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371篇 您的检索式:作者名="M.K."
    题名 作者 年代 出处 被引量
1足尺磁流变阻尼器的建模及动态特性显示文摘在过去三十年左右的时间里,结构保护系统受到了广大研究者的普遍关注。这种保护系统可以用来降低自然灾害(如地震、强风)对土木工程建筑的损害。由于磁流变阻尼器机械结构简单,动态范围大,能耗低、回复力大,鲁棒性良好,能够在满足不同工程项目需求的同时提供有效的结构抗震抗风手段,目前它是一种非常有前途的半主动结构减震装置。本文首先介绍了磁流变液体和装置的主要特性和优点,建立了磁流变阻尼器的伪静力轴对称模型.并将其结果和平行板模型以及阻尼器实验结果进行了比较。尽管伪静力模型对于阻尼器的设计十分有效,但是它们还不足以描述阻尼器的动态特性。对实际工程应用来说,动态响应时间是一项非常重要的性能指标。文章还讨论了影响磁流变阻尼器动态响应时间的因素,建立了基于Bouc—Wen模型的阻尼器动态模型。同时文章也提出了优化阻尼器动态响应的途径和方法以及其实验验证。杨广强 B.F SpencerJr J.D.Carlson M.K. Sain 2001地震工程与工程振动2001,21,S1:32
2重新设计图书馆服务显示文摘图书馆的首要目的是提供服务。由于信息新技术的出现 ,传统的图书馆服务面临着新的机遇和挑战。电子图书馆的出现已经使人们逐渐意识到 ,图书馆服务将可能发生巨大变化 ,而图书馆的用户也在发生变化。因此 ,在考虑图书馆管理时 ,至少在某种程度上要像关心图书的管理一样关心对服务的管理。由于操作和服务变得更加复杂和资本密集 ,草率决策可能使图书馆服务走上徒劳无功的道路 ,而纠正这些错误的代价也变得更加昂贵和具有破坏性。M.K.巴克兰 黄育馥 2001国外社会科学2001,,2:29
3Dominant pulse simulation of near fault ground motions显示文摘In this study, a new mathematical model is developed composed of two parts, including harmonic and polynomial expressions for simulating the dominant velocity pulse of near fault ground motions. Based on a proposed velocity function, the corresponding expressions for the ground acceleration and displacement time histories are also derived. The proposed model is then fitted using some selected pulse-like near fault ground motions in the Next Generation Attenuation (NGA) project library. The new model is not only simple in form but also simulates the long-period portion of actual velocity near fault records with a high level of precision. It is shown that the proposed model-based elastic response spectra are compatible with the near fault records in the neighborhood of the prevailing frequency of the pulse. The results indicate that the proposed model adequately simulates the components of the time histories. Finally, the energy of the proposed pulse was compared with the energy of the actual record to confirm the compatibility.S.R. Hoseini Vaez M.K. Sharbatdar G. Ghodrati Amiri H. Naderpour A. Kheyroddin 2013Earthquake Engineering and Engineering Vibration2013,12,2:9
4细粒分级新技术的比较评价显示文摘工业生产中 ,传统分级技术在分级粒度为 15 0 μm或 15 0 μm以下时的分级效率很低。为了精确分级细颗粒 ,本研究考查了当前细粒分级技术的现状 ,其中包括最新研制的Pansep筛分机 ,以及安装或不安装底流喷水系统 (Cyclonwash)的新设计的 gMax旋流器。用筛面面积为 0 5m2 的Pansep筛分机在分级粒度为 15 0和 45 μm下进行分级 ,据此来评价其性能 ,而对安装或不安装Cyclonwash系统的直径为 15cm的gMax旋流器 ,则只用来研究分级粒度为 45 μm的细粒分级。本研究结果表明 ,在对 -1mm的煤浆按 15 0 μm分级粒度分级时 ,Pansep筛分机的筛分性能明显好于传统技术 ,如旋流器和弧形筛。在伊利诺伊州的一个选煤厂中 ,Pansep筛分机的筛分效率达到了 98%的满意结果 ,而弧形筛的筛分效率为 44 % ,原煤分级旋流器的分级效率为 5 7%。对于 45 μm的分级粒度 ,采用gMax旋流器可将传统旋流器的筛分效率从 3 7%提高到 68% ,采用Cyclowash系统的gMax旋流器分级效率则可提高到 70 % ,而用Pansep筛分机筛分技术则几乎达到 99%。对于 45 μm的分级粒度 ,Pansep筛分机的以粗粒计的生产能力可达到 5t/ (h·m2 ) ,而对总的分级效率没有任何大的负面影响 ;在 15 0 μm分级粒度下分级时 ,获得相同的以粗粒计的生产能力 。M.K.莫哈蒂 田洪贵 尚衍波 张覃 李长根 2003国外金属矿选矿2003,40,6:8
5补偿硅的温度敏感特性显示文摘采用低电阻率的p型单晶硅,在高温条件下扩散金属锰的方法,可以得到高补偿和过补偿硅.在常温下,测试扩散后电阻率分别为3.2×103、4.8×104、1.3×105、3.2×105Ω·cm的几种样品的温度敏感特性,其相应的B值分别为5 103,5 600,6 103,6 502 K.这种扩锰硅是一种温度敏感材料,笔者将报道这些实验结果并讨论其热敏特性.张建 巴维真 陈朝阳 丛秀云 陶明德 M.K.巴哈迪尔哈诺夫 2004电子元件与材料2004,23,5:7
6高补偿硅的阻-温特性显示文摘采用5·cm的p型单晶硅,通过在高温下扩散金属锰的方法,可以得到高补偿硅。笔者选择没有光照下,室温电阻率为5.84×104·cm的样品,进行测量电阻随温度的变化关系(温度从77 K上升到300 K)。测试结果表明:在没有光照条件下测试时,电阻随温度的变化同普通的半导体;但在受到光照时,却出现极不相同的情况,这种不同,可能来自所掺杂的硅是一种光敏材料及掺入的杂质是一种深能级杂质。张建 巴维真 陈朝阳 丛秀云 陶明德 M.K.巴哈迪尔哈诺夫 2004电子元件与材料2004,23,4:6
7男女性糖尿病患者与无糖尿病人群相比年龄与心血管疾病的相关性:基于人群的回顾性队列研究Booth G.L. Kapral M.K. Fung K. 吴晓燕 2006世界核心医学期刊文摘(心脏病学分册)2006,0,11:5
