The study investigated the concentration of Lead, Cadmium, Nickels and Chromium in sediment and seagrass tissues at six selected sites along the Sudanese Red Sea coast. The findings of the study added some important a...The study investigated the concentration of Lead, Cadmium, Nickels and Chromium in sediment and seagrass tissues at six selected sites along the Sudanese Red Sea coast. The findings of the study added some important and necessary information about the status and condition of the coastal environment in the Sudanese Red Sea coast in terms of the extent of pollution with heavy metals. The study sites included: Marsa Bashayer, Marsa Dama Dama, Green Area, Shipyard, Marsa Halout and Dungonab Bay. The Atomic Absorption Spectrophotometer was used to measure Lead, Cadmium and Nickels. The colorimetric detection method was used for Chromium using the Spectrophotometer. Marsa Dama Dama site revealed high levels concentration of heavy metals in sediment for Lead (60.5) μg/g, Cadmium (0.22) μg/g and Chromium (146.65) μg/g. Marsa Halout showed the highest mean concentration of Nickel in sediment at 14 μg/g. The variation of concentration of metals in sediment between the sites was not significant. The mean concentration of metals in seagrass species tissues ranged from 3.9 to 26.25 μg/g for Lead, 0.1 to 0.90 μg/g for Cadmium, 0.38 to 5.96 μg/g for Nickel and 0.15 to 0.495 μg/g for Chromium. The differences of concentration of heavy metals in seagrass tissues among the sites were significant for Lead and not significant for Cadmium;Nickel and Chromium.展开更多
In this paper, the design of a proportional integral controller (PIC) plus fuzzy logic controller (FLC) for the negative output elementary super lift Luo converter (NOESLLC) operated in discontinuous conduction mode (...In this paper, the design of a proportional integral controller (PIC) plus fuzzy logic controller (FLC) for the negative output elementary super lift Luo converter (NOESLLC) operated in discontinuous conduction mode (DCM) is presented. In spite of the many benefits viz. the high voltage transfer gain, the high efficiency, and the reduced inductor current and the capacitor voltage ripples, it natured with non-minimum phase. This characteristic makes the control of NOESLLC cumbersome. Any attempt of direct controlling the output voltage may erupt to instability. To overcome this problem, indirect regulation of the output voltage based on the two-loop controller is devised. The savvy in the inductor current control improves the dynamic response of the output voltage. The FLC is designed for the outer (voltage) loop while the inner (current) loop is controlled by the PIC. For the developed ?19.6 V NOESLLC, the dynamic performances for different perturbations (line, load and component variations) are obtained for PIC plus FLC and compared with PIC plus PIC. The study of two cases is performed at various operating regions by developing the MATLAB/Simulink model.展开更多
To guarantee the accuracy and real-time of the 3D reconstruction method for outdoor scene,an algorithm based on region segmentation and matching was proposed.Firstly,on the basis of morphological gradient information,...To guarantee the accuracy and real-time of the 3D reconstruction method for outdoor scene,an algorithm based on region segmentation and matching was proposed.Firstly,on the basis of morphological gradient information,obtained by comparing color weight gradient images and proposing a multi-threshold segmentation,scene contour features were extracted by a watershed algorithm and a fuzzy c-means clustering algorithm.Secondly,to reduce the search area,increase the correct matching ratio and accelerate the matching speed,the region constraint was established according to a region's local position,area and gray characteristics,the edge pixel constraint was established according to the epipolar constraint and the continuity constraint.Finally,by using the stereo matching edge pixel pairs,their 3D coordinates were estimated according to the binocular stereo vision imaging model.Experimental results show that the proposed method can yield a high stereo matching ratio and reconstruct a 3D scene quickly and efficiently.展开更多
