时滞离散网络模型的动力学分析与同步

复杂网络广泛存在于日常生活,首先,给出几类标准的网络模型;然后,利用稳定性控制方法设计并实现了具有时滞与非时滞耦合的复杂网络模型快速控制;最后,通过构造优化Lyapunov函数,讨论其模型的射影同步问题,得到了系统全局稳定的条件和有效的控制器,以实例数值验证其方法的可行性。     

保持底空间度量的Fell拓扑的相容度量

对于任意的局部紧可分(完备)度量空间(X,d),令Cld(X)为赋予了Fell拓扑的X上的非空闭集族.证明存在Cld(X)上一个相容(完备)度量D使得其保持X上的度量d.对于n维度欧式空间Rn,可以构建这样的度量D.不幸的是,这个具体构造的度量D不是完备的.所以,寻找一个满足上面条件的完备度量是一个有意义的问题.而如果...     

Multi-scale computation methods: Their applications in lithium-ion battery research and development

Based upon advances in theoretical algorithms, modeling and simulations, and computer technologies, the rational design of materials, cells, devices, and packs in the field of lithium-ion batteries is being realized incrementally and will at some point trigger a paradigm revolution by combining calculations and experiments linked by a big shared database,enabling accelerated development of the whole industrial chain. Theory and multi-scale modeling and simulation, as supplements to experimental efforts, can help greatly to close some of the current experimental and technological gaps,as well as predict path-independent properties and help to fundamentally understand path-independent performance in multiple spatial and temporal scales.     

First principle study of LiXS_2(X=Ga,In) as cathode materials for Li ion batteries

From first principle calculations, we demonstrate that LiXS_2(X = Ga, In) compounds have potential applications as cathode materials for Li ion batteries. It is shown that Li can be extracted from the LiXS_2 lattice with relatively small volume change and the XS_4 tetrahedron structure framework remains stable upon delithiation. The theoretical capacity and average intercalation potential of the LiGaS_2(LiInS_2) cathode are 190.4(144._2) m Ah/g and 3.50 V(3.53 V). The electronic structures of the LiXS_2 are insulating with band gaps of _2.88 eV and 1.99 eV for X = Ga and In, respectively.However, Li vacancies, which are formed through delithiation, change the electronic structure substantially from insulating to metallic structure, indicating that the electrical conductivities of the LiXS_2 compounds should be good during cycling.Li ion migration energy barriers are also calculated, and the results show that Li ion diffusions in the LiXS_2 compounds can be as good as those in the currently widely used electrode materials.     

蘑菇培养料中微生物的研究

本文对蘑菇培养料中分离获得的霉菌、放线菌和细菌进行鉴定和对其生理、生化特性进行测定,对某些菌株在蘑菇生长过程中的作用及作用规律也作了研究.通过研究,初步认为在放线菌和霉菌中有数株菌株对蘑菇的生长有直接或间接的促进作用     

应力对硅烯上锂吸附的影响

本文采用基于密度泛函理论的第一性原理平面波赝势方法研究了双轴应力作用下锂原子吸附硅烯的结构及其稳定性. 计算结果表明,在拉应力和一定的压应力作用下,锂吸附的硅烯体系基本保持原有的结构. 而当更大的压应力作用时,硅烯产生了向锂原子方向凸起的结构变化,所得到的体系的总能也有明显地下降. 本文通过对各种应力下的硅烯声子谱的计算,分析了在压应力作用下锂吸附的硅烯结构不稳定的原因. 关键词： 硅烯 应力 第一性原理 声子谱     

Radiation Induced Optical Absorption of Cubic Lead Fluoride Crystals and the Effect of Annealing

Transparent and colorless lead fluoride crystals with sizes of 20 × 20 × 20 （ram3） are irradiated with several doses of γ-rays from a ^60Co source. Their transmittance spectra before and after irradiation are measured, and a new parameter ΔT = Tb - Ta is defined to evaluate the irradiation damage. Three optical absorption bands peaking at 27Onto, 37Onto and 50Onto are found in the plots of AT versus wavelength, and their intensities increase with the irradiation dose. These optical absorption bands, except the one at 27Onto, can recover spontaneously with time. Thermal annealing treatment can enhance this recovery of the transmittance, while the optimum annealing temperature for different samples depends on the irradiation dose.     

首颗土壤湿度和海洋盐度观测卫星升空

不久前,由欧洲航天局(ESA)研发的全球首颗土壤湿度和海洋盐度观测卫星(Smos)从俄罗斯西北部的普列谢茨克发射场顺利升空,俄罗斯“轰鸣”运载火箭承担了发射任务。欧洲航天局称,该卫星能精确地描绘出水在陆地、海洋表面及大气层间的交换情况,至少每3d绘出一幅地球土壤湿度图,每30d绘出一幅海水含盐量图。科研人员可根据这些数据研究土壤湿度和海洋盐度的变化过程及对地球天气的影响,从而提高气候变化及极端自然现象预测的准确性,并了解地球冰层的情况。此外,在中短期天气预报、农业以及水资源管理等方面,这些数据也具有重要的应用价值。Smos携带了一台展开直径约为8m、外形类似直升机螺旋桨的综合孔径微波成像辐射计,整套系统采用折叠的方式置于火箭之中。这台名为Miras的科学仪器能通过对地球表面微波变化的观测确定地球土壤的湿度和海水的盐度。首颗土壤湿度和海洋盐度观测卫星升空@英     

德开发出可准确分辨危险液体的检测仪

出于安全考虑,世界上大多数民航机场都对乘客携带液体做了严格管制。主要原因是,目前还没有一种检测仪可以准确快捷地把危险液体和普通液体区分开。德国尤利西研究中心发表新闻公告说,该中心研究人员最近开发出一种检测仪,可以在几分之一秒内准确检测出危险液体。目前这种仪器的原型已成功通过相关测试。据介绍,在此之前就有类似的仪器,原理是利用不同液体反射电磁波射线的特征来判别它们的成分构成,这种构成是各种液体物质具有唯一性的“指纹”。但是,以前的仪器只能对范围比较窄的电磁波频率段进行扫描,这样得到的液体“指纹”只是一小部分,因此依据这些有限的“指纹”并不能保证准确判定各类液体的性质。尤利西研究中心研究人员说,新型检测仪扩大了电磁波频率的扫描范围,可以从几千兆赫兹到几百万兆赫兹。在完整记录下来的液体“指纹”帮助下,新型检测仪就可以准确分辨出各种危险液体。研究人员说,下一步将对这种新型检测仪进行技术细节改进,并使之小型化,不久这种仪器将会进入市场。德开发出可准确分辨危险液体的检测仪@英     

标准曲线法测定硫酸多粘菌素B的抗生素效价

硫酸多粘菌素B是多肽类抗生素,临床上主要用于敏感菌引起的感染及绿脓杆菌引起的泌尿系统感染、脑膜炎、败血症、烧伤感染以及皮肤粘膜感染等.2005年版<中国药典(二部)>规定用二剂量法或三剂量[1]法测定硫酸多粘菌素B抗生素微生物效价.笔者用标准曲线法(又称一剂量法)[2]测定其效价,取得了良好效果.