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Anisotropy in mechanical properties and corrosion resistance of 316L stainless steel fabricated by selective laser melting 预览
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作者 Xiao-qing Ni De-cheng Kong +5 位作者 Ying Wen Liang Zhang Wen-heng Wu Bei-bei He Lin Lu De-xiang Zhu 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2019年第3期319-328,共10页
The corrosion behavior and mechanical properties of 316L stainless steel (SS) fabricated via selective laser melting (SLM) were clarified by potentiodynamic polarization measurements, immersion tests, and tensile expe... The corrosion behavior and mechanical properties of 316L stainless steel (SS) fabricated via selective laser melting (SLM) were clarified by potentiodynamic polarization measurements, immersion tests, and tensile experiments. The microstructural anisotropy of SLMed 316L SS was also investigated by electron back-scattered diffraction and transmission electron microscopy. The grain sizes of the SLMed 316L SS in the XOZ plane were smaller than those of the SLMed 316L SS in the XOY plane, and a greater number of low-angle boundaries were present in the XOY plane, resulting in lower elongation for the XOY plane than for the XOZ plane. The SLMed 316L was expected to exhibit higher strength but lower ductility than the wrought 316L, which was attributed to the high density of dislocations. The pitting potentials of the SLMed 316L samples were universally higher than those of the wrought sample in chloride solutions because of the annihilation of MnS or (Ca,Al)-oxides during the rapid solidification. However, the molten pool boundaries preferentially dissolved in aggressive solutions and the damage of the SLMed 316L in FeCl3 solution was more serious after long-term service, indicating poor durability. 展开更多
关键词 selective laser MELTING mechanical property corrosion resistance 316L STAINLESS steel ANISOTROPY MOLTEN POOL boundary
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Comparative Study of Isolated Polysaccharides from Triploid Poplar Using Different Solvents and Chemicals 预览
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作者 YingYing Chai Ning Zhao +2 位作者 YunShan Ju QingTao Fan Kun Wang 《造纸与生物质材料:英文版》 2019年第1期7-16,共10页
The conversion of lignocellulose to value-added products is normally focused on fuel production;however,large-scale biorefineries require a cost-effective pretreatment process that can effectively fractionate the thre... The conversion of lignocellulose to value-added products is normally focused on fuel production;however,large-scale biorefineries require a cost-effective pretreatment process that can effectively fractionate the three main constituents of lignocellulose for the production of chemicals,fuels,and materials.In this study,a hemicellulosic biopolymer from poplar was fractionated by a mild organosolv process and the effects of various chemicals(sodium hydroxide,triethylamine,and