Dense sintered bodies of proton conducting BaZrO3 (BZ) and Y-doped BaZrO3 (BZ-Y) were obtained at 1600℃ for a short sintering time of 5 hours, by the addition of NiO as a sintering promotion agent. The relative densi...Dense sintered bodies of proton conducting BaZrO3 (BZ) and Y-doped BaZrO3 (BZ-Y) were obtained at 1600℃ for a short sintering time of 5 hours, by the addition of NiO as a sintering promotion agent. The relative density and grain growth of samples, Ni-doped BaZrO3 (BZ-N) and Ni, Y co-doped BaZrO3 (BZ-NY), were increased with increasing Ni addition. The sinterability of BZ-NY was greatly improved just to add only 0.6 mol% Ni and the relative density of this sample was more than 98%, in contrast to that of 60% at most for BZ-Y without Ni addition. Electrical conductivity of BZ-NY added Ni 1.0 mol%, BaZr0.91Ni0.01Y0.08O3-α, was more than 10-3 S.cm-2 at 900℃?in a wet 1% hydrogen atmosphere, which value was 10 times higher than that of BZ-Y. In addition, the kind of electrical conduction carrier and an ionic transport number were also examined by employing various concentration cells. It was found that the proton conduction was dominant for both BZ-N and BZ-NY samples, although BZ-NY showed scarcely oxygenion conduction approximately 10% in a high temperature range higher than 800℃. From these results, as mall amount of Ni addition found to be effective for improvement of both the sinterability and the electrical conductivity.展开更多
目的:研究低剂量无细胞短棒状杆菌纳米级制剂(NCPP)对刀豆蛋白 A(Con A)诱导的小鼠急性肝损伤的保护作用及机理。方法:BALB/c 小鼠腹腔注射 NCPP(0.01 mg·只)后第7 d 以 Con A(25μg·g^(-1))尾静脉注射诱导小鼠急性肝损伤模...目的:研究低剂量无细胞短棒状杆菌纳米级制剂(NCPP)对刀豆蛋白 A(Con A)诱导的小鼠急性肝损伤的保护作用及机理。方法:BALB/c 小鼠腹腔注射 NCPP(0.01 mg·只)后第7 d 以 Con A(25μg·g^(-1))尾静脉注射诱导小鼠急性肝损伤模型。测定血清转氨酶(ALT/AST)及肝脏内的病理变化。同时设置 PBS 预处理对照组和 Con A 模型对照组,每组8只小鼠。用流式细胞仪检测肝脏内自然杀伤细胞(NK 细胞)的数量变化和 CD4~4T 淋巴细胞的活化情况。结果:与 Con A 模型组相比,NCPP 预处理组小鼠血清转氨酶明显降低[ALT 水平从(328±14)U·L^(-1)下降到(104±41)U·L^(-1),AST 水平从(141±9)U·L^(-1)下降到(98±17)U·L^(-1)],肝脏组织 HE 染色显示肝脏病理损伤明显减轻,同时流式细胞术的分析结果显示:与 Con A 模型组相比,小鼠肝脏 NK 细胞数量降低,且 CD4^+T 淋巴细胞的活化受到了明显抑制。结论:NCPP 对 Con A 诱导的小鼠急性肝损伤具有保护作用。其机理可能与抑制 CD4^+T 淋巴细胞活化和拮抗肝脏内 NK 细胞的回流有关。展开更多
应用 Con A-HRP-G 二步标记法,对健康人新鲜精子及经棉酚处理后的精子作了标记,并在光镜、透射电镜及扫描电镜下作了对比观察。结果表明,在人的精子的质膜表面,从头至尾均有金粒标记。以头部及尾部中段较为致密。在被棉酚破坏了质膜的...应用 Con A-HRP-G 二步标记法,对健康人新鲜精子及经棉酚处理后的精子作了标记,并在光镜、透射电镜及扫描电镜下作了对比观察。结果表明,在人的精子的质膜表面,从头至尾均有金粒标记。以头部及尾部中段较为致密。在被棉酚破坏了质膜的精子内部,在顶体膜及残破的线粒体内也出现金标记。说明不仅在精子的质膜表面,而且在顶体膜及线粒体等内膜系统,都有Con A 受体。本文还讨论了该受体在人精子存在的意义,以及 Con A-HRP-G 二步标记法和光镜、透射电镜、扫描电镜对比观察法的优点。展开更多
A Harten-Lax-van Leer-contact(HLLC) approximate Riemann solver is built with elastic waves(HLLCE) for one-dimensional elastic-plastic flows with a hypoelastic constitutive model and the von Mises' yielding criteri...A Harten-Lax-van Leer-contact(HLLC) approximate Riemann solver is built with elastic waves(HLLCE) for one-dimensional elastic-plastic flows with a hypoelastic constitutive model and the von Mises' yielding criterion. Based on the HLLCE,a third-order cell-centered Lagrangian scheme is built for one-dimensional elastic-plastic problems. A number of numerical experiments are carried out. The numerical results show that the proposed third-order scheme achieves the desired order of accuracy. The third-order scheme is used to the numerical solution of the problems with elastic shock waves and elastic rarefaction waves. The numerical results are compared with a reference solution and the results obtained by other authors. The comparison shows that the presented high-order scheme is convergent, stable, and essentially non-oscillatory. Moreover,the HLLCE is more efficient than the two-rarefaction Riemann solver with elastic waves(TRRSE).展开更多
