黄斑大蚊的喜湿性及其翅膀、腿表面的超疏水性

黄斑大蚊的翅膀、腿表面有很好的超疏水性, 水滴在其表面的静态接触角分别为150°,155°, 滚动角接近5°, 通过扫描电子显微镜观察发现, 在黄斑大蚊的翅膀、腿表面分布有大量呈规则排列的微纳米级复合凹槽、乳突, 复合结构及其表面的低表面能物质的协同作用使其表面具有良好的超疏水性, 这一特性使黄斑大蚊能在潮湿的环境中自由生存. 本文用 Cassie 理论对这种超疏水性进行了理论分析.     

四坐标线切割机切丝位置计算

导出了四坐标线切割机切丝位置计算了一般方法，该算法可以在工件上下表面轮廓为任意空间曲线时，由直纹面的设计数据求出切丝位置。     

Quality evaluation for air plasma spray thermal barrier coatings with pulsed thermography

Pulsed thermography(PT) as a non-contact non-destructive evaluation(NDE) technique was employed to examine as-sprayed air plasma spray(APS) thermal barrier coatings(TBCs) for quality evaluation.Thickness and micro-structural characteristics play a vital role in determining the quality.In this paper,PT logarithmic peak second-derivative method was adopted to measure the thickness of top coat.Time dependent thermal images were used to characterize the microstructure which was confirmed by scanning electron...     

Distributed Estimation in Sensor Networks with Repetition Coding

This paper considers the distributed estimation of a source parameter using quantized sensor observations in a wireless sensor network with noisy channels. Repetition codes are used to transmit quantization bits of sensor observations and a quasi best linear unbiased estimate is constructed to estimate the source parameter. Simulations show that the estimation scheme achieves a better power and spectral efficiency than the previous scheme.     

3-D Design and Numerical Simulation of Two-Phase Flow in the Laser Rapid Prototyping Coaxial Powder Delivery System

The metal powder direct and rapid prototyping technology is one of the most developing methods in the laser rapid prototyping technique. The coaxial powder delivery system is the key technique. The purpose of this paper is to introduce a new type of coaxial powder delivery system and simulate the metal powder and shield gas flow in the powder nozzle. 2-D and 3-D model of the new coaxial powder delivery system are established. Then gas-solid two-phase flow model and the k-ε turbulent model are selected to simulate the flow of metal powder in powder nozzle. The Euler-Lagrange method is used in the simulating computation. The results show that the new coaxial powder delivery system has stable performance, uniform powder flux, high cooling efficiency, and long useful life.     

索氏提取法抽提筒使用改进

针对传统索氏抽提法实验中抽提筒的不足进行改进。在抽提筒下端虹吸口处垫上约1 cm高度的脱脂棉,或在抽提筒距离底部约0.5 cm处固定孔径为20～30μm的砂芯板。选用花生、猪肥膘为原材料,进行对比实验,在实验过程中可以看出改进后的装置每次的虹吸彻底、效果明显,从实验数据中看出改进后的装置提取效率更高,可减少实验时间。     

Adaptive fuzzy controller for a class of strict-feedback nonaffine nonlinear systems

A robust adaptive fuzzy control scheme is presented for a class of strict-feedback nonaffine nonlinear systems with modeling uncertainties and external disturbances by using a backstepping approach.Fuzzy logic systems are employed to approximate the unknown parts of the desired virtual controls,and the approximation errors of fuzzy systems are only required to be norm-bounded.The function tanh(·) is introduced to avoid problems associated with sgn(·).The tracking error is guaranteed to be uniformly ultimately bounded with the aid of an additional adaptive compensation term.Chua’s circuit system and R o¨ssler system are presented to illustrate the feasibility and effectiveness of the proposed control technique.     

Study on the photosynthetic performances of Enteromorpha prolifera collected from the surface and bottom of the sea of Qingdao sea area

In this work, the photosynthetic performances of Enteromorpha prolifera thalli collected from the sur- face and bottom of the sea of Qingdao sea area were studied with chlorophyll fluorescence and oxy- graph technology. The samples with the highest photosynthetic activity among their kinds, the floating thalli from the sea surface of the south of the Qingdao Olympic Sailing Center and the sedimentary thalli from the mud surface of the bottom Tuandao bay, were chosen as representatives of surface thalli and ...     

用VRML实现虚拟燕大校园的浏览设计

VRML是一种崭新的网上虚拟现实技术，在众多应用中，虚拟旅游可以把你带入一个三维世界，实现旅游梦想。一些新技术如光照技术，触发器技术，多媒体技术的采用会使得三维场景更加生动逼真。对虚拟燕大校园的浏览设计到的VRML的相关技术进行了介绍。     

A Case Study of Search Engine on World Wide Web for Chemical Fiber Engineering

Search engine is an effective approach to promote the service quality of the World Wide Web. On terms of the analysis of search engines at home and abroad, the developing principle of search engines is given according to the requirement of Web information for chemical fiber engineering. The implementation method for the communication and dynamic refreshment of information on home page of the search engines are elaborated by using programming technology of Active Server Page 3.0 (ASP3.0). The query of chemical fiber information and automatic linking of chemical fiber Web sites can be easily realized by the developed search engine under Internet environment according to users' requirement.