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Properties of Cross-Rolled Low Alloy White Cast Iron Grinding Ball

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Journal of Iron and Steel Research International 2007年第5期14卷 47-51页

作者： chang Li-min LIU Lin LIU Jian-hua Analysis and Measure Center Jilin Normal University Siping 136000 Jilin China Department of Basic Medical Tangshan Vocational Technology College Tangshan 063000 Hebei China State Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao 066004 Hebei China

The low-energy, multi-impact fracture resistance and the abrasiveness of the cross-rolled low alloy white cast iron grinding balls were studied after heat treatments at residual rolling temperature. Moreover, the means by which they are damaged and characters of the wear surface were analyzed. The results show that high resistance to impact fracture and high abrasiveness can be achieved after appropriate heat treatment at residual rolling temperature. This kind of heat treatment technology has several advantages under low impact and hard abrasive. These results are very useful for determining the optimized heat treatment technology at residual rolling temperatures.

关键词： low alloy white cast iron grinding ball cross rolling impact fracture resistance abrasiveness

Development of micro milling force model and cutting parameter optimization

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中国有色金属学会会刊：英文版 2012年第S3期22卷 851-858页

作者： Shih-ming WANG Da-fun CHEN min-chang JANG Shambaljamts TSOOJ Department of Mechanical Engineering Chung Yuan Christian University

Taking the minimum chip thickness effect,cutter deflection,and spindle run-out into account,a micro milling force model and a method to determine the optimal micro milling parameters were *** micro milling force model was derived as a function of the cutting coefficients and the instantaneous projected cutting area that was determined based on the machining parameters and the rotation trajectory of the cutter *** an allowable micro cutter deflection is defined,the maximum allowable cutting force can be *** optimal machining parameters can then be computed based on the cutting force model for better machining efficiency and *** verify the proposed cutting force model and the method to determine the optimal cutting parameters,micro-milling experiments were conducted,and the results show the feasibility and effectiveness of the model and method.

关键词： micro-milling cutting force spindle run out cutter deflection optimal parameter

Field released transgenic papaya effect on soil microbial communities and enzyme activities

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Journal of Environmental Sciences 2006年第4期18卷 734-740页

作者： WEI Xiang-dong ZOU Hui-ling CHU Lee-min LIAO Bin YE chang-min LAN Chong-yu School of Life Sciences Sun Yat-sen University Guangzhou 510275 China Department of Biology The Chinese University ofHong Kong Shatin Hong Kong China

Soil properties, microbial communities and enzyme activities were studied in soil amended with replicase （RP）-transgenic or non-transgenic papaya under field conditions. Compared with non-transgenic papaya, significant differences （P〈0.05） were observed in total nitrogen in soils grown with transgenic papaya. There were also significant differences （P〈0.05） in the total number of colony forming units （CFUs） of bacteria, actinomycetes and fungi between soils amended with RP-transgenic plants and non-transgenic plants. Compared with non-transgenic papaya, the total CFUs of bacteria, actinomycetes and fungi in soil with transgenic papaya increased by 0.43-1.1, 0.21-0.80 and 0.46-0.73 times respectively. Significantly higher （P〈0.05） CFUs of bacteria, actinomycetes and fungi resistant to kanamycin （Km） were obtained in soils with RP-transgenic papaya than those with non-transgenic papaya in all concentrations of Km. Higher resistance quotients for Km＇（kanamycin resistant） bacteria, actinomycetes and fungi were found in soil planted with RP-transgenic papaya, and the resistance quotients for Km＇ bacteria, actinomycetes and fungi in soils with transgenic papaya increased 1.6-4.46, 0.63-2.5 and 0.75-2.30 times. RP-transgenic papaya and non-transgenic papaya produced significantly different enzyme activities in arylsulfatase （5.4-5.9x）, polyphenol oxidase （0.7-1.4x）, invertase （0.5-0.79x）, cellulase （0.23-0.35x） and phosphodiesterase （0.16-0.2x）. The former three soil enzymes appeared to be more sensitive to the transgenic papaya than the others, and could be useful parameters in assessing the effects of transgenic papaya. Transgenic papaya could alter soil chemical properties, enzyme activities and microbial communities.