formic acid)and alcohols on the fractionation efficiency and structural variation of hemicellulose were examined.Comparative studies indicated that an acidic catalyst decreased the purity of hemicelluloses by partial degradation of cellulose,and the core of the hemicellulosic biomacromolecule could be released and dissolved under alkaline conditions with 5.8%~19.0%yields.In addition,the use of alcohol with longer alkyl chains facilitated the release of the hemicellulosic biomacromolecule by partially cleaving the ether bonds in the lignincarbohydrate complex(LCC);this is probably due to steric hindrance.The thermal degradation behavior showed that complete pyrolysis was easily achieved for the hemicellulosic polymer with minimal branches irrespective of its molecular weight. 展开更多
关键词 ORGANOSOLV FRACTIONATION BIOREFINERY hemicelluloses thermal property
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莎士比亚喜剧中的孤女童话
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作者 张佳 《赤峰学院学报:汉文哲学社会科学版》 2019年第1期110-113,共4页
戏剧奇才莎士比亚在为婚恋喜剧创作女主人公的时候多次选用孤女的形象,赋予她们的身份横跨贵族、中产和平民等各个社会阶层。尽管家世、性情不尽相同,这些女性在追求个人婚姻幸福时大都顺利扫除障碍,获得了童话般完美的结局。本文将围... 戏剧奇才莎士比亚在为婚恋喜剧创作女主人公的时候多次选用孤女的形象,赋予她们的身份横跨贵族、中产和平民等各个社会阶层。尽管家世、性情不尽相同,这些女性在追求个人婚姻幸福时大都顺利扫除障碍,获得了童话般完美的结局。本文将围绕《威尼斯商人》《第十二夜》《无事生非》和《终成眷属》这四部剧中孤女主人公的人物设计,探讨家世和性情与她们命运发展的关联性,并结合时代背景分析莎士比亚善待孤女的“仙女教母”情趣对此类主题创作的意义。 展开更多
关键词 孤女 家世 财产 父权
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Development and application of the multi-wavelength cavity ring-down aerosol extinction spectrometer
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作者 Junling Li Weigang Wang +3 位作者 Kun Li Wenyu Zhang Maofa Ge Chao Peng 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第2期227-237,共11页
To better characterize the optical properties of atmospheric aerosols, the multi-wavelength cavity ring-down aerosol extinction spectrometer (MCRD-AES) is developed and applied in this study. By using tunable light so... To better characterize the optical properties of atmospheric aerosols, the multi-wavelength cavity ring-down aerosol extinction spectrometer (MCRD-AES) is developed and applied in this study. By using tunable light source and four parallel cavities, the MCRD-AES covers a wide and atmospherically relevant wavelength range from 360 to 663nm. Four wavelengths (375nm, 440nm, 532nm, and 620nm) are particularly tested with ammonium sulfate and nigrosine. The refractive index values obtained from this study agree well with literature data. The stability and accuracy of the MCRD-AES are tested, and the minimum detectable extinction coefficient is 0.5 1/Mm. The high sensitivity, high precision, and wavelength changeable of MCRD-AES indicate its great application prospect in comprehensively quantifying the optical properties of atmospheric aerosols. 展开更多
关键词 MCRD-AES Optical PROPERTY Refractive indices WAVELENGTH DEPENDENCE
Soil Erodibility and Physicochemical Properties of Collapsing Gully Alluvial Fans in Southern China
