phase precipitation of cemented carbides with different heat treatments were *** results show that there are significant changes of microstructure and properties in the samples with CT and TCT,especially due to the precipitation of metastable nanoparticles W_(x)Co_(y)C_(z) in the binder during the heat treatments of CT and *** the simultaneous combination of microstructure and nanoparticle-reinforced binder,a dramatically improved combination of hardness and wear resistance of the samples after TCT has been achieved.

关键词： Cryogenic treatment Tempering Coarsegrained cemented carbide Carbon content Nanoparticlereinforced binder

Effects of Heat Treatment on Surface Recrystallization and Stress Rupture Properties of a Fourth-Generation Single-Crystal Superalloy after Grit Blasting

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Acta Metallurgica Sinica(English Letters) 2017年第7期30卷 614-620页

作者： Zhen-Xue Shi Shi-zhong liu Xiao-guang Wang Jia-Rong li Science and Technology on Advanced High Temperature Structural Materials Laboratory Beijing Institute of Aeronautical Materials Beijing 100095 China

The specimens of a fourth-generation single-crystal superalloy were grit-blasted and heat-treated in vacuum at 1100, 1150, 1200, 1250 and 1300 °C for 4 h, respectively. Then, the microstructure and the stress rupture properties of the recrystallized alloy were investigated at 1150 °C/120 MPa. The results showed that a cellular recrystallization occurred in the surface layer after heating at 1100, 1150 and 1200 °C for 4 h. An equiaxed recrystallization formed as the specimen was heat-treated at 1300 °C for 4 h, while a mixed recrystallization occurred in the specimen heat-treated at 1250 °C for 4 h. The recrystallized depth clearly increased with a rise of the heat treatment temperature. The stress rupture life continuously decreased with a rise of the heat treatment temperature up to 1250 °C. Although the overall stress rupture life reduced to different degrees, the stress rupture life of specimen after heat treatment at 1300 °C was relatively high and intermediate between those of specimens treated at 1150 and 1200 °C. The fact that the stress rupture life reduced to different degrees after heat treatment can be attributed to the recrystallization of the surface layer and to the microstructure evolution of the interior of the specimen. The small γ’ phase precipitated again after heat treatment at 1300 °C for 4 h. So,the stress rupture life was relatively longer than that after heat treatment at 1200 or 1250 °C although the equiaxed recrystallization formed in the surface layer.

关键词： Single-crystal superalloy Heat treatment Recrystallization Stress rupture properties

Recent insights into farnesoid X receptor in non-alcoholic fatty liver disease

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World Journal of Gastroenterology 2014年第37期20卷 13493-13500页

作者： Jiao-Ya Xu zhong-Ping li li Zhang guang Ji Institute of Digestive Diseases Longhua HospitalShanghai University of Traditional Chinese Medicine E-Institute of Shanghai Municipal Education Com-mission Shanghai University of Traditional Chinese Medicine

Non-alcoholic fatty liver disease(NAFLD) is the hepatic manifestation of metabolic syndrome and is one of the most prevalent liver disorders worldwide. NAFLD can gradually progress to liver inflammation, fibrosis, cirrhosis and even hepatocellular carcinoma. However, the pathogenesis of NAFLD is complex, and no efficient pharmaceutic treatments have yet been established for NAFLD. Accumulating data have shown that the farnesoid X receptor(FXR) plays important roles not only in bile acid metabolism, but also in lipid and carbohydrate homeostasis, inflammatory responses, among others. In this review, we aim to highlight the role of FXR in the pathogenesis and treatment of NAFLD.

关键词： Farnesoid X receptor Non-alcoholic fatty liver disease Mechanism Therapy lipid metabolism

Clinical effectiveness of a pneumatic compression device combined with low-molecular-weight heparin for the prevention of deep vein thrombosis in trauma patients:A single-center retrospective cohort study

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World Journal of Emergency Medicine 2022年第3期13卷 189-195页

作者： Peng-chao Guo Nan li Hui-ming zhong guang-feng Zhao Emergency Department the Second Affiliated Hospital of Zhejiang University School of MedicineHangzhou 310009China Plastic Surgery Department the Second Affiliated Hospital of Zhejiang University School of MedicineHangzhou 310009China

BACKGROUND:To investigate the clinical effectiveness of a pneumatic compression device(PCD)combined with low-molecular-weight heparin(LMWH)for the prevention and treatment of deep vein thrombosis(DVT)in trauma ***:This study retrospectively analyzed 286 patients with mild craniocerebral injury and clavicular fractures admitted to our department from January 2016 to February *** treated with only LMWH served as the control group,and patients treated with a PCD combined with LMWH as the observation *** incidence of DVT,postoperative changes in the visual analogue scale(VAS)score,and coagulation function were observed and compared between the two *** the influence of other single factors,binary logistic regression analysis was used to evaluate the use of a PCD in the patient’s postoperative coagulation ***:After excluding 34 patients who did not meet the inclusion criteria,252 patients were were *** incidence of DVT in the observation group was significantly lower than that in the control group(5.6%vs.15.1%,χ^(2)=4.605,P0.05).According to logistic regression analysis,the postoperative risk of DVT in patients who received LMWH alone was 1.764 times that of patients who received LMWH+PCD(P<0.05).The area under the receiver operating characteristic(AUROC)curve of partial thromboplastin time(APTT)and platelet(PLT)were greater than 0.5,indicating that they were the influence indicators of adding PCD to prevent *** the influence of other variables,LM

关键词： Deep vein thrombosis Pneumatic compression device Low-molecular-weight heparin Trauma Logistic regression analysis

Multilayered flexible nanocomposite for hybrid nano- generator enabled by conjunction of piezoelectricity and triboelectricity

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Nano Research 2017年第3期10卷 785-793页

作者： Huayang li li Su Shuangyang Kuang Youjun Fan Ying Wu zhong lin Wang guang Zhu Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences National Center for Nanoscience and Technology (NCNST) Beijing 100083 China Chongqing University of Science and Technology Chongqing 401331 China School of Materials Science and Engineering Georgia Institute of Technology A tlanta GA 30332 USA

We fabricate a flexible hybrid nanogenerator （HNG）, based on multilayered nanocomposite materials, which integrates a piezoelectric nanogenerator （PENG） and a triboelectric nanogenerator （TENG） into a single structure with only two electrodes. The HNG enables enhancement of the electrical output of the nano- generators. An open-circuit voltage of 280 V and a short-circuit current of 25 μA are achieved by a HNG of 2.5 cm × 2.5 cm in size, superior to the performance of previously reported HNGs. In addition, the energy-conversion process of the HNG relies on the working mechanism of both the PENG and TENG. The polarization direction and doping content of BTO are the two major factors that affect the electrical output. Biomechanical energy harvesting from walking motion or the bending of an arm is also demonstrated.

关键词： energy harvesting nanocomposite hybrid nanogenerator piezoelectricity triboelectricity