微量掺碳nc-SiC:H薄膜用于p-i-n太阳电池的窗口层

采用等离子增强化学气相沉积方法(PECVD)制备了微量掺碳的p型纳米非晶硅碳薄膜(p-nc-SiC：H)，反应气体为硅烷和甲烷，掺杂气体采用硼烷，沉积温度分别采用333K，353K和373K.测量结果表明随着沉积温度增加和碳含量的增加，薄膜的光学带隙增加；薄膜具有较宽的带隙和较高的电导率，同时有较低的激活能(0.06eV).Raman和XRD测量结果表明薄膜存在纳米晶.优化的p型纳米非晶硅碳薄膜作为非晶硅p-i-n太阳电池的窗口层，使得太阳电池的开路电压达到0.94V. 关键词： 光学带隙 纳米硅 薄膜 太阳能电池     

离子-电子导电中呈现协同效应的互穿网络聚合物

用2,4-甲苯二异氰酸酯将蓖麻油及聚乙二醇(PEG)偶联成聚氨酯,同时通过自由基聚合使2-乙烯基吡啶(VP)与蓖麻油的双键共聚,生成互穿网络聚合物(IPN),其产率及凝胶含量大多超过93%,力学性能很好.当IPN与LiClO₄络合后呈现离子导电现象;与TCNE或TCNQ络合后产生电子导电,与LiClO₄及TCNE(TCNQ)络合后,呈现比上述两种导电率更大且具有协同效应的混合导电率,在25℃混合电导率可达到10^-3～10^-2S/cm.     

Drag forces of interacting spheres in power-law fluids

Drag forces of interacting particles suspended in power-law fluid flows were investigated in this study. The drag forces of interacting spheres were directly measured by using a micro-force measuring system. The tested particles include a pair of interacting spheres in tandem and individual spheres in a cubic matrix of multi-sphere in flows with the particle Reynolds number from 0.7 to 23. Aqueous carboxymethycellulose (CMC) solutions and glycerin solutions were used as the fluid media in which the interacting spheres were suspended. The range of power-law index varied from 0.6 to 1.0. In conjunction to the drag force measurements, the flow patterns and velocity fields of power-law flows over a pair of interacting spheres were also obtained from the laser assisted flow visualization and numerical simulation.

Both experimental and computational results suggest that, while the drag force of an isolated sphere depends on the power-index, the drag coefficient ratio of an interacting sphere is independent from the power-law index but strongly depends on the separation distance and the particle Reynolds number. Our study also shows that the drag force of a particle in an assemblage is strongly positions dependent, with a maximum difference up to 38%.     

Circular geodesics and accretion disk in the spacetime of a black hole including global monopole

We study circular time-like geodesics in the spacetime of a black hole including global monopole. We show that when the range of parameter changed the properties of the circular geodesics and the radiation of accretion disks are different. It follows that the properties of the accretion disk around black hole including global monopole can be different from that of a disk around Schwarzschild black hole.     

激光脉冲前后沿相干叠加对多程放大的影响

针对多程放大过程中激光脉冲经腔镜折返前后沿交叠的问题,建立了激光脉冲在增益介质中前后沿相干叠加放大的物理模型.理论分析表明,脉冲前后沿完全相干叠加形成驻波场,使得反转粒子数出现烧孔效应,影响输出脉冲的增益和波形.基于此物理模型,模拟计算了脉冲在多程放大过程中波形的演化,比较了不交叠、完全非相干叠加和完全相干叠加三种情况下对放大器的增益和对脉冲波形的影响.为高功率固体激光器的设计提供指导.     

One-pot synthesis of oxygen and nitrogen-bridged calix[2]arene[2]triazines

A simple and powerful one-pot reaction method was developed for the synthesis of heteracalixaromatics. In the presence of a base, one-pot macrocyclic condensation reaction between cyanuric chloride and 1,3-phenylene diols and diamines proceeded effectively under very mild conditions to afford a number of functionalised oxygen and nitrogen-bridged calix[2]arene[2]triazines in 33–54% yields. The method was applied in a multigram-scale (14.4 g) preparation of tetraoxacalix[2]arene[2]triazine.     

