激光雷达回波信号的蒙特卡罗模拟研究:I.均匀薄雾的多重散射强度分布(英文)

本文简要报道了激光雷达回波信号及多重散射强度分布的蒙特卡罗模拟计算结果。激光雷达系统采用共轴设计 ,计算中采用具有一定厚度、均匀分布的球形薄雾粒子来模拟大气环境 ,研究了粒子尺寸对回波信号的影响 ,获得了不同粒子半径、不同接受视场角条件下多重散射信号强度分布的经验公式。以上两套经验公式具有良好的校正系数 ,可以直接用于激光雷达系统设计中多重散射效应的研究 ,节省大量的模拟计算时间 ,提高设计效率     

噻胺酮麻醉剂对鼠S180肿瘤31P MRS的影响

对实验动物肿瘤进行活体³¹P MRS研究首要的是有效地固定动物.本文初步研究了用噻胺酮麻醉后的小鼠S180肿瘤在麻醉过程中³¹P MRS随时间的变异性.研究发现噻胺酮是一个安全系数高、起效快、麻醉过程适宜且对肿瘤的³¹P MRS无显著影响的麻醉药.因而噻胺酮适用于连续测定³¹P MRS的需要.     

LNG化学能与冷(火用)综合梯级利用的多重联合循环

本文提出了综合梯级利用LNG化学能和冷(火用)的多重联合循环。住对多重联合循环系统集成的设计构思基础上,通过不同物性工质和不同循环方式的系统集成,实现了LNG化学能和冷(火用)的高效梯级利用。新循环的(火用)效率与参比循环相比提高了2.3个百分点。本文成果为更高效综合利用LNG提供新的构思和方案。     

感染减毒鼠伤寒沙门氏菌对小鼠粪样代谢组的影响——WIPM和Bruker 500 MHz核磁共振波谱仪检测结果的比较

鼠伤寒沙门氏菌属于胞内侵袭性兼性厌氧菌,减毒后的鼠伤寒沙门氏菌安全性大大提高,已被广泛用于病毒、细菌及寄生虫疫苗的研制.但是目前还没有研究利用代谢组学方法来分析减毒鼠伤寒沙门氏菌感染对宿主和肠道菌群相互作用的影响.同时中国科学院武汉物理与数学研究所自主研发的WIPM 500 MHz核磁共振(NMR)波谱仪已经研制成功,但是该谱仪是否可以用于代谢组学研究尚未经过考证.本研究同时使用WIPM和Bruker500 MHz核磁共振波谱仪对同一批减毒鼠伤寒沙门氏菌感染小鼠的粪样进行检测,并结合多变量数据分析方法来研究减毒鼠伤寒沙门氏菌感染对小鼠粪样代谢组的影响.研究结果表明,WIPM NMR波谱仪检测数据的分析结果与Bruker NMR波谱仪的实验结果具有高度的一致性,表明WIPM谱仪可以用于代谢组学研究.研究发现减毒鼠伤寒沙门氏菌感染能够引起小鼠粪样代谢物中多种氨基酸和尿嘧啶含量的上升,并伴有胆汁酸、乳酸和丙酸含量的下降.以上代谢物含量的改变表明,减毒鼠伤寒沙门氏菌感染使小鼠肠道微生物的代谢功能发生了紊乱.     

百兆电子伏特/核子原子核诱发乳胶核反应靶核反冲质子多重数涨落分析(英文)

