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排序方式: 共有499条查询结果,搜索用时 46 毫秒
1.
Rainwater collection as a possible water source in developing countries is introduced. The major parameters in calculating the size of the tank are defined. Six methods that have been used previously to relate demand, storage, reliability and the rainfall pattern are compared to the Ottawa Model over a wide range of demands. 相似文献
2.
Giant Electric Dipole Resonance (GDR) parameters for γ decay to excited states with finite spin and temperature are compiled. Over 100 original works have been reviewed and from some 70 of them, about 350 sets of hot GDR parameters for different isotopes, excitation energies, and spin regions have been extracted. All parameter sets have been brought onto a common footing by calculating the equivalent Lorentzian parameters. The current compilation is complementary to an earlier compilation by Samuel S. Dietrich and Barry L. Berman (At. Data Nucl. Data Tables 38 (1988) 199-338) on ground-state photo-neutron and photo-absorption cross sections and their Lorentzian parameters. A comparison of the two may help shed light on the evolution of GDR parameters with temperature and spin. The present compilation is current as of July 2006. 相似文献
3.
Rogier Schonenborg Adalberto Costessi Peter Schiller 《Microgravity science and technology》2007,19(5-6):219-224
This paper gives a quick overview of how various scientific, operational and safety related requirements drove the development of hardware for the Bone Proteomics (BOP) experiment that was conducted on the International Space Station during the Italian Soyuz Mission in 2005. The experiment objectives will be highlighted briefly and design solutions will be presented. Comments will be given regarding the choice of a particular design solution and the impact on the complexity, cost and development time. Conclusions in this paper are based on the experience gained when developing the BOP experiment hardware and other relatively small experiment hardware packages, typical of European Soyuz Missions. The observations should not be extrapolated to large payloads. The objective of this paper is not to produce a recipe for developing experiment hardware; dedicated documents for that purpose are available elsewhere. Rather, the objective is to help others profit from experience gained in the development of relatively small experiment hardware packages, and to highlight where time and cost saving decisions can be made. 相似文献
4.
Gaku Yamanaka Shinichiro Morichi Tomoko Takamatsu Yusuke Watanabe Shinji Suzuki Yu Ishida Shingo Oana Takashi Yamazaki Fuyuko Takata Hisashi Kawashima 《International journal of molecular sciences》2021,22(9)
Accumulating evidence has demonstrated that the pathogenesis of epilepsy is linked to neuroinflammation and cerebrovascular dysfunction. Peripheral immune cell invasion into the brain, along with these responses, is implicitly involved in epilepsy. This review explored the current literature on the association between the peripheral and central nervous systems in the pathogenesis of epilepsy, and highlights novel research directions for therapeutic interventions targeting these reactions. Previous experimental and human studies have demonstrated the activation of the innate and adaptive immune responses in the brain. The time required for monocytes (responsible for innate immunity) and T cells (involved in acquired immunity) to invade the central nervous system after a seizure varies. Moreover, the time between the leakage associated with blood–brain barrier (BBB) failure and the infiltration of these cells varies. This suggests that cell infiltration is not merely a secondary disruptive event associated with BBB failure, but also a non-disruptive event facilitated by various mediators produced by the neurovascular unit consisting of neurons, perivascular astrocytes, microglia, pericytes, and endothelial cells. Moreover, genetic manipulation has enabled the differentiation between peripheral monocytes and resident microglia, which was previously considered difficult. Thus, the evidence suggests that peripheral monocytes may contribute to the pathogenesis of seizures. 相似文献
5.
L. Ponsatí V. Acuña I. Aristi M. Arroita E. García‐Berthou D. von Schiller A. Elosegi S. Sabater 《河流研究与利用》2015,31(8):1003-1016
Dams regulate downstream hydrology and modify water quality, which in turn can impinge on the biota, especially in rivers naturally subject to large hydrological variability, such as those under Mediterranean climate. The effect of dams on biofilms was analysed in three tributaries (Cinca, Siurana and Montsant) of the Ebro River (NE Spain). We hypothesized that flow regulation would lead to lower spatial variability of biofilms on the streambed and to a decrease in their metabolic rate per unit biomass, especially during low flow periods. Biofilm characteristics were studied in five transects evenly spaced along river reaches upstream (control) and downstream (impact) of dams in each river, along with riverbed granulometry, hydraulics and water chemistry. Chlorophyll‐a, respiratory activity, photosynthetic capacity and efficiency, and extracellular enzymatic activities (β‐d ‐glucosidase, alkaline phosphatase and leucine‐amino‐peptidase) of epilithic biofilms were measured in different seasons. Spatial variability of chemical and biological variables was reduced downstream of the dams. Chlorophyll‐a concentration, photosynthetic efficiency and respiration capacity were higher in impact than in control reaches, but generally, low inorganic phosphorus concentrations resulted in comparable phosphatase activities downstream and upstream of dams. On the other hand, β‐d ‐glucosidase and leucine‐amino‐peptidase activities were higher at impact reaches. Biofilms were thicker and metabolically more active at the impact reaches, with higher ability to transform dissolved organic matter. Overall, results from this study provide evidence that dams can largely affect the structure and activity of river biofilms, with foreseeable important consequences for river ecosystem functioning. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
6.
7.
Partial cognates are pairs of words in two languages that have the same meaning in some, but not all contexts. Detecting the
actual meaning of a partial cognate in context can be useful for Machine Translation tools and for Computer-Assisted Language
Learning tools. We propose a supervised and a semi-supervised method to disambiguate partial cognates between two languages:
French and English. The methods use only automatically-labeled data; therefore they can be applied to other pairs of languages
as well. The aim of our work is to automatically detect the meaning of a French partial cognate word in a specific context.
相似文献
Diana InkpenEmail: |
8.
N. M. Sitnikov V. A. Yushkov A. A. Afchine L. I. Korshunov V. I. Astakhov A. E. Ulanovskii M. Kraemer A. Mangold C. Schiller F. Ravegnani 《Instruments and Experimental Techniques》2007,50(1):113-121
A fluorescent airborne stratospheric hygrometer (FLASH) for precise water vapor measurements on board a high-altitude airplane in the upper troposphere and the lower stratosphere has been developed and produced at the Central Aerological Observatory. The range of measured water vapor concentrations is 0.5–300 ppmv at altitudes of 8–21 km. The results of laboratory tests of the instrument are compared to the data of the other hygrometers. Some results of water vapor measurements on board the Geofizika M55 high-altitude airplane in different regions of the Earth are presented. 相似文献
9.
This paper presents the first (randomized) algorithm for implementing self-stabilizing group communication services in an asynchronous system. Our algorithm converges rapidly to legal behavior and is communication adaptive, namely, the communication volume is high when the system recovers from the occurrence of faults and is low once a legal state is reached. Communication adaptability is achieved by a new technique that combines transient fault detectors. 相似文献
10.