压铸模CAD中知识库的设计与建立的研究

KBE技术关键是设计中体现知识获取、知识表示、知识推理和知识管理。基于KBE的开发,本系统使用Visual C++语言,以面向对象的技术为指导建立知识库,采用对象的概念表示问题域中的实体,规则的具体内容则分布在相关对象的属性和方法中,从而充分地发挥了信息隐蔽、继承和多态等面向对象的特点。     

Exploratory and higher-order factor analyses of the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) adolescent subsample.

The factor structure of the Wechsler Adult Intelligence Scale–Fourth Edition (WAIS-IV; Wechsler, 2008a) with the adolescent participants (ages 16–19 years; N = 400) in the standardization sample was assessed using exploratory factor analysis, multiple factor extraction criteria, and higher-order exploratory factor analyses. Results from exploratory factor analyses were not included in the WAIS-IV Technical and Interpretation Manual (Wechsler, 2008b) and are necessary for determining convergence or divergence with the reported confirmatory factor analyses. As found with the total WAIS-IV standardization sample (Canivez & Watkins, in press), the present results with the adolescent subsample found all WAIS-IV subtests (10- and 15-subtest configurations) were properly associated with their four theoretically proposed first-order factors, but only one factor extraction criterion (standard error of scree) recommended extraction of four factors. Hierarchical exploratory analyses with the Schmid and Leiman (1957) procedure found that the second-order g factor accounted for major portions of total and common variance, while the four first-order factors accounted for small portions of total and common variance. It was concluded that the WAIS-IV provides strong measurement of general intelligence in adolescents and clinical interpretation should be primarily at that level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Extraction of rare earth elements from their oxides using organophosphorus reagent complexes with HNO3 and H2O in supercritical CO2

Direct extraction of metals from solids with complexing agents in supercritical CO2(SC-CO2) has recently attracted interests in separation,purification,recovery,and analysis of metals.In the present study,the static/dynamic extraction of rare earth elements(Nd,Ce) from their oxides(Nd2O3,CeO2) with organophosphorus complexes with HNO3 and H2O in SC-CO2 was investigated.The static extraction efficiency of Nd from Nd2O3 with the tri-n-butylphosphate(TBP)-HNO3 complex could reach 95% under optimized experiment...     

Characteristic of synergistic extraction of oxalic acid with system from rare earth metallurgical wastewater

Large amount of high concentration acidic wastewater would be produced in the conversion process of chloride rare earth into oxide rare earth.It was a mixed solution of oxalic acid and hydrochloric acid,so the recycling use was very difficult.The method of liquid-liquid extraction was proposed in this paper to achieve wastewater treatment and reclamation.The mechanism of extraction of oxalic acid from the wastewater with the systems of 50% TOB+45% kerosene and 5% 2-ethyl hexanol was investigated.The composition and structure of the extracted species and the establishment of the mathematical model of the oxalic acid extraction were determined by the use of saturation method,equimolar series method.The results showed that extraction of oxalic acid by TOB was a neutral association extraction,oxalic acid existed mainly in a molecular form in the organic phase,and the extraction combination ratio was 2:1.The duality extraction system composed of extractant TOB and TOC had synergistic extraction effect on oxalic acid and chlorhydric acid,and the extraction dislribution ratio was improved greatly.The optimum volume fiaction of TOB was 0.6-0.8.     

电子物证提取和检验前的“污染”研究

文章分别从电子物证的定义、特征等方面进行阐述,分析总结造成电子物证在提取和检验前环节被＂污染＂的原因及可能造成的结果,对电子物证现场勘验提取提出了三个方面的建议,以期对规范电子物证的提取工作有借鉴意义。     

Robust facial feature points extraction in color images

A method of facial feature points extraction based on improved active appearance model (AAM) with Gabor wavelet features was presented in the paper. After the pre-processing of a standard face detector and lighting compensation, the paper proposed a hybrid AAM by combining the local skin similarity with the original local grey-level appearance model. Moreover, the feature points by the hybrid AAM and their neighbors were considered by a classification problem to further refine the results. Namely, the Gabor feature around the feature points was extracted, trained by linear discriminant analysis (LDA) and classified by K Nearest Neighbor (KNN) to give the precise location of the feature points. Experimental results indicated that facial feature points can be located robustly and precisely by the proposed method.     

The impact of wave energy farms in the shoreline wave climate: Portuguese pilot zone case study using Pelamis energy wave devices

This paper describes the study of the impact of energy absorption by wave farms on the nearshore wave climate and, in special, the influence of the incident wave conditions and the number and position of the wave farms, on the nearshore wave characteristics is studied and discussed. The study was applied to the maritime zone at the West coast off Portugal, namely in front of São Pedro de Moel, where it is foreseen the deployment of offshore wave energy prototypes and farms between the 30 m and 90 m bathymetric lines, with an area of 320 Km². In this study the REFDIF model was adapted in order to model the energy extraction by wave farms. Three different sinusoidal incident wave conditions were considered. Five different wave farm configurations, varying the position of the wave farm, its number and the width of the navigation channels at each wave farm were analysed. The results for each configuration in terms of the change of the wave characteristics (wave height and wave direction) at the nearshore are presented, compared and discussed for three representative wave conditions.     