利用标度阶乘矩方法对290 A MeV $^{12}$C-AgBr, 400 A MeV $^{12}$C-AgBr, 400 A MeV $^{20}$Ne-AgBr及500 A MeV $^{56}$Fe-AgBr 作用靶核反冲质子在二维正常相空间及累积变量空间发射过程中的多重数涨落分别进行了分析。实验结果表明:在正常相空间,对于秩数q较小时标度阶乘矩（$ln$）随相空间的分割数的增加而增加,而对于秩数较大时标度阶乘矩（$ln$）随相空间的分割数的增加表现出先增加后趋于饱和或减小的趋势;在累积变量空间,标度阶乘矩（$ln$）随相空间的分割数的增加而减小,这表明对于我们所研究的核作用体系靶核反冲质子发射过程中不存在非统计涨落。Multiplicity fluctuation of the target recoil protons emitted in $290$\,A MeV $^{12}$C-AgBr, $400$\,A MeV $^{12}$C-AgBr, $400$\,A MeV $^{20}$Ne-AgBr and $500$\,A MeV $^{56}$Fe-AgBr interactions are studied using the scaled factorial moment (SFM) method in two-dimensional normal phase space and cumulative variable space, respectively. It is found that in normal phase space the SFM ($\ln$) increases linearly with the increase of the divided number of phase space ($\ln{M}$) for lower q-values and increases linearly and then becomes saturation or decrease with the increase of $\ln{M}$ for higher q-values, and in cumulative variable space $\ln$ decreases linearly with the increase of $\ln{M}$, which indicates that no evidence of non-statistical multiplicity fluctuation is observed in our data sets.     

肿瘤和正常组织的FT—Raman与FT—IR研究

本文运用ＦＴ－Ｒａｍａｎ光谱法研究肠、胃、十二指肠、口腔腮腺等部位正常组织与肿瘤组织，发现正常组织与肿瘤组织在Ｒａｍａｎ光谱上表现出较为明显的差别，这一结果与我们先前所得到的红外光谱结果相一致。此研究说明Ｒａｍａｎ光谱亦有潜力发展成为一种活体，原位，无损诊断肿瘤的新方法。     

绿茶和红茶中微量元素初级形态含量的研究

本文采用沸水浸泡法对茶叶的初级形态进行分离 ,原子吸收光谱法测定了绿茶和红茶初级形态中 8种微量元素含量 ,计算并讨论了微量元素初级形态分析参数 ,获得茶叶中微量元素初级形态的有关信息。结果表明 ,绿茶和红茶中 8种微量元素初级形态含量各有差异 ,初级形态分析参数自符合程度为87.2 0 %— 10 3.73% ,样品的回收率为 87.1%— 10 2 %。     

惊恐对鼠体组织损伤和中药保护机理的FTIR光谱法研究

首次利用微钻石衰减全反射傅里叶变换红外光谱法 (ATR/FTIR)研究了天敌惊恐对小鼠组织的损伤。结果表明 :惊恐后小鼠肾与足表面脂类化合物明显增高 ;服用补肾天然药物后 ,与正常对照组相比 ,脂类化合物变化不明显 ,进而说明药补可缓和压力 ,起到一定的调节作用。惊恐后小鼠心、肝和脑组织的红外谱没有变化 ,这是因为各个脏器对皮质激素的敏感程度不完全一样。     

~(12)C~(6 )离子辐照小鼠Lewis肿瘤的研究

研究了HIRFL提供的12C6 离子辐照C57BL/6J小鼠右后腿移植的Lewis肿瘤的生长延迟和碳离子辐照对Lewis肿瘤小鼠寿命的延长.结果表明,碳离子照射的小鼠肿瘤生长体积明显地小于对照的体积.在剂量相同、分次数辐照越多时,肿瘤生长就越缓慢,肿瘤抑制就越高.在辐照分次数相同时,不同剂量对受照肿瘤生长体积未产生差异.在4Gy×3,8Gy×3和12Gy×2组3种辐照剂量下,小鼠寿命的P值小于0.05;可知小鼠的寿命延长具有统计学意义.     

正常和嵌合肿瘤乳腺温度分布特征的有限元分析

基于乳腺解剖学结构和生理学特征,建立了适合应用于正常和嵌合肿瘤乳腺三维热传递的分析模型.该模型综合考虑了乳腺代谢产热、血液灌注和动静脉血管与乳腺组织之间的热交换等因素对温度场的影响.数值研究了正常和嵌合肿瘤乳腺的温度分布特征,着重分析代谢产热、血液灌注率、乳腺肿瘤的大小、位置与数目以及空气对流系数、环境温度等因素对乳腺温度分布的影响.结果表明:血液灌注率、代谢产热、乳腺肿瘤的大小、位置与数目对乳腺温度分布特征的影响明显;环境条件对嵌含肿瘤乳腺的体表温度分布影响较大.研究结果将有助于指导乳腺红外热图像的实验并为其定性分析提供重要的参考.     

