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1.
High dielectric loss materials have an important application in electromagnetic (EM) absorption fields. In this paper, the ternary nanocomposites: 1T/2H-MoS2/Mo2S3 with heterogeneous interfaces are synthesized by hydrothermal method. XRD, XPS, FTIR, SEM, and TEM measurements are applied to study the structure, morphology, and composition. The frequency spectra of complex permittivity (εr-f) are measured in 2–18 GHz by vector network analyzer. The results show that the nanocomposites have higher dielectric loss angle tangents than the reported 2H-MoS2 absorbers. Based on the εr-f spectra, the reflection loss-frequency curves () are simulated at given thicknesses. An effective absorption bandwidth of 5.2 GHz (12.8–18 GHz) and a peak of −29.49 dB are achieved in a thin thickness of 1.62 mm, which are comparable to the reported 2H-MoS2 absorbers with complex composition, showing that the 1T/2H-MoS2/Mo2S3 nanocomposites have great application potential as an EM wave absorber in the Ku band. 相似文献
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The Electrostatic Discharge (ESD) phenomenon has been described through the IEC 61000-4-2. ESD current parameters' values, have been set in this Standard. The theoretical ESD current waveform defined in this standard, describing the conventional Contact discharge mode, needs to be re-evaluated on the basis of accurate experimental data. Even though the standard deals with commercial ESD generators, its goal is to simulate the natural phenomenon as good as possible. More and accurate data may contribute to the better simulation of the natural phenomenon. New values and better comprehension of the phenomenon demand new measurements based on high end measuring equipment. Such works and publications have been carried out the past years. Yet, the need to systematize and integrate this work remains. Larger and trust-worthy series of measurements need to be carried out and presented clearly.This paper deals with new ESD-current data, taken with broadband equipment. New and more detailed measurements like these, were never before taken at such a large number of individuals. The goal of this work is that the data acquired can serve as a basis for re-evaluating the conventional approach of the scientific community to the ESD event.In this paper, using a broadband measuring system, new parameters' values are measured and relations are presented, following standard statistical procedures. The results, which occur from measurements carried out on tenths of human individuals, are questioning the Standard in many points. A new way of approaching the standardization of the ESD current is proposed, as the excuse of the poor measuring equipment that sets barriers on the measuring accuracy, does not apply any more. The charging voltages of 500 V and 1000 V were also examined since such range of voltages are often met at ESD events and they are considered very harmful. 相似文献
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Chinese Annals of Mathematics, Series B - In the present article, the authors find and establish stability of multiplier ideal sheaves, which is more general than strong openness. 相似文献
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Dengue fever is one of the most common viral infections affecting humans. It is an expanding public health problem, particularly in tropical and subtropical regions. No effective vaccine or antiviral therapies against Dengue virus (DENV) infection are available. Therefore, there is a strong need to develop safe and effective therapeutic strategies that can reduce the burden and duration of hospitalizations due to this life-threatening disease. Oligonucleotide-based strategies are considered as an attractive means of inhibiting viral replication since oligonucleotides can be designed to interact with any viral RNA, provided its sequence is known. The resultant targeted destruction of viral RNA interferes with viral replication without inducing any adverse effects on cellular processes. In this review, we elaborate the ribozymes, RNA interference, CRISPR, aptamer and morpholino strategies for the inhibition of DENV replication and discuss the challenges involved in utilizing such approaches. 相似文献
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生物分子与纳米材料作用形成的“蛋白冠”影响纳米材料的物理和化学性质, 目前缺少有效的原位实时技术监测蛋白冠的形成过程. 本研究基于二氧化硅胶体晶体薄膜和反射干涉光谱法, 研究了三种代表性血液蛋白质在二氧化硅纳米粒子表面的蛋白冠形成过程, 结果表明这三种蛋白具有不同的蛋白冠形成过程及参数; 研究了人血清白蛋白在三种表面曲率的二氧化硅表面的蛋白冠形成过程, 结果表明曲率越大时, 蛋白冠形成速率越快, 厚度越大. 以血浆和全血样品为生物环境开展蛋白冠形成过程研究, 结果表明本研究的监测方法可以直接用于血浆和全血在纳米粒子表面蛋白冠的形成过程监测, 为纳米材料与生物分子的相互作用研究提供了一种简单可靠的评价技术. 相似文献
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《Arabian Journal of Chemistry》2021,14(12):103443
Accumulation of chlorpyrifos (CP), a pesticide, causes a significant environmental problem in food, surface/ground waters further to human health. The removal of the CP pollutant in surface/wastewater could be achieved by biochar due to the improved physical and chemical properties. In this work, the CP removal capacities of biochar samples derived from walnut shells at various temperatures from 450 to 900 °C were investigated. The experiments were performed as laboratory batch type study and the adsorption efficiency was determined at various conditions such as adsorbent dosage (10–500 mg/L), sorbate concentrations (100–1500 µg/L), contact time (0–300 min), initial pH (3–10), and the number of recycle.By subtracting the pyrolysis temperature from 450 °C to 900 °C, the surface areas were found to increase from 12.9 m2/g to 353.3 m2/g, respectively.The 143 experimental data were evaluated by a pair of kinetics and isotherm models and the Adaptive Neural Fuzzy Inference System (ANFIS). The developed ANFIS model was 98.56% successful in predicting the CP removal efficiency depending on the adsorption conditions. Walnut Shell Biochar (WSBC) can be applied for CP adsorption with 86.64% removal efficiency under optimum adsorption conditions (adsorbent = 250 µg/L, sorbate = 1000 µg/L, pH = 7.07 and contact time 15 min) thanks to its improved porosity. It was determined that the biochar samples could be reused 5 times. Equilibrium adsorption was observed to conform to the Langmuir isotherm, and the maximum adsorption capacity for WSBC@900 was 3.536 mg/g. 相似文献
10.
Guangxiao Hu Wei Xiong Hailiang Shi Zhiwei Li Jing Shen Xuejing Fang 《Journal of Raman spectroscopy : JRS》2016,47(3):289-298
Spatial heterodyne Raman spectroscopy (SHRS) is a new type of effective method for the analysis of structure and composition of liquid and solid targets with the characteristics of no moving parts, high spectral resolution, high optical throughput and large field of view. The technique is very suitable for detecting the targets from long distances or under the conditions with ambient light, which is essential for the exploration of planetary surface. In order to have a better understanding of the ability of SHRS for the detection of liquid and solid targets, a breadboard was designed, built and calibrated. Signal to noise was estimated at different integration time or laser power for carbon tetrachloride. Pure materials or materials contained in bottles were both tested. The mixture of organic liquids or inorganic solids were tested. In order to test the detection ability for natural targets, some composition‐unknown rocks and pebbles were tested. The results have shown that SHRS can meet the requirements for the detection of weak Raman signal scattered from artificial or natural targets. Standoff detection of sulfur from 5‐m or 10‐m distance without using any telescope or collimation optics was also tried to test the high optical throughput of SHRS. The potential feasibility of standoff detection has been proved. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献