首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   34篇
  免费   2篇
化学工业   10篇
建筑科学   1篇
能源动力   1篇
轻工业   8篇
无线电   3篇
一般工业技术   7篇
自动化技术   6篇
  2022年   3篇
  2021年   1篇
  2020年   1篇
  2019年   1篇
  2018年   2篇
  2017年   1篇
  2016年   3篇
  2015年   1篇
  2014年   1篇
  2013年   3篇
  2012年   5篇
  2011年   2篇
  2010年   5篇
  2009年   3篇
  2006年   1篇
  2004年   1篇
  1996年   2篇
排序方式: 共有36条查询结果,搜索用时 15 毫秒
1.
Sport is important internationally; but in Australia, it is part of the national identity. The enjoyment of public open space for sport is, therefore, an assumed community right. We interviewed key staff from inner Sydney councils about management issues associated with public open space. The greatest concern was sporting fields – formal and informal – which were considered to have exceeded carrying capacity mainly because of the unintended outcomes of government programmes/policies spanning; (1) ‘healthy lifestyles’ which increased public open space use; (2) ‘urban consolidation’ increased inner-city population density with associated increased usage and loss of open space; (3) ‘temporal water restriction’ during drought (not ‘water budgets’) which intensify management issues; and (4) ‘building the education revolution’, meaning that public open space lost from schools results in increased pressure on public open space. Consequences have increased human pressure on public open space without commensurate consideration for the management and/or expansion of these areas.  相似文献   
2.
Two spontaneous Malaysian cocoa bean box fermentations (one farm, two plantation plots) were investigated. Physical parameters, microbial community dynamics, yeast and bacterial species diversity [mainly lactic acid bacteria (LAB) and acetic acid bacteria (AAB)], and metabolite kinetics were monitored, and chocolates were produced from the respective fermented dry cocoa beans. Similar microbial growth and metabolite profiles were obtained for the two fermentations. Low concentrations of citric acid were found in the fresh pulp, revealing low acidity of the raw material. The main end-products of the catabolism of the pulp substrates glucose, fructose, and citric acid by yeasts, LAB, and AAB were ethanol, lactic acid, acetic acid, and/or mannitol. Hanseniaspora opuntiae, Lactobacillus fermentum, and Acetobacter pasteurianus were the prevalent species of the two fermentations. Saccharomyces cerevisiae, Lactobacillus plantarum, Lactobacillus pentosus, and Acetobacter ghanensis were also found during the mid-phase of the fermentation processes. Leuconostoc pseudomesenteroides and Acetobacter senegalensis were among the prevailing species during the initial phase of the fermentations. Tatumella saanichensis and Enterobacter sp. were present in the beginning of the fermentations and they could be responsible for the degradation of citric acid and/or the production of gluconic acid and lactic acid, respectively. The presence of facultative heterofermentative LAB during the fermentations caused a high production of lactic acid. Finally, as these fermentations were carried out with high-quality raw material and were characterised by a restricted microbial species diversity, resulting in successfully fermented dry cocoa beans and good chocolates produced thereof, it is likely that the prevailing species H. opuntiae, S. cerevisiae, Lb. fermentum, and A. pasteurianus were responsible for it.  相似文献   
3.
Background: End-stage renal disease (ESRD) is associated with alterations in T-cell immunity, including increased CD28null and reduced regulatory T cells (Tregs). However, whether immune disturbances are due to ESRD or primary disease is not yet clear. As diabetes mellitus is the leading cause of ESRD, we evaluated its impact on the immune profile of ESRD patients. Methods: CD28null, Tregs, and natural killer cells were initially analyzed by flow cytometry in 30 predialysis ESRD patients due to diabetes (DM), 30 non-DM (NDM), and 25 healthy controls. Measurements were repeated after 6 months on hemodialysis (HD) or peritoneal dialysis (CAPD). Results: The percentage of CD4 + CD28null cells, CD8 + CD28null cells, and Tregs showed significant differences in DM, NDM, and controls; mean rank 33.71 vs. 25.68 vs. 18.88, p = 0.006, 37.79 vs. 28.82 vs. 17.08, p = 0.008, and 20.79 vs. 26.12 vs. 41.33, p = 0.001, respectively. DM vs. NDM had increased CD4 + CD28null and CD8 + CD28null cells, 11.5% (1.5%–24%) vs. 4.1% (0–42.3%), p = 0.02 and 61.3% (24%–76%) vs. 43% (5.7%–85%), p = 0.04, respectively. After 6 months on HD but not CAPD, DM showed a significant further increase in CD4 + CD28null cells, from 30 (14–100) to 52.7 (15–203), p = 0.02; and CD8 + CD28null cells, from 137 (56–275) to 266 (103–456), p = 0.01. Conclusions: Diabetes mellitus affects T-cell subtypes even at predialysis stage, though changes become more prominent after commencement on HD.  相似文献   
4.
A member of the ribonuclease A superfamily, human angiogenin (hAng) is a potent angiogenic factor. Heteronuclear NMR spectroscopy combined with induced‐fit docking revealed a dual binding mode for the most antiangiogenic compound of a series of ribofuranosyl pyrimidine nucleosides that strongly inhibit hAng's angiogenic activity in vivo. While modeling suggests the potential for simultaneous binding of the inhibitors at the active and cell‐binding sites, NMR studies indicate greater affinity for the cell‐binding site than for the active site. Additionally, molecular dynamics simulations at 100 ns confirmed the stability of binding at the cell‐binding site with the predicted protein–ligand interactions, in excellent agreement with the NMR data. This is the first time that a nucleoside inhibitor is reported to completely inhibit the angiogenic activity of hAng in vivo by exerting dual inhibitory activity on hAng, blocking both the entrance of hAng into the cell and its ribonucleolytic activity.  相似文献   
5.
