Surface Biochemical Modification for the Titanium Implants

综述近年来钛植入体表面生物化学设计和改性的研究进展,重点介绍植入体表面自组装改性新技术及其在生物医用材料中的应用。This paper reviews the progress in biochemical design and modification for the surfaces of titanium implants in recent years,the emphasis being laid on the introduction of the surface molecular construction, self-assembly technique and its application in biomedical materials

医院感染多重耐药菌分布及耐药性分析

目的了解医院感染多重耐药菌分布及耐药性分析,为临床诊疗提供依据。方法 25 618例临床感染标本分离株培养鉴定后,监测常见分离菌的多重耐药菌株(MdrO)。结果 1 087株分离菌以革兰阴性菌925株为主,革兰阳性菌162株。革兰阴性菌中分离率前5位分别是肺炎克雷伯菌、大肠埃希菌、铜绿假单胞菌、鲍曼不动杆菌、阴沟肠杆菌。革兰阳性菌中分离率前5位分别是金黄色葡萄球菌、凝固酶阴性葡萄球菌、肺炎链球菌、屎肠球菌、粪肠球菌。大肠埃希菌、肺炎克雷伯菌产超广谱β-内酰胺酶(ESblS)株的检出率分别为75.53%、37.14%;金黄色葡萄球菌中耐甲氧西林的金黄色葡萄球菌(MrSA)的检出率为78.20%,凝固酶阴性葡萄球菌中耐甲氧西林的凝固酶阴性葡萄球菌(MrCnS)的检出率为84.60%。13株屎肠球菌中发现3株万古霉素耐药株(VrE)。结论医院感染多重耐药菌分布主要以革兰氏阴性杆菌为主,其次是革兰氏阳性球菌。MdrO的增多是医院面临的重要问题,在临床上应改进治疗手段,合理使用抗菌药物,减少MdrO的产生和播散

非标准岩样岩石力学参数试验研究

通过对非标准岩样的室内试验来获取岩石力学参数是试验研究中必须处理的技术问题。对某矿4种不同岩石的非标准岩样进行单轴抗压实验和巴西劈裂实验,分析了岩样的强度分布特点,考虑尺寸效应和形状效应,对岩石强度试验结果进行了修正,获得了岩石的单轴抗压、抗拉强度、弹性模量、帕松比、粘聚力和内摩擦角等力学参数,并对所得参数进行了分析。所得力学参数为该矿山的岩石力学和地压研究提供了基础资料

A DDA Calculation on the Optical Properties of Silver Nanorods

【中文文摘】利用离散偶极近似 (Discretedipoleapproximation ,简称DDA)的方法 ,从理论上对粒子的形状、尺寸及周围介质等因素对银纳米粒子 ,特别是银纳米棒的光学性质的影响进行了较系统的研究 .计算表明 ,置于空气中的棒状银纳米粒子的光学性质与其形状密切相关 ,纵向表面等离子体共振吸收峰的位置随纳米棒长径比的增加呈现线性红移关系 .给出了空气中银纳米棒纵向表面等离子体共振吸收峰的位置随长径比变化的DDA拟合公式 .如果将金属纳米粒子置于折射率更高的介电环境中 ,其纵向等离子体共振吸收峰的位置进一步呈现线性红移关系 .合成的银纳米粒子的TEM图像及相关的UV VIS消光光谱显示DDA计算结果与实验值相当一致 .DDA算法与Mie′s理论在计算球状银纳米粒子的消光系数时给出很接近的结果 ,这表明用DDA的方法来分析银的光学性质是准确可靠的 ;而DDA算法对银纳米棒消光特性的成功拟合则表明 ,该算法相对Gans′理论而言 ,在研究纳米粒子的光学性质时具有更广的适用性及更高的准确性 . 【英文文摘】The optical properties of metal nanoparticles are quite different from those of the bulk materials mainly due to the collective oscillations of their conduction electrons known as the surface plasmon resonance (SPR), which is strongly dependent on the particle shape and size, and the dielectric properties of the local environment where the nanoparticles are embedded in. Based on the discrete dipole approximation (DDA) method, we studied the optical properties of silver nanorods with different aspect ratios ...Project supported by the National Natural Science Foundation of China (2 0 2 2 80 2 0,2 0 0 2 10 0 2