8Association of asymptomatic otitis media with effusion in patients with adenoid hypertrophy显示文摘Objective: Clinical symptoms of otitis media with effusion are rarely brought forward to the guardians of young children who the disease is most prevalent in. This often leads to poor scholastic performances and difficult social interactions. The objective of this study was to identify asymptomatic cases of otitis media with effusion present in individuals with adenoid hypertrophy. Material and Methods: In a cross sectional study advocated in Justice K.S.Hegde Hospital, Karnataka India we evaluated one hundred patients above the age of three from August 2016 to December 2017. Candidates who presented with an adenoid nasopharyngeal ratio of more than 0.5 were selected for the study. Individuals who complained of otological symptoms were not considered for the study. Patients cleared of other pathological otological conditions were underwent audiological evaluation with pure tone audiometry and tympanometry for evaluating the middle ear status and hearing loss. Results: The study showed a total of 36% of patients evaluated presented with asymptomatic otitis media with effusion. In candidates who presented with a bilateral B tympanogram, 40% had significant conductive hearing loss of more than 25dB. Conclusion: An objective test such as impedance audiometry in all patients with adenoid hypertrophy would aid in the diagnosis of fluid in the middle ear, so that timely intervention can be done and possible complications be averted.Vadisha Bhat Ivan Paraekulam Mani Rajeshwary Aroor Marina Saldanha M.K. Goutham Deepika Pratap 2019Journal of Otology2019,14,3:4
9视网膜血管直径与卒中风险的关系:鹿特丹研究显示文摘Background: Retinal vessels may provide information on cerebral vascular pathology, because they share many features with cerebral vessels. A smaller ratio of the retinal arteriolar-to-venular diameters reportedly predicts the risk of stroke. It is unclear if this is due to arteriolar narrowing or venular dilation. Objective: To investigate whether smaller arteriolar or larger venular diameters are related to the risk of stroke and cerebral infarction. Methods: This study was based on the prospective population-based Rotterdam Study and included 5,540 participants of 55 years or over, who had gradable fundus transparencies and were free of stroke at baseline (1990 to 1993). For each participant, retinal arteriolar and venular diameters were measured on digitized images of one eye. Follow-up for first-ever stroke was complete until January 1, 2002. Results: After a mean follow-up of 8.5 years, 411 participants had a stroke, of whom 259 had cerebral infarction. Larger venular diameters were associated with an increased risk of stroke (hazard ratio [HR] adjusted for age and sex per SD increase: 1.12 [95%CI: 1.02 to 1.24]) and cerebral infarction (HR: 1.15 [95%CI: 1.02 to 1.29]). Smaller arteriolar diameters were neither related to the risk of stroke (HR per SD decrease: 1.02 [95%CI: 0.93 to 1.13]) nor to the risk of cerebral infarction (HR: 1.02 [95%CI: 0.90 to 1.15]). After additional adjustment for other cardiovascular risk factors, the results did not change. Conclusions: Larger retinal venular diameters are associated with an increased risk of stroke and cerebral infarction. The role of venules in cerebrovascular disease warrants further exploration.Ikram M.K. De Jong F.J. Bos M.J. P.T.V.M. De Jong 邱伟庆 2006世界核心医学期刊文摘(神经病学分册)2006,2,9:4
10高补偿硅的光敏感特性显示文摘对电阻率为5 ·cm的p型单晶硅,在高温条件下采用扩散金属锰的方法,得到高补偿硅。并在室温(25℃)和液氮温度(196℃)下,测试了这种高补偿硅材料对光强的敏感性。测试结果表明:这种材料是一种光敏感材料,其敏感性受外加的电压、样品的温度及补偿后样品的电阻率影响。张建 巴维真 陈朝阳 丛秀云 陶明德 M.K.巴哈迪尔哈诺夫 2004电子元件与材料2004,23,3:3
