儿童用品TBT通报数据可视化预警研究

探索采用数据可视化技术分析儿童用品TBT通报数据,以可视化图形图像呈现通报热点并揭示趋势信息,提出对策与建议,助力为儿童用品产业升级、TBT预警数据分析和信息传播工作提供新思路,提高中小企业的国外市场准入机会。     

Storage and permeation of hydrogen molecule,atom and ions (H+ and H−) through silicon carbide nanotube; a DFT approach

The barriers for the encapsulation and decapsulation of hydrogen ions (cationic hydrogen and hydride), atom, and molecule through silicon carbide nanotube are thoroughly studied. DFT method is selected to measure the kinetic barriers for the passage of hydrogen atom, ions and molecule through nanotube via scanning potential energy surface. The kinetic barriers for the passage (encapsulation and decapsulation) of hydrogen are very important to understand the mechanism of hydrogen storage and release. The barriers for the permeation of H, H⁺ and H^? across SiC nanosheet are lower compared to hydrogen molecule (H₂). The exohedral and endohedral adsorption of hydrogen ions (cation and anion), atom and exohedral hydrogen molecule on silicon carbide are exothermic in nature. Whereas the encapsulation of hydrogen molecule in silicon carbide is endothermic. Electronic properties are analyzed through measurement of energy gap between highest occupied and lowest unoccupied molecular orbitals gap (G_H-L) and the density of state (DOS) spectra. The G_H-L analysis reveals that endohedral complexes have more pronounced effect on electronic properties compared to exohedral complexes. The SiC nanotube has highly favorable properties for storage and release of hydrogen ions, and atom.     

An integrated DEMATEL-MMDE-ISM based approach for analysing the barriers of IoT implementation in the manufacturing industry

Incorporation of smart devices within the older framework has brought along significant challenges. This paper presents a detailed analysis of the barriers faced during the implementation of Internet of Things (IoT) within the manufacturing sector. In addition, the authors aim to obtain a hierarchical structure, which will help the policymakers to identify the most crucial barriers enabling them to make an informed decision. With the help of databases like Scopus, Web of Science, etc. a comprehensive list of 22 barriers was initially obtained. This list was further narrowed down to 10 critical barriers. The first step of the analysis involved the application of Decision Making Trial and Evaluation Laboratory (DEMATEL) technique, which quantifies the influence of the barriers amongst one another. Maximum Mean De-Entropy (MMDE) technique is then used to obtain a scientific threshold value, which is later used in the Interpretive Structural Modelling (ISM) technique from which a hierarchical structure of the barriers is obtained. The results of this study are expected to highlight the most crucial barriers wherein the researchers and practitioners can focus their strategic efforts. This will facilitate the addressal of implicit issues while implementing IoT Techniques in the manufacturing industry.     

Autonomous detection and ascent of a step for an electric wheelchair

With the number of individuals using a wheelchair on the rise, the issue of removing architectural barriers, or at least overcoming them, has to be faced to improve independence, inclusiveness, and participation of wheelchair users. Some electric wheelchairs can climb and descend stairs and obstacles, however, the actual operations required to do so safely may be complex and may require an experienced or trained user. To overcome this issue, a method to first detect and classify a step and then autonomously climb it safely is proposed here. The same method is then applied and tested on an actual stair-climbing wheelchair prototype to prove its reliability in different conditions.     