The ineffective utilization of power resources has attracted much attention in current years. This paper proposes a real-time distributed load scheduling algorithm considering constraints of power supply. Firstly, an ...The ineffective utilization of power resources has attracted much attention in current years. This paper proposes a real-time distributed load scheduling algorithm considering constraints of power supply. Firstly, an objective function is designed based on the constraint, and a base load forecasting model is established when aggregating renewable generation and non-deferrable load into a power system, which aims to transform the problem of deferrable loads scheduling into a distributed optimal control problem. Then, to optimize the objective function, a real-time scheduling algorithm is presented to solve the proposed control problem. At every time step, the purpose is to minimize the variance of differences between power supply and aggregate load, which can thus ensure the effective utilization of power resources. Finally, simulation examples are provided to illustrate the effectiveness of the proposed algorithm.展开更多
文摘The study investigated the concentration of Lead, Cadmium, Nickels and Chromium in sediment and seagrass tissues at six selected sites along the Sudanese Red Sea coast. The findings of the study added some important and necessary information about the status and condition of the coastal environment in the Sudanese Red Sea coast in terms of the extent of pollution with heavy metals. The study sites included: Marsa Bashayer, Marsa Dama Dama, Green Area, Shipyard, Marsa Halout and Dungonab Bay. The Atomic Absorption Spectrophotometer was used to measure Lead, Cadmium and Nickels. The colorimetric detection method was used for Chromium using the Spectrophotometer. Marsa Dama Dama site revealed high levels concentration of heavy metals in sediment for Lead (60.5) μg/g, Cadmium (0.22) μg/g and Chromium (146.65) μg/g. Marsa Halout showed the highest mean concentration of Nickel in sediment at 14 μg/g. The variation of concentration of metals in sediment between the sites was not significant. The mean concentration of metals in seagrass species tissues ranged from 3.9 to 26.25 μg/g for Lead, 0.1 to 0.90 μg/g for Cadmium, 0.38 to 5.96 μg/g for Nickel and 0.15 to 0.495 μg/g for Chromium. The differences of concentration of heavy metals in seagrass tissues among the sites were significant for Lead and not significant for Cadmium;Nickel and Chromium.
文摘In this paper, the design of a proportional integral controller (PIC) plus fuzzy logic controller (FLC) for the negative output elementary super lift Luo converter (NOESLLC) operated in discontinuous conduction mode (DCM) is presented. In spite of the many benefits viz. the high voltage transfer gain, the high efficiency, and the reduced inductor current and the capacitor voltage ripples, it natured with non-minimum phase. This characteristic makes the control of NOESLLC cumbersome. Any attempt of direct controlling the output voltage may erupt to instability. To overcome this problem, indirect regulation of the output voltage based on the two-loop controller is devised. The savvy in the inductor current control improves the dynamic response of the output voltage. The FLC is designed for the outer (voltage) loop while the inner (current) loop is controlled by the PIC. For the developed ?19.6 V NOESLLC, the dynamic performances for different perturbations (line, load and component variations) are obtained for PIC plus FLC and compared with PIC plus PIC. The study of two cases is performed at various operating regions by developing the MATLAB/Simulink model.
基金Supported by the Ministerial Level Advanced Research Foundation(40401060305)
文摘To guarantee the accuracy and real-time of the 3D reconstruction method for outdoor scene,an algorithm based on region segmentation and matching was proposed.Firstly,on the basis of morphological gradient information,obtained by comparing color weight gradient images and proposing a multi-threshold segmentation,scene contour features were extracted by a watershed algorithm and a fuzzy c-means clustering algorithm.Secondly,to reduce the search area,increase the correct matching ratio and accelerate the matching speed,the region constraint was established according to a region's local position,area and gray characteristics,the edge pixel constraint was established according to the epipolar constraint and the continuity constraint.Finally,by using the stereo matching edge pixel pairs,their 3D coordinates were estimated according to the binocular stereo vision imaging model.Experimental results show that the proposed method can yield a high stereo matching ratio and reconstruct a 3D scene quickly and efficiently.
