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91.
暗翅筒天牛的生物学特性及空间格局   总被引:2,自引:0,他引:2  
暗翅筒天牛在四川和重庆1年发生1代,以老熟幼虫越冬。成虫发生于4月下旬至7月上旬,补充营养取食桑树等植物的叶脉,产卵于桑树等植物的新梢端部,卵期为8d,孵化的幼虫依靠蛀食桑树枝条获得营养,先向上蛀食产卵槽上部的枝条,至一定距离后再调头向下蛀食产卵槽以下的枝条,且在向下蛀食过程中多次调头向上蛀食侧枝,幼虫期长达180d,至翌年4月化蛹,蛹期为16d。在幼虫期常有污翅姬蜂寄生于体内,其寄生率达37.1%。卵的空间格局呈负二项分布。  相似文献   
92.
DC-CIK细胞的生物学活性及抗淋巴瘤细胞的作用   总被引:2,自引:0,他引:2  
目的研究细胞因子诱导的杀伤细胞(CIK)与树突状细胞(DC)共培养后DC-CIK细胞的体外增殖能力、免疫表型变化、分泌细胞因子水平以及抗淋巴瘤细胞活性。方法正常人外周血单个核细胞诱导DC和CIK细胞,将DC与CIK共培养,以CIK细胞单独培养为对照。用台盼蓝活细胞计数计算细胞扩增倍数,MTT法测定杀伤活性,流式细胞术分析免疫表型,ELISA双抗体夹心法检测分泌干扰素-γ(IFN-γ)、白细胞介素-12(IL-12)的水平。结果DC-CIK细胞增殖能力明显高于CIK细胞(P<0.05);DC、CIK细胞共培养后,CD3+CD8+、CD3+CD56+双阳性细胞比率较同条件下CIK细胞组显著增多(P<0.05);共培养3 d,DC-CIK细胞上清液中IL-12、INF-γ的分泌量均比CIK细胞单独培养的分泌量高(P<0.01,P<0.05);在5∶1-40∶1的效靶比范围内,DC-CIK细胞对淋巴瘤细胞的杀伤率显著高于CIK细胞(P<0.05),且杀伤率与效靶比呈正相关。结论DC-CIK细胞的增殖能力、分泌细胞因子水平、抗淋巴瘤细胞活性均高于CIK细胞,为DC-CIK细胞免疫治疗提供了实验和理论依据。  相似文献   
93.
Analysis of household activity scheduling has to date been limited to one-day periods. This paper extends the study of household task allocation to a one-week period. Using a one-week time use survey held under couples in The Netherlands in 2003, the paper proposes indicators for measuring task allocation on a daily and weekly scale and investigates to what extent role expectations, work status and indicators of time pressure influence task allocation patterns. The outcomes suggest that egalitarian role expectations and higher female work status lead to a more balanced allocation of work and households tasks between spouses. More traditional role views and increased time pressure lead to more specialisation and inequality between spouses. Interestingly, households under time pressure apply day-to-day specialisation to arrive at balanced weekly allocation totals.
Tanja van der LippeEmail:
  相似文献   
94.
闫娟 《机电设备》2007,24(12):1-4
介绍了人脸识别技术的发展概况,从人脸识别的三个步骤:人脸的检测与定位、人脸的特征提取和人脸的识别和验证对人脸识别技术的方法进行了分析和总结,指出了其优缺点所在和人脸识别技术面临的关键问题,最后对人脸识别技术的研究发展趋势进行了展望.  相似文献   
95.
该文以广州开发区西区污水处理厂工艺改造为例,介绍了将传统活性污泥工艺改造为复合生物处理工艺的方法,并通过运行数据的对比,分析了复合生物处理工艺改造的效果和取得的经济、工程效益,同时对改造中的关键问题进行了总结。  相似文献   
96.
Submarine pipelines can utilize sleepers to control global buckling location, which mitigates potential risks under high temperature and pressure. However, pipelines with sleepers require execution in three-dimensional space and experience lateral buckling modes. As such, this paper proposes a 3D pipeline element for lateral buckling analysis, building on previous 2D element formulations. This new element considers non-linear pipe-soil interactions, thermal expansion, axial load, initial imperfections, large deflection, and other major factors that affect lateral buckling. The derivations of the 3D pipeline element are provided in detail, and the numerical analysis procedure is elaborated. To validate the accuracy and efficiency of the proposed 3D pipeline element, several examples are presented.  相似文献   
97.
