索理绪机内煮熟茧滞留时间分布推定问题的频谱分析法

本文用平稳随机过程的线性系统分析理论,提出了索理绪机内煮熟茧滞留时间分布推定的一种解决方法,并讨论了该分布推定的误差问题。     

虚拟仪器软件平台设计

目的　设计一通用的虚拟仪器软件平台 .方法　采用 Visual C++面向对象设计语言和数据库技术 .结果　VC通用虚拟仪器软件平台为用户提供了仪器驱动程序的部件函数库、软面板控件、数据处理、结果分析、数据显示函数 ,组建了数据采集、频谱分析仪、信号发生器 .结论　虚拟仪器软件平台是一开放的、通用的软件系统 ,用户可以方便地组建虚拟仪器软件 .     

一种先进的TTL超高速比较器

文章介绍了一种新型TTL超高速比较器，并对其工作原理、制作工艺、技术性能及可靠性设计等进行了简要描述。该产品具有工作电压低（ 3V)、功耗小（6mA)、响应时间快（10ns)等显著特点，可以广泛应用于高速时序逻辑、线性接收器、数字通讯、模拟信号高速采样以及PCMCIA卡等领域。     

Racial differences in fetal morphometry in Singapore

A systematic collection of fetal morphometric measurements was started seven years ago in 1987 with the prospective entry of data into personal computer-based stations in the Department of Obstetrics and Gynaecology, Singapore General Hospital. A cross-sectional study was done, comparing 2392 Chinese fetuses with 2117 Malay fetuses and 459 Indian fetuses from 18 to 40 weeks. The mean values of the head circumference (HC), abdominal circumference (AC) and femur length (FL) of the 3 ethnic groups were analysed. There were no statistical significant differences in the head circumference and abdominal circumference of Chinese, Malay and Indian fetuses in Singapore. The Chinese and Malay fetal femur length appeared similar but were apparently shorter than the Indian femur length. Nomograms of head circumference, abdominal circumference and femur length were constructed for application to fetuses of all 3 ethnic groups.     

Optimized acquisition time and image sampling for dynamic SPECT ofTl-201

With the recent development in scatter and attenuation correction algorithms, dynamic single photon emission computerized tomography (SPECT) can potentially yield physiological parameters, with tracers exhibiting suitable kinetics such as thallium-201 (Tl-201). A systematic way is proposed to investigate the minimum data acquisition times and sampling requirements for estimating physiological parameters with quantitative dynamic SPECT. Two different sampling schemes were investigated with Monte Carlo simulations: (1) Continuous data collection for total study duration ranging from 30-240 min. (2) Continuous data collection for first 10-45 min followed by a delayed study at approximately 3 h. Tissue time activity curves with realistic noise were generated from a mean plasma time activity curve and rate constants (K₁-k₄) derived from Tl-201 kinetic studies in 16 dogs. Full dynamic sampling schedules (DynSS) were compared to optimum sampling schedules (OSS). The authors found that OSS can reliably estimate the blood flow related K₁ and V_d comparable to DynSS. A 30-min continuous collection was sufficient if only K₁ was of interest. A split session schedule of a 30-min dynamic followed by a static study at 3 h allowed reliable estimation of both K₁ and V_d avoiding the need for a prolonged (>60-min) continuous dynamic acquisition. The methodology developed should also be applicable to optimizing sampling schedules for other SPECT tracers     

一种新的油气藏预测方法——概模法

提出新的储层分类和油气藏预测方法——概模法.介绍用该法对莺歌海盆地LD15-1气田的分布范围及CO_2.含量变化的描述分析和二连盆地阿尔善油田的反射特征异常解释.     

传统艾灸与替代物灸和人体穴位红外辐射光谱比较

对传统艾灸、替代物灸和人体穴位红外辐射光谱的分析比较发现，隔附子饼灸、隔姜灸和隔蒜灸三种传统间接灸与人体穴位归一化红外辐射光谱有惊人的一致性，其辐射峰均在7。5μm附近；而几种替代物灸与相应传统艾灸和人体穴位的辐射光谱相差甚远，其温热作用也远不如传统艾灸；传统艾条黄灸与人体穴位红外辐射光谱也有很大差异。结果提示，在传统间接灸的治疗效应中，间接灸和穴位的红外共振辐射起重要作用；从艾灸的红外物理特性看，替代物灸尚不能替代传统艾灸。     

WISE: a World Wide Web resource database system

The paper describes the World Wide Web Index and Search Engine (WISE) for Internet resource discovery. The system is designed around a resource database containing meta information about WWW resources and is automatically built using an indexer robot, a special WWW client agent. The resource database allows users to search for resources based on keywords, and to learn about potentially relevant resources without having to directly access them. Such capabilities can significantly reduce the amount of time that a user needs to spend in order to find the information of his/her interest. We discuss WISE's main components: the resource database, the indexer robot, the search engine, and the user interface, and through the technical discussions, we highlight the research issues involved in the design, the implementation and the evaluation of such a system     

TA2钛板的复合氧化及耐蚀性

研究了TA2钛板复合氧化 (热氧化与阳极氧化的迭加 )获得氧化膜的形貌、成分和耐蚀性。结果表明 ,迭加方式不同 ,氧化膜形状特征不同。经复合氧化处理后 ,氧化膜外层由TiO2 和Ti2 O3 组成 ,内层由Ti2 O3 和TiO组成 ;随深度的增加 ,TiO2 含量逐渐减少 ,TiO含量逐渐增加 ,Ti2 O3 含量先增加后减少。复合处理后 ,TA2耐蚀性显著提高。     

The influence of VTES on the hydration process of C3S

This paper investigated the hydration process of tricalcium silicate (C₃S) in which a small amount of vinyltriethoxysilane (VTES) was added by using the techniques of ¹H NMR, ²⁹Si MAS-NMR and XRD. In comparison with the hydration process of C₃S without adding any additives, not only the average molecular weight of hydrated calcium silicate in C₃S paste, but also the ordering of the silicon nuclei in it increased. This indicates that the VTES has joined effectively into the real hydration process of C₃S. These results imply some possible reasons why the intrinsic properties of low porosity hardened cement paste (HCP) in which a small amount of VTES was added could be improved. Besides, it has been found that in early stage hydration of C₃S with or without VTES, Ca(OH)₂ crystal in the paste appears earlier than Q₁ which shows that in the first several hours of hydration, there only exists Si(OH)₄ and other basic salts and no dimer and polymer of silicate anion when Ca(OH)₂ crystal begins to form.