宁波-舟山港蛇移门40万t航道工程设计

蛇移门航道位于宁波-舟山港北部海域,采用世界最大的矿石船作为设计船型,是我国第一条设计建成并投入运营的40万t航道。受周边岛礁和港口布局等限制,航道水流条件复杂,船舶航行及靠泊条件差,所在海域为舟山通航条件最为复杂的水域之一,航道设计难度大。经综合分析航道特点及难点,提出合理的船舶交通流组织和通航方式,结合船模试验进一步优化航道设计方案,经理论计算和实船通航分析确定船舶通航窗口期,并给出试运行期实时潮流监测方案。

An Effective Approach for Improving the Real-Time Prediction of Summer Rainfall over China

This paper has two purposes. One is to evaluate the ability of an atmospheric general circulation model (IAP9L-AGCM) to predict summer rainfall over China one season in advance. The other is to propose a new approach to improve the predictions made by the model. First, a set of hindcast experiments for summer climate over China during 1982-2010 are performed from the perspective of real-time prediction with the IAP9L-AGCM model and the IAP ENSO prediction system. Then a new approach that effectively combines the hind-cast with its correction is proposed to further improve the model's predictive ability. A systematic evaluation reveals that the model's real-time predictions for 41 stations across China show significant improvement using this new approach, especially in the lower reaches between the Yellow River and Yangtze River valleys.

Research on Integrated Monitoring and Prevention System for Stray Current in Metro

On the basis of analyzing the influencing factors and harmfulness of stray current, and discussing the existing problems of monitoring and prevention system for stray current, the integrated monitoring and prevention system for stray current in metro was developed. A net system of distributed computers for monitoring was set up. It can monitor the distribution of stray current in metro and the corrosion of the metal structure in the whole line. According to the situation of monitoring it can also control the drainage of its tank to reach the best effect and eliminate the negative effect of polarity drainage. By using the new type unilateral electric device, the problem of burning the rail by electric arc can be avoided. The unilateral electric device can be connected with the monitoring net system directly to realize the monitor in line and improve the reliability of the device.

Managing High Volume Data for Network Attack Detection Using Real-Time Flow Filtering

In this paper, we present Real-Time Flow Filter (RTFF) -a system that adopts a middle ground between coarse-grained volume anomaly detection and deep packet inspection. RTFF was designed with the goal of scaling to high volume data feeds that are common in large Tier-1 ISP networks and providing rich, timely information on observed attacks. It is a software solution that is designed to run on off-the-shelf hardware platforms and incorporates a scalable data processing architecture along with lightweight analysis algorithms that make it suitable for deployment in large networks. RTFF also makes use of state of the art machine learning algorithms to construct attack models that can be used to detect as well as predict attacks.

Development of the detonation-driven expansion tube for orbital speed experiments

The hypersonic flow at orbital speeds is a fundamental issue for the ground tests of aerospace crafts.The detonation-driven high-enthalpy expansion tube(JF16 expansion tube)was developed to investigate re-entry physics.A forward detonation cavity(FDC)driver was applied in the JF16 expansion tube to create stable driving flows.The sound speed ratio of the detonated to test gas was examined to minimize the magnitude of test flow perturbations.The acceleration section length,incident shock decay and diaphragms thickness were investigated in detail to obtain optimal operation parameters.Flow visualization was also carried out with schlieren system to demonstrate the test flow stability and the effective test duration.Experimental data showed that the test flow with a velocity of 8.3 km/s and a total enthalpy up to 40 MJ/kg can be generated successfully and the test duration lasts for more than 50μs.

Monitoring diesel engine parameters based on FBG probe

This paper proposes an unprecedented systematic approach for real-time monitoring the temperature and flow of diesel engine by using embedded fiber Bragg grating(FBG). By virtue of FBG's temperature effect, we design a novel sensitive FBG temperature sensing probe to measure the temperature of cylinder head and inlet flow of diesel engine. We also establish the corresponding software platform for intuitive data analysis. The experimental and complementary simulation results simultaneously demonstrate that the FBG-based optical fiber technique possesses extraordinary reproducibility and sensitivity, which makes it feasible to monitor the temperature and inlet flow of diesel engine. Our work can provide an effective way to evaluate the thermal load of cylinder head in diesel engine.