China’s Oil & Gas Imports and Exports in 2013

Demand for imported oil is weakened by economic growth decline, In 2013＇ growth of China＇ s oil imports dropped to the lowest in 8 years, but net imports topped 300 million tons. Domestic oil demand will continue to grow slightly in 2014, and development of alternative fuels will restrict growth of oil import.     

Structure of Cu-Sn Melt at High Temperature

The temperature-dependent viscosity and X-ray diffraction (XRD) patterns of a Cu₆₅Sn₃₅ melt were investigated at high temperatures. The viscosity of the melt changed discontinuously at about 1283?K (1010?°C). An XRD analysis of the Cu₆₅Sn₃₅ melt revealed no obvious changes in the correlation radius, whereas the coordination number increased abruptly at a similar temperature with that mentioned previously, i.e., 1283?K (1010?°C) during the cooling process. The results indicate a redistribution of atoms in the nearest environment. The structural transition at the higher temperature was attributed to a change of combination mode of nearest atoms in the short-range order cluster of the Cu₆₅Sn₃₅ melt.     

图解法砼施工技术交底的应用--惠州百利通广场项目案例分析

工程主体施工中，砼浇注分项工程施工具有劳动量大、时间持续长、质量要求高等特点，且涉及人、机、料、法、环五大要素。为做好计划、调配、组织、协调工作，落实施工方案，实现预定的工期、质量、安全目标，做好技术交底显得尤为重要。     

应用于配电网的STATCOM电压与无功功率综合控制方法

本文首先介绍STATCOM的基本工作原理,并简述项目应用的基本概况;针对配电网对动态无功补偿装置提出的要求,设计了STATCOM电压与无功功率综合控制算法及控制参数整定方法,通过PSIM仿真模型验证了控制方法的可行性。该STATCOM设备已经在广东电网取得了良好的应用,通过对比STATCOM投运前后系统的电压与无功情况,进一步验证了控制方法的有效性,保证了配电网供电的可靠与稳定。     

An Improved Probabilistic Approach for Fire Detection in Videos

This paper proposes an improved probabilistic approach using two improved feature representations. These features are color and motion. First, an improved probabilistic model for color-based fire detection is proposed, and candidate fire regions are generated from this model. Then, an improved motion feature is used for final decision. The performance of the proposed approach showed about 0.2758 accuracy in false positive rate, and 0.2636 accuracy in false negative rate on a benchmark fire video database, which represents a decrease of 46.6% in false positive rate, and a decrease of 52.1% in false negative rate compared to the probabilistic approach.     

生物除铬的机理研究

本论文主要是研究厌氧微生物作为生物絮凝剂吸附六价铬的吸附特性及机理。污泥中的微生物以杆菌为主。污泥吸附沉降性良好。污泥在吸附时间40 min内,不会解析,吸附效果最好。在污泥吸附能力达到饱和时,加入营养经过一段时间后,其吸附能力会部分恢复。     

Characterizing sources and emissions of volatile organic compounds in a northern California residence using space‐ and time‐resolved measurements

We investigate source characteristics and emission dynamics of volatile organic compounds (VOCs) in a single‐family house in California utilizing time‐ and space‐resolved measurements. About 200 VOC signals, corresponding to more than 200 species, were measured during 8 weeks in summer and five in winter. Spatially resolved measurements, along with tracer data, reveal that VOCs in the living space were mainly emitted directly into that space, with minor contributions from the crawlspace, attic, or outdoors. Time‐resolved measurements in the living space exhibited baseline levels far above outdoor levels for most VOCs; many compounds also displayed patterns of intermittent short‐term enhancements (spikes) well above the indoor baseline. Compounds were categorized as “high‐baseline” or “spike‐dominated” based on indoor‐to‐outdoor concentration ratio and indoor mean‐to‐median ratio. Short‐term spikes were associated with occupants and their activities, especially cooking. High‐baseline compounds indicate continuous indoor emissions from building materials and furnishings. Indoor emission rates for high‐baseline species, quantified with 2‐hour resolution, exhibited strong temperature dependence and were affected by air‐change rates. Decomposition of wooden building materials is suggested as a major source for acetic acid, formic acid, and methanol, which together accounted for ~75% of the total continuous indoor emissions of high‐baseline species.     

Applied electric field on the reaction between submerged entry nozzle and alloy in the steel

In this study, the reactivity between nozzle and submerged entry nozzle and alloy elements in the steel (Al and Ce) under different electric field conditions was investigated. The results show that the decarburization of the nozzle is an important factor affecting the clogging behavior and steel quality. The external electric field directly affects and changes the decarburization, clogging, and reaction behavior between the nozzle and alloy in the steel. If the chemical reaction force between alloys and the nozzle is greater than the applied electric field force in actuality, the clogging will also occur on the submerged entry nozzle. In the future, this new method of controlling and changing the interfacial electric fields can be used to solve the problem of decarburization and clogging of the submerged entry nozzle.     

Experimental and numerical investigation on three-point bending behaviors of unidirectional warp-knitted composites

This study develops a novel specimen model, which considers the progressive damage of the layers, the knitting yarns, and the interlaminar cohesive zone, to investigate the flexural properties and the interlaminar shear properties of the unidirectional warp-knitted composites. Three-point bending tests are conducted as verification of the numerical model. Improved strain-based Hashin criteria are proposed to analyze the shear nonlinearity. Results show that specimens with small span-to-thickness ratios exhibit obvious nonlinear behaviors and the corresponding simulation results are sensitive to the value of the shear nonlinear factor. Failure mechanism and stress distributions are analyzed based on numerical simulations. The effect of the specimen size on bending behaviors is discussed. The influence of the width is found to be negligible but that of the span-to-thickness ratio is significant. The ranges of the span-to-thickness ratio corresponding to different failure modes are given. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48132.