冲破WTO过渡期后的贸易藩篱

列举了自2003年初以来我国出口商品屡遭外国限制若干案例,剖析了相关背景原因,提出了反倾销具体的对策举措。     

Characterization of sputtered Ta-C-N film in the Cu/barrier/Si contact system

Characterization of sputtered tantalum carbon nitride (Ta-C-N) film in Cu/barrier/Si system was reported for the first time. With a 50∶50 wt.% TaC target and an optimum N₂/Ar flow rate (in sccm) ratio of 2/24, a 600 Å-thick sputtered Ta-C-N layer was shown metallurgically stable up to 650°C annealing for 30 min, which is about 100°C higher as compared to the case without nitrogen doping. Cu diffusion through the local defects or grain boundaries of the Ta-C-N barrier layer into Si substrate is the dominant factor responsible for the failure of the Ta-C-N barrier layer after high temperature annealing.     

Characterization of a redox-modified clay mineral with respect to its suitability as a barrier in radioactive waste confinement

Engineered barriers for high-level nuclear waste (HLW) consist of excavated repositories in sub-surface rock formations where canisters holding the radionuclide are stored. Clay minerals, particularly the swelling 2:1 types, are used as backfill material, both in the canisters and in the bore hole, in order to prevent radionuclide transport to surrounding groundwater. One of the most important risks that can occur is the corrosion of the canister, which could be coupled with reduction of iron (Fe) in the clay structure. Such changes could greatly decrease the long-term stability of the clay and, consequently, of the barriers themselves. In order to test the potential effects of such redox interactions, an Fe-bearing clay mineral from a commercial source located in the Kutch region, India, was selected for study. This particular mineral is one of the candidate clay minerals to serve as such a barrier material, and is the one with the largest structural Fe content. Results from it should, therefore, provide maximum insight into the potential effects of redox interactions between the barrier and its surroundings. The unaltered clay was characterized by X-ray powder diffractometry (XRD), thermal gravimetric analysis (TGA/DTGA), Fourier-transform infrared (FTIR) spectroscopy, and variable-temperature Mössbauer spectroscopy. The chemically reduced and reoxidized forms of the clay were characterized by variable-temperature Mössbauer spectroscopy and chemical analysis. In the unaltered state the clay is comprised of smectite, maghemite, superparamagnetic goethite, and hematite, with a possible trace of kaolinite. In the reduced state the Fe (oxyhydr)oxides were dissolved. Upon reoxidation no six-line pattern was observed, indicating that the Fe remained only in the structure of the silicates. The final structure of the reduced–reoxidized clay contained more defects than the original clay, as revealed by greater quadrupole splitting values for structural Fe(III) in the clay. These findings indicate that upon exposure to natural redox cycles the Kutch clay could undergo permanent changes in its mineralogical composition and clay mineral structure, but further study is required to ascertain the effects that such changes would have on its long-term stability as a barrier material.     

Moisture barrier and physical properties of acetylated derivatives with increasing acetylation degree

Four acetostearin products with increasing acetylation degree were synthesized by chemical interesterification followed by fractionation/blending stages. Their physical properties and functional barrier properties were studied and compared to the properties of technical tristearin. Increasing acetylation degree (AD) modified the triacylglycerols crystal habits and probably led to an increase in acyl chain fluidity, which induced, at macroscopic levels, a decrease in solid fat content (SFC), in melting point, in surface and bulk material hydrophobicity, and an increased moisture effective diffusivity. Water vapor permeability (WVP) coefficients of the materials were partially influenced by the AD factor, but also by the development of macroscopic cracks in lipids presenting high SFC. Acetylated stearin up to 47% (acetyl mol/mol of esterified chain) presented the lowest WVP at 20 °C resulting from an adequate balance between hydrophobicity and mechanical properties of the material.     

Quantifying molecular surface barriers and intracrystalline diffusion in nanoporous materials by zero-length column

The zero-length column (ZLC) method has been frequently used to measure the effective diffusivity of guest molecules in nanoporous crystalline materials. Recent studies unveiled that the mass transport of guest molecules could originate from either intracrystalline diffusion and/or surface barriers. Directly quantifying the intracrystalline diffusivity and surface permeability of guest molecules. therefore, is essential for understanding the mass transfer and thus optimizing the design of nanoporous crystalline materials. In this work, we extended the ZLC method, based on a derived theoretical expression of the desorption rate, to decouple the surface barriers and intracrystalline diffusion from effective diffusion of guest molecules in nanoporous materials. The diffusivities of ethane, propane and n-pentane in SAPO-34 and Beta zeolites have been experimentally measured to verify the effectiveness of this method.     

