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Silicon assistant carbothermal reduction for SiC powders

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Journal of University of Science and Technology Beijing 2008年第4期15卷 484-488页

作者： Kezhi li jian wei Hejun li Chuang Wang Gengsheng Jiao National Key Laboratory of Thermostructure Composite Materials Northwestern Polytechnical University Xi＇an 710072 China

The silicon assistant method to increase the reaction yield of carbothermal reduction of silica at a lower temperature is reported. The effect of silicon on the carbothermal reduction process has been investigated in detail. Compared with traditional reduction, the introduction of silicon can change the reaction path and further increase the conversion of silicon carbide at a lower temperature. It is considered that the assistant reduction consists of three steps： vaporizing and melting of silicon, formation of silicon monoxide, and synthesis of silicon carbide. The morphology of the synthesized SiC powders through the silicon assistant method can be affected apparently by the experimental temperature.

关键词： carbide powders solid state reaction electron microscopy X-ray diffraction

Effect of low-intensity pulsed ultrasound on posterolateral lumbar fusion of rabbit

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Asian Pacific Journal of Tropical Medicine 2015年第1期8卷 68-72页

作者： jian Wang jian-wei li Lei Chen 3rd Department of Orthopedics Rizhao People's Hospital Affiliated to Shandong University

Objective:To observe the effect of low-intensity pulsed ultrasound in the posterolateral Lumbar fusion of ***:A total of 48 New Zealand white rabbits were randomly divided into the observation group and control group,including the autogenous iliac observation *** bone observation group,artificial bone control group and autogenous iliac control group according to the different bone *** posterolateral lumbar fusion of rabbits in each group was analyzed and ***:After 4 weeks of treatment using the low-intensity pulsed ultrasound,the fusion in the bone grafting area of observation group was *** was the relatively dense fusion area between the right transverse process and artificial *** left transverse process had been completely fused,with the clear bone trabecula through the fusion *** was no significant fusion sign in the control *** to the fusion comparison between two groups,the fusion rale of the observation group was 83.3%and it was significantly higher than the one of the control group(37.5%).Results of the comparison were statistically significant(Pliac observation group were significantly higher than ones of the iliac control group(P<0.05).The number of chondrocytes and the increase in the relative gray-scale in the fusion area of the artificial bone observation group were significantly higher than ones of the artificial bone control group(P<0.05).The expression of ***-6 and IL-17 4 weeks after the treatment of the observation group was significantly lower than the one of the control group,with the statistical significance(P<0.05).It indicated that the treatment of low-intensity pulsed ultrasound could reduce the expression level of inflammatory ***:The low-intensity pulsed ultrasound can significantly increase the bone grafting fusion rate of the rabbit's poster

关键词： Low-intensity pulsed ultrasound Lumbar posterolateral Fusion Ilium

Quantitatively Evaluating the Erosion and Preservation of Supergene Oxide Zones:Evidence from the Yulong Porphyry Cu Deposit,Eastern Tibetan Plateau

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Journal of Earth Science 2024年第1期35卷 280-282页

作者： Xiao-Dong Deng jian-wei li State Key Laboratory of Geological Processes and Mineral Resources and School of Earth ResourcesChina University of GeosciencesWuhan 430074China

*** and erosion of sulfide ore deposits are important for understanding the post-mineralization processes that have significant effects on the preservation of primary orebodies(Velasco et al.,2013;Braxton et al.,2009;Brimhall et al.,1985).Supergene oxide zones are often developed in sulfide ore deposits,and are mainly composed of iron oxides and hydroxides zones in weathering profile(Andrew,1984;Thornber et al.,1981).

关键词： Eastern Tibetan weathering

Regional Evaluation of Winter Rapeseed Response to K Fertilization, K Use Efficiency, and Critical Level of Soil K in the Yangtze River Valley

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Agricultural Sciences in China 2011年第6期10卷 911-920页

作者： ZOU Juan LU jian-wei li Yin-shui li Xiao-kun College of Resources and Environment Huazhong Agricultural University Wuhan 430070 P.R. China

The investigation was carried out to study the response of winter rapeseed to potassium （K） feritlization and the critical soil available K level for current winter rapeseed production in the Yangtze River Valley （YRV） of China. A total of 132 field experiments were conducted in fields of farmers in the major winter rapeseed growing areas in YRV in 2000/2001 and 2004/2005 to 2006/2007 during growing season. Results of these field experiments showed that the average rapeseed yield increment resulting from 100 kg K ha-1 application was 358 kg ha-1, an increase over the control CK （no K） of 18.0% in 2005/2006 and 2006/2007. The average internal use efficiency （IE） of K was higher in the CK treatment （21.9 kg grain, kg-1 K uptake） than in the ＋K （100 kg K ha-1） treatment （17.7 kg grain, kg-1 K uptake）. Winter rapeseed required 68.1 kg of K to produce 1 000 kg seed. The recovery efficiency of K fertilizer in rapeseed production averaged 39.3%. The K balance was negative, with an average net removal of 117.6 kg K ha-1 in the CK treatment annually, and 56.8 kg K ha-1 in the ＋K treatment. The results indicated that there was a significant negative relationship between yield increments by K application and soil available K content. Based on the relative yield of CK/＋K at 90% level, the critical level of soil available K （NH4OAc-extractable K） was 135 mg kg-1.

