钢板组合梁桥设计要点分析

钢板组合梁桥构造简单、设计和建造的适用条件广泛、制作与施工方便，是一种非常经济和耐久的结构。为大力推广钢板组合梁桥的应用，文章对该种桥型的梁高、板厚、横梁、主梁分段及连接方式、桥面板等进行了介绍，对相关构造及设计理念提出了一些建议及想法，总结得出钢板组合梁只要构造合理，工法适宜，在20～150m跨度范围内均具有很强的竞争力。     

直线型GPS偏心观测法

GPS定位技术具有全天候、高效率、高精度且GPS点间无需通视、作用距离远等特点,在控制点无法架设GPS观测时,可采用偏心观测。介绍了从实用角度出发,在高精度GPS偏心观测中归心元素的测定方法,并介绍了其应用与其分析。     

EFFECT OF PREOPERATIVE CHEMOTHERAPY ON METASTASIZED LYMPH NODES IN PATIENTS WITH ADVANCED ESOPHAGEAL CARCINOMA

Recent advances in surgical teChniques and pe-rioperative management have significantly im-proved the resect rate, long-term survival and op-erative mortality of patients with esophageal can-cer. However, treatment of surgery only does notimprove the extremely poor prognosis of the pa-tients with local advanced squamous cell carcino-ma[lj. Multimodal therapy is needed to improve theprognosis for patients with locally advancedesophageal cancer. Most investigators have foundthat adjuvant treatme…     

旅客列车上水费清算系统的设计与实现

介绍了"铁路旅客运输清算系统"中的列车上水费清算子系统的设计与实现,就系统结构(包括在清算系统中的位置)、功能以及特点进行了阐述.     

铁路旅客运输清算分析系统技术方案的研究

利用数据仓库理论和智能决策分析工具,建立铁路客运清算分析系统,对于推动铁路财务体制改革,促进铁路市场化经营具有重要意义.在概述系统设计方案的基础上,对几个关键技术及其解决方案进行了重点论述.     

Bivariate Constant-Stress Accelerated Degradation Model and Inference Based on the Inverse Gaussian Process

Modern highly reliable products may have two or more quality characteristics (QCs) because of their complex structures and abundant functions. Relations between the QCs should be considered when assessing the reliability of these products. This paper conducts a Bayesian analysis for a bivariate constant-stress accelerated degradation model based on the inverse Gaussian (IG) process. We assume that the product considered has two QCs and each of the QCs is governed by an IG process. The relationship between the QCs is described by a Frank copula function. We also assume that the stress on the products affects not only the parameters of the IG processes, but also the parameter of the Frank copula function. The Bayesian MCMC method is developed to calculate the maximum likelihood estimators (MLE) of the model parameters. The reliability function and the mean-time-to-failure (MTTF) are estimated through the calculation of the posterior samples. Finally, a simulation example is presented to illustrate the proposed bivariate constant-stress accelerated degradation model.     

Pressure-Based Approach to Estimating the Injection Start and End in Single and Split Common Rail Injection Processes

The deep understanding on sand and sand dunes scale can be useful to reveal the formation mechanism of the sandstorm for early sandstorm forecast. The current sandstorm observation methods are mainly based on conventional meteorological station and satellites remote sensing, which are difficult to acquire sand scale information. A wireless sensing network is implemented in the hinterland of desert, which includes ad hoc network, sensor, global positioning system (GPS) and system integration technology. The wireless network is a three-layer architecture and daisy chain topology network, which consists of control station, master robots and slave robots. Every three robots including one master robot and its two slave robots forms an ad hoc network. Master robots directly communicate with radio base station. Information will be sent to remote information center. Data sensing system including different kinds of sensors and desert robots is developed. A desert robot is designed and implemented as unmanned probing movable nodes and sensors’ carrier. A new optical fiber sensor is exploited to measure vibration of sand in particular. The whole system, which is delivered to the testing field in hinterland of desert (25 km far from base station), has been proved efficient for data acquisition.     

铅酸蓄电池密度测量传感器研究

研究船用铅酸蓄电池电解液密度测量方法,分析了力学密度传感器、振动管式密度传感器、声学量密度传感器、光学量密度传感器等测量方法的优缺点。     

GIS-aided prediction for sea-ice distribution

A method of applying the geographic information system (GIS) to predict sea-ice distribution is proposed. The prediction computations are performed using the distributed mass/discrete floe (DMDF) model. The GIS is used to prepare the initial data for the DMDF model, and to display the simulation results together with a digital map and observational data for evaluation and further use. Two areas in the Arctic Ocean were selected to test the computations in this study. The results of the case studies show that this method can help with (1) free-area and free-scale prediction fitting for various purposes, (2) a high-resolution output to provide more detailed data, and (3) a reasonable combination of different data sets to make the best use of the information obtained. The results also suggest that the DMDF model is a good simulation of the ice motion not only for large-scale but also for local-scale predictions. Received: March 19, 2002 / Accepted: June 20, 2002 Acknowledgments. This study was financially supported by the Japan Science and Technology Corporation. The SSM/I sea-ice data were obtained from the EOSDIS NSIDC Distributed Active Archive Center (NSIDC DAAC), University of Colorado at Boulder. The authors thank the persons concerned. Address correspondence to: H. Yamaguchi (yama@fluidlab.naoe.t.u-tokyo.ac.jp)     

前列腺特异性抗原诊断前列腺癌的临床意义

随机选择泌尿外科就诊男性４００例，用前列腺特异性抗原（ＰＳＡ）检测前列腺癌，３２２例无前列腺疾患者中，３５例ＰＳＡ为４～１０μｇ／Ｌ，２例大于１０μｇ／Ｌ。血清ＰＳＡ水平随年龄的增长而增高。临床诊断良性前列腺增生症７５例，ＰＳＡ为４～１０μｇ／Ｌ及大于１０μ／Ｌ分别为２２例和７例。病理证实３例前列腺癌者的ＰＳＡ均明显升高（３／３），但用ＰＳＡ诊断前列腺癌的假阳性率高达９５．７％（６６／６９）。作者认为采用ＰＳＡ诊断前列腺癌的意义很小。