Seasonal patterns of deaths in Matlab, Bangladesh

BACKGROUND: Deaths exhibit a seasonal pattern in most parts of the world. Analyses of deaths for the years 1972-1974 from the vital registration system of Matlab, Bangladesh, published in this journal 17 years ago, showed sinusoidal seasonal patterns. As death rates have declined in other nations, the seasonal pattern is attenuated. Death rates have declined substantially in Bangladesh in the past two decades. Thus, the present study examines monthly counts of deaths from Matlab data for a period 15 years later and tests the hypothesis of a decrease or shift in seasonality over time. METHODS: Trigonometric regression models were fit to monthly data by age and cause of death from the Matlab vital registration system for the years 1982-1990. A total of 20,328 death records were available for analyses. RESULTS: In the recent period significant sinusoidal seasonal patterns are found in all but one of the age and cause of death groups. Total deaths peak in the winter as do neonatal deaths but post-neonatal and child deaths are maximum in April and July respectively. Among cause groups, injury deaths (mostly attributed to drowning) show the greatest seasonal swing. The time of peak has only shifted for one age group--neonates--since the 1972-1974 period. The magnitude of the seasonal swing has declined significantly only for the neonatal age group and injury cause of death group. CONCLUSION: Marked seasonal patterns of deaths persist in the Matlab area of Bangladesh even as the level of mortality has declined.     

秦山核电厂一回路辅助工艺系统调试

本文叙述了秦山核电厂一回路主要调试项目以及在预运运行试验和初始启动试验阶段的实施情况。调试结果表明，系统已具备所要求的功能，运行参数达到了设计要求，能安全、可靠地配合反应堆冷却剂系统，满足各种工况的运行要求。     

Studies of the neutralizing activity and avidity of anti-human immunodeficiency virus type 1 Env antibody elicited by DNA priming and protein boosting

DNA vaccination is an effective means of eliciting strong antibody responses to a number of viral antigens. However, DNA immunization alone has not generated persistent, high-titer antibody and neutralizing antibody responses to human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env). We have previously reported that DNA-primed anti-Env antibody responses can be augmented by boosting with Env-expressing recombinant vaccinia viruses. We report here that recombinant Env protein provides a more effective boost of DNA-initiated antibody responses. In rabbits primed with Env-expressing plasmids, protein boosting increased titer, persistence, neutralizing activity, and avidity of anti-Env responses. While titers increased rapidly after boosting, avidity and neutralizing activity matured more slowly over a 6-month period following protein boosting. DNA priming and protein immunization with HIV-1 HXB-2 Env elicited neutralizing antibody for T cell line-adapted, but not primary isolate, viruses. The most effective neutralizing antibody responses were observed after priming with plasmids which expressed noninfectious virus-like particles. In contrast to immunizations with HIV-1 Env, DNA immunizations with the influenza virus hemagglutinin glycoprotein did not require a protein boost to achieve high-titer antibody with good avidity and persistence.     

对梁,底组合步进式加热炉半热滑轨的改进实践

介绍了间断式半热滑轨的研制和应用过程，以及经过节能技术改造，用新型半热滑轨代替老式滑轨的使用。实践表明，不但解决了以往的水梁漏水的问题，而且使线Ｃ级品率提高了３．３９％，每年可增产３５００ｔ线材，吨钢热涌单耗降低０．１４ＧＪ，年创经济效益２３９万元。     

