轴对称加载的阶梯式压力容器的径向振动

用奇异函数建立轴对称加载的阶梯式压力容器径向自由振动和强迫强振的微分方程并求得其通解,用Ｗ算子给出主振型函数的表达式及常见支承条件下容器的频率方程。     

Asymmetric diffusion model for oblique-incidence reflectometry

A diffusion theory model induced by a line source distribution is presented for oblique-incidence reflectometry.By fitting to this asymmetric diffusion model,the absorption and reduced scattering coefficients μa and μ’s of the turbid medium can both be determined with accuracy of 10% from the absolute profile of the diffuse reflectance in the incident plane at the negative position-1.5 transport mean free path(mfp’) away from the incident point;particularly,μs’ can be estimated from the data at positive positions within 0-1.0 mfp’ with 10% accuracy.The method is verified by Monte Carlo simulations and experimentally tested on a phantom.     

Synthesis of Ag/AgCl-mesoporous silica nanocomposites using a simple aqueous solution-based chemical method and a study of their antibacterial activity on E. coli

Simple aqueous solution-based chemical methods have been developed for the synthesis of Ag/AgCl nanoparticle-mesoporous silica nanocomposites. Ag loading in the mesoporous silica was accomplished using a wet-impregnation method. The AgCl-mesoporous silica nanocomposite material(AgCl-mSi) was synthesized by using a 'one pot' method. Synthesized materials were characterized using X-ray diffraction,N2 adsorption-desorption analysis and high-resolution transmission electron microscopy. Antibacterial activity of...     

Synthesis and cytotoxicity of novel podophyllotoxin derivatives

In order to find novel synthetic antitumor agents with superior cytotoxicity and overcoming multidrug resistance,a novel series of 4β-N-substituted podophyllotoxin derivatives were synthesized and evaluated as potential antitumor agents.Seven novel podophyllotoxin derivatives were synthesized by linking 4β-amino-4-deoxypodophyllotoxin with N-substituted 5-methylindol-3- yl-glyoxyl chlorides and tested against K562 and K562/A02 using SRB methods in vitro,KB and KBV using MTT methods in vitro.     

Synthesis and antitumor activity of novel podophyllotoxin derivatives

In order to find compounds with superior bioactivity and overcoming multidrug resistance,a novel series of 4β-N-substituted podophyllotoxin derivatives were synthesized and evaluated as potential antitumor agents.Seven novel podophyllotoxin derivatives were synthesized by linking-4β-amino-4-deoxypodophyllotoxin with alcohols through maleic acid and tested against K562 and K562/A02 using MTT assay in vitro.     

Effect of a portable ultra-clean exponential airflow unit on the particle distribution in an operating room

The effects of a mobile laminar airflow unit on the concentration,deposition and distribution of bacteriacarrying particles in an operating room are investigated.The exploration is carried out using numerical calculation schemes(computational fluid dynamics approach).The model validation was performed through result comparisons with published measurement data from literature.Two types of mobile screen units were evaluated as an extension of turbulent-mixing operating-room ventilation.Airborne particle concentration/sedimentation was recorded with and without a screen unit on the operating table and two instrument tables.Both active and passive air sampling were examined and the results are compared.It was found that the additional mobile ultra-clean laminar airflow unit reduces the counts of airborne bacteria and surface contamination to a level acceptable for infection-prone surgeries.     

STUDIES ON PHOTOOXIDATION (Ⅲ)——ELECTRON TRANSFER PHOTOOXIDATIONS OF 2-ALKYL-SUBSTITUTED DIPHENYLETHYLENES

The photooxidations of 2-alkyl-1, 1-diphenylethylenes 1a-1c (Ph_2C=CHR, R=Me,Et,Pr)sensitized by electron-deficient 9, 10-dicyanoanthracene (DCA) in MeCN have been studied-The reactions took place rapidly to yield the major product benzophenone 2 and minor onesof the corresponding epoxides 3a-3c which further underwent a facile rearrangement to formdiphenylmethyl alkyl ketones 4a-4c. The quantum yields for the disappearances of 1a-1cwere measured to be～0.45. Based on the product distribution fashion, an electron transfer(ET) mechanism was adopted to account for the title reactions. Evidence obtained supportsthe mechanism suggested, including cyclic voltammetry measurement, favorable free energychange predicted by Rehm-Weller theory, the pronounced quenching effect on the fluorescenceof DCA by 1a-1c as well as ESR studies of DCA~-. It is concluded that the DCA-sensitizedphotooxidation of aromatic olefins 1a-1c with alkyl substituents possessing relatively lowoxidation potentials still proceeds via ET me     

ICP-AES法测定镍基高温合金中16个元素的方法研究

该方法采用ICP-AES法对镍基高温合金中16个元素进行了测定,系统研究了基体元素和共存元素对分析元素谱线的光谱干扰情况,进行了分析线的选择,测定了方法检出限,通过准确度试验和精密度试验,表明该方法准确、可靠、简便、快速。