11Effect of (Ba_(0.6)Sr_(0.4))TiO_3(BST) Doping on Dielectric Properties of CaCu_3Ti_4O_(12)(CCTO)显示文摘The effect of (Ba(0.6)Sr(0.4))TiO3(BST) addition on dielectric properties of CaCu3Ti4O(12) (CCTO) ceramic was investigated. Ceramic samples with the chemical formula (1-x)CaCu3Ti4O(12) + x(Ba(0.6),Sr(0.4))TiO3 (x=0, 0.05, 0.1, and 0.2) were synthesized from high purity oxide powders by the conventional solid-state synthesis method. X-ray diffraction (XRD) analysis showed the existence of BST as a secondary phase alongside CCTO. Scanning electron microscopy (SEM) investigation showed a slight decrease in grain size of doped CCTO samples. Density measurements showed that porosity content increased with increasing BST addition indicating low densification due to high melting point secondary phase addition. Dielectric constant of undoped CCTO (x=0) showed lack of stability with frequency which dropped drastically between 104 and 105Hz and accompanied by high dielectric loss. Addition of BST into CCTO caused the dielectric constant to slightly decrease but improved stability with frequency compared to the undoped sample. The decrease in dielectric constant of doped CCTO samples was suggested to be partly due to the decrease in average grain size and increase in porosity with BST addition. Nevertheless, a high value of dielectric constant was still maintained around ~104 range for all doped samples. The dielectric loss (tanδ) of all BST-doped samples was lower than that of pure CCTO sample at the frequency range of 103 to 105 Hz probably due to the increase of grains boundary resistivity. The activation energy of grains boundary (E(gb)) showed higher values as compared to the activation energy of grains (Eg ) for all samples and conforms to the internal barrier layer capacitor (IBLC) model.I. Norezan A.K. Yahya M.K. Talari 2012Journal of Materials Science & Technology2012,28,12:3
12Combustion in porous media and its applications – A comprehensive survey显示文摘M. Abdul Mujeebu M.Z. Abdullah M.Z. Abu Bakar A.A. Mohamad R.M.N. Muhad M.K. Abdullah 2008Journal of Environmental Management2008,,8:2
13Influence of Eu 3+ , Bi 3+ co-doping content on photoluminescence of YVO 4 red phosphors induced by ultraviolet excitation显示文摘W.J. Park M.K. Jung D.H. Yoon 2007Sensors & Actuators: B. Chemical2007,,:2
14关于母亲孕期维生素D状况与儿童9岁时骨量关系的纵向研究显示文摘Background: Vitamin D insufficiency is common in women of childbearing age and increasing evidence suggests that the risk of osteoporotic fracture in adulthood could be determined partly by environmental factors during intrauterine and early postnatal life. We investigated the effect of maternal vitamin D status during pregnancy on childhood skeletal growth. Methods: In a longitudinal study, we studied 198 children born in 1991-92 in a hospital in Southampton, UK; the body build, nutrition, and vitamin D status of their mothers had been characterised during pregnancy. The children were followed up at age 9 years to relate these maternal characteristics to their body size and bone mass. Findings: 49 (31%) mothers had insufficient and 28 (18%) had deficient circulating concentrations of 25(OH)-vitamin D during late pregnancy. Reduced concentration of 25(OH)-vitamin D in mothers during late pregnancy was associated with reduced whole-body (r = 0.21, p = 0.0088) and lumbar-spine (r = 0.17, p = 0.03) bone-mineral content in children at age 9 years. Both the estimated exposure to ultraviolet B radiation during late pregnancy and the maternal use of vitamin D supplements predicted maternal 25(OH)-vitamin D concentration (p < 0.0001 and p = 0.0110, respectively) and childhood bone mass (p = 0.0267). Reduced