微波元件与加速结构的有限元分析

研究了有限元方法在二维均匀结构和轴对称加速结构中的应用,采用了带宽优化技术和子空间求解特征值方法,并给出了部分例子,结果表明该方法精度高、速度快.这些方法可直接用于三维程序、并行计算.     

中药红花总黄酮及微量元素含量的分析研究

采用紫外分光光度法测定了新疆地产中药红花中总黄酮的含量,在200～400 nm波长范围内扫描,最大吸收波长为λ=267.00 nm。原子吸收分光光度法测定了K, Na, Ca, Mg, Fe, Cr, Ni, Mn, Cu和Zn十种微量、常量元素的含量。结果显示红花中含有丰富的微量元素和较高的总黄酮,微量元素含量较高的是Ca, Mg, Cr, Cu和Zn元素。实验结果为探讨中药红花中总黄酮含量与微量元素的关系及研究红花中微量元素与治疗心脑血管疾病的关系提供了有用的数据。     

SXRF分析恐龙脊椎头化石微量元素

利用同步辐射X射线荧光成像方法(SXRF)检测了二件不同地区的脊椎头恐龙化石,在每件化石截面上的二个不同区域分别获取了8种元素的分布图及其荧光光谱。在两件样品靠外层的骨密质部位,发现有较密集的稀土元素Y(钇)。在姜驿恐龙化石中Y的富集,来自于化石的成岩过程,在元素分布图中与稀土元素Y共生的含Ca化合物是氟磷酸钙。武定田心恐龙脊椎头化石中,在稀土元素钇的富集的区域,其它元素包括Ca的含量均特别少。此种稀土元素的富集可能是由于化石中含有分解不完全的有机物的吸附所致。在姜驿恐龙脊椎头化石中,微量元素Mn、Fe和Al属于共生矿物;As、Sr、Y元素集中分布在化石的外边缘处,也是三者共生。在田心恐龙脊椎头化石中,微量元素Mn、Fe和Al属于共生矿物,Sr、Y元素共生,Cu元素的分布相对集中。研究表明,恐龙化石中矿物的元素含量及其分布与骨骼所属的部位无关,只与源地有关。恐龙化石中稀土钇富集的地方,呈现白色。同步辐射X射线荧光探测法,能原位、快速、无损地检测出化石样品各种元素的荧光光谱,给出恐龙化石元素分布的二维信息,对于分析恐龙化石所蕴含的侏罗纪时期的古地质特征和古生物信息,给出了重要的依据。     

傅里叶变换红外光谱用于食管癌及癌旁正常组织结构的相关研究

应用傅里叶变换红外光谱法(FTIR)对43例食管癌及癌旁正常组织进行了分析,结果表明,食管癌组织和癌旁正常组织的红外光谱具有较大的差异:正常组织的红外光谱在1550 cm-1附近的酰胺Ⅱ带吸收峰相对较强,峰型高尖,与酰胺Ⅰ带的相对峰高比(I1647/I1550)在癌组织中比较高;正常组织中酰胺Ⅰ带的吸收峰峰位比癌组织的高1-6 cm-1;正常组织中1453 cm-1处的峰强大于1402 cm-1处,而在癌组织中则相反,1402 cm-1附近的吸收峰峰高大于1453cm-1处;癌组织中1080 cm-1附近的峰位和正常组织相比显得高而强,癌组织的相对峰高比(I1080/I1550)高于正常组织。说明傅里叶变换红外光谱法可以用于对良、恶性组织进行鉴别诊断,有希望发展成为肿瘤快速诊断的一种新方法。     

Whole Body Protein Metabolism Estimated by 15N Tracer Experiments and Body Composition of Mice Selected for Different Growth Parameters