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作者 DENG Yusong SHEN Xue +3 位作者 XIA Dong CAI Chongfa DING Shuwen WANG Tianwei 《土壤圈:英文版》 SCIE CAS CSCD 2019年第1期102-113,共12页
In southern China, collapsing gully erosion produces massive deposits of sediment on the plough layer of alluvial fan farmland,leading to reduced nutrients, increased erodibility, and even desertification. The aim of ... In southern China, collapsing gully erosion produces massive deposits of sediment on the plough layer of alluvial fan farmland,leading to reduced nutrients, increased erodibility, and even desertification. The aim of this study was to investigate soil erodibility(the factor K in the Universal Soil Loss Equation, USLE) and physicochemical properties of the alluvial fans of the most severe collapsing gully erosion areas(Hubei, Jiangxi, Fujian, and Guangdong provinces) in southern China. The soils of the collapsing gully alluvial fans had a higher bulk density, but a lower total porosity, saturated water content, and silt and clay fractions than the control(CK) soils from the farmland without desertification. Soil quality gradually decreased from fan edge to fanhead. Significant decreases were found in soil p H, organic matter, cation exchange capacity, and total potassium, nitrogen, and phosphorus, as well as available nitrogen, phosphorus, and potassium, resulting in a gradual decrease in soil nutrients from the fanedge to the fanhead. Soil erodibility was greatest in the fanhead, and soil erodibility K values of the alluvial fans were 53.71%, 66.28%, 67.53%, and 71.68% greater than that in those of the CK soils of Hubei, Jiangxi, Fujian, and Guangdong, respectively, indicating a significant correlation between the soil erodibility K values and physicochemical properties, particularly sand fraction and organic matter content. The results provide new insights into the relationship between soil physicochemical properties and erodibility of alluvial fans, and suggest that improving soil structure might increase soil fertility in the collapsing gully alluvial fan farmland. 展开更多
关键词 SOIL erosion SOIL FERTILITY SOIL property SOIL quality SOIL structure
Electronic structures and optical properties of Si-and Sn-doped β-Ga2O3: A GGA+U study
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作者 党俊宁 郑树文 +1 位作者 陈浪 郑涛 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第1期502-510,共9页
The electronic structures and optical properties of β-Ga2O3 and Si-and Sn-doped β-Ga2O3 are studied using the GGA + U method based on density functional theory. The calculated bandgap and Ga 3d-state peak of β-Ga2O... The electronic structures and optical properties of β-Ga2O3 and Si-and Sn-doped β-Ga2O3 are studied using the GGA + U method based on density functional theory. The calculated bandgap and Ga 3d-state peak of β-Ga2O3 are in good agreement with experimental results. Si-and Sn-doped β-Ga2O3 tend to form under O-poor conditions, and the formation energy of Si-doped β-Ga2O3 is