关键词： transgenic papaya soil microbes enzyme activity kanamycin resistance resistance quotient

minimizing pest aluminum in magnesium for the production of high-purity titanium

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Journal of Magnesium and Alloys 2023年第11期11卷 4189-4196页

作者： Bo Yang Rui Zheng Ge Wu Zhi-min chang Zhi-Wei Shan Engineering Research Center for Magnesium-based New Materials Center for Advancing Materials Performance from the Nanoscale(CAMP-Nano)State Key Laboratory for Mechanical Behavior of MaterialsXi’an Jiaotong UniversityXi’an 710049PR China

It is practically difficult to find titanium sponges with low and stable aluminum impurities on the market even though it is the precondition to prepare high-purity titanium. Analysis indicates that almost all the aluminum impurities in the titanium sponge are inherited from the magnesium used to reduce titanium tetrachloride. However, it remains elusive for decades why magnesium produced through the silicothermic reduction method contains a high content of aluminum impurities with large fluctuations. By recourse to thermodynamic calculations and comparative experiments, we demonstrate that fluorite, a material used as a catalyst in the silicothermic reduction method to produce magnesium, is the chief culprit for the pest aluminum and propose a mechanism to rationalize the observed phenomena. Our findings indicate that one practical way to produce qualified magnesium for the production of high-purity titanium is to abandon fluorite during the production of magnesium with the silicothermic reduction method.

关键词： High-purity titanium Titanium sponge Magnesium Aluminum impurity Silicothermic reduction

Unique MicroRNAs Signature of Lymphocyte of Yang and Yin Syndromes in Acute Ischemic Stroke Patients

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Chinese Journal of Integrative Medicine 2019年第8期25卷 590-597页

作者： ZHAO Hai-ping LIU Ping XU chang-min LI Guang-wen GAO Li LUO Yu-min Cerebrovascular Diseases Research Institute and Department of Neurology Xuanwu Hospital of Capital Medical University Beijing (100053)China Beijing Geriatric Medical Research Center Beijing (100053)China Beijing Institute for Brain Disorders Beijing (100053)China Key Laboratory of Neurodegenerative Diseases of ministry of Education and Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases Beijing (100053)China

Objective: To identify the differentially expressed microRNAs (miRNAs) profiles of yang and yin syndromes in patients with acute ischemic stroke, and to provide the molecular basis of the classification of these two syndrome types in acute ischemic stroke patients. Methods: A microarray assay was performed to assess the expression pattern of miRNAs in the lymphocyte of acute ischemic stroke patients. Target genes for the deregulated miRNAs were predicated using the online bioinformatic algorithms and functional annotation via Kyoto encyclopedia of genes and genomes pathway analysis for miRNAs predicted targets was carried out. Based on the predicted target genes of differentially expressed miRNAs, the miRNA-gene-network and miRNA-pathway network were constructed. Results: Yang score based on tongue texture, urine, dejecta, and appearance, etc. showed that clinical symptoms were distinct between yang and yin syndromes. There were significantly higher total leukocyte number and lower total protein level in patients with yang syndrome compared with those in patients with yin syndrome (P<0.05). Comprehensive miRNA analysis identified 36 unique down-regulated miRNAs in yang syndrome group, and 20 unique down-regulated and 2 unique up-regulated miRNAs in yin syndrome group. The key regulatory miRNAs, gene, and pathways in the yang syndrome were hsa-miR-93-5p and -320b, enabled homolog, the metabolic pathways and mitogen-activated protein kinase signaling pathways, respectively, while those in the yin syndrome were hsa-miR-424-5p and -106b-5p, CNOT4, hepatitis B and pathways in cancer, respectively. Conclusion: These results offered insight into the molecular basis underlying the different pathogenesis of yang or yin syndrome, providing clues for the individualized therapeutic strategies of acute ischemic stroke.

关键词： acute ischemic stroke yang syndrome yin syndrome microRNAs profile diagnosis Chinese medicine

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航空发动机燃油系统定压活门参数优化设计

航空发动机 2024年第2期50卷 134-138页

作者：王涛柴文伟罗畅敏李文强叶志锋南京航空航天大学能源与动力学院南京210016 中国航发贵州红林航空动力控制科技有限公司贵阳550009

定压活门在燃油系统中为多个伺服机构供油,针对其稳定性、稳态精度、鲁棒性等设计要求,以及多个设计参数相互竞争又相互矛盾的选择,提出了一种基于优化算法的参数设计方法。建立了定压活门数学模型,基于稳态模型进行了参数设计分析。结... 详细信息

定压活门在燃油系统中为多个伺服机构供油,针对其稳定性、稳态精度、鲁棒性等设计要求,以及多个设计参数相互竞争又相互矛盾的选择,提出了一种基于优化算法的参数设计方法。建立了定压活门数学模型,基于稳态模型进行了参数设计分析。结果表明:定压活门存在流量稳态工作区,在流量稳态工作区内,阀芯截面积增大,流量敏感度增大,但阀芯截面积过大会增大定压活门的体积。根据定压活门压力范围计算了稳态参数,以调节时间和超调量为目标,取3组不同定压腔容积,将弹簧腔容积、阻尼孔径、运动阻尼、阀芯质量作为参数,基于非支配排序遗传算法(NSGA-Ⅱ)进行了动态优化。Pareto解集表明调节时间和超调量相互矛盾。选取1组解经AMESim仿真验证,优化后的结构参数能够使调节时间缩短20%以上,超调量降低15%以上,定压活门动态性能得到改善。