Abstract

Whole body protein synthesis was investigated in growing male mice which were long-time selected for high carcass protein amount (DU-6P, protein line) or for high body weight (DU-6, growth line) and in the unselected randomly bred control (DU-Ks). Six mice/line were housed singly in metabolic cages for the estimation of N balance, whole body protein synthesis (end-product method, single dose of ¹⁵N-labelled amino-acid mixture), and N distribution in the body. Another six mice/line were used for the determination of the body composition. All mice had free access to a commercial stock diet (crude protein 268 g, gross energy 19 MJ/kg dry matter) and to water. Body weight of both selection lines was about twice that of control mice at the same age. Selection for high body weight resulted in higher body fat content. Scaled to the corresponding body protein pools, the protein synthesis rates of selected mice were significantly higher than in controls, but were not significantly different between both selection lines in contrast to the protein deposition rates. The higher protein accretion in the protein line in comparison to the growth line seems to be due to a combination of a lower protein breakdown and an increased protein synthesis rate.     

Feasibility of Laser-Induced Breakdown Spectroscopy for the Study of the Temporal Distribution of Trace Elements Trapped in Snow Collected from Greater Himalayan Range

The potential merit of laser-induced breakdown spectroscopy (LIBS) has been demonstrated for detection and quantification of trace pollutants trapped in snow/ice samples. In this technique, a high-power pulsed laser beam from Nd:YAG Laser (Model no. Surelite III-10, Continuum, Santa Clara, CA, USA) is focused on the surface of the target to generate plasma. The characteristic emissions from laser-generated plasma are collected and recorded by a fiber-coupled LIBS 2000+ (Ocean Optics, Santa Clara, CA, USA) spectrometer. The fingerprint of the constituents present in the sample is obtained by analyzing the spectral lines by using OOI LIBS software. Reliable detection of several elements like Zn, Al, Mg, Fe, Ca, C, N, H, and O in snow/ice samples collected from different locations (elevation) of Manali and several snow samples collected from the Greater Himalayan region (from a cold lab in Manali, India) in different months has been demonstrated. The calibration curve approach has been adopted for the quantitative analysis of these elements like Zn, Al, Fe, and Mg. Our results clearly demonstrate that the level of contamination is higher in those samples that were collected in the month of January in comparison to those collected in February and March.     

A Novel Fabrication Technique of Long Period Fiber Gratings Using a Holographic Optical Element

We develop a new flexible and precise ultraviolet exposure technique to fabricate a long period fiber grating using a computer-generated holographic optical element (HOE). The HOE can generate a striped beam pattern with about a 300 #x03BC;m period from a KrF excimer laser. This method offers (1) ease in varying the grating period and (2) grating period precision. We achieve a grating period within an accuracy of #x00B1;0.04 #x03BC;m. This means that the peak wavelength can be controlled within an accuracy of #x00B1;0.2nm with an operating wavelength of 1.55 #x03BC;m.This paper was originally presented at the 2nd International Conference on Optical Design and Fabrication, ODF2000 which was held on November 15-17, 2000 at the International Conference Center, Tokyo, Waseda University, Japan.     

A Rapid Method for the Determination of Trace Element Impurities in Silicons Oils by ICP-MS After Microwave-Assisted Digestion

Abstract

A microwave-assisted digestion procedure has been developed for the treatment of silicone oil samples. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the concentration level of 40 trace element impurities, like Li, Na, Mg, Al, P, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Sr, Rb, Zr, Nb, Mo, Ag, Cd, Sn, Sb, Ba, La, Ce, Nd, Hf, W, Au, Pb, Hg, Th, Bi and U in these samples, having obtained average relative standard deviation values of 9.6%. The methodology developed has been tested by recovery studies on different natural samples spiked with known amounts of Mg, Cr, Mn, Fe, Zn and Pb at concentration levels of 10, 0.5, 5, 5, 10 and 1 μg g^?1 and recovery percentage values varies from 97 to 105 %.     

广寄生及其不同寄主黄酮总量和微量元素含量的研究

用紫外分光光度法测定广西玉林产5种广寄生及其不同寄主的黄酮总量;原子吸收分光光度法测定广寄生和寄主的Fe、Mg、Zn、Ca、Mn、Cu、Na、K8种微量元素的含量。结果表明:寄主不同,广寄生黄酮总量和微量元素含量存在差异;广寄生的黄酮总量比寄主高,广寄生的K、Mg元素含量比寄主高。