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China & the World Cultural Exchange 2005年第3期71卷 30-31页

作者： t by rao rao

Microstructure, properties and hot workability of M300 grade maraging steel

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Defence technology（防务技术） 2018年第1期14卷 51-58页

作者： K.V.A.Chakravarthi N.t.B.N.Koundinya S.V.S.Narayana Murty B.Nageswara rao Materials and Mechanical Entity Vikram Sarabhai Space Centre Research scholar Department of Mechanical Engineering K L University Department of Metallurgical Engineering and Materials Science Indian Institute of Technology Department of Mechanical Engineering K L University

this paper presents isothermal uniaxial compression test results of M300 grade maraging steel over a wide range of temperatures(900 e1200℃) and strain rates(0.001 e100 s^(-1)) to examine hot deformability and concurrent microstructural evolution. Processing map is generated and indicated the optimum processing parameters in the temperature range of 1125℃-1200℃ and strain rate range of 0.001 e0.1 s^(-1). High values of the efficiency of power dissipation, microstructural observations and EBSD results indicate softening mechanism to be the occurrence of dynamic recrystallisation. Material constants in a constitutive relation are evaluated from the flow stress data useful in computer modelling.

关键词： Activation energy Constitutive relation Hot deformation M300 grade maraging steel Processing map

Geochemical assessment of a siliceous limestone sample for cement making

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Chinese Journal Of Geochemistry 2011年第1期30卷 33-39页

作者： rao D.S. Vijayakumar t.V. Prabhakar S. Bhaskar Raju G. National Metallurgical Laboratory-Madras Centre CSIR Madras Complex Taramani Chennai-600 113 India

A low grade siliceous limestone sample from the Jayantipuram mine of Andhra Pradesh, India, has been investigated for its suitability for cement making. Petrological as well as X-ray diffraction pattern studies indicated that the limestone sample was crystalline and dominantly composed of calcite and quartz. they are simple in mineralogy, and yet they have variable silica and lime contents. Geochemical analysis results of twenty five hand picked samples indicated that the limestone from the Jayantipuram mine shows a wide range of variations in LOI (29.94% to 40.64%), SiO2 (6.14% to 27.18%), CaO (37.93% to 50.78%), Al2O3 (0.49% to 2.27%) and Fe2O3 (0.28% to 2.4%). MgO, K2O, Na2O, tiO2 and MnO2 are present in traces. CaO with LOI shows a strong positive correlation where as CaO with SiO2 shows a strong negative correlation because of mineralogical factors. the chemical composition of the limestone reflects its mineralogical composition. the distribution of various elements in the acid-soluble fraction has been studied by the factor analysis method in order to interpret in terms of their mineralogy, sedimentary environment and diagenesis. Mineralogy, recrystallization and other diagenetic changes are the main factors affecting the distribution of the elements and their mutual relationships in the limestone. the aim of this paper is also to analyze how significantly the two parameters, silica modulus and lime saturation factor, influence this low grade siliceous limestone sample from the Jayantipuram mine of Andhra Pradesh, India, for the cement making process from the geochemical data.

关键词：灰岩样品水泥生产地球化学硅质石灰石矿评估因子分析方法化学数据处理

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ZrV2O7的热膨胀和非简谐振动

硅酸盐学报 2009年第5期37卷 696-702页

作者： SAKUNtALA t[印度] ARORA A K[印度] rao Rekha[印度] 印度巴巴原子研究中心高压物理部孟买400085 英迪拉甘地原子研究中心材料科学部马德拉斯603102

因零膨胀材料在工程上的潜在应用,近10多年来,对材料的热膨胀特性得以深入了解。本文对ZrW2O8的负热膨胀现象的研究进展进行了简要回顾,并特别指出理解非简谐振动的重要性。讨论了ZrV2O7的声子特性和非简谐振动,其负热膨胀的高温相和具... 详细信息

因零膨胀材料在工程上的潜在应用,近10多年来,对材料的热膨胀特性得以深入了解。本文对ZrW2O8的负热膨胀现象的研究进展进行了简要回顾,并特别指出理解非简谐振动的重要性。讨论了ZrV2O7的声子特性和非简谐振动,其负热膨胀的高温相和具有正的热膨胀的低温相特征。此外,还比较了ZrV2O7和ZrW2O8的热膨胀特性。