文摘Dense sintered bodies of proton conducting BaZrO3 (BZ) and Y-doped BaZrO3 (BZ-Y) were obtained at 1600℃ for a short sintering time of 5 hours, by the addition of NiO as a sintering promotion agent. The relative density and grain growth of samples, Ni-doped BaZrO3 (BZ-N) and Ni, Y co-doped BaZrO3 (BZ-NY), were increased with increasing Ni addition. The sinterability of BZ-NY was greatly improved just to add only 0.6 mol% Ni and the relative density of this sample was more than 98%, in contrast to that of 60% at most for BZ-Y without Ni addition. Electrical conductivity of BZ-NY added Ni 1.0 mol%, BaZr0.91Ni0.01Y0.08O3-α, was more than 10-3 S.cm-2 at 900℃?in a wet 1% hydrogen atmosphere, which value was 10 times higher than that of BZ-Y. In addition, the kind of electrical conduction carrier and an ionic transport number were also examined by employing various concentration cells. It was found that the proton conduction was dominant for both BZ-N and BZ-NY samples, although BZ-NY showed scarcely oxygenion conduction approximately 10% in a high temperature range higher than 800℃. From these results, as mall amount of Ni addition found to be effective for improvement of both the sinterability and the electrical conductivity.
文摘目的:研究低剂量无细胞短棒状杆菌纳米级制剂(NCPP)对刀豆蛋白 A(Con A)诱导的小鼠急性肝损伤的保护作用及机理。方法:BALB/c 小鼠腹腔注射 NCPP(0.01 mg·只)后第7 d 以 Con A(25μg·g^(-1))尾静脉注射诱导小鼠急性肝损伤模型。测定血清转氨酶(ALT/AST)及肝脏内的病理变化。同时设置 PBS 预处理对照组和 Con A 模型对照组,每组8只小鼠。用流式细胞仪检测肝脏内自然杀伤细胞(NK 细胞)的数量变化和 CD4~4T 淋巴细胞的活化情况。结果:与 Con A 模型组相比,NCPP 预处理组小鼠血清转氨酶明显降低[ALT 水平从(328±14)U·L^(-1)下降到(104±41)U·L^(-1),AST 水平从(141±9)U·L^(-1)下降到(98±17)U·L^(-1)],肝脏组织 HE 染色显示肝脏病理损伤明显减轻,同时流式细胞术的分析结果显示:与 Con A 模型组相比,小鼠肝脏 NK 细胞数量降低,且 CD4^+T 淋巴细胞的活化受到了明显抑制。结论:NCPP 对 Con A 诱导的小鼠急性肝损伤具有保护作用。其机理可能与抑制 CD4^+T 淋巴细胞活化和拮抗肝脏内 NK 细胞的回流有关。
文摘应用 Con A-HRP-G 二步标记法,对健康人新鲜精子及经棉酚处理后的精子作了标记,并在光镜、透射电镜及扫描电镜下作了对比观察。结果表明,在人的精子的质膜表面,从头至尾均有金粒标记。以头部及尾部中段较为致密。在被棉酚破坏了质膜的精子内部,在顶体膜及残破的线粒体内也出现金标记。说明不仅在精子的质膜表面,而且在顶体膜及线粒体等内膜系统,都有Con A 受体。本文还讨论了该受体在人精子存在的意义,以及 Con A-HRP-G 二步标记法和光镜、透射电镜、扫描电镜对比观察法的优点。
基金Project supported by the National Natural Science Foundation of China(Nos.11172050 and11672047)the Science and Technology Foundation of China Academy of Engineering Physics(No.2013A0202011)
文摘A Harten-Lax-van Leer-contact(HLLC) approximate Riemann solver is built with elastic waves(HLLCE) for one-dimensional elastic-plastic flows with a hypoelastic constitutive model and the von Mises' yielding criterion. Based on the HLLCE,a third-order cell-centered Lagrangian scheme is built for one-dimensional elastic-plastic problems. A number of numerical experiments are carried out. The numerical results show that the proposed third-order scheme achieves the desired order of accuracy. The third-order scheme is used to the numerical solution of the problems with elastic shock waves and elastic rarefaction waves. The numerical results are compared with a reference solution and the results obtained by other authors. The comparison shows that the presented high-order scheme is convergent, stable, and essentially non-oscillatory. Moreover,the HLLCE is more efficient than the two-rarefaction Riemann solver with elastic waves(TRRSE).
文摘The ineffective utilization of power resources has attracted much attention in current years. This paper proposes a real-time distributed load scheduling algorithm considering constraints of power supply. Firstly, an objective function is designed based on the constraint, and a base load forecasting model is established when aggregating renewable generation and non-deferrable load into a power system, which aims to transform the problem of deferrable loads scheduling into a distributed optimal control problem. Then, to optimize the objective function, a real-time scheduling algorithm is presented to solve the proposed control problem. At every time step, the purpose is to minimize the variance of differences between power supply and aggregate load, which can thus ensure the effective utilization of power resources. Finally, simulation examples are provided to illustrate the effectiveness of the proposed algorithm.
