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排序方式: 共有165条查询结果,搜索用时 15 毫秒
1.
The economic relationship between China and Myanmar is regarded as a win–win cooperation. However, Chinese investments, especially in extractive and natural resource sectors, are associated with a number of unwanted environmental consequences. Moreover, the environmental impact assessment (EIA) quality of Chinese enterprises has often been criticized. EIA identifies adverse impacts to the environment through evidence-based decision making. On this basis, this paper provides an evaluation of Chinese EIA performance within the natural resources sector through a structured review of 15 environmental impact statements (EISs). This research also evaluates the EISs of the three largest and most controversial projects, the Myitsone Hydropower Dam, Lappadaung Copper Mine and Sino-Myanmar oil and gas pipelines. The findings reveal several omissions, inadequacies and deficiencies in all the projects with a significant number of EISs falling short of satisfactory quality. Through the analysis, the paper summarizes the factors affecting the EIA performance and proposes feasible recommendations to improve EIA practices in Chinese development projects in Myanmar. 相似文献
2.
H. N. Cheng Mason W. Rau Michael K. Dowd Michael W. Easson Brian D. Condon 《Journal of the American Oil Chemists' Society》2014,91(8):1461-1469
There is current interest in reducing the trans fatty acids (TFA) in hydrogenated vegetable oils because consumption of foods high in TFA has been linked to increased serum cholesterol content. In the interest of understanding the TFA levels, hydrogenation was carried out in this work on soybean oil and cottonseed oil at two pressures (2 and 5 bar) and 100 °C using commercially available Ni, Pd, and Pt catalysts. The TFA levels and the fatty acid profiles were analyzed by gas chromatography. The iodine value of interest is ~70 for all-purpose shortening and 95–110 for pourable oil applications. In all cases, higher hydrogen pressures produced lower levels of TFA. In the range of 70–95 iodine values for the hydrogenated products, the Pt catalyst gave the least TFA, followed closely by Ni, and then Pd, for both oils. For all three catalysts at 2- and 5-bar pressures and 70–95 iodine values, cottonseed oil contained noticeably less TFA than soybean oil; this is probably because cottonseed oil contains a lower total amount of olefin-containing fatty acids relative to soybean oil. Approximate kinetic modeling was also done on the hydrogenation data that provided additional confirmation of data consistency. 相似文献
3.
Ana M. Herrera-González Martín Caldera-Villalobos Jesús García-Serrano Marissa Vargas Ramírez Azdrubal Lobo Guerrero-Serrano 《Designed Monomers and Polymers》2018,21(1):137-144
In this paper we report the synthesis of a new polyacrylate named poly(1,1?-BP4MA) which is a derivate from 4-biphenylmethanol monomer. Poly(1,1?-BP4MA) was obtained by solution and bulk polymerization techniques to yield polymers with high molecular weight and high solubility. The study of the optical properties showed that poly(1,1?-BP4MA) is a fluorescent material with emission in the UV-green region and it has similar quantum yield to tryptophan. 相似文献
4.
Christopher S. SzotCara F. Buchanan Paul Gatenholm Marissa Nichole RylanderJoseph W. Freeman 《Materials science & engineering. C, Materials for biological applications》2011,31(1):37-42
Tissue engineering and the use of nanofibrous biomaterial scaffolds offer a unique perspective for studying cancer development in vitro. Current in vitro models of tumorigenesis are limited by the use of static, two-dimensional (2D) cell culture monolayers that lack the structural architecture necessary for cell-cell interaction and three-dimensional (3D) scaffolds that are too simplistic for studying basic pathological mechanisms. In this study, two nanofibrous biomaterials that mimic the structure of the extracellular matrix, bacterial cellulose and electrospun polycaprolactone (PCL)/collagen I, were investigated as potential 3D scaffolds for an in vitro cancer model. Multiple cancer cell lines were cultured on each scaffold material and monitored for cell viability, proliferation, adhesion, infiltration, and morphology. Both bacterial cellulose and electrospun PCL/collagen I, which have nano-scale structures on the order of 100-500 nm, have been used in many diverse tissue engineering applications. Cancer cell adhesion and growth were limited on bacterial cellulose, while all cellular processes were enhanced on the electrospun scaffolds. This initial analysis has demonstrated the potential of electrospun PCL/collagen I scaffolds toward the development of an improved 3D in vitro cancer model. 相似文献
5.
