2010年12月15日江西雨雪天气的微物理数值模拟分析

利用常规观测资料和中尺度数值模式WRF的输出产品,对2010年12月14—15日发生在江西的雨雪过程进行了分析。结果表明,微物理参数化方案输出的物理因子可以较好地揭示本次过程的雨雪转换;在雨转雪阶段,由于中低层冷空气南移较强,没有形成逆温,因此未能形成冻雨,而是由雨转为降雪天气。     

长山列岛邻近海域褐牙鲆资源丰度的时空分布及其与环境因子的关系

本文根据2016?2017年在长山列岛邻近海域开展的渔业资源和环境季度调查数据,利用两阶段广义可加模型分析了该海域褐牙鲆资源丰度的时空分布及其与相关因子之间的关系.结果表明,长山列岛邻近海域褐牙鲆资源丰度具有明显的季节变化,春、秋季资源丰度高于冬、夏季;褐牙鲆春、秋季主要分布在120.5°～122.5°E水域,夏、冬季...     

鄂尔多斯盆地宜川—黄陵地区马家沟组流体包裹体特征及其意义

通过单偏光、荧光显微镜和显微冷热台测温观察等方法,对宜川—黄陵地区下古生界马家沟组流体包裹体进行系统研究,归纳流体包裹体岩相学、均一温度和冰点温度等特征,结合盆地热演化史分析推测储层内烃类充注史。综合分析结果显示研究区马家沟方解石内发现的沥青包裹体证明早期形成古油藏已遭受改造破坏;研究区马家沟组顶部古油藏的形成时间在早侏罗世—中侏罗世,而气藏的形成时间在早白垩世。     

Evaluation of unconfined aquifer parameters from flow to partially penetrating wells in Tailan River basin, China

Effective evaluation, management and abstraction of groundwater resources of any aquifer require accurate and reliable estimates of its hydraulic parameters. This study, therefore, looks at the determination of hydraulic parameters of an unconfined aquifer using both analytical and numerical approaches. A long-duration pumping test data obtained from an unconfined aquifer system within the Tailan River basin in Xinjiang Autonomous Region in the northwest of China is used, in this study, to investigate the best method for estimating the parameters of the aquifer. The pumping test was conducted by pumping from a radial collector well and measuring the response in nine observation wells; all the wells used in the test were partially penetrating. Using two well-known tools, namely AquiferTest and MODFLOW, as an aid for the analytical and numerical approaches, respectively, the parameters of the aquifer were determined and their outputs compared. The estimated horizontal hydraulic conductivity, vertical hydraulic conductivity, and specific yield for the analytical approach are 38.1–50.30 m/day, 3.02–9.05 m/day and 0.204–0.339, respectively, while the corresponding numerical estimates are 20.50–35.24 m/day, 0.10–3.40 m/day, and 0.27–0.31, respectively. Comparing the two, the numerical estimates were found to be more representative of the aquifer in the study area since it simulated the groundwater flow conditions of the pumping test in the aquifer system better than the analytical solution.     

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??????е??????????????淶????DZ/T 0082??2006????????????????±??????γ?????????????????????????????????Li??Gotze??1996????????????????????????????????????????????????????????????????3????????ж????????????????й?????????????????????????????????й?????????????淶?е???????????????????????????????????н???????????0.24×10^-5 m/s²???????????????????????????????     