关键词：定压活门状态空间模型多目标优化非支配排序遗传算法燃油系统航空发动机

Review of MXenes as new nanomaterials for energy storage/delivery and selected environmental applications

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Nano Research 2019年第3期12卷 471-487页

作者： Byung-Moon Jun Sewoon Kim Jiyong Heo chang min Park Namguk Her min Jang Yi Huang Jonghun Han Yeomin Yoon Department of Civil and Environmental Engineering University of South Carolina Columbia 300 Main Street SC 29208 USA Department of Civil and Environmerttal Engineering Korea Army Academy at Young-Cheon 495 Hogook-ro Kokyungmeon Young-Cheon Gyeongbuk 38900 Republic of Korea Department of Environmental Engineering Kyungpook National University 80 Daehak-ro Buk-gu Daegu 41566 Republic of Korea Department of Environmental Engineering Kwangwoon University 447-1 Wolgye-Dong Nowon-Gu Seoul 01897 Republic of Korea School of Engineering Institute for Materials & Processes (IMP) The University of Edinburgh Colin Maclaurin Road Edinburgh EH9 3DW Scotland UK

Energy and environmental issues presently attract a great deal of scientific attention. Recently, two-dimensional MXenes and MXene-based nanomaterials have attracted increasing interest because of their unique properties (e.g., remarkable safety, a very large interlayer spacing, environmental flexibility, a large surface area, and thermal conductivity). In 2011, multilayered MXenes (Ti3C2Tx, a new family of two-dimensional (2D) materials) produced by etching an A layer from a MAX phase of Ti3AlC2, were first described by researchers at Drexel University. The term “MXene” was coined to distinguish this new family of 2D materials from graphene, and applies to both the original MAX phases and MXenes fabricated from them. We present a comprehensive review of recent studies on energy and environmental applications of MXene and MXene-based nanomaterials, including energy conversion and storage, adsorption, membrane, photocatalysis, and antimicrobial. Future research needs are discussed briefly with current challenges that must be overcome before we completely understand the extraordinary properties of MXene and MXene-based nanomaterials.

关键词： MXenes MXene-based nanomaterials energy storage environment applications

Basic study on contour tracing method in softwood cell contour extraction

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Forestry Studies in China 2009年第2期11卷 127-131页

作者： ZHOU Xu chang Jian-min College of Materials Science and Technology Beijing Forestry University Beijing 100083 P. R. China

The application of digital image analysis to calculate the parameters of softwood cells and to understand their microstructure is of importance in the area of basic micro-wood research such as wood anatomy. In order to obtain cell parameters, the most important part is to separate the cells from their background in an image, which is accomplished by drawing cell contours. In this study, a contour tracing method based on digital image binarization is introduced to extract the contours of softwood cells. As well, a comparison with other traditional methods is included. The results show that using this contour tracing method, clear and complete contours can be obtained, which solves the problems of traditional methods where sharp comers and turning points in an image could not be addressed.

关键词： softwood binarization contour tracing

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鸭肝油脂提取工艺优化及其品质分析

粮食与油脂 2024年第7期37卷 17-23页

作者：叶双双刘安琪肖骏王殿勤苑博华常世敏河北工程大学生命科学与食品工程学院河北邯郸056038 邯郸市天然产物与功能食品开发重点实验室河北邯郸056038 河北乐寿鸭业有限责任公司河北沧州062250

探究粗制鸭肝油脂的最佳提取工艺,考察精炼工艺主要参数对鸭肝油脂精炼效果的影响,并分析精炼过程中脂肪酸组成及含量变化。结果表明:最优提取工艺为料液比4∶1(g/mL)、无水乙醇与正己烷体积比1∶1、超声温度50℃、超声时间30 min,在此... 详细信息

探究粗制鸭肝油脂的最佳提取工艺,考察精炼工艺主要参数对鸭肝油脂精炼效果的影响,并分析精炼过程中脂肪酸组成及含量变化。结果表明:最优提取工艺为料液比4∶1(g/mL)、无水乙醇与正己烷体积比1∶1、超声温度50℃、超声时间30 min,在此条件下,鸭肝油脂提取率55.74%;最佳精炼工艺为脱胶水添加量(以粗制鸭肝油脂质量计)10%、脱酸超碱量(以脱胶油质量计)0.6%、活性白土用量(以脱酸油质量计)10%、真空脱臭2.0 h。精炼后油脂的酸价为1.17 mg/g,过氧化值为0.1538 g/100 g;鸭肝油脂中共检测出16种脂肪酸,其中饱和脂肪酸5种,单不饱和脂肪酸4种,多不饱和脂肪酸7种。

关键词：鸭肝油脂提取超声辅助提取脂肪酸组成