An energy conversion system based on deep-sea pressure

A novel seawater pressure energy conversion system that utilizes seawater pressure to generate electricity has been studied in this paper. The energy conversion system utilizes the pressure difference between the pressurized seawater and the empty pressure container to drive hydraulic motor and the coaxially coupled generator to generate electric power. The output electric energy is recorded by the data logger throughout the process. In the current study, technical analysis is performed with the emphasis on conversion efficiency between seawater pressure energy and output electric energy. The analysis is conducted at various pressure differences through the throttle valve so as to obtain maximum conversion efficiency. Research shows that the optimum pressure difference through the throttle valve and the maximum conversion efficiency can be theoretically calculated when the properties of the conversion system are given. Simulation results have demonstrated the influence of pressure difference on conversion efficiency. The test apparatus has been designed, built and tested in 2004. It successfully generated electric energy of approximately 0.85 kW h at the depth of 2400 m with empty pressure container's holding capacity of 200 L in the voyage “DY105-16” in South China Sea on June 12, 2004. The actual conversion efficiency from seawater pressure energy to electric energy reaches as high as 63.8% which is attractive for underwater equipments. The success of the experiment has tested the feasibility of utilizing seawater pressure energy and brings a new power supply way for long-term in-situ underwater equipments.     

Growth of new designated cities in China

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平稳序列密度函数随机窗宽核估计

在平稳序列｛ｘｎ｝∞ｎ＝１是强混合的情况下,讨论具有随机窗宽的密度核估计的强一致相合性,得到了一般核下最近邻估计具有强一致相合性的结果。     

<江苏省矿产资源管理条例>的立法背景、主要特点及其重要意义

简要介绍了江苏省矿产资源形势、开发现状和存在的主要地质环境问题.介绍了<江苏省矿产资源管理条例>的立法背景、主要内容和重要意义.提出在当前形势下,认真学习、贯彻实施<条例>,应抓好5个方面的工作.     

北极涛动对河南省降水的可能影响

采用连续小波变换和交叉小波变换方法,分析了北极涛动指数和河南省月降水距平序列的时频变化特征,并讨论了近50多年来北极涛动对河南省降水的可能影响.结果表明,北极涛动指数和河南省降水距平序列中都存在着不同时间尺度的周期振荡,且时域中的分布特征和振荡强度也不尽相同;两者之间在6～8 a、12～16 a和25 a以上尺度的周期振荡呈正相关,而在9～11 a和16～24 a尺度上表现为负相关关系.     

省级GRAPES模式预报系统的构建

利用9210卫星广播的T213资料作为初始场,在联想深腾1800机群系统上构建了省级GRAPES中尺度数值预报系统,实现了GRAPES-MESO V2.5的高效运行,一方面可提供日常的业务预报产品,另一方面也可为广大预报员提供一个诊断模拟的平台.     

大气激发和观测极移之间的转换变化分析

本文采用１９８４—１９９２年期间日本气象厅（ＪＡＭ）推算出的大气激发函数序列（χ１，χ２），和美国喷气推进实验室（ＪＰＬ）提供的Ｓｐａｃｅ９３极坐标序列经过反卷积而推出的测地激发函数（ψ１，ψ２）进行了比较。同时也比较了极移（ｘ，ｙ）和从大气激发序列归算出（经过卷积）激发极移（ｍ１，ｍ２）。     

地平式望远镜轴系误差对指向精度和跟踪精度的影响

采用球面几何的方法推导轴系位置误差对地平式望远镜指向、跟踪精度影响的计算模型.介绍2米级地平式望远镜轴系误差检测及数据处理方法.通过对目标星体指向、跟踪仿真,得到轴系位置误差对指向、跟踪精度影响规律,为轴系精度及轴系位置要求提供理论依据,并为后续控制修正提供参考模型.     

Variations of snow temperature and their influence on snow cover physical parameters in the Western Tianshan Mountains, China

This article discussed about snow temperature variations and their impact on snow cover parameters. Automatic temperature recorders were used to sample at 10-minute intervals at the Tianshan Station for Snow-cover and Avalanche Research, Chinese Academy of Sciences. 10-layer snow temperature and the snow cover parameters were measured by the snow property analyzer (Snow Fork) in its Stable period, Interim period and Snow melting period. Results indicate that the amplitude of the diurnal fluctuation in the temperature during Snow melting period is 1.62 times greater than that during Stable period. Time up to the peak temperature at the snow surface lags behind the peak solar radiation by more than 2.5 hours, and lags behind the peak atmospheric temperature by more than 0.2 hours during all three periods. The optimal fitted function of snow temperature profile becomes more complicated from Stable period to Snow melting period. 22 h temperature profiles in Stable period are the optimal fitted by cubic polynomial equation. In Interim period and Snow melting period, temperature profiles are optimal fitted by exponential equation between sunset and sunrise, and by Fourier function when solar radiation is strong. The vertical gradient in the snow temperature reaches its maximum value at the snow surface for three periods. The peak of this maximum value occurs during Stable period, and is 4.46 times greater than during Interim period. The absolute value of temperature gradient is lower than 0.1°C cm⁻¹ for 30 cm beneath snow surface. Snow temperature and temperature gradient in Stable period∼Interim period indirectly cause increase (decrease) of snow density mainly by increasing (decreasing) permittivity. While it dramatically increases its water content to change its permittivity and snow density in Snow melting period.     

Wave-tide-surge coupled model simulation for Typhoon Maemi

1 IntroductionThe main reason for coupling the tide and surgehydrodynamic model with a surface wave model canbe found in the physical interactions taking place inthe surface and bottom boundary layers. During thesevere storm conditions such interactions a…