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Gorenstein FP∞-Injective Modules and w-Noetherian Ring

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Algebra Colloquium 2022年第4期29卷 687-712页

作者： Shiqi Xing xiaoqiang luo Kui Hu College of Applied Mathematics Chengdu University of Information Technology Chengdu 610225China Departments of Mathematics Sichuan University of Arts and Science DazhouSichuan 635000China College of Science Southwest University of Science and Technology MianyangSichuan 621010China

We study some homological properties of Gorenstein FP∞-injective modules,and we prove(1)a ring R is not necessarily coherent if every Gorenstein FP∞-injective R-module is injective,and(2)a ring R is not necessarily coherent if every Gorenstein injective R-module is *** addition,we characterize w-Noetherian rings in terms of Gorenstein FP∞-injective modules,and we prove that a ring R is w-Noetherian if and only if every GV-torsion-free FP∞-injective R-module is Gorenstein FP∞-injective,if and only if any direct sum of GV-torsion-free FP∞-injective R-modules is Gorenstein FP∞-injective.

关键词： Gorenstein FP∞-injective module Gorenstein FP∞-dimension FP-module w-Noetherian ring

Mechanisms of Solidification Structure Improvement of Ultra Pure 17 wt% Cr Ferritic Stainless Steel by Ti,Nb Addition

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Journal of Materials Science & Technology 2011年第4期27卷 352-358页

作者： Yating Shan Xinghong luo xiaoqiang Hu Shi Liu Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

The grain structures and the precipitates in the solidification microstructure of the ultra pure 17 wt% Cr ferritic stainless steels with different Ti and/or Nb micro-alloying were investigated both experimentally and theoretically. It was found by the grain structure observation that the addition of Ti or Nb to the steel reduced the grain size （D） and elongation factor （E）, and improved the equiaxed grain proportion （P） and globularity factor （￡）. Among the four steels studied, the minimum grain size and maximum equiaxed grain proportion were obtained by jointly adding both Ti and Nb to the steel. The SEM observation indicated that several kinds of precipitations, such as TiN, MC （rich in Nb）, Laves phase （Fe2Nb） and so on, formed in the corresponding steels. In addition, the results calculated using the Thermo-Calc software illustrated that TiN precipitates in the liquid at proper Ti and N contents. Meanwhile, the solidification interval （△T） was enlarged by the addition of Ti or Nb, and the effectiveness of Nb was stronger than Ti. Based on the experimental and calculation results, the mechanisms of grain refinement and increment in equiaxed grain proportion were discussed.

关键词： Ultra pure ferritic stainless steel Micro-alloying Solidification structure Titanium Niobium

Effect of Pouring Temperature by a Novel Micro Fused-Casting on Microstructure and Properties of ZL101 Semisolid Slurry

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Journal of Wuhan University of Technology(Materials Science) 2023年第5期38卷 1179-1183页

作者： luo xiaoqiang HAN Yongjun HOU Yanmin LI Qingbin JIN Yu Pingdingshan University Pingdingshan 467000China Institute of Mechanics Chinese Academy of SciencesBeijing 100190China

A novel micro fused-casting(MFC)process is developed for semisolid aluminum alloy *** microstructure evolution and properties of semisolid ZL101 aluminum alloy slurry with difierent pouring temperature by MFC are investigated in this *** the cooling process,the effects of the pouring temperature on microstructure and properties is primarily *** microstructure of the semisolid ZL101 aluminum alloy is more homogeneous and the grain is smaller under proper pouring *** of liquids and solids of ZL101 aluminum alloy is measured by difierential scanning calorimetry(DSC).Distribution and characteristics of the microstructure of samples are examined by optical microscope(OM),scanning electron microscopy(SEM)equipped with energy dispersive spectrometer(EDS).The results show that the ZL101 semisolid slurry fabricated by MFC presents uniform shape and good grain size under the pouring temperature of 594°C and the stirring velocity of 600 r/min,and the fine grains of the primary a-Al phase with average grain size of 55μm and shape factor up to 0.67 were ***,the ultimate tensile strength and the average Vickers hardness for semisolid ZL101 aluminum slurry are 178.19±1.37 MPa and 86.15±1.16 HV,respectively.

关键词： ZL101 aluminum alloy semisolid micro fused-casting pouring temperature

Effect of Pouring Temperature on Microstructure and Properties of A356 Alloy Strip by a Novel Semisolid Micro Fused-Casting for Metal

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Journal of Wuhan University of Technology(Materials Science) 2019年第5期34卷 1205-1209页

作者： luo xiaoqiang HAN Yongjun Henan Key Laboratory of Research for Central Plains Ancient Ceramics Pingdingshan UniversityPingdingshan 467000China Institute of Mechanics Chinese Academy of SciencesBeijing 100190China

A novel semisolid micro fused-casting(MFC) for preparing A356 alloy strips is proposed, and the effects of process parameters of pouring temperature on the microstructure and properties of A356 alloy strips are investigated. MFC means that the semisolid metal slurry was pressed out from the outlet of bottom of crucible to the movable plate, and directly solidified and formed layer by layer. The microstructure and properties of A356 semisolid alloy slurry were influenced by the cooling conditions. Results show that the aluminu alloy A356 strip samples fabricated by micro fused-casting had good performances and uniform structures with the pouring temperature at 595 ℃ and the substrate movement speed at 18 mm/s. The fine grains of the primary a-Al phase with average grain size of 53 μm and shape factor up to 0.72 was obtained, the ultimate tensile strength of the aluminum alloy A356 strip reaches 243.79±3.91 MPa, while the average vickers hardness is 82.65±1.86 HV.

