Preparation of water-dispersible graphene by facile surface modification of graphite oxide

Water-dispersible graphene was prepared by reacting graphite oxide and 6-amino-4-hydroxy-2-naphthalenesulfonic acid (ANS). X-ray diffraction study showed that the basal reflection (002) peak of graphite oxide was absent in the ANS-functionalized graphene (ANS-G), indicating crystal layer delamination. Ultraviolet-visible spectral data were recorded to assess the solubility of the ANS-G in water. Fourier transform infrared spectral analysis suggested the attachment of ANS molecules to the surface of graphene. Raman and x-ray photoelectron spectroscopy revealed that oxygen functionality in the graphite oxide had been removed during reduction. Atomic force microscopy found that the thickness of ANS-G in water was about 1.8 nm, much higher than that of single layer graphene. Thermal stability measurements also indicated successful removal of oxygen functionality from the graphite oxide and the attachment of thermally unstable ANS to the graphene surfaces. The electrical conductivity of ANS-G, determined by a four-point probe, was 145 S m(-1) at room temperature.     

Fabrication of three-dimensional autocloned photonic crystal on sapphire substrate

We applied the laser interference lithography method to form a patterned sapphire substrate (PSS). A three-dimensional photonic crystal was formed by autocloning the PSS with alternate Ta2O5/SiO2 coatings. A high total integrated reflectance (TIR) band was obtained around the 410 to 470?nm wavelength range that matched the emission spectrum of the gallium nitride (GaN) light-emitting diode (LED) for application in manipulating the light extraction of the sapphire-based GaN LED.     

利用双窗口检测和粒子滤波提取高分辨率SAR图像道路中心点

各种干扰、阻塞以及遮挡的存在使得高分辨率合成孔径雷达图像道路提取异常困难。该文提出一种局部检测和全局跟踪相结合的道路中心点提取方法。在局部检测时,设定内外双窗口,外窗口根据护栏、绿化带等干扰物与道路的边缘呈现一致的方向性,采用非线性结构张量获取该区域内的道路方向;内窗口根据方向结果调整转向,搜索道路区域,进而确定道路的宽度及中心点。在全局跟踪阶段,为克服路上阻塞及路旁建筑物遮挡造成跟踪频繁失败的影响,采用粒子滤波器变步长跟踪的策略。使用1 m机载高分辨率SAR图像进行实验,结果证明该方法的有效性。     

On the robust control of nonlinear systems

In this paper we consider robust stabilization of the class of nonlinear plants of the form $$\dot x = f(x) + \sum\limits_{i = 1}^m {g_i } (x)u_i (t),$$ which are equivalent, under smooth state space coordinate transformations and nonlinear state feedback, to controllable systems. This approach is very sensitive for unknown parameters' values. Parameter adaptation may be used as a technique to robustify minimum-phase systems [3]. We give an example of a locally stable adaptive tracking system in which the last assumption is weakened. The minimum-phase plant considered in the paper is a current-controlled squirrel cage induction motor.     

Passive fuzzy controller design via observer feedback for stochastic Takagi-Sugeno fuzzy models with multiplicative noises

This paper investigates the fuzzy control problem of a class of nonlinear continuous-time stochastic systems with achieving the passivity performance. A model-based observer feedback fuzzy control utilizing the concept of so-called parallel distributed compensation (PDC) is employed to stabilize the class of nonlinear stochastic systems that are represented by the Takagi-Sugeno (T-S) fuzzy models. Based on the Lyapunov criteria, the Linear Matrix Inequality (LMI) technique is used to synthesize the observer feedback fuzzy controller design such that the closed-loop system satisfies stability and passivity constraints, simultaneously. Finally, a numerical example is given to demonstrate the applicability and effectiveness of the proposed design method.     

抛光垫使用期对300 mm Si片Haze值影响研究

抛光垫是化学机械抛光(CMP)过程中重要的消耗材料之一.由于抛光垫与Si片直接接触,所以抛光垫的物理特性会直接影响到所加工Si片品质的优劣.通过研究不同使用时间的抛光垫结构以及所抛光Si片表面haze值,发现抛光Si片表面haze值在抛光垫使用前期逐渐减小,中期稳定缓慢升高,后期快速升高.从理论上系统地对结果进行了分析,充分证实了在CMP过程中,保持抛光垫特性的稳定对Si片表面质量具有非常重要的意义.     

Long-term follow-up (8 to 17 years) after thromboexclusion operation for thoracic aortic aneurysms

Forty-eight Russell's viper bite patients (40 males, 8 females), age ranging from 16-76 years were studied. Out of 48 patients, 14 were found to have a prolonged whole blood clotting time test (WBCT) (i.e. incoagulable blood) (Group 1); 23 had a normal WBCT (i.e. clotted blood) (Group II); and 11 patients had a normal WBCT on admission which changed to non-clotting during the clinical course (Group III). Four patients from group I developed hypotension and 2 expired. The serum cortisol concentration (mean +/- SEM) on admission among groups I and II were 639 +/- 45.6 and 424 +/- 33.2 nmol/l respectively. The blood cortisol level in 35 subjects (controls) were 370.7 +/- 17.7 nmol/l (mean +/- SEM). There was a significant rise of blood cortisol in patients with incoagulable blood when compared to controls at the time of admission to the hospital (p < 0.05); but there was no significant difference among those patients with clotted blood. A much higher mean serum cortisol level was observed in 4 patients with hypotension as compared to 10 patients without shock. These patients with hypotension according to our study shown to have a favorable response to steroid therapy and eventually recovered. Whether higher doses of steroid in addition to antiserum confer extra benefit in suppressing nonspecific venom effects on the pituitary and/or adrenal is not known.     

To secure XML documents with the extension function of XSLT

XSLT is a very popular and flexible language for transforming XML documents which provides a powerful implementation of a tree‐oriented transformation language for transmuting instances of XML using a single vocabulary into a desired output. In this paper, we propose a processing model that enables the XSLT processor to encrypt and decrypt XML documents. The details of the implementation are presented. Our model supports a more general encryption scope than previous models. The implementation and experimental results demonstrate the practicality of the proposed model. Copyright © 2006 John Wiley & Sons, Ltd.