生物还原药物AQ4N在肿瘤治疗增敏中的研究进展

目的观察尼美舒利(nimesulide)对人乳腺癌细胞MCF-7辐射敏感性的影响,并探讨其可能机制。方法实验分为对照组、加药组、单纯照射组(radiation treatment,RT)及加药照射组,用噻唑蓝(MTT)法检测尼美舒利对MCF-7细胞生长抑制率的影响,并选择用药后72h测得的IC20-IC30(抑制浓度,inhibiting concentration,IC)对应的药物浓度作为辐射增敏工作浓度;克隆形成实验检测尼美舒利对MCF-7的放射增敏作用;通过流式细胞仪检测细胞周期分布的变化。Western印迹法检测与凋亡相关蛋白Bcl-2和Bax的表达水平;并用单细胞凝胶电泳技术检测DNA的损伤及修复。结果尼美舒利对MCF-7细胞的生长抑制作用呈时间依赖性和剂量依赖性,但对周期分布无明显变化。尼美舒利加药照射组与单纯照射组比较,克隆存活曲线的肩区变窄,bcl-2表达下调,但对Bax表达没有明显影响。尼美舒利本身不明显增加MCF-7的DNA损伤,但可明显延缓放射引起的SSB的修复。结论提示尼美舒利对人乳腺癌MCF-7细胞株具有辐射增敏作用,其放射增敏机制可能通过抑制DNA损伤修复并下调bcl-2来得以实现。

Nucleon Superfluidity in Asymmetric Nuclear Matter and Neutron Star Matter

We have investigate the nucleon superfluidity in asymmetric nuclear matter and neutron star matter by using the Brueckner-Hartree-Fock approach and the BCS theory. We have predicted the isospin-asymmetry dependence of the nucleon superfluidity in asymmetric nuclear matter and discussed particularly the effect of microscopic three-body forces. It has been shown that the three-body force leads to a strong suppression of the proton S-1(0) superfluidity in beta -stable neutron star matter. Whereas the microscopic three-body force is found to enhance remarkably the (PF2)-P-3 neutron superfluidity in neutron star matter and neutron stars.

丰质子奇异轻核反应总截面测量

核反应总截面是表征原子核反应基本特征的一个基本量，从实验测得的核反应总截面中可以得到有关核反应、核结构和核内核子分布的信息。在由放射性束流所产生奇的结构与各种反应机制研究中，反应总截面的测量更是具有特殊的重要性，具有奇异晕核结构的核的一个典型的物理现象就是其反应总截面要比稳定核大很多，Tanihata等人最早就是通过对放射性束流的相互作用截面的测量发现了具有奇异结构的核，即中子晕核。这次实验结果得出的跟放射性奇异核性质等有关的一些有趣现象，为放射性束核物理的研究注入了新的活力。我们采用能量为80MeV/u的初级~(20)Ne束轰击3mm厚的初级Be靶，在RIBLL上测量了由初级靶上产生碎裂反应所得到的次级~(12)N, ~(17)F和~(17)Ne等质子滴线核在硅靶上的中能核反应总截面，从而进一步补充了现有的中能区奇异核反应总截面测量的空白，并对现有的数据进行了检验。由于~(12)N, ~(17)F和~(17)Ne都是有争议的可能具有奇异质子结构（质子晕或质子皮）的核，测量它们在中能区的核反应总截面，可以对上述说法的成立与否提供实验上的验证。在与相邻同位素核的反应截面测量结果的比较中，发现实验得出的这些奇异核的截面值都偏大，而且由相对论平均场（RMF）计算得到的它们的质子密度分布明显比中子分布松散的多，因此推断它们可能具有奇异质子分布结构。并且基于库仑修正后的微观Glauber模型的理论计算出这些奇异核反应截面的结果同我们得出的实验数据吻合得很好。为了更精确地进行奇异核反应总截面的测量，研制了两种双维位置灵敏平行板雪崩电离室（PPAC），可以放在待测硅靶前，用来选择小于一定入射角的次级束粒子，有助于得到更准确的结果。该PPAC的有效探测面积为50 * 50mm~2，分别采用电荷分除法和延迟线读出的方法确定入射粒子的位置，并具有结构简单、价格便宜的特点。用三组分α源(5.155Mev~(239)Pu, 5.486 Mev~(241)Am, 5.806Mev~(244)Cm) 对探测器进行了测试，由阴极电荷分除读出法得到的位置分辨（FWHM）约为1.5mm。