larger than that of Sn-doped β-Ga2O3 because of the large bond length variation between Ga–O and Si–O. Si-and Sn-doped β-Ga2O3 have wider optical gaps than β-Ga2O3, due to the Burstein–Moss effect and the bandgap renormalization effect. Si-doped β-Ga2O3 shows better electron conductivity and a higher optical absorption edge than Sn-doped β-Ga2O3, so Si is more suitable as a dopant of n-type β-Ga2O3, which can be applied in deep-UV photoelectric devices. 展开更多
关键词 density functional theory GGA + U method Si-doped β-Ga2O3 Sn-doped β-Ga2O3 electronic structure OPTICAL property
气体氮碳共渗中NH3和CO流量对低碳钢渗层组织及其性能的影响
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作者 徐强 洪悦 +1 位作者 李楠 伍翠兰 《材料导报》 EI CAS CSCD 北大核心 2019年第2期330-334,341共6页
通过调控气体氮碳共渗过程中的NH 3和CO流量来调控气氛中的氮化势和碳势,从而调控共渗层的微观组织和性能。采用扫描电镜、X射线衍射仪、显微硬度计和电化学分析仪研究了气体氮碳共渗过程中的NH 3和CO流量对低碳钢氮碳共渗层的微观组织... 通过调控气体氮碳共渗过程中的NH 3和CO流量来调控气氛中的氮化势和碳势,从而调控共渗层的微观组织和性能。采用扫描电镜、X射线衍射仪、显微硬度计和电化学分析仪研究了气体氮碳共渗过程中的NH 3和CO流量对低碳钢氮碳共渗层的微观组织结构及其性能的影响。研究结果表明:气体氮碳共渗气氛中,随着NH 3流量的增加,化合物层厚度增大但致密性降低;随着CO流量的增加,化合物层致密性逐渐增大,但渗层厚度先增大后减小。氮碳共渗过程中C的加入可抑制γ′相的形成而促进ε相的产生,过量的C会形成θ相,但是C的渗入对渗层腐蚀性能影响较小。NH 3和CO对氮碳共渗过程中的协同作用表现为,当NH 3流量增加时,可相应增加CO流量来获得较厚、致密、耐腐蚀的化合物层。 展开更多
关键词 气体氮碳共渗 化合物层 相变 微观组织 性能
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改性羟基磷灰石制备及除氟特性研究 预览
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作者 胡家朋 刘瑞来 +3 位作者 林皓 赵瑨云 饶瑞晔 吴代赦 《人工晶体学报》 EI CAS 北大核心 2019年第1期81-89,100共10页
为了提高羟基磷灰石(HAP)的除氟容量,利用羟基铝(Al-OH)改性HAP制备羟基铝-羟基磷灰石复合材料(Al-OH-HAP),通过红外光谱(FTIR)、扫描电镜(SEM)、X-射线粉末衍射(XRD)和N2吸附-脱附曲线等方法对样品进行表征分析,结合吸附热力学和动力... 为了提高羟基磷灰石(HAP)的除氟容量,利用羟基铝(Al-OH)改性HAP制备羟基铝-羟基磷灰石复合材料(Al-OH-HAP),通过红外光谱(FTIR)、扫描电镜(SEM)、X-射线粉末衍射(XRD)和N2吸附-脱附曲线等方法对样品进行表征分析,结合吸附热力学和动力学模型拟合,探讨Al-OH-HAP对水溶液氟离子的吸附特性。实验结果表明:Al-OH改性后Al3+和OH-进入HAP晶格中,且改性后HAP的衍射峰更尖锐,结晶度增大。Al-OH改性后HAP的比表面积分别从106.75m2/g增加到220.45m2/g,且大部分孔为介孔结构。吸附拟合模型表明Al-OH-HAP对氟离子的吸附更加遵循Langmuir模型,说明Al-OH-HAP对F-的吸附更趋近于单层吸附,吸附过程中化学吸附占主导地位。热力学参数吸附吉布斯自由能(ΔGo)小于0、焓变(ΔHo)和熵变(ΔSo)大于0,说明Al-OH-HAP对F-的吸附是一个自发吸热的熵增过程,Al-OH-HAP对F-的吸附更符合拟二级反应动力学过程。Al-OH-HAP可以成为一种有潜力的饮用水除氟剂。 展开更多
关键词 羟基磷灰石 改性 除氟 特性
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多主元高熵合金组织性能及塑性变形的研究进展
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作者 李美艳 张琪 +1 位作者 韩彬 王稼林 《材料热处理学报》 EI CAS CSCD 北大核心 2019年第1期1-8,共8页
多主元高熵合金因其高的混合熵倾向于形成具有简单结构固溶体,具备优异的耐磨性能、耐腐蚀性能及力学性能的同时,还具备良好的塑韧性,其塑性变形行为及变形机制受到广泛关注。本文论述了高熵合金组织结构、力学性能、摩擦磨损性能及耐... 多主元高熵合金因其高的混合熵倾向于形成具有简单结构固溶体,具备优异的耐磨性能、耐腐蚀性能及力学性能的同时,还具备良好的塑韧性,其塑性变形行为及变形机制受到广泛关注。本文论述了高熵合金组织结构、力学性能、摩擦磨损性能及耐腐蚀性能,对比阐述了高熵合金在准静态及动态变形条件下的塑性变形性能、变形机制及晶粒细化机制方面的研究现状,最后指出了高熵合金塑性变形行为研究中尚存在的问题并展望了塑性变形理论的研究方向,为扩展高熵合金的应用领域提供参考。 展开更多
关键词 高熵合金 组织 性能 塑性变形 晶粒细化
球磨研磨对荞麦淀粉结构及性质的影响 预览
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作者 郎双静 王立东 《农产品加工》 2019年第4期4-8,共5页
为探究球磨研磨对荞麦淀粉颗粒结构及性质的影响,采用激光粒度分析仪、扫描电子显微镜、X-射线衍射仪、差示扫描量热仪、快速黏度分析仪等先进仪器及分析手段研究球磨处理前后荞麦淀粉颗粒大小及分布、颗粒形貌、晶体结构、热力学性质... 为探究球磨研磨对荞麦淀粉颗粒结构及性质的影响,采用激光粒度分析仪、扫描电子显微镜、X-射线衍射仪、差示扫描量热仪、快速黏度分析仪等先进仪器及分析手段研究球磨处理前后荞麦淀粉颗粒大小及分布、颗粒形貌、晶体结构、热力学性质及糊化特性的变化。结果表明,球磨研磨处理后淀粉颗粒粒径增大,平均径由11.99μm增大到18.52μm,粒径分布主要集中在10.0~45.0μm范围内;颗粒形貌由光滑颗粒变成粗糙不均颗粒,颗粒呈扁平状,颗粒晶体结构受到严重破坏,由多晶态向无定形态转变;淀粉热焓值及糊化温度下降,黏度值降低,球磨研磨荞麦淀粉具有良好的冷糊及热糊稳定性,可应用到高浓低黏体系中。研究为荞麦淀粉物理改性及技术应用提供理论指导和技术支撑。 展开更多