关键词：热膨胀 Raman光谱学非简谐振动釩酸锆钨酸锆

Microstructure and mechanical properties of friction stir welded AA7075-t651 aluminum alloy thick plates

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transactions of Nonferrous Metals Society of China 2015年第6期25卷 1770-1778页

作者： t.SRINIVASA rao G.MADHUSUDHAN REDDY S.R.KOtESWARA rao Department of Mechanical Engineering Tagore Engineering College Metal Joining Group Defense Metallurgical Research Laboratory Department of Mechanical Engineering SSN College of Engineering

Friction stir butt welding of AA7075-t651 plates with thicknesses of 10 and 16 mm was investigated. Defect-free, full- penetration welds were obtained after careful process parameter selection. While the nuggets in both welds exhibited very fine reerystallized grains, and finer grains were observed in welds made on 10 mm thick plates. Microhardness surveys revealed that significant loss in hardness occurs in the heat-affected zone. the reduction in hardness due to the welding process is higher in the case of welds made on 16 mm thick plates. Welds made on 10 mm thick plates exhibited superior tensile properties compared with those made on 16 mm thick plates. Fracture during tensile test occurred in the heat-affected zone in both cases. tEM images of specimens revealed that the heat-affected zone consisted of widened precipitate-free zones along grain boundaries and partial dissolution of precipitates in the grain interiors. It is concluded that defect-free single pass welds can be made on AA7075-t651 thick plates using friction stir welding and the welds made on 10 mm thick plates exhibit high joint efficiency.

关键词： AA7075-t651 aluminum alloy friction stir welding microstructure mechanical properties

Curcumin encapsulated dual cross linked sodium alginate/montmorillonite polymeric composite beads for controlled drug delivery

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Journal of Pharmaceutical Analysis 2021年第2期11卷 191-199页

作者： O.Sreekanth Reddy M.C.S.Subha t.Jithendra C.Madhavi K.Chowdoji rao Department of Chemistry Sri Krishnadevaraya UniversityAnanthapuramu515003India Department of Polymer Science and technology Sri Krishnadevaraya UniversityAnanthapuramu515003India

the aim of the present work is fabrication of dual cross linked sodium alginate(SA)/montmorillonite(MMt) microbeads as a potential drug vehicle for extended release of curcumin(CUR). the microbeads were prepared using in situ ion-exchange followed by simple ionotropic gelation technique. the developed beads were characterized by Fourier transform infrared spectroscopy(FtIR), differential scanning calorimetry(DSC), thermogravimetric analysis(tGA), X-ray diffraction(X-RD) and scanning electron microscopy(SEM). the effect of MMt on encapsulation efficiency of CUR and intercalation kinetics was investigated. Dynamic swelling study and in vitro release study were investigated in simulated intestinal fluid(pH 7.4) and simulated gastric fluid(pH 1.2) at 37 ℃. Results suggested that both the swelling and in vitro release studies were influenced by the pH of test media, which might be suitable for intestinal drug delivery. the release mechanism was analyzed by fitting the release data into KorsmeyerPeppas equation.

关键词： Curcumin Sodium alginate Montmorillonite Microbeads Drug delivery

Piezo1通道激活促进大鼠冠脉平滑肌细胞内钙浓度升高的机制研究

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中国病理生理杂志 2024年第1期40卷 9-17页

作者：蔡泳江郑燕湘王梓帆邝素娟杨慧饶芳邓春玉南方医科大学药学院广东广州510515 南方医科大学附属广东省人民医院广东省医学科学院医学研究部临床药理重点实验室广东广州510080 华南理工大学医学院广东广州510006

目的:探讨机械敏感性离子通道Piezo1激活促进冠状动脉平滑肌细胞(CASMCs)内Ca^(2+)浓度([Ca^(2+)]i)升高的机制。方法:采用原代成年大鼠CASMCs为研究对象,用细胞免疫荧光技术观察Piezo1在CASMCs中的表达与亚细胞定位情况;利用Western b... 详细信息