New Terpenoids from Potentilla freyniana Bornm. and Their Cytotoxic Activities

Two new A-ring contracted triterpenoids, madengaisu A and madengaisu B, and one undescribed ent-kaurane diterpenoid, madengaisu C, along with 20 known compounds were isolated from the roots of Potentilla freyniana Bornm. The structures were elucidated using extensive spectroscopic techniques, including 1D and 2D-NMR, HR-ESI-MS, ECD spectra, IR, and UV analysis. Moreover, all isolated constituents were evaluated for their anti-proliferative activity against RA-FLS cells and cytotoxic activities against the human cancer cell lines Hep-G2, HCT-116, BGC-823, and MCF-7. Ursolic acid and pomolic acid displayed moderate inhibitory activity in RA-FLS cells with IC₅₀ values of 24.63 ± 1.96 and 25.12 ± 1.97 μM, respectively. Hyptadienic acid and 2α,3β-dihydroxyolean-12-en-28-oic acid 28-O-β-d-glucopyranoside exhibited good cytotoxicity against Hep-G2 cells with IC₅₀ values of 25.16 ± 2.55 and 17.66 ± 1.82 μM, respectively. In addition, 2α,3β-dihydroxyolean-13(18)-en-28-oic acid and alphitolic acid were observed to inhibit HCT-116 cells (13.25 ± 1.65 and 21.62 ± 0.33 μM, respectively), while madengaisu B and 2α,3β-dihydroxyolean-13(18)-en-28-oic acid showed cytotoxic activities against BGC-823 cells with IC₅₀ values of 24.76 ± 0.94 and 26.83 ± 2.52 μM, respectively, which demonstrated that triterpenes from P. freyniana may serve as therapeutic agents for RA and cancer treatment.     

Crystal and molecular structure of main adduct of benzaldoxime dehydrodimer and styrene

Three 1:1 adducts have been obtained by heating benzaldoxime dehydrodimer with styrene. The main product possesses the structure of bis-nitrone type. A radical addition mechanism is proposed.     

基于药效团模型从中草药数据库中搜索gpⅡb/Ⅲa受体抑制剂

选择20个3,4-二氢-1(1H)-异喹啉酮类gpⅡb/Ⅲa受体抑制剂作为训练集,利用Catalyst软件包建立了gpⅡb/Ⅲa受体抑制剂三维药效团模型.探讨了药效团作用模式.并通过建立的可靠性最佳的药效团模型(线性回归系数r=0.7715),从中草药数据库中虚拟筛选了gpⅡb/Ⅲa受体抑制剂,通过实验活性测定得到了8个抑制ADP活化全血血小板聚集的IC50从40到100μmol·L-1的化合物,进一步证明了所建药效团模型的有效性.     

Syntheses and crystal structures of three copper(II) complexes with bulky Schiff bases derived from rimantadine

The reactions of copper(II) chloride dihydrate and three bulky Schiff base ligands derived from rimantadine and salicylaldehyde (or methoxy-substituted salicylaldehydes), generated C₃₈H₄₈CuN₂O₂ (1), C₄₀H₅₂CuN₂O₄ (2), and C₄₀H₅₂CuN₂O₄ (3), respectively. These complexes were characterized by infrared spectra, UV–vis, elemental analysis and molar conductance. X-ray single-crystal diffraction analysis reveals that 1 has two different spatial configurations, 1a and 1b. For 1a, each asymmetric unit consists of one mononuclear copper(II) molecule. For 1b, each asymmetric unit consists of two copper(II) mononuclear molecules. All the complexes crystallize in the monoclinic system, P2₁/c space group for 1a and 2; P2₁/n space group for 1b; C2/c space group for 3. Each complex for 1–3 consists of one copper(II) and two corresponding deprotonated ligands. The central copper(II) in all complexes is four-coordinate via two nitrogens and two oxygens from the corresponding Schiff base ligands. The geometry around copper in 1a, 1b, and 2 is distorted square planar, but square planar in 3.