Non-specific immune response of bullfrog <Emphasis Type="Italic">Rana catesbeiana</Emphasis> to intraperitoneal injection of bacterium <Emphasis Type="Italic">Aeromonas hydrophila</Emphasis>     

张俊杰  邹文政  鄢庆枇 《中国海洋湖沼学报》2008,26(3):248-255

Non-specific immune response of bullfrog Rana catesbeiana to pathogenic Aeromonas hydrophila was studied to 60 individuals in two groups. Each bullfrog in bacterium-injected group was injected intraperitoneally （i.p.） with 0.2 ml bacterial suspension at a density of 5.2 × 10^6 CFU/ml, while each one in control group injected i.p. with 0.2 ml sterile saline solution （0.85%, w/v）. Three bullfrogs in both groups were sampled at 0, 1, 3, 7, 11, 15 and 20 days post-injection （dpi） for the evaluation of non-specific immune parameters. It was observed that intraperitoneal injection of A. hydrophila significantly increased the number of leucocytes and that of NBT-positive cells in peripheral blood. Significant increases in serum bactericidal activity and serum acid phosphatase activity were also observed in the bacterium-injected frogs when compared with those in the control group. However, a significant reduction was detected in vitro in phagocytosis activity of peripheral blood phagocytes. No significant difference in changes in the number of peripheral erythrocytes, serum superoxide dismutase （SOD） activity, and lysozyme activity was detected between the two groups. It is suggested that bullfrogs may produce a series of non-specific immune reactions in response to the A. hydrophila infection.  相似文献   

Location choices of Chinese enterprises in Southeast Asia: The role of overseas Chinese networks     

Liang  Yutian  Zhou  Zhengke  Liu  Yi 《地理学报(英文版)》2019,29(8):1396-1410

Journal of Geographical Sciences - With the implementation of the “Going out” strategy and the Belt and Road Initiative, China’s investments have become increasingly influential...  相似文献   

Decomposition analysis on direct material input and dematerialization of mining cities in Northeast China     

Fangdao Qiu  Lianjun Tong  Huimin Zhang  Na Zhang 《中国地理科学(英文版)》2009,19(2):104-112

Material dematerialization is a basic approach to reduce the pressure on the resources and environment and to realize the sustainable development. The material flow analysis and decomposition method are used to calculate the direct material input (DMI) of 14 typical mining cities in Northeast China in 1995-2004 and to analyze the demateri-alization and its driving factors in the different types of mining cities oriented by coal, petroleum, metallurgy and multi-resources. The results are as follows: 1) from 1995 to 2006, the increase rates of the DMI and the material input intensity of mining cities declined following the order of multi-resources, metallurgy, coal, and petroleum cities, and the material utilizing efficiency did following the order of petroleum, coal, metallurgy, and multi-resources cities; 2) during the research period, all the kinds of mining cities were in the situation of weak sustainable development in most years; 3) the pressure on resources and environment in the multi-resources cities was the most serious; 4) the petro-leum cities showed the strong trend of sustainable development; and 5) in recent years, the driving function of eco-nomic development for material consuming has continuously strengthened and the controlling function of material utilizing efficiency for it has weakened. The key approaches to promote the development of circular economy of min-ing cities in Northeast China are put forward in the following aspects: 1) to strengthen the research and development of the technique of resources' cycling utilization, 2) to improve the utilizing efficiency of resources, and 3) to carry out the auditing system of resources utilization.  相似文献   

天文光学望远镜轴系驱动方式发展概述   总被引：4，自引：0，他引：4  

王国民 《天文学进展》2007,25(4):364-374

该文首先介绍了已投入使用的2.5米口径以上的25架地平式光学望远镜和11架赤道式光学望远镜轴系驱动方式,并概述了天文光学望远镜轴系驱动及其相关技术的发展过程;然后对目前国际上在研的6架大型光学望远镜和预研的10架极大光学望远镜轴系所采用的驱动形式进行了归类;最后分析了未来极大光学望远镜轴系驱动的发展趋势和与之相关的研究内容.  相似文献   

浅议海上责任保险第三人直接请求权的行使条件     

郑文姣 《广东海洋大学学报》2009,29(2)

随着海上责任保险第三人权利保护的问题受到人们的日益重视,各国普遍赋予了海上责任保险第三人对保险人的直接请求权,但各国立法基本上未考虑到强制海上责任保险的特殊性,从而没有明确区分自愿海上责任保险中第三人直接请求权与强制海上责任保险中第三人直接请求权不同的权利属性,因而只笼统地对海上责任保险第三人行使直接请求权的条件做出概括性规定,这无法真正实现强制海上责任保险充分维护第三人利益与社会公共利益的立法价值。针对这一立法缺陷,提出应在明确自愿海上责任保险中的第三人直接请求权与强制海上责任保险中的第三人直接请求权具有不同权利属性的前提下,针对这两种不同的海上责任保险规定第三人不同的权利行使条件。  相似文献   