Ozone application in a modified screw conveyor to treat grain for insect pests, fungal contaminants, and mycotoxins 总被引:1,自引:0,他引:1
Marissa X. McDonough Linda J. Mason Adrian Denvir 《Journal of Stored Products Research》2011,47(3):249-254
Recent efforts have focused on improving the application of ozone technology as a pest management tool for stored grain. This study evaluated the efficacy of a modified screw conveyor to treat grain with ozone in a continuous-flow system. The ozone concentration delivered into the screw conveyor was 47,800 ppm and the average retention time for a corn kernel moving through the system was 1.8 min. Under these conditions, 100% mortality of adult red flour beetle (Tribolium castaneum (Herbst)) and adult maize weevil (Sitophilus zeamais (Motsch.)) was achieved after three passes through the screw conveyor, which equated to a concentration × time (CT) product value of 258,120 ppm-min. The potential effectiveness of the continuous treatment to reduce mold on the surface of corn kernels was also explored. Aspergillus flavus counts were reduced by 96% in a single pass through the screw conveyor. Three passes through the screw conveyor reduced the mold count by more than 2-log units. Ozone treatment also reduced aflatoxin applied to the grain; however, the reduction was not sufficient enough to be of commercial value. The results of this study provide valuable information for estimating the parameters needed for effectively treating grain in a commercial scale continuous-flow treatment system. 相似文献
6.
In this paper, an asymptotic expansion is constructed to solve second-order differential equation systems with highly oscillatory forcing terms involving multiple frequencies. An asymptotic expansion is derived in inverse of powers of the oscillatory parameter and its truncation results in a very effective method of dicretizing the differential equation system in question. Numerical experiments illustrate the effectiveness of the asymptotic method in contrast to the standard Runge–Kutta method. 相似文献
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9.
Marissa Vargas‐Ramirez Antonio Romero‐Serrano Rodolfo Morales Miguel Angeles‐Hernandez Federico Chavez‐Alcala Javier Castro‐Arellano 《国际钢铁研究》2001,72(5-6):173-181
A mathematical model earlier proposed has been improved to predict the kinetics of multicomponent reactions in the hot metal pretreatment through the injection of reactive fluxes. It is assumed that there are two reaction zones along the flux injection operation: a transitory reaction between the rising particles and the bulk metal, and the permanent reaction between the metal and the top slag. A criterion to estimate the fraction of solids which will react with molten iron in a three‐phase jet (gas‐solid‐liquid) was considered; this fraction of solids carries out the transitory reaction. The model also takes into account the thermodynamic changes produced in the metal and slag due to the chemical reactions. Calculated results of the model are in good agreement with experimental results for the desulfurization of hot metal through the injection of CaO‐SiO2‐CaF2‐FeO‐Na2O reagents at 1400 ‐ 1450 °C. Two kinds of hot metal were tested, one with a low carbon mass content of 3 % and the other with a high carbon mass content of 4.5 %. 相似文献
10.
Marissa Chatterjee Fernanda Faot Cassia Correa Jente Kerckhofs Katleen Vandamme 《International journal of molecular sciences》2021,22(12)
The aim of the study was to quantify the micro-architectural changes of the jaw bone in response to ovariectomy, exposed or not to bisphosphonate treatment. A total of 47 Wistar rats were ovariectomized (OVX) or sham-operated (shOVX) and exposed to osteoporosis preventive treatment for eight weeks either with bisphosphonates (alendronate, ALN; group OVX-ALN) three days/week at a dose of 2 mg/kg or with saline solution (untreated control condition; group OVX). The bone morphometric parameters of the trabecular jaw bone were assessed using ex vivo micro-computed tomography. The regions of interest investigated in the maxilla were the inter-radicular septum of the second molar and the tuber. The regions quantified in the mandible included the three molar regions and the condyle. A one-way analysis of variance followed by pairwise comparison using Tukey’s HSD and the Games–Howell test was conducted to explore significant differences between the groups. In the maxilla, OVX decreased the bone volume in the inter-radicular septum of the second molar. Bisphosphonate treatment was able to prevent this deterioration of the jaw bone. The other investigated maxillary regions were not affected by (un)treated ovariectomy. In the mandible, OVX had a significant negative impact on the jaw bone in the buccal region of the first molar and the inter-radicular region of the third molar. Treatment with ALN was able to prevent this jaw bone loss. At the condyle site, OVX significantly deteriorated the trabecular connectivity and shape, whereas preventive bisphosphonate treatment showed a positive effect on this trabecular bone region. No significant results between the groups were observed for the remaining regions of interest. In summary, our results showed that the effects of ovariectomy-induced osteoporosis are manifested at selected jaw bone regions and that bisphosphonate treatment is capable to prevent these oral bone changes. 相似文献