~(16)O + ~(28)Si全熔合激发函数研究及ΔE-E探测器系统的研制调试

ΔE-E望远镜探测器是用于重离子校反应测量的一种装置，它可以测量产物的电荷数和能量。在单路ΔE-E的基础上，我们研制了一路ΔE气体探测器和十路E金硅石垒探测器构成的多路ΔE-E望远镜探测系统。电离室窗直径为8cm，阴极到栅极距离为6cm，栅极到阳极距离为2cm，充入50的Ar(90%) + CH_4 (10%)气体，测得对~(241)Am的5.41Mev/α其能量分辩为13%。所用的十块金硅石垒探测器能量为1%左右。此系统可以同时测量22 °范围内的10个角度点，这对角分布测量将十分有利。该探测器系统对~(16)O + ~(12)C反应体的Z分辩约为6%，它可以清楚的分开C到Mg的各种元素。利用上述多路ΔE-E探测系统，我们测量了E_(16O) = 50Mev-90Mev的16_O束流轰击~RC、~(24)Mg、~(28)Si和~(32)S等四个体系校反应产物的角分布、能谱和激发函数。在测量激发函数时，我们选取能量步长为ΔE_(Lab) = 1Mev，以便观察振荡结构在角分布测量时，对于三个能量点，我们测量了5.1 °- 39 °范围内的13个角度点。由于时间限制，本毕业论文仅给出~(16)O + ~(28)Si反应的全熔合激发函数和角分布。并且运用G-M模型和Wiecki公式对全熔合截石进行了理论计算。从激发函曲线看，实验结果的平均趋势与G-M模型的理论结果符合的相当好，同时还发现了该体系全熔合截石随能量有规律的起伏，这种起伏具有公认的振荡结构和某些特征，因此这些起伏极有可能就是振荡结构

八单元一维位置灵敏雪崩室

In the experiment of nuclear reaction, it is important to measure the mass, charge, energy and emitted direction of particles. For multiparameter measurement, we must use a detector or a group of detectors which can give the time, energy, and position information. The Large Area position sensitive Ionization Chamber(LAIC) is one of the eight experiment terminals of HIRFL. It is built for researching nuclear reactions from low energy to intermediate energy. It is an excellent equipment for energy measurements and atomic number identification of emitted fragments in this energy region. It is also designed to give the time and position information of the emitted fragments by itself. Obviously, an IC can not supply a good timing signal. Moreover, the mechanical installation is different from the original design by some other reasons. In this case, it is not enough to obtain the correct direction information of the emitted fragments. To obtain good timing signals and the correct direction information, some modifications must be made. It is well known that a PPAC can give us excellent timing signals. It also can be easily built as a position sensitive detector. For this reason, a specially designed PPAC is installed in the entrance of the LAIC. For the different purposes, two types of PPACs were designed and tested. Both are OCTPSACs (OCTunit one dimension Position Sensitive Avalanche Counter). In this paper, both OCTPSACs will be introduced. Based on the requirements of the LAIC, the OCTPSACs consist of eight position sensitive PPACs. Each PPAC has an anode and a cathode. In both cases, the sizes are same. But different type of cathodes are used. In one type of OCTPSAC, its cathode is made of wire plane. It consists of gold-plated tungsten wires with the diameter of 20μm, spaced 0.5 mm apart from each other. The anode is a mylar foil which was evaporated by gold layer with the thickness of 50μg/cm~2 mounted on a printed plate in the shape of rectangle. the thickness of mylar foil is 1.5μm. The gap between anode and cathode is 3mm. The performance of the OCTPSAC has been tested by using a ~(252)Cf source in flowing isobutylene gas at the pressure of 3.4mb. The intrinsic time resolution of 289ps and position resolution of 2 mm have been obtained. In another type of OCTPSAC, the cathode is made of mylar foil, which is composed of gold strip by vacuume evaporation method with a special mask on the mylar foil. The thickness and the width of the gold strip is 50μg/cm~2 and 1.7mm. The strips are spaced 0.3 mm apart from each other. The anode is the same as the former type. We have obtained the time resolution of 296ps and position resolution of 2mm by using ~(241)Am-a source when the gas pressure is 6 mb and high voltage is 600V. The working gas is heptane