东盟食品安全标准协调与监管一体化现状研究

随着东盟贸易协定与贸易政策推动贸易的快速发展,东盟在食用农产品领域充分发挥区域优势,并与我国成为最大的贸易合作伙伴。东盟地区日益增长的食品贸易技术壁垒措施表明,各成员国在本国优势产业及产品制定标准与监管措施方面存在较大差异。东盟目前已初步建立统一的食品安全标准法规框架,包括确立食品协调与互认标准、技术规范、食品安全政策等,以扩大区域贸易影响力。掌握东盟地区贸易壁垒措施实施情况,以及东盟食品安全标准协调与监管现状,有利于维护公共安全、降低贸易成本和应对可能的贸易壁垒,并进一步加强我国与东盟在重点领域标准、技术法规及监管等方面的一体化合作。     

An advanced framework for leakage risk assessment of hydrogen refueling stations using interval-valued spherical fuzzy sets (IV-SFS)

The extensive population growth calls for substantial studies on sustainable development in urban areas. Thus, it is vital for cities to be resilient to new situations and adequately manage the changes. Investing in renewable and green energy, including high-tech hydrogen infrastructure, is crucial for sustainable economic progress and for preserving environmental quality. However, implementing new technology needs an effective and efficient risk assessment investigation to minimize the risk to an acceptable level or ALARP (As low as reasonably practicable). The present study proposes an advanced decision-making framework to manage the risk of hydrogen refueling station leakage by adopting the Bow-tie analysis and Interval-Value Spherical Fuzzy Sets to properly deal with the subjectivity of the risk assessment process. The outcomes of the case study illustrate the causality of hydrogen refueling stations' undesired events and enhance the decision-maker's thoughts about risk management under uncertainty. According to the findings, jet fire is a more likely accident in the case of liquid hydrogen leakage. Furthermore, equipment failure has been recognized as the most likely cause of hydrogen leakage. Thus, in order to maintain the reliability of liquid hydrogen refueling stations, it is crucial that decision-makers develop a trustworthy safety management system that integrates a variety of risk mitigation measures including asset management strategies.     

多排弹性空心管桩屏障对平面SV波的隔离

假定土体和管桩为各向同性的均质弹性体，将多排空心管桩构成的非连续屏障对入射平面SV波的隔离问题简化成二维平面问题，运用复变函数的保角映射方法和波场位移势函数展开法，根据管桩与周围土体介质完全联结(即应力和位移连续)以及管桩内侧自由的边界条件，得到了所研究问题的理论解。通过与有限元软件ABAQUS的模拟结果进行对比，验证了上述理论解及其计算程序的正确性，并进一步分析了管桩的壁厚、排数、数量以及入射SV波的频率等因素对隔离效果的影响，结论表明：隔离效果随着管桩壁厚的减小而提高；管桩由一排增加到两排时，最佳隔离区域向远处扩展，而由两排增加到三排时，最佳隔离区域则向两侧扩展；管桩排数不变，而数量增多时，屏障宽度范围内的隔离效果明显提高；入射频率增大时，隔离效果有所减小。这为多排桩屏障的隔振设计提供了理论依据和参考。     

Hot wire chemical vapor processing (HWCVP) — A prospective tool for VLSI

Today the Very Large Scale Industry (VLSI) is looking towards process solutions, which will avoid the problems associated with the conventional or presently employed technologies. This demand has become more intense with the VLSI industry extending their horizons towards Micro electro-mechanical systems (MEMS) based devices and Application-Specific Integrated Circuits ASICs). The areas of concern are development of high-k dielectric thin films, highly conducting polysilicon thin films, ultra thin diffusion barriers on low dielectric constant layers with electromigration resistant metal interconnects. Over the last few years, work carried out on the hot wire chemical vapor process (HWCVP) has shown that, this technique has great potential to yield the desired materials at low processing temperatures. This paper discusses the results we have obtained in the above areas and also the extension of application of this technique to areas like MEMS and ASICs.     

对我国关税征收中名义税率与实际税率差距过大问题的思考

通过对我国关税征收现状的分析，指出了目前存在的一个严重的问题：名义关税率与实际征收率之间差距过大；进一步剖析了这种现象形成的原因及其产生的一系列负面影响；结合我国国情和国际经贸发展趋势，提出了一些具有建设性的意见和建议．