Forced heat loss from body surface reduces heat flow to body surface

Heat stress is commonly relieved by forced evaporation from body surfaces. The mode of heat stress relief by heat extraction from the periphery is not clear, although it reduces rectal temperature. Radiant surface temperature (Ts) of the right half of the body surface was examined by thermovision in 4 lactating Holstein cows (30 kg of milk/d) during 7 repeated cycles of forced evaporation created by 30 s of wetting followed by 4.5 min of forced airflow. Wetting was performed by an array of sprinklers (0.76 m³/h), and forced airflow (>3 m/s velocity) over the right side of the body surface was produced by fans mounted at a height of 3 m above the ground. Sprinkling wetted the hind legs, rump, and chest, but not the lower abdomen side, front legs, or neck. The animals were maintained in shade at an air temperature of 28°C and relative humidity of 47%. Coat thickness was 1 to 2 mm, so Ts closely represented skin temperature. Mean Ts of 5 × 20 cm areas on the upper and lower hind and front legs, rump, chest, abdomen side, and neck were obtained by converting to temperature their respective gray intensity in single frames obtained at 10-s intervals. Little change occurred in Ts during the first wetting (0.1 ± 0.6°C), but it decreased rapidly thereafter (1.6 ± 0.6°C in the fifth wetting). The Ts also decreased, to a smaller extent, in areas that remained dry (0.7 ± 1.0°C). In all body sites, a plateau in Ts was reached by 2 min after wetting. The difference between dry and wet areas in the first cooling cycle was approximately 1.2°C. The Ts of different body areas decreased during consecutive cooling cycles and reached a plateau by 3 cooling cycles in dry sites (front leg, neck, abdomen side), by 5 cooling cycles in the hind leg, and 7 cooling cycles in the rump and chest. The reduction in mean Ts produced by 7 cycles was 4.0 to 6.0°C in wetted areas and 1.6 to 3.7°C in sites that were not wetted. Initial rectal temperature was 38.9 ± 0.1°C; it remained unchanged during first 5 cooling cycles, decreased by 0.1°C after 7 cooling cycles, and decreased to 38.4 ± 0.06°C after 8 to 10 cooling cycles, with no additional subsequent decrease. The concomitant reduction in Ts in dry and wet areas suggests an immediate vasoconstrictor response associated with heat extraction and later development of a cooler body shell. The reduction in rectal temperature represents a response involving transfer of heat from the body core to the body shell. This response mode requires consideration in settings of heat stress relief.     

Oil extraction,environmental degradation and poverty in the Niger Delta region of Nigeria: a viewpoint

In Nigeria, environmental problems are severe, particularly in the Niger Delta region of the country. In that region, crude petroleum activities damage the fertility of the soil, and destroy wildlife and the breeding ground for marine fishes because of the toxicity of oil and gas. Consequently, the indigenous people are impoverished, with attendant increase in environmental abuse occasioned by their struggle for survival. The various government programmes aimed at ameliorating their plight have failed due to inefficiency and corruption. The federal government is also thwarting efforts by Niger Deltans at resource control that would help to distribute equitably the oil resources of the region. This opposition to a derivation‐based redress to the development problems of Niger Delta is partly responsible for the anarchy that the region is experiencing. Unless the underlying problems are addressed, the Niger Delta will remain a source of instability for the Nigerian federation. Therefore, the oil of the Niger Delta needs exploitation in ways that advance the cause of development in Nigeria without compromising the environmental values of that region and the welfare of its people.     

Optimisation of the supercritical extraction of toxic elements in fish oil

This study aims to optimise the operating conditions for the supercritical fluid extraction (SFE) of toxic elements from fish oil. The SFE operating parameters of pressure, temperature, CO₂ flow rate and extraction time were optimised using a central composite design (CCD) of response surface methodology (RSM). High coefficients of determination (R²) (0.897–0.988) for the predicted response surface models confirmed a satisfactory adjustment of the polynomial regression models with the operation conditions. The results showed that the linear and quadratic terms of pressure and temperature were the most significant (p < 0.05) variables affecting the overall responses. The optimum conditions for the simultaneous elimination of toxic elements comprised a pressure of 61 MPa, a temperature of 39.8ºC, a CO₂ flow rate of 3.7 ml min^?1 and an extraction time of 4 h. These optimised SFE conditions were able to produce fish oil with the contents of lead, cadmium, arsenic and mercury reduced by up to 98.3%, 96.1%, 94.9% and 93.7%, respectively. The fish oil extracted under the optimised SFE operating conditions was of good quality in terms of its fatty acid constituents.