不同初始分布向列相液晶电容特性的相场法研究

液晶盒内的液晶分子在不同的外加电场作用下重新排布,其极化指向发生改变,从而影响液晶盒整体的电学特性。本文考虑液晶材料的挠曲电效应,分析液晶盒的整体自由能表达式,包含弹性形变自..

Electrochemical property of spinel LiMn_2O_4 prepared by sol-gel method

利用循环伏安法 (CV )、恒流充放电、电化学阻抗谱 (EIS)等电化学手段研究了溶胶凝胶法制备的尖晶石型LiMn2 O4 的电化学性质。结果表明用溶胶凝胶法制备的样品放电容量大 ,可逆性好 ,其中 5 5 0℃煅烧的样品电化学性能最好 ;XRD结果表明 ,样品经过充放电 ,尖晶石结构仍保留 ,但出现深度放电产物Li2 Mn2 O4 。The electrochemical properties of spinel LiMn 2O 4 electrodes prepared by a sol gel method were studied by cyclic voltammetry, constant current charge discharge and electrochemical impedance spectrum(EIS) techniques. The experimental results showed that the electrochemical performance of the samples prepared by sol gel method was better than that of the sample prepared by normal method. The electrochemical performance of the sample prepared by sol gel method at 550℃ showed the best electrochemical performance. After constant current charge discharge the spinel structures in all samples were reserved and deeply discharging product Li 2Mn 2O 4 was detected from XRD results.国家自然科学基金 ( 2 98330 90 );; “86 3”高技术发展计划 ( 715 -0 0 4-0 2 5 0

非小细胞肺癌肿瘤白细胞介素的表达模式对免疫治疗疗效和预后的作用

目的为了明确对免疫检查点阻断（ICB）治疗应答反应较差的非小细胞肺癌（NSCLC）患者与肿瘤组织白细胞介素（ILs）表达水平之间的潜在关联，探讨其在NSCLC患者肿瘤中的表达差异及其对患者ICB疗效和预后的影响。方法从既往研究数据中回顾性收集确诊为NSCLC且经过ICB治疗的61例患者，取得其ICB治疗前的肿瘤组织转录组测序及生存相关的数据，通过生物信息学方法，筛选出显著影响患者ICB治疗疗效与预后的ILs，以无进展生存期（PFS）评价疗效和总生存期（OS）评价患者的预后，使用Kaplan-Meier生存曲线和ROC曲线分析ILs对NSCLC患者ICB疗效和预后的预测作用及效能。结果通过单因素Cox回归分析，筛选出9个与NSCLC患者OS相关的ILs（P < 0.1），经过多因素Cox回归分析进一步筛选得到与NSCLC患者不良预后显著相关的ILs，结果提示IL-11、IL-17D和IL-36A高表达与NSCLC患者ICB治疗的不良预后相关（P < 0.05）。Kaplan-Meier生存曲线结果表明IL-17D高表达与NSCLC患者的PFS和OS显著负相关，高表达患者的中位PFS为3.1个月对比低表达患者6.5个月［95%CI为（1.178，3.655），P = 0.009］，中位OS高表达组对比低表达组为9.8个月对比21.8个月［95%CI（1.116，4.392），P = 0.018］，ROC曲线表明其预测性能较好［AUCPFS = 0.702，95%CI（0.562，0.842），P = 0.027；AUCOS = 0.684，95%CI（0.550，0.818），P = 0.014］。虽然IL-11和IL-36A不能很好地预测NSCLC患者的PFS和OS（P > 0.05），但当两者与IL-17D的表达模式联合时，发现上述3种ILs均为高表达的NSCLC患者，中位PFS与OS分别缩短至2.2个月（P = 0.003）和3.0个月（P < 0.001），ROC曲线表明其预测效能得到提升［AUCPFS = 0.748，95%CI（0.615，0.880），P = 0.007；AUCOS = 0.703，95%CI（0.573，0.833），P = 0.007］。结论IL-11、IL-17D和IL-36A高表达提示NSCLC患者疾病进展的风险较高，与患者不良的PFS和OS相关，可能为NSCLC的ICB辅助治疗提供新的策略

Investigation of lithium manganese oxides with large tunnel structure as electrode material in Li ion batteries