关键词： rapeseed (Brassica napus L.) K fertilizer K use efficiency yield critical level of soil available K

Enhanced mechanical properties in Al/diamond composites by Si addition

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Rare Metals 2016年第9期35卷 701-704页

作者： jian-Hua Wu Hai-Long Zhang Yang Zhang jian-wei li Xi-Tao Wang Shandong Engineering Research Center for lightweight Automobiles Magnesium Alloy New MaterialsShandong Academy of Sciences State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing

Diamond particles reinforced aluminum–silicon matrix composites,abbreviated as Al（Si）/diamond composites,were fabricated by squeeze *** effect of Si content on the microstructure and mechanical properties of the composites were *** mechanical properties are found to increase monotonically with Si content increasing up to 7.0 wt%.The Al-7.0 wt% Si/diamond composite exhibits tensile strength of 78 MPa,bending strength of 230 MPa,and compressive strength of426 ***–Si eutectic phases are shown to connect with Al matrix and diamond particles tightly,which is responsible for the enhancement of mechanical properties in the Al（Si）/diamond composites.

关键词： Composite materials Diamond particles Mechanical properties Interfaces

An approach to synthesis of(Z)-2-chloro-1,3-diarylpropen-1-ones by Vilsmeier reagent(bis-(trichloromethyl)carbonate/DMF)

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Chinese Chemical Letters 2011年第12期22卷 1395-1398页

作者： Yi Yi Weng jian Jun li wei Ke Su Key Laboratory of Pharmaceutical Engineering of Ministry of Education College of Pharmaceutical Sciences Zhejiang University of Technology Hangzhou 310014 China

A series of（Z）-2-chloro-1,3-diarylpropen-1-ones were unexpectedly synthesized in moderate yields by treatment of easily available 2,3-epoxy-1,3-diarylpropan-1-ones with Vilsmeier reagent,which was derived from bis（trichloromethyl） carbonate（BTC, triphosgene） and DMF.A possible mechanism was also proposed,where sequential ring-opening,halogenation and elimination reactions were involved.

关键词： Ring-opening Halogenation Vilsmeier reagent Bis-(trichloromethyl)carbonate (Z)-2-Chloro-1 3-diaryl-2-enones

Spin-resolved quantum transport in graphene-based nanojunctions

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Frontiers of physics 2017年第4期12卷 29-41页

作者： jian-wei li Bin Wang Yun-Jin Yu Ya-Dong wei Zhi-Zhou Yu Yin Wang College of Physics and Energy Shenzhen University Shenzhen 518060 China Department of Physics The University of Hong Kong Hong Kong China

First-principles calculations were performed to explore the spin-resolved electronic and thermoelectric transport properties of a series of graphene-nanoribbon-based nanojunctions. By flipping the mag- netic moments in graphene leads from parallel to antiparallei, very large tunneling magnetoresistance can be obtained under different gate voltages for all the structures. Spin-resolved alternating-current conductance increases versus frequency for the short nanojunctions but decreases for the long nano- junctions. With increasing junction length, the behavior of the junctions changes from capacitive-like to inductive-like. Because of the opposite signs of spin-up thermopower and spin-down thermopower near the Fermi level, pure spin currents can be obtained and large figures of merit can be achieved by adjusting the gate voltage and chemical potential for all the nanojunctions.

关键词： TMR AC conductance thermoelectric transport NEGF-DFT

Effect of Extrusion Temperature on the Microstructure and Mechanical Properties of Mg–5Al–2Ca Alloy

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Acta Metallurgica Sinica(English Letters) 2015年第8期28卷 1015-1023页

作者： Kun Su Kun-kun Deng Fang-jun Xu Kai-bo Nie li Zhang Xiao Zhang wei-jian li College of Materials Science and Engineering Shanxi Key Laboratory of Advanced Magnesium-Based MaterialsTaiyuan University of Technology

In this work, the Mg–5Al–2Ca alloy was extruded at 573, 623 and 673 K, with a ratio of 16：1 and a constant speed of 3 mm/s. Results demonstrate that the Al2Ca particle is formed in Mg–5Al–2Ca alloy. The size, amount and distribution of Al2Ca particles are influenced evidently by extrusion temperature. Unlike previous reports, the intensity of basal texture increases with increasing extrusion temperature, and the reasons are analyzed and given. Even though the average grain size increases as the extrusion temperature increased from 573 to 623 K, the YS, UTS and elongation of asextruded Mg–5Al–2Ca alloy are almost kept the same at 573 and 623 K. The reason is speculated as the balance of grain size, Al2Ca phase and texture at the two temperatures. The work hardening rate depends on extrusion temperature, and the largest θ value of Mg–5Al–2Ca alloy is obtained when the extrusion was performed at 623 K.

关键词： Mg–Al–Ca alloy Extrusion Microstructure Mechanical properties Work hardening

Surface modification of 316L stainless steeldiamond-like carbon films

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Journal of Iron and Steel Research International 2020年第7期27卷 867-874页

作者： Rui-wu li Zheng Zhang jian-wei li Ke-xin Ma Yuan-yuan Guo Yan-wen Zhou Fa-yu Wu School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051LiaoningChina liaoning Censcience Industrial Co. Ltd.Research and Design InstituteLiaoyang 111200LiaoningChina

The diamond-like carbon(DLC)film on 316L stainless steel substrate was preparedpulsed plasma-enhanced chemical vapor deposition,and the performance of the films was optimizedregulating the pulse *** and properties of DLC film on 316L stainless steel were characterizedatomic force microscopy,field-emission scanning electron microscopy,Raman spectra,nano-indenter and electrochemical *** results showed that DLC films with smooth and dense morphology have a low friction coefficient and high nano-indentation hardness,and the surface hardness of 316L stainless steel substrate was enhancedmore than 3 *** mechanical properties of DLC films and their bond with 316L stainless steel could be further optimizedincreasing pulse *** films on 316L stainless steel substrate increased the self-corrosion potential0.173 V and decreased self-corrosion current99%,which significantly improved the anti-corrosive properties of 316L substrate.

关键词： 316L stainless steel Diamond-like carbon film Plasma enhanced chemical vapor deposition Frictional wear Nano-indentation Corrosion resistance