关键词 球磨研磨 荞麦淀粉 结构 性质
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Optimizing mechanical property and cytocompatibility of the biodegradable Mg-Zn-Y-Nd alloy by hot extrusion and heat treatment
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作者 Yiyuan Kang Beining Du +5 位作者 Yueming Li Baojie Wang Liyuan Sheng Longquan Shao Yufeng Zheng Tingfei Xi 《材料科学技术学报:英文版》 SCIE EI CAS CSCD 2019年第1期6-18,共13页
The Mg-Zn-Y-Nd alloy is a new type of degradable material for biomedical application. In the present study, Mg-6Zn-1.2Y-0.8Nd alloy was fabricated, and then extrusion and heat treatment were conducted to optimize its ... The Mg-Zn-Y-Nd alloy is a new type of degradable material for biomedical application. In the present study, Mg-6Zn-1.2Y-0.8Nd alloy was fabricated, and then extrusion and heat treatment were conducted to optimize its mechanical properties and cytocompatibility. The microstructure observation, mechanical property, degradation behavior and cytocompatibility tests were conducted on the Mg-Zn-Y-Nd alloy with three different states: as-cast(alloy C), as-extruded(alloy E) and extruded + heat treated(alloy EH).The results show that alloy C consists of coarse grains and continuous secondary phases. The extrusion process has caused incomplete recrystallization, and results in a mixed grain structure of elongated grains and small equiaxed grains(alloy E). The heat treatment process has promoted the recrystallization and homogenized the grain structure(alloy EH). Both the strength and ductility of the alloy has been improved by extrusion, but the following heat treatment has decreased the strength and increased the ductility.The degradation behavior of the alloy C and E alloys does not show much difference, but improves slightly in alloy EH, because the heat treatment has homogenized the microstructure and released the residual stress in the alloy. The directly and indirectly cell viability tests indicate that alloy EH exhibits the best cytocompatibility, which should be ascribed to its relative uniform degradation and low ion releasing rate. In summary, the combination of hot extrusion and heat treatment could optimize the mechanical property and cytocompatibility of the Mg-Zn-Y-Nd alloy together, which is beneficial for the future application of the alloy. 展开更多
关键词 Mg-Zn-Y-Nd ALLOY Microstructure Mechanical property BIODEGRADABLE behavior Biocompatibility
机械合金化制备具有纳米相复合结构的互不溶体系轴承合金的研究进展
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作者 吴志方 张磊 +1 位作者 吴江 刘超 《粉末冶金工业》 CAS 北大核心 2019年第1期63-68,共6页
机械合金化制备的具有纳米相复合结构的互不溶体系轴承合金表现出与其微米尺度结构合金所不同的性能。综述了机械合金化制备的具有纳米相复合结构的互不溶体系轴承合金的研究进展,着重介绍了轴承合金的组织和性能要求、具有纳米相复合... 机械合金化制备的具有纳米相复合结构的互不溶体系轴承合金表现出与其微米尺度结构合金所不同的性能。综述了机械合金化制备的具有纳米相复合结构的互不溶体系轴承合金的研究进展,着重介绍了轴承合金的组织和性能要求、具有纳米相复合结构的互不溶体系轴承合金的机械合金化制备和性能。 展开更多
关键词 机械合金化 纳米相复合结构 互不溶体系轴承合金 性能
