A triboelectric nanogenerator (TENG), fabricated by soft materials with advantages of flexibility, stretchability, and water resistance, is a potential means for biomechanical energy harvesting. Herein, a soft tubular TENG (ST-TENG) is proposed, which is composed of a flexible conductive sponge as the inner electrode and a soft silicone tube as the dielectric layer with the helix outer electrode. The ST-TENG can be built in outsoles and harvest various biomechanical energy including pressing, bending, and twisting. The output performance of ST-TENG was thoroughly investigated and the surface charge density can reach to 175.4 mu C m(-2). The ST-TENG has stable and durable characteristics for 1.2 x 10(6) working cycles, 100 h soaking, and 5000 times bending. By walking or jogging with the ST-TENG tubes, several portable electronics such as thermometer, digital watch, and calculator can be continuously powered. The soft energy harvester in this work has made a significant progress in self-powered devices.

In mineral resources prediction and other research of geological variables, stability exactness of quantitative models concern modeling conditions, geological variables from model and the status of the variable. In traditional geological modeling process, variable support is measured under some contains weight and this kind of weight is characterized by constant coefficients. Constant weight has some limitations due to structuredness and dependency of variable. For overcoming the inflexibility of constant weight, this paper proposes geological variable mathematics model based state variable vector. We revise existing form of state variable weight and provide logarithm state variable vector as measurement level of geological variable weight coefficients. According to 1:200000 scale geochemistry measured data from Baishan area, we calculate the samples unit connection degree based on exponent and logarithm state variable vector and compare the connection degree based on constant weight. The connection degree sorting has the similarity as a whole among them, but there is the obvious difference locally. We can conclude that geological variable weight function based on state variable vector is more flexible and fine.

A nonlinear PID control method based on Smith predictor is presented in this paper to control the time delay systems. This method combines the Smith predictor with nonlinear controller. And the simulation study had been done for a first-order time-delay system. The results show that this method offer good static and dynamic characteristics, at the same time its disturbance-rejection and robustness are better.

To further understand the underlying physical mechanisms of dealloying of multiphase alloys and control dissolution processes among different phases, the dealloying behavior of melt-spun Al 40 atom % Cu alloy comprising Al(2)Cu and AlCu intermetallic compounds in a 10 wt % sodium hydroxide (NaOH) aqueous solution was studied. The microstructure of as-dealloyed samples was characterized using x-ray diffraction, scanning electron microscopy, and energy dispersive x-ray analysis. The experimental results show that the alloy with the amount of Al(2)Cu comparable to that of AlCu can be partially dealloyed, which eventually results in the formation of a unique kind of nanoporous copper/AlCu composite. Additionally, the formation mechanism has been well established to describe the morphology and composition evolutions during the dealloying process based upon kinetic competitions between dissolution of Al atoms and diffusion-rearrangement of Cu atoms, which includes three stages, sequentially, defined as "Al(2)Cu dealloying," "AlCu dealloying," and "coarsening accompanying underlying AlCu re-dealloying." (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3511771] All rights reserved.

To further enhance the photoactivity of virgin TiO2, we prepared N-doped TiO2 (N-TiO2) by sol-gel method and used it to remove Cr(VI) ions from water under visible light. The catalysts were characterized by TEM, XRD, BET and UV-vis techniques. Better crystalline structure, larger specific surface area and decreased band-gap width were obtained after the insertion of N atoms into TiO2 lattice. Several influencing factors were also investigated. The removal efficiency of Cr(VI) increases with the decrease of initial Cr(VI) concentration or the increase of catalyst dosage. Addition of glucose or some inorganic ions (Mg2+, Al3+) can promote the photoreduction process by improving the quantum efficiency. The kinetics and mechanism were discussed as well.

<正>Wen Liu is a senior researcher and doctoral supervisor in College of Environmental Sciences and Engineering at Peking University,China.He is also the vice-director of Department of Environmental Engineering,and the head of Environmental Nanotechnology Lab in Peking University.

Under rhodium(III) catalysis, substituted propenoic acids successfully reacted with aryl isocyanates to provide cyclic imides via direct functionalization of the beta-alkenyl C-H bond followed by intramolecular cyclization. The cascade process has been corroborated by the isolated intermediate. The reaction provides direct access to cyclic imides from readily available starting materials.