锂锰氧化物材料是一类重要的锂离子电池电极材料。文中报道一种新型大隧道结构镁锰复合氧化物〔结构类型：钡镁锰矿（TOdOrOkITE）型〕的合成方法及其电化学性能表征。X-光衍射（Xrd）谱证实了合成物具有所预想的（3x3）隧道结构。在慢速循环伏安图中可发现该类电极材料分别在3.35V及2.45V（VS.lI）出现一对锂离子的脱出-嵌入峰。充放电实验结果表明：该类大隧道结构复合氧化物可作为一种3V锂离子电池的电极材料，当充放电电流密度为0.1MA/CM2时，材料的初次容量可达158MAg/H，经过4次充放电循环后其容量仍可保持在约130MAH/g。Lithium manganese oxide is one kind of the important electrode material of Li ion batteries.In this paper, investigations of a novel Li Mn oxide electrode material with large tunnel structure such as todorokite type electode material For Li ion batteries are carried out in the lab.It is demonstrated that the material synthesized has a todo rokite structure (i.e.3×3 tunnel)using X ray diFFraction(XRD) method.It is also observed that a couple of deintercalation/intercalation peaks of lithium ion appear at 3.35V and 2.46V (vs.Li) respectively in the slow rate cyclic voltammograms.In addition,it is Found that the material shows quite good cyclic perFormance,the initial capacity of the material is 158mAh/g,and its discharge capacity is still kept at about 130mAh/g aFter Four cycles at charging/discharging current density of 0.1mA/cm 2.福建省自然科学基金;杰出青年基

Preparation of Cu/Sr_3Ti_2O_7 and Its Photocatalytic Activity of Water-splitting for Hydrogen Evolution

[中文文摘]采用聚合合成法(PCM)合成出层状钙钛矿结构的Sr_3Ti_2O_7,进而负载Cu离子,制成Cu/Sr_3Ti_2O_7催化剂.以超纯水和甲醇牺牲剂体系的光催化分解反应为探针,通过检测氢气生成速率评价了催化剂的光催化性能,并借助光电子能谱(XPS)、X射线衍射(XRD)分析、紫外-可见漫反射光谱(UV-VisDRS)等手段对催化剂进行了表征.实验结果表明,Cu在催化剂中以多价态存在,Cu+和吸附氧有利于光生电子的转移.Cu/Sr_3Ti_2O_7催化剂较之纯Sr_3Ti_2O_7催化剂活性大大提高,Cu最佳负载量为1.5%(w).产氢速率可稳定在550-600μmol·h~(-1).还原过的Cu/Sr_3Ti_2O_7催化剂产氢速率最高可达1140.8μmol·h~(-1).[英文文摘]Sr_3Ti_2O_7 photocatalyst with perovskite-layered structure was synthesized by polymerized complex method (PCM). Cu ion as an effective dopant was loaded onto Sr_3Ti_2O_7 catalyst. Cu/Sr_3Ti_2O_7 catalyst was applied in the mixture of water and methanol, methanol was used as a sacrificial agent under ultra-violet irradiation, and the catalyst was characterized by XPS, XRD, and UV-Vis DRS. The results showed that Cu existed in several kinds of valence and the photocatalytic activity of Cu/Sr_3Ti_2O_7 was superior to that of pure Sr3Ti2O7. Cu+ and adsorbed oxygen can accelerate the interfacial electron transfer. When the amount of Cu was 1.5%(w), the best catalytic effect was obtained and the stable average hydrogen evolution rate was about 550- 600 μmol·h- 1. The Cu/Sr3Ti2O7 after reduction attained the highest hydrogen evolution rate that was close to 1140.8 μmol·h- 1.国家自然科学基金(20673089,20273053,20023001, 29933040); 973项目(001CB108906); 福建省科技重大专项(2005HZ01-3)资助

Novel cathode material for lithium ion batteries Investigation of the intercalation behavior of manganese dioxide nano fiber

采用TEM、Xrd分析等方法对新型二氧化锰纳米纤维电极材料进行表征，TEM观测结果显示这种锰材料是由许多二氧化锰纳米纤维缠绕成巢状，其纤维直径约为1nM~10nM之间；从Xrd分析表明，它是一种复合结构的锰氧化物，以钡镁锰矿为主体结构，并含有其他钠水锰矿及水羟锰矿结构。从样品电极在1MOl/llIClO4的PC-dME（1∶1）溶剂中的循环伏安曲线，可以看出在扫描的电压范围内，在3.8V和2.8V附近出现一对可逆对称的氧化还原峰，它对应于二氧化锰纳米纤维电极中锂离子的脱出-嵌入反应。通过二氧化锰纳米纤维电极在不同电流密度下的放电，可以看出该电极采用小电流放电（0.24MA/CM2），其容量可达到约190MAH/g，而且具有3V的放电平台；而在较大的电流密度（0.96MA/CM2）放电仍具有约150MAH/g的放电容量。可见，该电极具有良好的负荷特性和较高的放电容量。A novel cathode material (MnO 2) has been characterized by using transmission electron microscope (TEM) and X ray diffraction (XRD). From the TEM examination, it was found that the MnO 2 has a distinct birds nest shaped nano fiber with the diameter in the range of 1nm～10 nm. XRD data shows that the MnO 2 has a complex structure that is in the form of todorokite (3×3 tunnel) birnessite, and vernadite structure. Cyclic voltammetry has been performed in 1 mol/L LiClO 4的PC DME(1∶1) electrolyte solution. It can be seen that a pair of reversible redox peaks, which mainly occurs in the potential ranged from 2.8 to 3.8 V vs.Li/Li +, it can be described by a lithium intercalation mechanism. The galvanostatic charge discharge experiments at various current density reveal that the MnO 2 nano fiber electrodes have a high electrochemical performance and stability. The reversible capacity can reach 190 mAh/g, 150 mAh/g at lower and higher current density respectively, i.e. 0.24mA/cm 2 and 0.96mA/cm 2.国家“863”高技术发展计划课题;中国大洋矿产资源研究开发课题;国家自然科学基

