合成脂肪酸废水的厌氧处理

对合成脂肪酸废水首先采用氧化钙处理，使其浓度降低到３０００ｍｇ／Ｌ以下，再采用中温厌氧生物处理。在平均水力停留时间为５天时，废水的ＣＯＤＣｒ去除率达７９．１％，沼气产率为０．４１ＮＭ３／ｋｇＣｏＤＣｒ试验还发现，的存在失使厌氧发酵的ｐＨ值上升。     

现代航材管理理念在我军航材管理上的应用

本文介绍了现代航材管理的理念和当前我军航材管理的传统理念,同时也阐述了应在空军航材管理部门建立新型航材管理系统的必要性,以促进实物流、资金流和信息流的结合,以提高航材管理水平,更好的保障飞行训练任务.     

The marine electronic highway in the Straits of Malacca and Singapore—an assessment of costs and key benefits

The Straits of Malacca and Singapore are an important trade route linking the Indian Ocean to the South China Sea and Pacific Ocean. They are also rich in resources and support a range of activities that benefit the economies of the littoral states (Indonesia, Malaysia and Singapore). This important shipping route is a very congested waterway and the authorities are keen to improve navigation facilities to promote ship safety and reduce the risk of groundings, collisions and accidents. This will also help to protect the marine environment from the effects of pollution and hence reduce its damaging impact on activities related to the Straits, e.g. fisheries and tourism. The Marine Electronic Highway (MEH) is an attempt to bring together maritime safety technologies and environmental management systems. The paper examines the costs of providing such a highway and considers some of the benefits which could accrue from its implementation. The analysis, conducted in the form of a cost-benefit study, clearly shows the economic viability of the scheme.     

A high order linear model for the prediction of internal lee waves at the main sill of the Strait of Gibraltar

A linear theory for the physical fields in the water column under the action of large amplitude internal lee waves at the main sill of the Strait of Gibraltar is developed. The procedure is a combination of the perturbation and normal modes methods in order to study steady resonant conditions. The lowest order linear approach of the methodology resumes the Taylor–Goldstein equation, which can reconstruct the main features of the observed fields but the high order approach gives the finest structure and sometimes the largest contributions. The role of the non-linear terms is investigated up to the second order taking into account the non-linear interactions between modes, leading to an effective reconstruction of the whole water column for the velocity field.     

Estimation of origin‐destination matrices for a multimodal public transit network

This paper presents a procedure for the estimation of origin‐destination (O‐D) matrices for a multimodal public transit network. The system consists of a number of favored public transit modes that are obtained from a modal split process in a traditional four‐step transportation model. The demand of each favored mode is assigned to the multimodal network, which is comprised of a set of connected links of different public transit modes. An entropy maximization procedure is proposed to simultaneously estimate the O‐D demand matrices of all favored modes, which are consistent with target data sets such as the boarding counts and line segment flows that are observed directly in the network. A case study of the Hong Kong multimodal transit network is used to demonstrate the effectiveness of the proposed methodology.     

A traffic flow simulator for short‐term travel time forecasting

This paper presents an off‐line forecasting system for short‐term travel time forecasting. These forecasts are based on the historical traffic count data provided by detectors installed on Annual Traffic Census (ATC) stations in Hong Kong. A traffic flow simulator (TFS) is developed for short‐term travel time forecasting (in terms of offline forecasting), in which the variation of perceived travel time error and the fluctuations of origin‐destination (O‐D) demand are considered explicitly. On the basis of prior O‐D demand and partial updated detector data, the TFS can estimate the link travel times and flows for the whole network together with their variances and covariances. The short‐term travel time forecasting by O‐D pair can also be assessed and the O‐D matrix can be updated simultaneously. The application of the proposed off‐line forecasting system is illustrated by a numerical example in Hong Kong.     

高性能混凝土预制箱梁裂纹成因分析与处理

通过对高性能混凝土的分析研究和预制箱梁现场调查,找出预制箱梁产生裂纹的各种原因并进行分析,制定相应的防治对策。     

Exact Equations for Tractrix Curves Associated with Vehicle Offtracking

Vehicle offtracking behavior at low speeds is closely approximated by a geometric entity called a tractrix. This paper presents differential equations for generalized coordinates of a planar multibody vehicle model based on tractrix behavior. The equations are exact, can be used with any type of input path, are valid for forward and backward movements, and are much simpler than previously published formulations used to compute transient offtracking. The differential equations can be integrated using conventional numerical integration algorithms to obtain plots of the low-speed tracking performance of articulated vehicles. The equations were formulated symbolically by a computer program used to analyze the kinematic and dynamic behavior of multibody systems. Example numerical results are plotted.     

阿尔斯通开发的PRIMA 3U15型电力机车

阿尔斯通公司运输部开发了PRIMATM机车系列,其类型满足了运营部门提出的模块化和系列化要求.投放欧洲市场的PRIMA型电力机车既满足了通用性要求,又有助于与公路的经济竞争取得成效.为此,阿尔斯通公司继法国双流制机车后又开发了一种三流制机车,该型机车可用于法国、德国和瑞士之间的跨境运输.文章介绍PRIMATM系列的开发过程以及得到法国国家铁路的订单.详细叙述了PRIMA 3U15型三流制机车,重点是PRIMA电力机车的维修、可靠性和可用性.