基于微地震技术的油田裂缝监测及模拟   总被引：2，自引：0，他引：2  

王爱国  周瑶琪  陈勇  王强 《中国海洋大学学报(自然科学版)》2008,38(1):116-120

研制了1套以三分量MEMS检波器为核心硬件的微地震监测系统,并结合GPS系统对监测过程进行精确授时.同时编制数据化记录和处理软件,实现网络化自动监测功能;通过开发计算机判别标准和实时定位理论系统,对数据和微震源进行自动化处理和计算.利用该系统对东辛油田营11进行了6个月现场注水微震监测,对监测数据的处理表明营11注水区域裂缝发育方向基本上为NE90°-NE125°,与地应力裂缝模拟结果相符较好,两者结合给出了这个地区合理开发部署建议.  相似文献   

A laboratory study on capillary sealing efficiency of Iranian shale and anhydrite caprocks     

《Marine and Petroleum Geology》2015

Caprock has the most important role in the long term safety of formation gas storage. The caprocks trap fluid accumulated beneath, contribute to lateral migration of this fluid and impede its upward migration. The rapid upward passage of invasive plumes due to buoyancy pressure is prevented by capillary pressure within these seal rocks. In the present study, two main seal rocks, from the Zagros basin in the southwest of Iran, a shale core sample of Asmari formation and an anhydrite core sample of Gachsaran formation, were provided. Absolute permeabilities of shale and anhydrite cores, considering the Klinkenberg effect, were measured as 6.09 × 10⁻¹⁸ and 0.89 × 10⁻¹⁸ m², respectively. Capillary sealing efficiency of the cores was investigated using gas breakthrough experiments. To do so, two distinct techniques including step by step and residual capillary pressure approaches were performed, using carbon dioxide, nitrogen and methane gases at temperatures of 70 and 90 °C, under confining pressures in the range 24.13–37.92 MPa. In the first technique, it was found that capillary breakthrough pressure of the cores varies in the range from 2.76 to 34.34 MPa. Moreover, the measurements indicated that after capillary breakthrough, gas effective permeabilities lie in range 1.85 × 10⁻²¹ – 1.66 × 10⁻¹⁹ m². In the second technique, the minimum capillary displacement pressure of shale varied from 0.66 to 1.45 MPa with the maximum effective permeability around 7.76 × 10⁻²¹ – 6.69 × 10⁻²⁰ m². The results indicate that anhydrite caprock of the Gachsaran formation provides proper capillary sealing efficacy, suitable for long term storage of the injected CO₂ plumes, due to its higher capillary breakthrough pressure and lower gas effective permeability.  相似文献   

GOCE+EGM08+RTM组合模型计算高程异常     

徐新强 《大地测量与地球动力学》2015,35(5):853-856

针对EGM08重力场模型构建过程中存在的不足,提出用GOCE重力场模型替换EGM08模型的中低频部分,用剩余地形模型RTM拓展EGM08模型的甚高频信号。模拟分析表明,GOCE模型能大幅提高高程异常计算的精度,而RTM对高程异常的贡献也不可忽视。实测GPS/水准数据表明,GOCE模型对高程异常的贡献达到43%,而RTM也贡献了1cm的精度。  相似文献   

融合光度参数估计的单目直接法视觉里程计     

谭涌  潘树国  高旺  盛超  章辉  喻国荣 《测绘工程》2021,30(3):59-65

针对单目直接法视觉里程计在光照变化大的场景下定位精度低、定位鲁棒性差的问题,文中提出一种融合光度参数估计的单目直接法视觉里程计。首先通过对图像帧进行特征匹配实现特征跟踪,建立起图像像素点之间的关联,接着利用非线性优化方法进行光度参数估计,然后在光度参数估计提供的光度参数先验信息的基础上对图像灰度值进行校正,最后利用校正后的图像采用单目直接法视觉里程计对相机运动进行估计。在EuRoC数据集上的实验结果表明,与传统方法相比,文中提出的算法提高单目直接法视觉里程计对光照变化的鲁棒性,定位精度平均提高约18%。  相似文献   

关于直播水稻观测方法问题的探讨     

胡世明  胡珀 《气象科技》2015,43(4):750-753

根据湖北江夏国家农业气象观测一级站在最近几年水稻观测中实际遇到的情况以及调查发现,直播水稻已形成不推而广的迅猛发展趋势,作为农业气象观测已不可回避地会遇到直播水稻的生育进程观测问题。由于种植方式的改变,大田植株分布形式也发生了根本的变化,仅以传统的移栽水稻制定的现行《农业气象观测规范》已无法处理好直播水稻的观测问题。为此,笔者依据《农业气象观测规范》,结合实际观测经验,分析直播水稻与移栽水稻的差异以及由此引出的新问题,提出了新的观测处理方法,以供同行探讨。  相似文献