人工挖孔桩施工过程中几个技术问题的处理措施

就某工程基础采用人工挖孔桩施工过程中遇到的几个技术问题进行了介绍。     

Effects of iron surface pretreatment on sorption and reduction kinetics of trichloroethylene in a closed batch system

The decline of trichloroethylene (TCE) in a metallic iron-water system results from the combination of reduction reaction and sorption onto iron surfaces. Sorption, particularly by highly impure iron, accelerates the removal of TCE from the aqueous phase, but delays the prevalence of steady-state conditions. In this case, an overly high value of reaction rate constant in the design of a treatment system would be used. In this work, the effects of an iron surface with 8.0% C, 6.1% O and 0.8% Si separately following HCl-washing and H2-reducing pretreatment on sorption and reduction rates were examined. The amounts of both aqueous and sorbed TCE were measured using a modified solvent-extraction method. TCE sorption onto an iron surface, as quantified by the Langmuir sorption maximum, followed the trend H2-reduced Fe0 > HCl-washed Fe0 > untreated Fe0 (0.887, 0.365 and 0.311 mg/g, respectively). Measurements of the concentration of sorbed TCE revealed that about 34-37% of the initial mass of TCE in the aqueous phase was removed by sorption by H2-reduced Fe0, 16-19% was removed by HCl-washed Fe0 and 13-16% was removed by untreated Fe0. A combination of new and previously reported data on cast iron's capacity to sorb TCE revealed a linear relationship between this capacity and the C fraction in the surface of the iron, with the coefficient of determination (r2) exceeding 0.99. The first-order observed rate constants (k(obs)) of the reduction of TCE in contact with Fe0 were obtained from the slope of a plot of total TCE loss rate (-dC(T)/dt) versus the amount of TCE in the aqueous phase (C(w)) using linear least-squares analysis. The k(obs) values were 0.080, 0.148 and 0.191 h(-1) for untreated, HCl-washed and H2-reduced Fe0, respectively. Normalized to iron surface area concentration, the specific rate constants (k(SA)) were 2.3 7x 10(-3) , 2.31 x 10(-3) and 5.62 x 10(-3) h(-1) m(-2) L, respectively. The results indicated that HCl-washing approximately doubled k(obs), primarily because of the increase in the surface area of the iron, and it slightly decreased k(SA) due to rapid corrosion during the rinsing process. Both the number of reactive sites and the sorption capacity per unit iron surface area through the H2-reducing pretreatment were increased due to the reduction of iron oxide layer and the carbonization of carbon-containing subjects on the iron's surface. Hence, the H2 reduction of cast iron promotes the removal of TCE from contaminated water by the concurrent sorption and reduction.     

Are more restrictive food cadmium standards justifiable health safety measures or opportunistic barriers to trade? An answer from economics and public health

In the past, Cd regulations have imposed trade restrictions on foodstuffs from some developing countries seeking to access markets in the developed world and in recent years, there has been a trend towards imposing more rigorous standards. This trend seems to respond more to public and private sectors strategies in some developed countries to create disguised barriers to trade and to improve market competitiveness for their industries, than to scientifically justified health precautions (sanitary and phytosanitary measures) and/or technical barriers to trade acceptable under the Uruguay Round Agreement of the WTO. Applying more rigorous Cd standards in some developed countries will not only increase production costs in developing countries but it will also have a large impact on their economies highly dependent on international agricultural markets. In the current literature there are large uncertainties in the cause-effect relationship between current levels of Cd intakes and eventual health effects in human beings; even the risk of Cd to kidney function is under considerable debate. Recent works on the importance of zinc:Cd ratio rather than Cd levels alone to determine Cd risk factors, on the one hand, and on the declining trends of Cd level in foods and soils, on the other, also indicate a lack of scientific evidence justifying more restrictive cadmium standards. This shows that developing countries should fight for changing and making more transparent the current international structures and procedures for setting sanitary and phytosanitary measures and technical barriers to trade.     