生物基苯并噁嗪的来源及性能研究进展
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作者 楼永坚 赵忠祥 +2 位作者 蔡东荣 付飞亚 刘向东 《浙江理工大学学报》 2019年第1期29-36,共8页
苯并噁嗪树脂作为一类新型热固性树脂,具有低收缩率、低介电常数、低吸水性和灵活分子设计性等独特性能,受到学术界和工业上极大关注。在石油资源逐渐枯竭和全球性气候变暖的背景下,以天然可再生原料为基础的生物基苯并噁嗪树脂在原料... 苯并噁嗪树脂作为一类新型热固性树脂,具有低收缩率、低介电常数、低吸水性和灵活分子设计性等独特性能,受到学术界和工业上极大关注。在石油资源逐渐枯竭和全球性气候变暖的背景下,以天然可再生原料为基础的生物基苯并噁嗪树脂在原料来源及性能提升等方面的研究均取得较多进展。文章聚焦于生物基苯并噁嗪树脂的酚类来源,以木质素分解酚类、植物提取酚类、以及生物质衍生酚类三个类别归纳分析近年来生物基苯并噁嗪的研究进展,探究各种生物基苯并噁嗪的结构与性能相关规律,并展望今后生物基苯并噁嗪的研发方向。 展开更多
关键词 生物基苯并噁嗪 酚类来源 合成 性能
LSTM Based Reserve Prediction for Bank Outlets
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作者 Yu Liu Shuting Dong +1 位作者 Mingming Lu Jianxin Wang 《清华大学学报自然科学版(英文版)》 EI CAS CSCD 2019年第1期77-85,共9页
Reserve allocation is a significant problem faced by commercial banking businesses every day.To satisfy the cash requirement of customers and abate the vault cash pressure,commercial banks need to appropriately alloca... Reserve allocation is a significant problem faced by commercial banking businesses every day.To satisfy the cash requirement of customers and abate the vault cash pressure,commercial banks need to appropriately allocate reserves for each bank outlet.Excessive reserve would impact the revenue of bank outlets.Low reserves cannot guarantee the successful operation of bank outlets.Considering the reserve requirement is effected by the past cash balance,we deal the reserve allocation problem as a time series prediction problem,and the Long Short Time Memory (LSTM)network is adapted to solve it.In addition,the proposed LSTM prediction model regards date property,which can affect the cash balance,as a primary factor.The experiment results show that our method outperforms some existing traditional methods. 展开更多
关键词 RESERVE PREDICTION TIME series PREDICTION LONG SHORT TIME Memory (LSTM)network DATE property
刑事诉讼视域下的国家监察机关:定位、性质及其权力配置
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作者 洪浩 《法学论坛》 CSSCI 北大核心 2019年第1期144-153,共10页
随着我国《宪法修正案》《监察法》的公布,我国监察体制改革蓝图业已确立、路径亦逐渐明晰。国家监察委员会作为国家反腐败的专门机构具有位阶高、职权强、覆盖广之属性,与刑事诉讼中的其他主体之间具有较强的互动性、发展性等特色。但... 随着我国《宪法修正案》《监察法》的公布,我国监察体制改革蓝图业已确立、路径亦逐渐明晰。国家监察委员会作为国家反腐败的专门机构具有位阶高、职权强、覆盖广之属性,与刑事诉讼中的其他主体之间具有较强的互动性、发展性等特色。但从2016年试点以来,相关试点单位的改革思路和做法存在差异性;2018年《宪法修正案》虽专章对监察委员会进行了规定,但目前尚未颁行专门的《监察委员会组织法》。理论上,国家监察制度的地位、性质、职权配置等尚需探究和厘清,以指导监察制度改革的进行。在试点中监察机关的职权表现出行政权的特征,同时兼具司法权的色彩;而从《宪法修正案》《监察法》的定位来看,监察机关的职权本质上属于行政权,职能应该定位于一般监督权。为了保证国家监察职权的有效运行,以刑事诉讼为视角,在厘清国家监察制度的定位、性质基础上,对监察委员会权力进行诉讼化配置,极为必要。 展开更多
关键词 国家监察委员会 法律定位 职权性质 权力配置
First Principle Calculation of Electromagnetic Mechanism for Fe2Si Bulk Material
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作者 李瑞杰 CEN Weifu +2 位作者 杨吟野 Lü Lin XIE Quan 《武汉理工大学学报:材料科学英文版》 SCIE EI CAS 2019年第1期64-68,共5页
