飞旋的意大利梦想

让我们把镜头闪回到2010年10月22日的北京751设计园。光影变幻之间，短片《意大利梦想（AnItalianDrearn）》正式首映。藉此庆祝并展开Tod’s品牌与米兰斯卡拉歌剧院为期一周年的合作。短片由著名艺术家马蒂亚斯·岑特纳（MattiasZentner）导演，     

Production of Camphene by Isomerization Reaction on Sulfated ZrO2

Abstract The kinetics of camphene production in liquid phase from α-pinene was experimentally determinedin an isothermal batch reactor.To this end,a sulfated ZrO_2 catalyst was used and the reaction studied in thetemperature range of 370-403K.By analyzing the experimental data,second reaction order for α-pinene wasfound.A kinetic model is presented which includes term for the catalyst load used.The specific rate constant at393K was 2.19×10~(-3)mol.L~(-1),min~(-1),the activation energy being 93kJ.mol~(-1).Both Vaues are within the rangeof literature results.     

Radio interferometric localization of WSNs based on Doppler effect

A novel distributed localization method based on the Doppler effect for wireless sensor networks is proposed in this paper, which only relies on radio transceivers without the need of other auxiliary measurement equipments. Based on radio interference, each sensor node can obtain a multi-group of distance variations from itself to a mobile anchor through the measurement of the cumulative phase variations caused by Doppler effect, by which its position can be determined. The proposed method has the following...     

Hydroturbine operating region partitioning based on analyses of unsteady flow field and dynamic response

The operating states of hydroelectric generating units vary widely as the operating condition change. The details of the operating characteristics and the operating region partitioning method are discussed for two types of large Francis turbines in the Wanjiazhai Hydropower Plant and two same type large Kaplan turbines in the Shuikou Hydropower Plant. For the Wanjiazhai Hydropower units, the most critical factor affecting the operating stability is the hydraulic pressure fluctuations caused by the vortex ro...     

New research trends on high-precision time transfer technology

High-precision time transfer plays an important role in the areas of fundamental research and applications. Accompanying with the remarkable improvements in the ability of generating and measuring high-accuracy time-frequency signal, seeking for new time-transfer techniques between distant clocks with much further improved accuracy attracts attentions world-widely. The time-transfer technique based on optical pulses has the highest precision presently, and the further improvement in the accuracy is heavily dependent on the time-domain properties of the pulse as well as the sensitivity of the applied measurement on the exchanged pulse. The application of optical frequency comb in time transfer for a precision up to femtosecond level are currently the focus of much interest, and has recently achieved many breakthroughs. Further investigations show that, utilizing quantum techniques, i.e. quantum measurement technique and quantum optical pulse source, can lead to a new limit on the measured timing information. Furthermore, it can be immune from atmospheric parameters, such as pressure, temperature, humidity and so on. Such quantum improvements on time-transfer have a bright prospect in the future applications requiring extremely high-accuracy timing and ranging. The potential achievements will form a technical basis for the future realization of sub-femtosecond time transfer system.     

无线网络中基于网络编码的可靠广播传输

Recently, network coding has been applied to the loss recovery of reliable broadcast transmission in wireless networks. Since it was proved that fi nding the optimal set of lost packets for XOR-ing is a complex NP-complete problem, the available time-based retransmission scheme and its enhanced retransmission scheme have exponential computational complexity and thus are not scalable to large networks. In this paper, we present an efficient heuristic scheme based on hypergraph coloring and also its enhanced ...     

QQ空间挂件免费用

有一种永久有效的方法,可以让你在不花钱的基础上也能用上那些好看的挂件。很多朋友都开通了QQ空间,并且一个比一个装扮得漂亮,各种小挂件挂在空间中,甚是好看。等我自己也想去装扮空间时,才发现那些装扮的东西都需要用"Q币"购买。是不是不花钱就不能装扮自己的空间了呢?寻问高手得知可以通过"代码"的方法实现,但QQ空间一旦有版本更新就容易失效。还有一种方法,相对麻烦一点,但能保证永久有效。     

让藻油DHA帮助海藻更好地阅读世界牛津大学新试验表明摄入DHA有助于提高孩子的阅读能力

对很多老师和家长来说，阅读能力不佳一直是困扰孩子的难题，不过，根据英国牛津大学一项最新的研究表明，在孩子膳食中增加藻油DHA（二十二碳六烯酸）的摄入量可有助于提高孩子的阅读能力，专家表示，对阅读能力不佳的孩子来说，补充DHA是一种简单可行且行之有效的方法。