目的:探讨机械敏感性离子通道Piezo1激活促进冠状动脉平滑肌细胞(CASMCs)内Ca^(2+)浓度([Ca^(2+)]i)升高的机制。方法:采用原代成年大鼠CASMCs为研究对象,用细胞免疫荧光技术观察Piezo1在CASMCs中的表达与亚细胞定位情况;利用Western blot检测用si RNA敲减CASMCs中Piezo1和基质相互作用分子1(StIM1)后CASMCs中的蛋白表达情况;利用激光共聚焦显微镜,通过基于Flou-4 AM负载的细胞内Ca^(2+)成像技术,测量CASMCs[Ca^(2+)]i的变化。结果:细胞免疫荧光染色结果显示,Piezo1在原代大鼠CASMCs中表达;Piezo1与肌浆/内质网Ca^(2+)-AtP酶2(SERCA2)、线粒体外膜蛋白tOM20和核膜蛋白lamin B1共定位程度较高。Western blot结果表明,si RNA转染后StIM1和Piezo1蛋白表达下调(PtG)排空内质网中Ca^(2+)后,Yoda1仍能诱导CASMCs中其它细胞器的Ca^(2+)释放(PtP2或敲减StIM1使Yo‐da1诱导CASMCs胞外Ca^(2+)内流减少(PtG诱导的CASMCs内质网Ca^(2+)释放增加(PtG诱导的胞外Ca^(2+)内流;抑制L型钙通道和SOCC后,敲减Piezo1导致Yoda1诱导的CASMCs胞内Ca^(2+)释放以及胞外Ca^(2+)内流均减少(P<0.01)。结论:Piezo1激动剂诱导CASMCs胞外Ca^(2+)内流主要通过细胞膜上的Piezo1通道和间接激活的SOCC,也可触发胞内细胞器Ca^(2+)释放,共同升高[Ca^(2+)]i。

关键词： Piezo1通道钙离子冠状动脉平滑肌细胞

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生物反馈盆底肌训练对儿童肛肠疾病术后大便失禁的治疗效果及对患儿心理的影响

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中华实用儿科临床杂志 2024年第6期39卷 460-464页

作者：韩光辉张海洋饶旺苏丹贾茹宋翠萍新乡医学院第一附属医院小儿外科新乡453100

目的:探讨生物反馈盆底肌训练对儿童肛肠疾病术后大便失禁的治疗效果及对患儿心理的影响。方法:回顾性病例对照研究。选择2021年7月至2023年4月于新乡医学院第一附属医院因肛肠疾病术后大便失禁就诊的37例患儿,采用加拿大Laborie生物反... 详细信息

目的:探讨生物反馈盆底肌训练对儿童肛肠疾病术后大便失禁的治疗效果及对患儿心理的影响。方法:回顾性病例对照研究。选择2021年7月至2023年4月于新乡医学院第一附属医院因肛肠疾病术后大便失禁就诊的37例患儿,采用加拿大Laborie生物反馈治疗仪进行生物反馈盆底肌训练治疗,并每天进行不少于200次的盆底肌收缩功能锻炼。分别测量其治疗前、1个疗程结束时、治疗1个月及1年时的肛管电流强度、肛管基础运动肌电值、肛管收缩肌电差值及肛门持续收缩时间。选取10例健康同龄儿作为健康对照组。采用长处和困难问卷对大便失禁的患儿在治疗前、治疗1年时分别进行心理评估。采用配对样本t检验与独立样本t检验对研究结果进行比较分析。结果:大便失禁患儿治疗前、1个疗程结束时、治疗1个月时、治疗1年时肛管电流强度值分别为(11.32±1.92)mA、(10.22±1.28)mA、(8.45±1.09)mA、(7.80±1.23)mA,肛管基础运动肌电值分别为(235.58±55.03)μV、(185.65±34.30)μV、(124.81±36.56)μV、(93.99±28.29)μV,肛管收缩肌电差值分别为(45.64±20.38)μV、(64.20±16.59)μV、(93.63±25.53)μV、(109.83±26.95)μV,肛门持续收缩时间分别为(1.27±0.43)s、(1.58±0.40)s、(2.04±0.39)s、(2.47±0.38)s。将治疗前、1个疗程结束时、治疗1个月时数据与健康对照组[(7.20±1.09)mA、(88.65±21.76)μV、(120.73±27.57)μV、(2.68±0.29)s]进行比较,差异均有统计学意义(均P0.05)。情绪症状、多动症状、同伴交往、亲社会行为及困难总分评分治疗前后比较[(3.46±1.88)分比(2.59±1.32)分、(5.78±2.12)分比(3.70±1.78)分、(3.05±1.72)分比(2.49±1.30)分、(7.30±1.54)分比(8.27±1.39)分、(21.57±4.57)分比(18.54±3.14)分],差异均有统计学意义(均P<0.05)。结论:生物反馈盆底肌训练是治疗儿童肛肠疾病术后大便失禁的一种可靠且无创伤的有效方法,且能有效改善患儿因大便失禁造成的心理及行为问题。

