Papers by Keyword: As

Abstract: Lateral MOSFET devices with a thin surface counter-doped layer using Sb and As with and without NO passivation have been fabricated and characterized. The results demonstrate that Sb and As counter-dope the interface without significant trap passivation while in combination with NO there is a superposition of both trap passivation and counter-doping related performance enhancement. In addition, by varying the counter doping level, a universal mobility characteristics of NO passivated devices has been identified.

Abstract: MANET(mobile ad-hoc network) is an independent NET AS SYSTEM, which has much difference with wired network. It does not depend on fixed main network ( but can be cooperated with main network). This article puts forward a kind of ASN structure during the design of MANET Tourism Network. So it solves the inadaptability between the net segmentation and combination in the MANET from wired ASN. It proves this MBGP can guarantee net MANET QQS in a simulated way.MANET is a kind of communication net with no central structure, which is contrary to the traditional wireless network with base station. It is also called self-organized net. The difference between MANET and wired autonomous network is that MANET gateway BGP agreement is very different from BGP agreement of wired autonomous network.

Abstract: Toxicity of As on soil neutral phosphatase was studied through a series indoor incubation experiments. Results showed that the activity of soil neutral phosphatase was significantly inhibited by As pollution, and the peak inhibiting ratio was appeared at the sixth incubation day. While the activity of soil neutral phosphatase was also decreased with concentration of As increasing in the same incubation day. The relationship between the concentration of as and soil neutral phosphatase was fit by model ①y=c/(1+bx)and ②y=c(1+ax)(1+bx).The model② was more suitable to describe the relationship between the concentration of As and soil enzyme. This means the effect mechanism of As on the soil neutral phosphatase was part of inhibition. The Km of neutral phosphatase was increase by As concentration adding, while the Vmax was lowered. This kind of inhibition belongs to mix competition inhibition. Phosphatase widely exists in the biological world, from lower organism Escherichia coli, yeast to higher animals and plant tissues, body fluid and human liver, prostate gland are found to have phosphatase exist. It can catalyze the phosphate hydrolysis of elemental and inorganic phosphate release, important enzymes of biological phosphorus metabolism [1-2]. Soil phosphatase is an enzyme that has a major impact on agricultural production, producing an important role in the cycle of soil phosphorus. Research show that phosphatase in soil and aquatic systems of phosphorus, organic phosphorus pesticide contaminated soil bioremediation is very important, so it can be used as material for ecosystem beneficial or deleterious effects of indicator. Therefore, some can be as the instructions of the beneficial or harmful effects of ecosystem biology. Arsenic is widespread nature of toxic heavy metals often pollute the environment with the waste material, pesticides, fertilizers and other. According to the statistics in early 1990s, each year around the world due to human activities the importation of soil arsenic content of 0.52-1.2 million tons, its impact on soil ecosystem is one of the important topics. This experiment which proposed indoor simulation method analysis different concentrations of arsenic contaminated soils of neutral phosphatase activity, to explore the effects of different concentrations of arsenic on soil phosphatase activity of short-term toxicity effect. Analysis of the influence degree and duration, further analysis between the two possible mechanism, provides the basis for environmental protection and monitoring.

Abstract: Calcium sulphoaluminate (3CaO·3Al₂O₃·CaSO₄, ) was synthesized with pure chemical reagents. The adsorbed amount of aminosulfonic acid-based superplasticizer (AS) on the surface of mineral and the mineral mixture (mixture of the , Ca(OH)₂ and CaSO₄·2H₂O) were detected by ultraviolet-visible absorption spectrometry. The adsorptive behaviors of AS on the surface of mineral particles in the hydration system were studied. The results showed that: the adsorbed amount of AS on mineral and the mineral mixture increased with higher initial concentration; the adsorption amount and the maximum adsorption amount increased with prolonged hydration time; the adsorption amount and the maximum adsorption amount of AS on the mineral mixture was more than those on the mineral in the hydration system within the same hydration time.

Abstract: The paper researched the method of using the L-Cysteine to pre-reduction and using hydrid atomic fluorescence spectrometry to determining the As、 Sb 、Bi and Hg elements.In the preparation determination condition,the elements have a wide linear rangeand, the sample analysis results coincided with the recommended values. Detection limit of each element wereAs0.08ng／mL、Sb 0.06ng／mL、Bi 0.07ng／mL、Hg 0.004ng／mL。After nearly more than 100,000 pieces of the determination of geochemical samples, the sample have a good parallel.