关键词： A356 alloy semisolid micro fused-casting pouring temperature

A comparative investigation of the properties of coal-water slurries prepared from Australia and Shenhua coals

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Mining Science and Technology 2011年第3期21卷 343-347页

作者： Yun Zengjie Wu Guoguang Meng Xianliang Zhang Yuliang Shi Frank He Yaqun luo xiaoqiang School of Chemical Engineering and Technology China University of Mining and Technology Xuzhou 221008 China Julius Kruttschnitt Mineral Research Centre Brisbane 4068 Australia

Two coal samples of similar rank were chosen from Australia and China to investigate the differences in Coal-Water Slurry （CWS） made from them. The effect of ash content and particle size gradation on these properties was also studied. Different grinding times were used when grinding the two coals and particle size analysis of these ground coals was used to select samples with a ＂double-peak＂ particle size distri- bution. All the ＂double-peak＂ samples were used to prepare a CWS. The concentration, viscosity, fluidity, and stability of each CWS were measured. The results show that the properties ofa CWS prepared from a coal sample with a ＂double-peak＂ size distribution are better than those CWS prepared from samples with a mono-modal particle distribution. The ash content of Australian coal is 21.72g higher than the ash content of Shenhua coal. The highest coal concentration in slurry from the Australia coal is 11.01% higher than in CWS from the Shenhua coat. The fluidity and stability of the CWS prepared from the Australian coal are both better than the fluidity and stability of slurry prepared from Shenhua coal. High ash content in the Australian coal imnroves the nulning results of a CWS made from it.

关键词： Coal-Water Slurry"Double-peak" gradationSlurry ability Rheological property Stability

Effects of the grinding process on the preparation and qualities of CWS

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Mining Science and Technology 2011年第6期21卷 767-771页

作者： Yuliang Zhang Guoguang Wu Xianliang Meng Zengjie Yun Frank Shi Yaqun He xiaoqiang luo School of Chemical Engineering and Technology China University of Mining ＆ Technology Xu.zhou 221008 China Julius Kruttschnitt Mineral Research Centre Brisbane 4068 Australia

Two different grinding processes were examined to determine the effect grinding has on the quality of a CWS. A series of slurries was prepared from Australian (Au) and Chinese (YZ) coals. Both types of coal were ground by a Chinese (CUMT) and an Australian (JK) grinding process. The performance tests of the prepared CWS showed that fluidity of all slurries was acceptable. The concentration of the CWS from YZ coal ground by the CUMT grinding process was higher than when the JK grinding process was used. The highest concentration was 70.14% in this case. The concentration of the CWS prepared from Au coal by the JK grinding process was higher than when the CUMT grinding process was used. The highest con- centration in this case was 70.97%. These differences are caused by the particle size distribution devel- oped during the different grinding processes.

关键词： Coal water slurry "Double-peak" gradation Slurry ability Grinding process Stability Fluidity

Microstructure and Properties of SemisolidA356 Alloy Strip Affected by Nozzle Temperature of a Novel Micro Fused-Casting

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Journal of Wuhan University of Technology(Materials Science) 2020年第3期35卷 653-657页

作者： luo xiaoqiang LI Qingbin XUE Lingwei LI Yanling HAN Yongjun ZHOU Yanbiao Henan Key Laboratory of Research for Central Plains Ancient Ceramics Pingdingshan UniversityPingdingshan 467000China .Insti-tute of Mechanics Chinese Academy of SciencesBeijing 100190China

The semisolid A356 alloy strip was prepared by a novel continuous micro fused-casting process. The microstructure evolution and mechanical property of A356 aluminum alloy strip with different nozzle temperatures were investigated. The nozzle temperature had great influences on the microstructure and property primarily accompanied with the crystal change in the fused-casting area through the cooling conditions. The results showed that the semisolid A356 alloy strip samples fabricated by micro fused-casting demonstrated good performances and uniform structures with the nozzle temperature at 593 ℃ and the stirring velocity at 700 r/min. The fine grains of the primary α-Al phase with average grain size of 51 μm and shape factor up to 0.71 were obtained under the micro fused-casting process, and the ultimate average vickers hardness came up to 83.39±0.89 HV, and the tensile strength and elongation of the A356 alloy strip reached 245.32 MPa and 7.85%, respectively.

关键词： semisolid A356 aluminum alloy nozzle temperature micro fused-casting

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Ding-内射模的函子伴随性

浙江大学学报（理学版） 2018年第5期45卷 529-532,544页

作者：罗肖强四川文理学院数学学院四川达州635000

主要研究了Ding-内射模以及有有限内射维数的模类的逼近,构造了Ding-内射模范畴对应的稳定范畴之间的两对伴随函子.

关键词： Ding-内射模稳定范畴伴随函子

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基于交往空间功能测度的城市路网间距研究

规划师 2012年第S2期28卷 22-25,29页

作者：罗小强蔡辉长安大学

基于城市道路的空间交往功能与道路网间距的关系分析,结合城市规划、环境心理和城市交通等方面,以实际调查、统计分析为基本手法,建立道路上常见的漫游、逗留等生活性行为,以及途经、出发或到达等交通性行为与路网间距之间的关系模型,... 详细信息

基于城市道路的空间交往功能与道路网间距的关系分析,结合城市规划、环境心理和城市交通等方面,以实际调查、统计分析为基本手法,建立道路上常见的漫游、逗留等生活性行为,以及途经、出发或到达等交通性行为与路网间距之间的关系模型,对道路活力与空间尺度间的制约关系进行量化分析与论证。研究表明:当道路间距在2 0 0 m以内时,较易形成具有浓郁生活气息的空间环境;当道路间距大于6 5 0 m后,则较难形成对人类空间交往需求的支持。

关键词：城市道路路网间距交往空间