Analysis of the dynamic response of ships in accident scenarios requires a realistic idealisation of environmental and operational conditions by multi-physics models. This paper presents a procedure that simulates the influence of strongly coupled FSI effects on the dynamic response of ships involved in typical collision and grounding events. Our method couples an explicit 6-DoF structural dynamic finite element scheme with a hydrodynamic method accounting for (a) 6-DoF potential flow hydrodynamic actions; (b) the influence of evasive ship speed in the way of contact and (c) the effects of hydrodynamic resistance based on a RANS CFD model. Multi-physics simulations for typical accident scenarios involving passenger ships confirm that suitable FSI modelling may be critical for either collision or grounding events primarily because of the influence of hydrodynamic restoring forces.  相似文献   
98.
UASB-SBR工艺处理淀粉废水的试验研究   总被引:8,自引:1,他引:7  
介绍升流式厌氧污泥床反应器 (UASB) 序批式活性污泥法 (SBR)处理淀粉废水的工艺 ,叙述该类废水的特点、试验系统组成、UASB的启动至污泥颗粒化的过程以及处理效果。试验结果表明 ,该处理系统具有耐冲击负荷 ,处理效果稳定 ,运行管理简单 ,运行成本低等特点。废水经颗粒化UASB稳定处理后 ,出水COD可降到 5 0 0mg/L以下 ,然后经SBR稳定处理后 ,出水COD可降到 10 0mg/L以下  相似文献   
99.
A one-dimensional coupled physical–biogeochemical model has been built to study the pelagic food web of the Ligurian Sea (NW Mediterranean Sea). The physical model is the turbulent closure model (version 1D) developed at the GeoHydrodynamics and Environmental Laboratory (GHER) of the University of Liège. The ecosystem model contains 19 state variables describing the carbon and nitrogen cycles of the pelagic food web. Phytoplankton and zooplankton are both divided in three size-based compartments and the model includes an explicit representation of the microbial loop including bacteria, dissolved organic matter, nano-, and microzooplankton. The internal carbon/nitrogen ratio is assumed variable for phytoplankton and detritus, and constant for zooplankton and bacteria. Silicate is considered as a potential limiting nutrient of phytoplankton's growth. The aggregation model described by Kriest and Evans in (Proc. Ind. Acad. Sci., Earth Planet. Sci. 109 (4) (2000) 453) is used to evaluate the sinking rate of particulate detritus. The model is forced at the air–sea interface by meteorological data coming from the “Côte d'Azur” Meteorological Buoy. The dynamics of atmospheric fluxes in the Mediterranean Sea (DYFAMED) time-series data obtained during the year 2000 are used to calibrate and validate the biological model. The comparison of model results within in situ DYFAMED data shows that although some processes are not represented by the model, such as horizontal and vertical advections, model results are overall in agreement with observations and differences observed can be explained with environmental conditions.  相似文献   
100.
Future aspects in marine ecosystem modelling   总被引:1,自引:0,他引:1  
Existing ecosystem models are briefly presented and summarised. The problem of coupling physical and biological models as well as aspects of prediction and predictability are discussed. The general perception that marine ecosystems are inherently unpredictable due to non-linearity becomes questionable if the response of climate variability in marine ecosystems is analysed. Many authors have shown correlations between climate variability and the variability of abundance or biomass of marine organisms such as phytoplankton, zooplankton, benthos or fish recruitment in different parts of the world ocean. In the northern hemisphere, certain species show a linear response to climate variability mainly during winter and spring. However, the underlying mechanisms are not well understood. Often, a phase lag can be observed between climate variability and the reaction of organisms. The identification of a plausible mediator between climate and biology is difficult, since all possible physicochemical mechanisms having a direct or indirect influence on the variability of abundance or biomass of marine organisms have to be considered as mediator.The understanding of the reason of the phase lag, which possibly implies a “biological memory”, and the identification of all possible mediators are necessary to predict the response of marine organisms to climate variability. The identification of mediators will result in an improvement of coupled models, a deeper understanding of physical–biological interaction and the improvement of predictive capability of marine ecosystem models.  相似文献   
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