concentration of umbilical-venous calcium also predicted reduced childhood bone mass (p = 0.0286). Interpretation: Maternal vitamin D insufficiency is common during pregnancy and is associated with reduced bone-mineral accrual in the offspring during childhood; this association is mediated partly through the concentration of umbilical venous calcium. Vitamin D supplementation of pregnant women, especially during winter months, could lead to longlasting reductions in the risk of osteoporotic fracture in their offspring.Javaid M.K. Crozier S.R. Harvey N.C. C. Cooper 柳蕴 2006世界核心医学期刊文摘(妇产科学分册)2006,0,4:2
15Perfluorinated compounds in the Pearl River and Yangtze River of China显示文摘M.K. So Y. Miyake W.Y. Yeung Y.M. Ho S. Taniyasu P. Rostkowski N. Yamashita B.S. Zhou X.J. Shi J.X. Wang J.P. Giesy H. Yu P.K.S. Lam 2007Chemosphere2007,,11:2
16Role of phenolic O-H and methylene hydrogen on the free radical reactions and antioxidant activity of curcumin显示文摘K.Indira Priyadarsini Dilip K. Maity G.H. Naik M.Sudheer Kumar M.K. Unnikrishnan J.G. Satav Hari Mohan 2003Free Radical Biology and Medicine2003,,:2
17The impact of electronic word-of-mouth communication: A literature analysis and integrative model显示文摘Christy M.K. Cheung Dimple R. Thadani 2012Decision Support Systems2012,,1:2
18Autologous iliac crest bone graft: Should it still be the gold standard for treating nonunions?显示文摘M.K. Sen T. Miclau 2007Injury2007,,:2
19TEXTURES, INTERFACE AND FRACTURE OF A 1D-C/C PREPARED BY CVD显示文摘TEXTURES,INTERFACEANDFRACTUREOFA1D-C/CPREPAREDBYCVDR.Shi;H.J.Li;Z.YangandM.K.Kang(Dept.ofMaterialsScienceandEngineering,North...R.Shi H.J. Li Z. Yang and M.K. Kang(Dept. of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, ) 1996Acta Metallurgica Sinica(English Letters)1996,9,6:2
20视网膜血管直径与脑卒中的风险:来自鹿特丹的研究显示文摘Background:Retinal vessels may provide information on cerebral vascular pathology,because they share many features with cerebral vessels.A smaller ratio of the retinal arteriolar-to-venular diameters reportedly predicts the risk of stroke.It is unclear if this is due to arteriolar narrowing or venular dilation.Objective:To investigate whether smaller arteriolar or larger venular diameters are related to the risk of stroke and cerebral infarction.Methods:This study was based on the prospective population-based Rotterdam Study and included 5,540 participants of 55 years or over,who had gradable fundus transparencies and were free of stroke at baseline(1990 to 1993).For each participant,retinal arteriolar and venular diameters were measured on digitized images of one eye.Follow-up for first-ever stroke was complete until January 1,2002.Results:After a mean follow-up of 8.5 years,411 participants had a stroke,of whom 259 had cerebral infarction.Larger venular diameters were associated with an increased risk of stroke(hazard ratio HR adjusted for age and sex per SD increase:1.12 95% CI:1.02 to 1.24)and cerebral infarction(HR:1.15 95% CI:1.02 to 1.29).Smaller arteriolar diameters were neither related to the risk of stroke(HR per SD decrease:1.02 95% CI:0.93 to 1.13)nor to the risk of cerebral infarction(HR:1.02 95% CI:0.90 to 1.15).After additional adjustment for other cardiovascular risk factors,the results did not change.Conclusions:Larger retinal venular diameters are associated with an increased risk of stroke and cerebral infarction.The role of venules in cerebrovascular disease warrants further exploration.Ikram M.K. De Jong F.J. Bos M.J. 桑延智 2006世界核心医学期刊文摘(眼科学分册)2006,2,9:2
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