The Size and Shape Effects on the Optical Properties of Gold Nanoparticles

【中文文摘】纳米尺度的金属及半导体呈现出特殊的光学、电学及磁学性质,采用近年发展起来的离散偶极近似(DDA)的方法,我们分析了金纳米粒子的尺寸及形状对其光学性质的影响。粒子周围介质的影响在文中亦作了分析。计算结果显示,金纳米粒子的等离子体吸收带同时受到粒子尺寸和形状的影响,但来自形状的影响更为明显。与米氏理论及扩展的甘氏理论相比较,DDA方法在粒子尺寸不再远小于入射光波长的时候更准确,并能应用于任何形状的纳米粒子。理论计算与实验结果能较好的吻合。 【英文文摘】Metals and semiconductors exhibit unusual optical, electronic, and magnetic properties at the nanometer scale. Based on the newly developed method, discrete dipole approximation (DDA), the dependence of the optical properties of the gold nanoparticles on the size and shape was analyzed. The effects of the surrounding medium were also taken into consideration in the calculation. The calculated results show that the plasmon absorption band depends on both the size and shape of the gold noanoparticles. However , the influence of the shape is more significant . Compared to the Mieps theory and the extension , Gansp theory , the DDA method is more accurate when the dimensions of the particles are not much smaller than the wavelength of the incident light and can be applied to particles of any shape. The theoretical results are in good agreement with the experimental data.国家自然科学基金项目,批准号为 :20003008,2983306

Progress of C_2-Symmetric Biphenyl Bisphosphine LigandsⅡ

手性膦配体的合成及其在手性诱导催化反应中的应用一直是不对称合成与催化研究中非常重要的研究领域之一。近十年来,大量的C2-轴对称手性双膦配体被合成出来并成功地应用于不对称催化研究,本文从C2-轴对称联苯类手性双膦配体的介绍、合成方法、C2-轴对称联苯类手性双膦配体在不对称催化氢化以及其在其他不对称诱导反应中的应用4个方面综述了相关研究进展。A vast number of biphenyl atropisomeric diphosphine ligands have been successfully applied in asymmetric catalysis.The synthesis and applications of this type of ligands are a continuous interesting theme in organic chemistry.This review describes recent progress in synthesis and application of C2-Symmetric diphosphine ligands on the asymmetric catalysis hydrogenation and other asymmetric induced reaction.国家自然科学基金(20272037); 教育部博士点基金(20080610022); 四川自然科学基金重点项目(07ZA109

Progress of C_2-Symmetric Biphenyl Bisphosphine Ligands Ⅲ

手性膦配体的合成及其在手性诱导催化反应中的应用一直是不对称合成与催化研究中非常重要的研究领域之一。近10年来,大量的C2-轴对称手性双膦配体被合成出来并成功地应用于不对称催化研究,本文从C2-轴对称联苯类手性双膦配体的介绍、合成方法、C2-轴对称联苯类手性双膦配体在不对称催化氢化、以及其在其他不对称诱导反应中的应用4个方面综述了相关研究进展,并对今后配体的合成及应用前景进行了展望。A vast number of biphenyl atropisomeric diphosphine ligands are successfully applied in asymmetric catalysis.The synthesis and applications of this type of ligands are a continuous interesting theme in organic chemistry.This review describes recent progress in synthesis and application of C2-Symmetric diphosphine ligands on the asymmetric catalysis hydrogenation and other asymmetric induced reaction,and the future ligand synthesis and application prospect.国家自然科学基金(20272037); 教育部博士点基金(20080610022); 四川自然科学基金重点项目(07ZA109

Progress of the Study on C_2-symmetric Biphenyl Bisphosphine Ligands(一)

手性膦配体的合成及其在手性诱导催化反应中的应用一直是不对称合成与催化研究中非常重要的研究领域之一。近10年来,大量的C2-轴对称手性双膦配体被合成出来并成功地应用于不对称催化研究,本文从C2-轴对称联苯类手性双膦配体的介绍、合成方法,C2-轴对称联苯类手性双膦配体在不对称催化氢化,以及其在其他不对称诱导反应中的应用4个方面综述了相关研究进展,并对今后配体的合成及应用前景进行了展望。A vast number of biphenyl atropisomeric diphosphine ligands are successfully applied in asymmetric catalysis.The synthesis and applications of this type of ligands are a continuous interesting theme in organic chemistry.This review describes recent progress in synthesis and application of C2-Symmetric diphosphine ligands in the asymmetric catalysis hydrogenation and other asymmetric induced reaction.And the future ligand synthesis and application are predicted.国家自然科学基金(20272037); 教育部博士点基金(20080610022); 四川自然科学基金重点项目(07ZA109

Impact of mountain biking and its management

published_or_final_versionEnvironmental ManagementMasterMaster of Science in Environmental Managemen