应用复形优化方法的船舶结构可靠性分析

本文根据Hasofer－Lind关于结构可靠性指标的定义，提出改进的复形优化方法来计算可靠性指标，可避免复杂非线性极限状态函数的求导问题，亦可处理随机变量相关的问题。其突出的优点是，方法的通用性强，编制程序简单，便于推广应用。计算实例证明了本文方法的有效性。     

Risk assessment for fire safety considering characteristic evacuees and smoke movement in marine fires

In the safety design of marine systems, the matter of human life in the event of a marine fire must be considered. It may be difficult to establish a safe evacuation system because a characteristic behavioral pattern based on human factors is elusive. This study consists of three analyses on (1) the state of smoke diffusion, calculated by the use of a two-layer zone model, (2) evacuation movements, simulated by a group behavioral model, and considering the occurrence of panic and the smoke spreading phase, and (3) the risk index for safety assessment using the results of smoke diffusion and escape movements. This risk index can be used for comparisons between various safety systems, and its validity is confirmed by an evacuation model of common spaces on a typical cruise ship.     

卫星侦察通信环境仿真技术研究

在分析卫星侦察通信环境的基础上，开发了卫星侦察通信环境仿真系统，给出了环境仿真软件流程，并分析了软件实现的关键技术。该系统能够模拟卫星侦察完全截获状态下的常规通信环境，为卫星侦察通信信号的研究提供了环境平台。     

The winter St. Helena climate index and extreme Benguela upwelling

Climate changes in the subtropical South-east Atlantic turn out to be well described by the St. Helena Island Climate Index (HIX) and observed fluctuations are in good agreement with inter-decadal variability of the entire South Atlantic Ocean. Year-to-year variations of the averaged austral winter HIX (July–September), representative of the main upwelling season, were compared with (i) corresponding averages of the geostrophic alongshore component of the south-east trade wind (SET) between St. Helena Island in the south-west and Luanda/Angola in the north-east, (ii) the meridional distribution of surface waters colder than 13 °C to characterise intense Benguela upwelling (IBU), and (iii) the meridional position of the Angola-Benguela Frontal Zone (ABFZ) determined by means of sea surface temperature images for offshore distances between 50 and 400 km. Temporal changes of these parameters were investigated and showed that the frequency of consecutive years of strong and relaxed Benguela upwelling is characterised by a quasi-cycle of about 11–14 years. It is proposed that the index of the winter HIX may be used as a ‘surveyor’s rod' to describe interannual changes in the Benguela upwelling regime as well as those of the embedded marine ecosystem.     

Geochemical impacts of waste disposal on the abyssal seafloor

The response of pore water oxygen, nitrate, sulfate, sulfide, ammonium and methane and particulate organic carbon distributions to the input of 8.5 million m³ (3.8×10¹² g) of organic-rich waste materials is simulated. The deposit is assumed to be conical with a maximum thickness of approximately 20 m. Remineralization reactions within the deposit rapidly deplete any initially available pore water oxidants such as oxygen, nitrate and sulfate, and are subsequently dominated by fermentation reactions. Diffusion downward of reduced metabolites, sulfide, ammonium and methane, depletes the available oxidants in the pore waters below the waste pile, increasing the thickness of the anoxic layer. While the impacted region is limited to essentially the deposition site, recovery of the pore waters is estimated to be >10⁴ years. The overall computational results are corroborated by the pore water distributions observed at turbidite boundaries. Numerous uncertainties in the parameterizations limit the overall accuracy of the calculations presented. The most significant of these are: (1) A quantitatively accurate assessment of the remineralization rate of the deposited organic matter including its rate of inoculation by abyssal microorganisms; (2) a detailed assessment of potential non-diffusive pore water transport processes including advection due to compaction and buoyancy-driven flows and enhanced exchange due to macrobenthic irrigation activities and (3) an assessment of the potential alteration of pore space and methane reactivity due to gas hydrate formation.     

A NOMENCLATURAL STUDY ON THE SUPRAORBITAL AND MEDIAL FRONTAL INCISURA OR FORAMEN OF THE UNEARTHED MODERN CHINESE ADULT CRANIA IN XI'AN REGION

Thenomenclaturesoftheminorbonytraitsofthesupraorbitalmarginarenotinagreementinliteraturesathomeandabroad."SurveyofAnatomicalDataandVariationsofChinese"tl)onlysummedthefrequenciesofsupraorbitalincisurae(foramina).Theaimofthispaperistoobservetheincisuraandforamenonsupraorbitalmarginandtoaccumulatephysicalanthropologicaldatainordertoinvestigatethedifferenceofracesandpopulations.MATERIALSANDMETHODSInthisstudy,190craniaofmodernChineseadultsofbothsexes(males118.females72)unearthedfromXi'an…     

高速公路贷车计重收费标准构建与方案优化研究

系统研究了如何以原分型收费标准和载货车辆质量分布为依据构建货车完全计重收费标准,并且研究了计重收费标准的评价指标和优化方法。最后以天津市为例,给出了应用本文方法所生成的两个计重收费标准方案。     

论防治船舶污染海洋环境

从船舶污染海洋的角度,分析了船舶造成海洋污染的种类及原因,提出了构建法律体系、建立反应机制、增强环保意识、完善接受设备、加强监管鉴定等措施防止船舶污染海洋环境。     

我国中小城市摩托车的发展方向

以江西省吉安市为例,根据吉安市2004年交通调查的数据,对中小城市摩托车的现状、由其带来的安全、环境、交通问题以及摩托车的发展方向进行了研究,并对摩托车的合理发展和管理提出了具体建议。     

基于改进的神经网络的船舶碰撞危险度的模型

针对船舶碰撞危险度具有模糊性、不确定性等特点,依据模糊理论方法建立的船舶碰撞危险度的数学模型,直接采用来船航速、来船航向、来船对本船的相对舷角和来船对本船距离作为神经网络的输入,采用Levenberg-Mrquardt优化算法这种改进的BP神经网络进行训练和仿真,并与标准BP算法和动量BP算法进行比较,发现经过改进的网络求得碰撞危险度比标准BP算法和动量BP算法具有更好的效果,网络能够更有效收敛,大大提高了网络的收敛速度和泛化能力。