保障性住房申购障碍及其对策研究——以重庆市为例

以重庆市为例,基于居住消费理论,调查分析公租房潜在申请者与已入住者在申请与购买公租房项目中存在的交易障碍因素。结果发现,就业地与居住地的远近、家庭规模与户型大小的匹配、公共配套设施的完善程度以及心理阻力是阻碍申请行为的主要因素;价格与户型面积则会对已入住群体的购买决策产生直接影响。在此基础上,提出破除申购障碍的对策与建议。     

Disaster Recovery Among Multiethnic Immigrants: A Case Study of Southeast Asians in Bayou La Batre (AL) After Hurricane Katrina

Problem, research strategy, and findings: Immigrants suffer disproportionately from disasters because they have limited capacity to prepare for, respond to, or recover from a disaster. Unfortunately, planners and emergency managers are often inadequately trained or educated about the unique sociocultural needs and assets among immigrant groups. Hurricane Katrina exposed challenges to long-term recovery among Southeast Asian immigrants in Bayou La Batre (AL). We employ qualitative research methods, including in-depth interviews, focus groups with immigrants, and site visits, to better understand the barriers to disaster recovery and to inform local, state, federal, and nongovernmental agencies on how to better prepare disaster plans that would improve disaster recovery for multiethnic, multicultural, immigrant populations. We find four significant categories of sociocultural barriers to disaster recovery for Southeast Asian immigrants in Bayou La Batre: 1) language, literacy, and communication; 2) cultural differences in help-seeking; 3) inability to navigate the disaster recovery bureaucracy; and 4) and lack of leadership. Despite these barriers to recovery, immigrant groups can also teach us about resiliency in the face of disaster. The levels of trust, cooperation, and collaboration within the ethnic immigrant community help to buffer the damaging effects during the response and recovery period.

Takeaway for practice: Our study reveals that cultural competency among staff members engaged in preparedness, response, and recovery is essential for an effective disaster recovery process. Furthermore, engaging immigrant groups in long-term recovery requires trust and relationship building prior to a disaster. In doing so, more culturally appropriate and effective disaster recovery plans can be developed.     

DEPOSITIONAL AND DIAGENETIC BARRIERS,BAFFLES AND CONDUITS: PERMIAN – CARBONIFEROUS UNAYZAH RESERVOIR,NUAYYIM FIELD,CENTRAL SAUDI ARABIA

The Unayzah Formation is one of the most important Palaeozoic reservoir systems in Saudi Arabia. In the Nuayyim field, Central Saudi Arabia, it produces light, sweet crude oil and consists of three main reservoir units, in descending stratigraphic order: Unayzah A, B and C. These reservoir units include a wide range of depositional facies deposited under a variety of climatic conditions, from high‐latitude glacio‐fluvial to more temperate playa/lacustrine, floodplain and braided‐fluvial to hot‐arid aeolian environments. Together with the diagenetic changes superimposed on the various depositional facies, this has produced complex reservoir heterogeneity. The effects of this diagenetic and sedimentologic complexity on reservoir quality and compartmentalization are the subject of this paper. Approximately 816 ft of core and 611 core plug samples were examined from three wells which penetrate, completely or in part, the Unayzah reservoir. We combine petrographic and scanning electron microscope analysis with porosity and permeability data and calculated pore throat dimensions to identify fluid conduits, barriers and baffles to fluid flow. A rock classification scheme is proposed which takes into account whether the pore‐level control on fluid flow is due to depositional or diagenetic processes and the composition of depositional or diagenetic phases within the pores. Distinguishing depositional versus diagenetic controls on fluid flow is important for predicting the three‐dimensional geometry of conduits, barriers and baffles, and a priori knowledge of potential reactions between injected fluids and reservoir rocks is important for designing enhanced oil recovery fluids. In the three wells studied, it appears that the Unayzah reservoir is compartmentalized vertically due to the occurrence of diagenetic and depositional barriers and baffles. There is insufficient data to assess the lateral or areal extent of the barriers, baffles and fluid conduits, but the understanding of pore‐level controls on reservoir quality and the rock classification schemes introduced here will provide a starting point for future studies. These studies should combine well logs, seismic and engineering data with data presented here to assist mapping conduits, barriers and baffles across the field. The proposed classification schemes may also prove to be useful for assessing reservoirs in other fields both within Saudi Arabia and elsewhere.