Thermally-induced optical bistability with two holding beams

Thermally-induced optical bistability with two holding beams has been experimentally investigated in a metal-dielectric-metal interference mirror. Steady-state responses different from the usual S-shaped curve and with potential interest for composite logic operations are reported.     

Generation of a novel monoclonal antibody against cortisol-[C-4]-bovine serum albumin conjugate: application to enzyme-linked immunosorbent assay for urinary and serum cortisol.

Measurement of cortisol levels in body fluids is important for monitoring pituitary gland and adrenal functions. To develop a specific and standardized enzyme-linked immunosorbent assay (ELISA), a novel monoclonal anti-cortisol antibody has been generated using a reasonably designed haptenic derivative. Spleen cells were prepared from the BALB/c or A/J mouse, which had repeatedly been immunized with a conjugate of 4-(2-carboxyethylthio)cortisol (CET) and bovine serum albumin, to be fused with P3/NS1/1-Ag4-1 myeloma cells. After four fusion experiments, one hybridoma clone secreting a practical antibody has been established. The resulting monoclonal antibody CS#38 (isotype gamma1, kappa) showed an affinity constant (K(a)) for cortisol of 1 x 10(9) M(-1) and provided a practical calibration curve (detection limit, 0.26 ng per assay) in a homologous ELISA system employing horseradish peroxidase-labeled CET as a labeled antigen. Cross-reactivities with related C-21 steroids were acceptably low: 11-deoxycortisol (4.3%), cortisone (4.0%), corticosterone (1.9%), progesterone (1.6%), 17alpha-hydroxyprogesterone (12%), 6beta-hydroxycortisol (8.4%), and tetrahydrocortisol (< 0.1%). Urinary and serum cortisol levels of healthy volunteers were determined by this method after methylene chloride extraction to be 39.0 +/- 17.0 microg/day (n = 7) and 80.8 +/- 38.9 ng/mL (n = 10), respectively, both of which are in the reference range.     

Photophysics and Photochemistry of z‐Chlorprothixene in Acetonitrile†

Chlorprothixene (CPTX, Taractan^®) is a low potency antipsychotic mainly used for the treatment of psychotic disorders (e.g. schizophrenia) and acute mania occurring as part of bipolar disorders. As in the case of other numerous drugs used in the treatment of psychiatric disorders, CPTX presents geometric isomerism. Therefore, in vitro irradiation induces a rapid Z/E isomerization, which can affect its pharmacokinetic properties. This photoisomerization is not dependent on the oxygen concentration. The Z/E quantum yields determined for zCPTX in acetonitrile are 0.22 and 0.21 in anaerobic and aerobic environments, respectively. In the presence of water, both isomers decompose to produce 2‐chlorothioxanthone (CTX) after prolonged irradiation. This process strongly depends on the water concentration and the irradiation time, i.e. it is autocatalyzed by the CTX through a triplet‐energy transfer mechanism. The protonation state of the terminal amino group, on the other hand, has no effect on the isomerization process, but inhibits the formation of CTX. These results indicate that the phototoxicity of zCPTX is somehow affected by the formation of CTX.     

Photoluminescence from CdS Quantum Dots in Silica Gel

CdS semiconductor nanocrystals were grown as quantum dots (QDs) inside a silica matrix obtained by the sol-gelmethod and assisted in the mother liquid by high powerultrasounds. Small-angle neutron scattering (SANS) accountsfor a 3.6 nm crystal size homogeneously distributed. Optical excitation from the third harmonic of a Nd:YAG ns laser wasfocused on the sample to study the photoluminescence (PL) atroom temperature. The PL spectrum shows radiative processfrom intrinsic transitions and a broad band corresponding tothe traps. Variable stripe length (VSL) method was used to measure the optical gain spectra by the growth of theamplified luminescence. A broad optical gain spectrumproduced by the biexciton-exciton transitions revealing thestimulated emission from the CdS QDs. It is also observed ared-shift of the PL emission crystal size-dependent.     

Water and fluorinated alcohol mediated/promoted tandem insertion/aerobic oxidation/bisindolylation under metal-free conditions: Easy access to bis(indolyl)methanes

A green tandem reaction, including insertion/aerobic oxidation/bisindolylation, starting from indoles and diazo compounds has been developed. The combination of water and fluorinated alcohol plays dual roles as solvent and promoter in this chemical transformation. Molecular oxygen in the air acts as an oxidant. 3,3′-Bis(indolyl)methanes with quaternary carbon were produced under metal-free conditions. No any catalyst and additive were required. N₂ and water were released as sole by-products. Absence of water and fluorinated alcohol resulted in Wolff rearrangement product.     

基于微结构损伤的珠光体材料本构行为研究

珠光体材料由许多随机取向的珠光体团组成,每一珠光体团又由铁素体片和渗碳体片交替 叠合而成. 实验表明具有较小片层间距的珠光体材料具有较高的强度和寿命. 通过分析构成 珠光体团的各相及界面的损伤特征,利用损伤耗散功的概念,得到了铁素体、渗碳体与界面 损伤的具有统一形式的演化规律,将其嵌入基于细片层微结构和非经典塑性理论的珠光体团 的弹塑性本构方程,利用Hill自洽方法,得到了珠光体材料的损伤本构描述. 所得到的损 伤本构描述显含表征微结构特征的片层间距,容易证明具有较小片层间距的珠光体材料具有 较好的综合力学性能. 对珠光体材料的拉伸和循环拉压特性进行了分析,得到了与实验一 致的结果.     

计及相变微结构演化的形状记忆合金本构描述

基于对NiTi形状记忆合金的实验观察及有限元分析,考虑两相间的应变不协调关系,采用应变修正法建立了计及片层状微结构的本构模型,本模型考虑了两相间的相互约束,及其约束随微结构演化的变化规律.研究了NiTi形状记忆合金微圆管在拉伸和扭转下的响应特性.计算结果与实验结果的对比表明所建本构模型较好地描述了伪弹性响应尤其是较好地描述了拉伸实验过程中的应力跌落现象.     

带裂纹的椭圆孔口问题的应力分析

断裂现象与材料和结构中的孔洞、缺口或裂纹等缺陷密切相关,这是因为缺陷附近的应力集中明显.该文利用复变方法,通过保角映射研究了带裂纹的椭圆孔洞的平面弹性问题,给出了应力强度因子的解析解.并由此计算了两互相垂直的裂纹问题.     

Influence of surface modification of SrFe12O19 particles with oleic acid on magnetic microsphere preparation

Oleic acid was used as surface modification agent to improve the hydrophobicity of magnetic strontium hexaferrite particles. The structure and properties of treated magnetic particles were characterized by scanning electronic microscopy (SEM), Fourier transform infrared spectra (FTIR), powder X-ray diffraction (XRD) and magnetic property measurement system (MPMS). The results show that oleic acid is chemically enwrapped on the surface of SrFe12O19 particles. Magnetic particles modified by oleic acid are highly dispersible and strongly responsive to magnetism but with slight decrease in saturated magnetization. The affinity between magnetic particles and monomers is improved by surface modification, resulting in increased particle incorporation in magnetic polymeric microspheres. The surface modification mechanism of magnetic particles by oleic acid is addressed in this work.