The electronic structure and the magnetic properties of Fe2Si bulk have been calculated by the first-principle density function theory method. The band structure shows that the hexagonal Fe2 Si bulk is ferromagnetic w... The electronic structure and the magnetic properties of Fe2Si bulk have been calculated by the first-principle density function theory method. The band structure shows that the hexagonal Fe2 Si bulk is ferromagnetic which is a metal structure under spin-up, and a semiconductor with the band gap of 0.518 eV under spin-down. The density of states shows the Fe1 3d–spin and Fe3 3d–spin in the electronic system are the main factors that is the source of the ferromagnetic properties of Fe2Si bulk. The electronic structure Si-ions is 3s23p6 and that of Fe-ions is eg2↑eg*1↓t2g3↑. The molecular magnetic moment of Fe2Si is 2.00 μB. The potential diagram of Fe2Si bulk shows the formation of covalent and ionic bonds between the Fe atom and the Si atom, it leads to the center charge of Fe is polarized and off center position. These special properties of Fe2Si bulk are mainly caused by d-d exchange and p-d hybridization. The results offer a certain reference for the magnetic semiconductor Fe2Si material. 展开更多
关键词 Fe2Si ELECTRONIC STRUCTURE MAGNETIC PROPERTY FIRST-PRINCIPLE
新型链状镍配合物的水热合成及其性质 预览
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作者 张力嫱 王莹 《合成化学》 CAS 北大核心 2019年第2期109-113,共5页
采用水热法合成了一种新型的镍配合物{[Ni(bipy)(H2O)4]·(H2Dhbs)2·(H2O)4}n(H2Dhbs=2,5-二羟基苯磺酸,bipy=4,4′-联吡啶),其结构和性能经FL,IR,元素分析,X-射线单晶衍射和TG表征。结果表明:bipy与镍离子配位,形成链状结构。... 采用水热法合成了一种新型的镍配合物{[Ni(bipy)(H2O)4]·(H2Dhbs)2·(H2O)4}n(H2Dhbs=2,5-二羟基苯磺酸,bipy=4,4′-联吡啶),其结构和性能经FL,IR,元素分析,X-射线单晶衍射和TG表征。结果表明:bipy与镍离子配位,形成链状结构。H2Dhbs^-配体没有参与配位,仅起平衡结构电荷的作用。在结构单元中,[Ni(bipy)(H2O)4]^2+,H2Dhbs^-和自由水分子之间通过氢键连接。与配体相比,配合物的荧光发射峰发生了红移,最大发射峰位于464nm,荧光寿命为2.0817ms。 展开更多
关键词 链状结构 镍配合物 水热合成 晶体结构 性质
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工程机械斜交轮胎蒸汽/氮气硫化工艺探讨 预览
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作者 刘敏 《轮胎工业》 CAS 2019年第3期172-174,共3页
对工程机械斜交轮胎蒸汽/氮气硫化工艺进行试验分析。结果表明:与采用过热水硫化工艺相比,采用蒸汽/氮气硫化工艺后,轮胎硫化时间延长,生产效率无明显优势;可节约能源成本但设备改造成本高,投资回收周期长;蒸汽/氮气硫化成品轮胎的物理... 对工程机械斜交轮胎蒸汽/氮气硫化工艺进行试验分析。结果表明:与采用过热水硫化工艺相比,采用蒸汽/氮气硫化工艺后,轮胎硫化时间延长,生产效率无明显优势;可节约能源成本但设备改造成本高,投资回收周期长;蒸汽/氮气硫化成品轮胎的物理性能、耐久性能和高速性能无明显变化。 展开更多
关键词 工程机械斜交轮胎 蒸汽/氮气硫化工艺 性能
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增材制造适用材料及产品机械性能研究 预览
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作者 陈宏庆 马志勇 +1 位作者 张家彬 骆云龙 《机械制造》 2019年第1期1-6,共6页
对增材制造技术原理和特点进行了介绍,从非金属和金属两方面对增材制造适用材料及其产品机械性能进行了研究,并分析了增材制造产品机械性能变化原因,同时提出了改进机械性能的方法。
关键词 增材制造 材料 产品 性能
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加热温度对无碳化物贝氏体截齿钢组织和性能的影响
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作者 程彦 程巨强 李振飞 《煤矿机械》 北大核心 2019年第2期62-64,共3页
研究了奥氏体化加热温度对贝氏体截齿钢组织和力学性能的影响。实验结果表明,随加热温度的提高,抗拉强度在880℃出现最大值,硬度值随加热温度的提高而下降,冲击值在920℃出现最大值。不同奥氏体化温度加热空冷,贝氏体钢截齿材料的组织... 研究了奥氏体化加热温度对贝氏体截齿钢组织和力学性能的影响。实验结果表明,随加热温度的提高,抗拉强度在880℃出现最大值,硬度值随加热温度的提高而下降,冲击值在920℃出现最大值。不同奥氏体化温度加热空冷,贝氏体钢截齿材料的组织主要为板条状贝氏体铁素体和少量残余奥氏体。贝氏体钢截齿生产时,可根据不同的钎焊焊料,钎焊硬质后的截齿热处理加热温度采用880℃加热或920℃加热,获得力学性能指标抗拉强度Rm=1 330~1 480 MPa,冲击功AKV=75~92J,材料具有良好的强韧性,力学性能能够满足截齿力学性能的要求。 展开更多
关键词 无碳化物贝氏体截齿钢 截齿 奥氏体化温度 组织 性能
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