Effect of dietary potassium on growth,nitrogen metabolism,osmoregulation and immunity of pacific white shrimp (Litopenaeus vannamei) reared in low salinity seawater

An 8 weeks feeding experiment was conducted to determine the effect of dietary potassium on the growth and physiological acclimation of Pacific white shrimp(Litopenaeus vannamei) reared in diluted seawater(salinity 4). Six semi-purified practical diets containing 0.59, 0.96, 1.26, 1.48, 1.74, and 2.17+ g potassium K per 100 g diet were formulated, respectively. The survival and feed conversion rate did not show significant difference among groups of shrimps given these diets(P0.05). The shrimps fed the diets containing 0.96-1.48 g K+ per 100 g diet gained the highest weight, specific growth rate, and protein efficiency ratio. Their ammonium-N excretion rate as well as hemolymph concentration of Na+ and Cl- were significantly lower than those of the control(P0.05), but a reverse trend was observed for their gill Na+/K+-ATPase. Moreover, the shrimps fed with 1.48 g K+ per 100 g diet were the highest in hemolymph urea level, and the phenoloxidase and lysozyme activities were significantly higher than those of the control(P0.05). The growth and physiological response of the test shrimps suggested that diet containing 1.48 g K+ per 100 g diet improved the growth of L. vannamei in low-salinity seawater, and enhanced the physiological acclimation of the organism.     

Characterization of a bacteriocin-like substance produced from a novel isolated strain of Bacillus subtilis SLYY-3

In the present research, the strain SLYY-3 was isolated from sediments of Jiaozhou Bay, Qingdao, China. The strain SLYY-3, which produced a bacteriocin-like substance(BLS), was characterized to be a strain of Bacillus subtillis by biochemical profiling and 16 S r DNA sequence analysis. It is the first time to report that Bacillus subtilis from Jiaozhou Bay sediments could produce a BLS. The BLS of B. subtillis SLYY-3 exhibited strong inhibitory activity against gram-positive bacteria(including Staphylococcus aureus and B. subtillis) and some fungi(including Penicillium glaucum, Aspergillus niger and Aspergillus flavus). The antimicrobial activity was detected from culture in the exponential growth phase and reached its maximum when culture entered into stationary growth phase. It was thermo-tolerant even when being kept at 100℃ for 60 min without losing any activity and stable over a wide p H range from 1.0 to 12.0 while being inactivated by proteolytic enzyme and trypsin, indicating the proteinaceous nature of the BLS. The BLS was purified by precipitation with hydrochloric acid(HCl) and gel filteration(Sephadex G-100). SDS-PAGE analysis of the extracellular peptides of SLYY-3 revealed a bacteriocin-like protein with a molecular mass of 66 k Da. Altogether, these characteristics indicate the potential of the BLS for food industry as a protection against pathogenic and spoilage microorganisms.     

一种转发式卫星授时新方法

为了减少对GPS提供的高精度授时服务的依赖,建设拥有自主知识产权的且具有投入成本低、精度高的授时系统。提出了一种利用地面高稳定度原子钟作为时频基准,通过通信卫星转发实现卫星广播授时的新方法。详细研究了利用地面高稳定度原子钟和通信卫星组成的导航星座进行多星授时、单星授时的原理和测量方法,分析研究了影响授时精度的原因。由于转发式卫星授时系统的时频基准源稳定度高,其测距精度也会相应的提高。只要精确扣除时延误差,同样可以实现高精度授时。粗码的授时精度可达20ns以内,短精码的授时精度可达10ns左右。总之该系统具有组建灵活简便、应用面广等优势和特色。     

淄博市淄川区地质灾害防治及建议

淄川区位于淄博市中部,属于经济发达区,除采矿业、陶瓷业的繁荣外,其他工业、交通及公共设施建设也在迅速发展,随着经济发展,地质灾害的危险因素也日益增加,滑坡、崩塌、采空塌陷随时可能发生。该文根据多年地质灾害防治工作情况,综合分析淄川区地质灾害现状和特点,对地质灾害防治提出建议。     

沈北新区地震区划研究

以GB18306-2001《中国地震动参数区划图》的编制过程中的基础资料为基础,参照国际上最新地震区划原则,以抗倒塌参数作为基准,结合沈北新区及周边地区不同场地地震动参数,以及地震、地质背景的研究,编制了沈北新区地震区划。该地震区划可为沈北新区一般建设工程的抗震设防提供科学依据,本项研究也为同类项目的开展提供借鉴。