FRP约束SRHC压弯构件正截面承载力计算

综合考虑钢骨混凝土柱的受力特性,提出一种在不增加构件截面尺寸的情况下,既提高其承载能力,又增加其抗剪能力和抗震延性的一种新型柱模式——FRP(纤维增强复合材料)与SRHC(钢骨高强混凝土)组合柱.在混凝土内部埋设型钢,形成SRHC柱,在进行施工的同时或待结构主体施工至一定高度后,再用FRP布横向包裹及纵向粘贴SRHC柱,形成FRP-SRHC组合柱.考虑到FRP钢骨混凝土柱多数是处于偏心受压状态,因此,分析环向FRP布对核心混凝土的约束作用及纵向FRP布对钢骨混凝土柱正截面承载力的贡献,确定FRP约束SRHC组合柱的界限相对受压区高度,分别给出FRP约束SRHC柱大(小)偏心受压柱的承载力计算公式.

Analysis of sulfur-containing compounds in crude oils by comprehensive two-dimensional gas chromatography with sulfur chemiluminescence detection

This paper reports an analytical method for separating, identifying, and quantifying sulfur-containing compounds in crude oil fraction (IBP-360degreesC) samples based on comprehensive two-dimensional gas chromatography coupled with a sulfur chemiluminescence detector. Various sulfur-containing compounds and their groups were analyzed with one direct injection. 3620 peaks were detected including 1722 thiols/thioethers/ disulfides/1-ring thiophenes, 953 benzothiophenes, 704 dibenzothiophenes, and 241 benzonaphthothiophenes. The target sulfur compounds and their groups were identified based on the group separation feature and structured retention of comprehensive two-dimensional gas chromatography as well as standard substances. The quantitative analysis of major sulfur-containing compounds and total sulfur was based on the linear response of the sulfur chemiluminescence detector using the internal standard method. The sulfur contents of target sulfur compounds and their groups in 4 crude oil fractions were also determined. The recoveries for standard sulfur-containing compounds were in the range of 90-102%. The quantitative result of total sulfur in the Oman crude oil fraction sample was compared with those from ASTM D 4294 standard method (total S by X-ray fluorescence spectrometry), the relative deviation (RD%) was 4.2% and the precision of the method satisfactory.

长白山北坡植物群落复杂性的海拔梯度变化(英文)

应用梯度格局法在长白山北坡海拔700m-2600m的坡面上每100 m海拔设置一样地,共计20块样地,通过对同一群落各样方间的相异性测定,对各海拔植物群落的复杂性进行了分析。结果表明,以主林层乔木种的二元数据计算的结果,除亚高山岳桦林外,其它各海拔群落的样方间均表现出较高的相异性,特别是低海拔的阔叶红松林平均相异系数达0.74,明显高于其它植被类型;暗针叶林各群落间差异不大,相对而言1400 m群落样方间的相异性略高于其它群落,表现出过渡性群落树种组成的复杂性;岳桦林树种组成简单,样[(\267\275\274\344\322\262\261\355\317\326\263\366\275\317\270\337\265\304\\317\340\313\306\320\324\241\243)-0.1(\322\324\271\340\304\276\326\326\265\304\266\376\324\252\312\375\276\335\\274\306\313\343\265\304\310\272)]落内的相异性,虽低海拔的阔叶红松林总体上高于其它群落,但差异趋势并不像乔木种那么明显。以各草本植物与所有植物种的二元数据计算的各海拔群落内样方间的相异性,表现出非常相近的趋势,群落内样方间草本植物及所有植物种均以阔叶红松林及高山冻原差异最大,暗针叶林基本稳定于比较相近的水平。图3表1参8。

放牧和封育条件下科尔沁沙地小叶锦鸡儿群落土壤种子库特征

以科尔沁沙地小叶锦鸡儿群落为研究对象,对比分析了放牧干扰和不同封育年限下土壤种子库特征。结果表明:①放牧和封育样地土壤种子库均以一年生植物为主,物种丰富度没有明显差异;②放牧样地土壤种子库密度为(3 475±519)粒/m2,封育6年和封育12年样地土壤种子库密度分别为(20 241±1 714)粒/m2和(28 777±3 946)粒/m2,显著高于放牧样地;③Shannon-W iener多样性指数、S impson多样性指数和P ielou均匀度指数在放牧样地分别为1.36,0.68和0.56,并随着封育年限的增加而降低;④放牧和封育样地土壤种子库主要分布于0~2 cm的土壤表层,封育样地各层的种子库密度均显著高于放牧样地;⑤放牧和封育样地土壤种子库均为聚集分布,但放牧样地种子库的空间异质性高于封育样地。