旋光效应对Bi12SiO20晶体中光动量及角动量的影响

从Maxwell方程组出发,将与旋光效应相关的二阶非线性电极化作为线性电极化的微扰项,并结合角谱表示理论,以傍轴高斯光束作为入射光场,研究了光束在具有自然旋光性的Bi12SiO20晶体中的传播问题,并分别采用Minkowski和Abraham两种形式的光动量,得出Bi12SiO20晶体中的光动量及角动量表达式。结果表明,旋光性的存在使得晶体中的Minkowski动量和Abraham动量的比值不再是晶体折射率的平方。采用Minkowski角动量密度形式,可以发现光场与晶体之间的角动量会发生耦合,虽然光场自身的角动量不守恒,但光场和晶体的总角动量守恒

Preparation of Cu/Sr3Ti2O7 and its photocatalytic activity of water-splitting for hydrogen evolution

Sr3Ti2O7 photocatalyst with perovskite-layered structure was synthesized by polymerized complex method (PCM). Cu ion as an effective dopant was loaded onto Sr3Ti2O7 catalyst. Cu/Sr3Ti2O7 catalyst was applied in the mixture of water and methanol, methanol was used as a sacrificial agent under ultra-violet irradiation, and the catalyst was characterized by XPS, XRD, and UV-Vis DRS. The results showed that Cu existed in several kinds of valence and the photocatalytic activity of Cu/Sr3Ti2O7 was superior to that of pure Sr3Ti2O7, Cu+ and adsorbed oxygen can accelerate the interfacial electron transfer. When the amount of Cu was 1.5%(w), the best catalytic effect was obtained and the stable average hydrogen evolution rate was about 550-600 mu mol.h(-1). The Cu/Sr3Ti2O7 after reduction attained the highest hydrogen evolution rate that was close to 1140.8 mu mol.h(-1)

Using wavelet transform to study the Lipschitz local singular exponent in wall turbulence

In this paper, wavelet,transform is introduced to study the Lipschitz local singular exponent for characterising the local singularity behavior of fluctuating velocity in wall turbulence. I, is found that the local singular exponent is negative when the ejections and sweeps of coherent structures occur in a turbulent boundary layer

与南海西边界流有关的区域海洋学进展

从动力学角度,回顾了与南海西部主流系及其涡旋研究有关的南海物理海洋学的进展.主要内容涉及南海西边界流漂流浮标观测、西边界流源区涡旋遥感观测、西边界流源区跨陆架交换、涡流相互作用、西边界流年际变化、西边界流区海气相互作用、南海贯穿流等方面的进展.西边界流是一个强流系,其与季节和年际变化相关的结构特征、变率及跟某些动力过程的关联有待研究.在西边界流变率、涡旋环流相互作用、海气过程以及南海贯穿流取得了以下成果:(1)利用漂流浮标观测样本对南海西边界环流进行分析,指出南海西边界表层环流在到达越南中部沿岸后伴随着流幅变窄的同时流速加强;探讨了南海北部环流变化机理,定量诊断南海西边界流北支冬季逆风流产生的动力机制;利用航次数据对18°n断面的经向地转流进行诊断,表明南海西边界流的经向输送年际变化明显;(2)结合航次观测数据,对2003/2004年冬季南海北部2个反气旋涡旋和2007年夏季18°n附近的3个反气旋涡旋进行研究,指出冬季2个涡旋产生后以罗斯贝(rOSSby)波速度(约0.1M/S)沿北部陆坡向西南方向传播,并初步揭示了南海西边界环流与夏季3个涡旋的相互作用;南海北部陆架区涡旋西南向传播最大(最大为0.09M/S),而越南以东海域涡动能(EkE)最大,这都说明涡旋活动与南海西边界流存在强的相互作用;(3)发现南海西边界流附近海表面温度(SST)强的季节内振荡特征,进一步研究表明此区域冬季SST季节内变化会使潜热季节内信号减弱20%;(4)探讨了南海贯穿流的长期变化特征以及与整个太平洋环流系统的相互关联.国家自然科学基金重点项目(40830851); 国家重点基础研究发展计划(2011CB403504); 中国科学院近海海洋观测研究网络——西沙南沙海洋观测研究站建设项目(KZCX2-EW-Y040)资