In this paper, we consider the efficient and reliable solution of distributed optimal control problems governed by parametrized elliptic partial differential equations. The reduced basis method is used as a low-dimensional surrogate model to solve the optimal control problem. To this end, we introduce reduced basis spaces not only for the state and adjoint variable but also for the distributed control variable. We also propose two different error estimation procedures that provide rigorous bounds for the error in the optimal control and the associated cost functional. The reduced basis optimal control problem and associated a posteriori error bounds can be efficiently evaluated in an offline–online computational procedure, thus making our approach relevant in the many-query or real-time context. We compare our bounds with a previously proposed bound based on the Banach–Ne?as–Babu?ka theory and present numerical results for two model problems: a Graetz flow problem and a heat transfer problem. Finally, we also apply and test the performance of our newly proposed bound on a hyperthermia treatment planning problem.  相似文献   
6.
7.
Young individuals who drive under the influence of alcohol have a higher relative risk of crash involvement; as such, the literature has extensively investigated the factors affecting such involvement through both post-accident surveys and simulator experiments. The effects of differentiated breath alcohol concentrations (BrAC) on young driver behavior, however, have been largely unaddressed, mainly as a result of the difficulty in collecting the necessary data. We explore young driver behavior under the influence of alcohol using a driving simulator experiment where 49 participants were subjected to a common pre-defined dose of alcohol consumption. Comparing reaction times before and after consumption allows for interesting insights and suggestions regarding policy interventions. As expected, the results indicate that increased reaction times before consuming alcohol strongly affect post-consumption reaction times, while increased BrAC levels prolong reaction times; a 10% increase in BrAC levels results in a 2% increase in reaction time. Interestingly, individuals with faster alcohol absorption times perform better regardless of absolute BrAC level, while recent meals lead to higher reaction times and regular exercising to lower.  相似文献   
8.
Die beweiskr?ftige elektronische Aufbewahrung relevanter Wahldokumente ist eine Voraussetzung für gesetzlich bindende Onlinewahlen. Dieser interdiszipli?re Beitrag gibt unter Berücksichtigung rechtlicher Anforderungen und technischer M?glichkeiten Empfehlungen zur Gestaltung einer beweissicheren elektronischen Aufbewahrung von Onlinewahldaten.  相似文献   
9.
The RDF(S) data model has been proposed for encoding metadata about Web resources. As more and more Web resources are annotated using RDF(S), there is an urgent need for efficiently dealing with this large volume of data. In this paper, we present Atlas, a peer-to-peer system for storing, updating and querying RDF(S) data. The Atlas system has been built using the distributed hash table Bamboo. Atlas was developed in the context of project OntoGrid, where it was used as a distributed repository for RDF(S) metadata describing Grid services and resources. The development of Atlas continues in other projects that our group participates currently. This paper gives an overview of the most recent version of Atlas and discusses a representative application.  相似文献   
10.
The use of different types of phenolic binding agents (PBA) in conjunction with the in vitro gas production technique for the assessment of phenolic related antinutritive factors in browse were compared. During a grazing trial by goats, three fractions, grazed leaves (GL), ungrazed leaves (UL) or stems of ungrazed leaves (US) of Robinia pseudoacacia, together with three harvests of leaves of Cistus incanus and a summer harvest of Fraxinus ornus or Carpinus duinensis were analysed for total extractable phenols (TEPH), total extractable tannins (TETa), condensed tannins (vanillin–HCl) (TECTa) and extractable and total proanthocyanidins (TEPAs and TOPAs). Gas production from the samples with or without adding insoluble polyvinylpolypyrrolidone (IPVP), soluble PVP or polyethylene glycol of different molecular weights was measured. The kinetics of gas production were determined using the equation p=a+b (1-ect). The effects of addition of the PBAs were assessed as percentage changes in the rate and volume of gas production or concentration of volatile fatty acids (VFA). Levels (mg g−1 DM) of TEPH varied from 4·9 to 100·4, TETa from 0·6 to 58·0, TECTa from 1·0 to 64·6, and TEPas or TOPAs from 5·7 to 283·0 and from 12·4 to 331·4. Except for PVP360 which depressed fermentation, addition of 200–500 mg of the other PBAs to rumen liquor/buffer or a tannin free hay, did not affect (P>0·05) fermentation. The highest increase in gas production was achieved with PEG4, PEG8 and PEG10 followed by PVP10, PVP40 and IPVP after 12–24 h incubation. The percentage increase in gas production as a result of adding the PEGs was best associated (r=0·83–0·96; P<0·01) with the higher concentrations of total VFAs after 96 h incubation and was also best related (r=0·89–0·91; P<0.01) to the levels of extractable condensed tannins (TECTa and TEPAs) in the browse. It was concluded that PEGs were more effective than PVPs in eliminating phenolic related antinutritive factors and would be preferred for use in conjunction with the gas technique for the assessment of phenolic related antinutritive factors in feeds.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号