锂原子激发态光电离的R—矩阵计算

使用Ｒ－矩阵方法,采用三态密耦图象计算了锂原子激发态１ｓ＾２２ｐ＾２Ｐ的光电离截面,并给出了不同分波及不同过程的截面,计算结果揭示了光电离过程中的Ｒｙｄｂｅｒｇ系列共振,并指出在非共振区光电离截面不是单调变化的。     

Ba_xWO_3的微波合成、晶体结构和超导电性研究

以分析纯的BaCO3、WO3以及W粉为原料,通过混合微波方法合成了钡物青铜BaxWO3(0.14≤x≤0.25).样品的晶体结构为正交和四方两相共存,随着x的增加正交相的衍射峰逐渐减弱,而四方相的衍射峰呈现出增强的趋势.当x从0.14增加到0.25时,电阻率ρ下降了约两个数量级,且在x=0.2附近发生了从半导体到金属的转变.交流磁化率测量显示Ba0.21WO3在Tc=2.4K时发生了超导转变.     

复域中扰动Fejér点上Hermite——Fejér插值逼近的稳定性

该文在Jordan区域上研究扰动Fejér点上Hermite--Fejér插值对的逼近阶与收敛性, 完全解决了美国数学会 1991年Transactions of the AMS中Chui和Shen提出的问题,并将其边界条件J₂改进为.       

基于似然比检验的红外小弱目标快速航迹起始方法

利用红外测量跟踪系统获取目标信号幅度信息,提出了一种基于序列似然比检验的小弱运动目标航迹快速起始方法。用动态2维分配算法关联量测-航迹,采用序列似然比检验衡量航迹质量,一旦似然函数比达到阈值则确认目标航迹。该方法可根据目标信噪比不同采取不同帧数来起始、确认目标航迹,做到信噪比越大起始帧数越少,目标航迹检测概率越高,而信噪比越小则起始帧数越多。理论分析和试验结果表明,该方法既能提高航迹起始速度,又能提高目标航迹检测概率,避免和解决了M/N逻辑法需要固定扫描帧数才能确认航迹的局限性。     

ZEROS OF BRAUER CHARACTERS

The authors obtain a sufficient condition to determine whether an element is a vanishing regular element of some Brauer character. More precisely, let G be a finite group and p be a fixed prime, and H = G ′O p ′ (G); if g ∈ G0 -H0 with o(gH ) coprime to the number of irreducible p-Brauer characters of G, then there always exists a nonlinear irreducible p-Brauer character which vanishes on g. The authors also show in this note that the sums of certain irreducible p-Brauer characters take the value zero on every element of G0-H0 .     

Analysis of the connectivity and robustness of inter-satellite links in a constellation

In the design of new constellation configurations or research of existing constellation performance,the connectivity and robustness of inter-satellite links (ISL) are needed for analysis.In this paper,graph theory is used to analyze the connectivity and robustness of the ISL in constellations,which are measured under the requirements of a short average distance and a small range of ISL azimuth angles,elevation angles and distances.The method to determine ISL connectivity by using the adjacency matrix of gra...     

Rapid and Cheap Synthesis of Benzimidazoles via Intermittent Microwave Promotion: A Simple and Potential Industrial Application of Air as Oxidant

Using inexpensive KI as the catalyst in the presence of ambient air, benzimidazoles were synthesized from aromatic aldehydes and o-phenylenediamine with excellent yields via intermittent microwave irradiation without reflux equipment. The synthesis process was mild and only needed only a short reaction time (7–10 min). As a simple example of the utilization of molecular oxygen under mild conditions, this method provides a novel way to synthesize benzimidazoles. The industrial synthesis of benzimidazoles may be realized by a cycle of microwave irradiation.     

NaYF_4:Yb/Er-碳纳米管功能纳米材料的制备、表征及其在肿瘤细胞的靶向检测和治疗中的应用

将叶酸分子(FA)和2,3-二巯基丁二酸(DMSA)修饰的稀土上转换发光纳米粒子NaYF4:Yb/Er通过酰胺键偶联在多壁碳纳米管(MWCNT)的表面,得到NaYF4:Yb/Er-MWCNT-FA功能化复合纳米材料,并通过透射电子显微镜(TEM)、X射线衍射(XRD)、紫外-可见吸收光谱(UV-vis)、荧光光谱(PL)和共聚焦激光扫描显微镜等手段表征了其形貌、结构、发光性能和靶向成像性能.共聚焦激光扫描显微镜结果表明,相对于正常的HLF细胞,所制备的复合材料能够靶向检测叶酸受体高表达的宫颈癌Hela细胞.此外,将阿霉素进一步通过ππ堆垛吸附在此复合材料后,该载药体系具有明显的抗肿瘤活性,能够实现对肿瘤细胞的一步检测和治疗.     

Preparation and Characterization of Core/Shell-like Intumescent Flame Retardant and its Application in Polypropylene

With a shell of starch-melamine-formaldehyde (SMF) resin, core/shell-like ammonium polyphosphate (SMFAPP) is prepared by in situ polymerization, and is characterized by SEM, FTIR and XPS. The shell leads SMFAPP a high water resistance and flame retardance compared with APP in polypropylene (PP). The flame retardant action of SMFAPP and APP in PP are studied using LOI, UL 94 test and cone calorimeter, and their thermal stability is evaluated by TG. The flame retardancy and water resistance of the PP/SMFAPP composite at the same loading is better than that of the PP/APP composite. UL 94 ratings of PP/SMFAPP can reach V-0 at 30 wt% loading. The flame retardant mechanism of SMFAPP was studied by dynamic FTIR, TG and cone calorimeter, etc.     

Synthesis of Some Novel 2,3-diaryl-Butadiene Analogues

The reductive coupling of carbonyl compounds is an important method of carbon-carbon bond formation. The reaction can be used in both an inter-and intramolecular manner. It is important for the formation of olefins. Mukaiyama T., et al1 reported that the reductive coupling of ketones with TiCl4/Zn in tetrahydrofuran (THF) afforded the corresponding pinacols or olefins in high yields. The pinacols were obtained at 0℃. After heating, the deoxygenation reaction of pinacols afforded olefins2.…