关键词：大便失禁肛肠疾病术后盆底肌训练生物反馈心理评估儿童

Low-loss Cd-substituted Mg ferrites with matching impedance for high-frequency-range antennas

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Journal of Magnesium and Alloys 2021年第4期9卷 1403-1413页

作者： Gongwen Gan Dainan Zhang Jie Li Gang Wang Xin Huang Yan Yang Yiheng rao Xueying Wang Huaiwu Zhang Ray t.Chen State Key Laboratory of Electronic thin Films and Integrated Devices University of Electronic Science and Technology of ChinaNo.4Section 2North Jianshe RoadChengdu 610054China Microelectronic Research Center Department of Electrical and Computer EngineeringUniversity of Texas at AustinAustinTX 78758USA

the effects of Cd^(2+) ions on the microstructure,magnetic properties,and dielectric properties of Bi_(2)O_(3)-added MgFe_(2)O_(4) ferrites(Cd_(x)Mg_(1-x)Fe_(2)O_(4),x=0.00,0.15,0.30 and 0.45)are obtained by adopting the solid-state reaction method at a low temperature(910℃).the objective is to achieve matching impedances,low magnetic and dielectric losses(tanδμand tanδε,respectively),and a relatively large miniaturization factor to reduce antenna *** results indicate that the cations occupying the tetrahedral(A)and octahedral(B)ion sites are redistributed,resulting in an enhanced super-exchange interaction between the two *** a result,improved magnetization,including the increase in saturation magnetization(41.74 emu/g)and decrease in coercivity(63.75 Oe),is *** real part of permeability(μ')also increases with increasing concentration of Cd^(2+) *** x is 0.15,matching impedances with equivalent μ'and ε'values are obtained over a long frequency range(1–150MHz).Moreover,the formation of a dense microstructure guarantees that losses occur at low orders of magnitude(tanδμ≈10−2 and tanδε≈10−3).Accordingly,these properties afford wide application perspectives for the proposed compounds in the high-frequency region,i.e.,from high-frequency to very-high-frequency bands.

关键词： Cd-substituted Mg compounds Magnetic properties Dielectric properties Matching impedance Low loss High frequency antenna

Engineered Wood/Bamboo Laminated Composites for Outdoor Hydrophilic Platforms:Structural Design and Performance

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Journal of Renewable Materials 2022年第9期10卷 2477-2487页

作者： Lifeng Ji Qiuxia Zhang Fei rao School of Art and Design Zhejiang Sci-Tech UniversityHangzhou310018China

Landscape designers increasingly prefer to use wood/bamboo-based composites for outdoor hydrophilic platforms owing to their natural surface texture,high performance,and sustainability to facilitate extensive interaction between people and water and enable the full range of ecological functions of water *** this study,four laminated composite(LC)structures were designed and manufactured using fluffed bamboo and wood *** surface textures,profile densities,water resistances,and mechanical properties were then *** type of fluffed veneer of the surface layer determined the texture of the LC *** specific structures of fluffed bamboo and wood veneer laminations were found to affect the LC profile density variability,water resistance,and mechanical properties owing to the differences in the strength and interfacial properties of bamboo and wood ***,the water resistance and mechanical properties of all four LCs were found to be much higher than the highest level specified in GB/t 20241-2006 for“laminated veneer lumber”and GB/t 30364-2013 for“bamboo scrimber flooring”,indicating that they are promising materials for structures and flooring,particularly for outdoor hydrophilic platforms.

关键词： Wood/bamboo laminated composites outdoor hydrophilic platform surface texture water resistance mechanical properties