Rate-smoothed schedule with tolerable data dropping for video coding stream

Most algorithms of smoothing schedule compute the required bit rate of video transmission to satisfy all the transmitted data. In this paper, our proposed tolerable data dropping algorithm can adjust transmitting data to fit available bit rate. MPEG-4 with fine grained scalability (FGS) can support partial data dropping to adapt to available bandwidth network. The algorithm is based on the minimum variance bandwidth allocation (MVBA) algorithm proposed by Salehi et al. to compute the bit rate such that still ensuring that the buffer never underflows and overflows for MPEG-4 FGS streams under the limited bandwidth resource. We prove that our proposed algorithm, named MVBADP, is smoother than the MVBA algorithm. The experimental results show the peak rate, the number of rate changes, and the ratio of total dropping data, and the PSNR for four test sequences with different content characteristics. They are varied by buffer sizes and tolerable dropping ratios. We found that the MVBADP algorithm can reduce the peak rate and the number of changes when the transmitted data are dropped by tolerable dropping ratio, especially on the video sequences with the high motion and complex texture characteristic and larger size change of the consecutive frame.     

基于KML的GPS数据轨迹可视化

针对GPS轨迹数据可视化的需求,采用KML技术设计具有针对性的数据管理构件。通过对NMEA-0183数据解析和基于Bursa-Wolf方法的空间数据转换等过程,实现一种空间数据精确转换到KML的方法,成功应用于某GPS数据管理平台,为其提供高效、可靠的GPS轨迹数据可视化与交互处理功能。     

“绕射积分偏移”的成象原理及提高其偏移剖面质量的探讨

“绕射积分偏移”的过程一直都是用绕射波收敛理论来描述的.但是这个理论不能解释为什么经过“绕射积分偏移”的剖面会有信噪比降低和弧形干扰的现象.在这时,我们用一个简单的数学模型,并理想化了一些条件,弄清了“绕射积分偏移”成像的真正原理.我们发现在任一CDP点下面的反射界面点的位置应与某一双曲线的顶点时间相当,这个双曲线正好处在与相应的反射t_0剖面上各道波至所形成的直线相切的位置上.在此结果的基础上,本文提出了减少干扰和改善剖面质量的有效措施.我们希望它能尽早为实际工作所采用.另外,本文也对目前流行的几种类型的所谓“克希霍夫积分偏移”进行评述并指出它们的缺点.     

γ—TiAl增压涡轮熔模铸造过程数值模拟研究

根据熔模型壳离心浇注的铸造工艺特点，建立了γ－TiAl增压涡轮凝固传热过程的数值模型，推导了离心压力下γ－TiAl金属间化合物的凝固收缩和补缩过程数学模型，模拟计算了γ－TiAl增压涡轮铸件的温度场和收缩缺陷，结果表明，模型能可靠计算γ－TiAl增压涡轮铸件凝固过程的温度分布和准确预测铸件的收缩缺陷，数值模拟结果与实验结果吻合良好，数值模拟结果证实了前期工作所提出的进一步减少及消除收缩缺陷的优化工艺措施的合理性。     

铸钢件准固态区域应力,应变数值模拟及热裂机制

对ＺＧ４５实验热裂试棒的数种工况进行了应力－应变的数值模拟，对热裂形成机制进行了讨论。研究认为：热裂起源于Ｂｉｎｇｈａｍ体，是塑性变形超过Ｂｉｎｇｈａｍ体塑性储备值所致。     

Stabilization of a class of fuzzy stochastic jump systems with partial information on jump and sojourn parameters

This paper addresses the problem of the design of controller for fuzzy semi-Markov jump systems with hidden modes against the incomplete information on probability density functions of sojourn time. Two ubiquitous circumstances in practice are taken into account, which are often ignored in other related work:(1) the phenomenon that system modes cannot be accessed entirely is considered proactively;(2) finitely accessible information on probability density functions is studied in this paper. By virtue of hidden semi-Markov chain, the underlying systems are modeled as hidden semi-Markov jump systems, which are more general than semi-Markov jump systems. Sufficient conditions on the existence of desired accessible-mode-dependent fuzzy controller are derived such that the fuzzy hidden semi-Markov jump systems is mean square stable. Based on the emission probability matrix, the presented control policy overcomes the possible mode-mismatch between the system mode and the accessible mode.Finally, an example is provided to demonstrate the effectiveness of the proposed control method.