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排序方式: 共有850条查询结果,搜索用时 15 毫秒
61.
德国KSP建筑设计事务所 《城市建筑》2010,(8):75-78
<正>经过慕尼黑火车总站走到阿努尔夫(Arnulf)大街上,可以看到美国ATMOS能源公司德国总部新办公楼。该办公楼的建设为慕尼黑市ArnulfPark区东部创造了一处开敞的空间环境,同时标志着这一地区新区建设的开始。ATMOS能源公司德国总部坐落在阿努尔夫大街与格拉瑟(Grasser)大街(也称作Hacker大桥)的交汇处,新办公楼就建于总部内,是园区内的第一栋建筑,该办公楼建成后成为公司新总部的标志。 相似文献
62.
David Ghezel-Ahmadi Alice Engel Lygia Therese Budnik Ulrich Frick Simone Hauser 《The Science of the total environment》2010,408(4):774-778
Background
Risks from electromagnetic devices are of considerable concern. Electrohypersensitive (EHS) persons attribute a variety of rather unspecific symptoms to the exposure to electromagnetic fields. The pathophysiology of EHS is unknown and therapy remains a challenge.Objectives
Heavy metal load has been discussed as a potential factor in the symptomatology of EHS patients. The main objective of the study was to test the hypothesis of a link between EHS and heavy metal exposure.Methods
We measured lead, mercury and cadmium concentrations in the blood of 132 patients (n = 42 males and n = 90 females) and 101 controls (n = 34 males and n = 67 females).Results
Our results show that heavy metal load is of no concern in most cases of EHS but might play a role in exceptional cases.Conclusions
The data do not support the general advice to heavy metal detoxification in EHS. 相似文献63.
Berge P Ratel J Fournier A Jondreville C Feidt C Roudaut B Le Bizec B Engel E 《Environmental science & technology》2011,45(15):6584-6591
The study investigated the feasibility of using volatile compound signatures of liver tissues in poultry to detect previous dietary exposure to different types of xenobiotic. Six groups of broiler chickens were fed a similar diet either noncontaminated or contaminated with polychlorinated dibenzo-p-dioxins/-furans (PCDD/Fs; 3.14 pg WHO-TEQ/g feed, 12% moisture), polychlorinated biphenyls (PCBs; 0.08 pg WHO-TEQ/g feed, 12% moisture), polybrominated diphenyl ethers (PBDEs; 1.63 ng/g feed, 12% moisture), polycyclic aromatic hydrocarbons (PAHs; 0.72 μg/g fresh matter), or coccidiostats (0.5 mg/g feed, fresh matter). Each chicken liver was analyzed by solid-phase microextraction - mass spectrometry (SPME-MS) for volatile compound metabolic signature and by gas chromatography - high resolution mass spectrometry (GC-HRMS), gas chromatography - tandem mass spectrometry (GC-MS/MS), and liquid chromatography - tandem mass spectrometry (LC-MS/MS) to quantify xenobiotic residues. Volatile compound signature evidenced a liver metabolic response to PAH although these rapidly metabolized xenobiotics are undetectable in this organ by the reference methods. Similarly, the volatile compound metabolic signature enabled to differentiate the noncontaminated chickens from those contaminated with PBDEs or coccidiostats. In contrast, no clear signature was pointed out for slowly metabolized compounds such as PCDD/Fs and PCBs although their residues were found in liver at 50.93 (±6.71) and 0.67 (±0.1) pg WHO-TEQ/g fat, respectively. 相似文献
64.
Currently, quality estimation (QE) is mostly addressed using supervised learning approaches. In this paper we show that unsupervised and weakly supervised approaches (using a small training set) perform almost as well as supervised ones, for a significantly lower cost. More generally, we study the various possible definitions, parameters, evaluation methods and approaches for QE, in order to show that there are multiple possible configurations for this task. 相似文献
65.
Composite materials with vibrations damping qualities can be made of two steel sheets enclosing a viscoelastic plasticcorelayer. These sandwich sheets often need to be formed. Material parameters are determined to describe the forming process. Based on these parameters, pilot studies are carried out in order to develop recommendations for forming this class of material. 相似文献
66.
Stream Temperature Dynamics in Upland Agricultural Watersheds 总被引:1,自引:0,他引:1
A numerical model to compute the free-surface flow hydrodynamics and stream temperature dynamics by solving the depth-averaged, 1D unsteady flow and heat transport equations is presented. The hydrodynamics model considers the effects of arbitrary stream geometry, variable slopes, variable flow regimes, and unsteady boundary conditions. The thermal transport model accounts for the effects of solar radiation, air temperature, relative humidity, cloud cover, wind speed, heat conduction between water and streambed, subsurface flow, and shading by riparian vegetation. The model is verified with measurements in a stream in an upland agricultural watershed located in Indiana. Diurnal variations in the streamflow and stream temperatures are highly transient. The proposed model predicted well the streamflow and stream temperatures that were measured every 15 min over 25 days. The results of this study demonstrate that the solar (shortwave) radiation and subsurface inflow are the most significant contributors to the stream heat budget. 相似文献
67.
A standard problem in intensity modulated radiation therapy is the representation of a given intensity matrix, i.e. a matrix
of nonnegative integers, as a nonnegative linear combination of special 0-1-matrices, called segments. These segments can
be practically realized by multileaf collimators. One important aim is the minimization of the sum of the coefficients of
the linear combination, i.e. the delivery time. In this article, we study the question how much the delivery time can be reduced
if some small deviation from the given intensity matrix is allowed. We characterize the optimal solutions for one-row matrices
and show that the approximation can be carried out in an iterative way. The structural characterization yields a fast algorithm
that minimizes the delivery time and then also the deviation. Moreover, algorithms for the general case together with numerical
results are presented. 相似文献
68.
Erwan Dumont-Botto Carole BourbonSébastien Patoux Patrick Rozier Mickaël Dolle 《Journal of power sources》2011,196(4):2274-2278
In the search of high-performance materials for lithium ion batteries, Li2CoPO4F offers many advantages like high theoretical capacity and high operating potential. The synthesis of Li2CoPO4F has been reinvestigated considering a conventional solid state reaction and an unconventional way. Due to the long heat-treatments required by the conventional approach, a beginning of grains coalescence is observed. Limiting particles growth has been allowed by a shorter reaction done by SPS (Spark Plasma Sintering). By this method, the synthesis of Li2CoPO4F was greatly shortened (from 10 h to 9 min), which favours the getting of submicrometric particles. The comparison of the electrochemical properties of the Li2CoPO4F obtained by the different ways confirms the advantages of SPS synthesis in performance enhancement. 相似文献
69.
The Software Engineering Education Project's objective is to recommend curricula to prepare professionals in software engineering. This article reports on SWEEP's initial progress and its future goals to address undergraduate- and graduate-level accreditation for software engineering and technology programs 相似文献
70.
Voltage and pH-induced channel closure of porin OmpF visualized by atomic force microscopy 总被引:1,自引:0,他引:1
Gram-negative bacteria are protected by an outer membrane in which trimeric channels, the porins, facilitate the passage of small solutes. The pores are formed by membrane-spanning antiparallel beta-strands, which are connected by short turns on the periplasmic side and long loops on the extracellular side. Voltage and pH-dependent conformational changes of these extracellular loops have now been visualized by atomic force microscopy of two-dimensional crystals of Escherichia coli porin OmpF. The observed conformational changes accompany the closure of the channel entrance, and suggest that this is a mechanism that the cells have evolved to protect themselves from drastic changes of the environment. 相似文献