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   36篇
  免费   2篇
电工技术   2篇
化学工业   8篇
轻工业   2篇
水利工程   2篇
一般工业技术   3篇
冶金工业   19篇
自动化技术   2篇
  2024年   1篇
  2023年   2篇
  2022年   1篇
  2021年   1篇
  2020年   1篇
  2019年   1篇
  2014年   1篇
  2013年   1篇
  2011年   1篇
  2010年   3篇
  2009年   1篇
  2007年   1篇
  2006年   1篇
  2004年   1篇
  2002年   2篇
  2001年   2篇
  2000年   1篇
  1998年   5篇
  1997年   5篇
  1996年   4篇
  1991年   1篇
  1932年   1篇
排序方式: 共有38条查询结果,搜索用时 15 毫秒
11.
Anticipation of others' actions is of paramount importance in social interactions. Cues such as gaze direction and facial expressions can be informative, but can also produce ambiguity with respect to others' intentions. We investigated the combined effect of an actor's gaze and expression on judgments made by observers about the end-point of the actor's head rotation toward the observer. Expressions of approach gave rise to an unambiguous intention to move toward the observer, while expressions of avoidance gave rise to an ambiguous behavioral intention (as the expression and motion cues were in conflict). In the ambiguous condition, observers overestimated how far the actor's head had rotated when the actor's gaze was directed ahead of head rotation (compared to congruent or lagging behind). In the unambiguous condition the estimations were not influenced by the gaze manipulation. These results show that social cue integration does not follow simple additive rules, and suggests that the involuntary allocation of attention to another's gaze depends on the perceived ambiguity of the agent's behavioral intentions. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
12.
Understanding the sensitivity of tidal flats to environmental changes is challenging. Currently, most studies rely on process-based models to systematically explain the morphodynamic evolution of tidal flats. In this study, we proposed an alternative empirical approach to explore tidal flat dynamics using statistical indices based on long-term time series of daily surface elevation development. Surface elevation dynamic (SED) indices focus on the magnitude and period of surface elevation changes, while morphodynamic signature (MDS) indices relate sediment dynamics to environmental drivers. The statistical analyses were applied to an intervention site in the Netherlands to determine the effect of recently constructed groynes on the tidal flat. Using these analyses, we were able to (1) detect a reduction in the daily SED and (2) determine that the changes in the daily SED were predominantly caused by the reduction in wave impact between the groynes rather than the reduction in tidal currents. Overall, the presented results showed that the combination of novel statistical indices provides new insights into the trajectories of tidal flats, ecosystem functioning, and sensitivity to physical drivers (wind and tides). Finally, we suggested how the SED and MDS indices may help to explore the future trajectories and climate resilience of intertidal habitats.  相似文献   
13.
The survival of insect herbivores typically is constrained by food choice and predation risk. Here, we explored whether movement from leaves to flowers increases survival of herbivores that prefer to feed on floral tissues. Combining field and greenhouse experiments, we investigated whether flowering influences the behavior of Pieris brassicae butterflies and caterpillars and, consequently, herbivore survival in the field. In this context, we investigated also if flowers of Brassica nigra can provide caterpillars refuge from the specialist parasitoid Cotesia glomerata and from predatory social wasps. By moving to flowers, caterpillars escaped from the parasitoid. Flowers are nutritionally superior when compared with leaves, and caterpillars develop faster when feeding on flowers. However, late-stage caterpillars can be preyed upon intensively by social wasps, irrespective of whether they feed on leaves or flowers. We conclude that flower preference by P. brassicae is more likely driven by nutritional advantages and reduced parasitism on flowers, than by risks of being killed by generalist predators.  相似文献   
14.
A group of 20 patients who met the DSM-III-R criteria for panic disorder with or without agoraphobia underwent a 35% carbon dioxide (CO2) challenge after either 1 mg alprazolam or placebo in a double-blind, randomized, cross-over design. Despite the anxiolytic potential of alprazolam, it produced no significant effects on CO2-induced anxiety and panic symptomatology when compared to placebo.  相似文献   
15.
OBJECTIVE: This article describes a consensus view of the role of psychiatrists in respect of alcohol and other drug (AOD) problems, in response to the view expressed by Wodak [1]. METHOD: The data were selected on the basis of the knowledge and experience of the authors. RESULTS: Psychiatrists have made major contributions in the primary, secondary and tertiary prevention of AOD problems over many years in Australia and New Zealand. In recent years there has been an explosion of new knowledge in the AOD area and a shift from mental health to primary and public health care for these patients. Substance use disorders (SUD) are highly prevalent in all areas of psychiatric practice, requiring treatment in their own right as well as complicating the treatment of coexisting psychiatric illness. CONCLUSION: It is argued that psychiatrists have important roles in harm reduction, prevention and policy development; brief and early intervention in SUD in liaison and child psychiatry; and systematic treatment for those with dependence and other psychiatric comorbidity. A research and collaborative approach to AOD services and patients should be encouraged, rather than engaging in divisive debate over "ownership' of this area of clinical practice.  相似文献   
16.
Low-dimensional perovskites have gained increasing attention recently, and engineering their material phases, structural patterning and interfacial properties is crucial for future perovskite-based applications. Here a phase and heterostructure engineering on ultrathin perovskites, through the reversible cation exchange of hybrid perovskites and efficient surface functionalization of low-dimensional materials, is demonstrated. Using PbI2 as precursor and template, perovskite nanosheets of varying thickness and hexagonal shape on diverse substrates is obtained. Multiple phases, such as PbI2, MAPbI3 and FAPbI3, can be flexibly designed and transformed as a single nanosheet. A perovskite nanosheet can be patterned using masks made of 2D materials, fabricating lateral heterostructures of perovskite and PbI2. Perovskite-based vertical heterostructures show strong interfacial coupling with 2D materials. As a demonstration, monolayer MoS2/MAPbI3 stacks give a type-II heterojunction. The ability to combine the optically efficient perovskites with versatile 2D materials creates possibilities for new designs and functionalities.  相似文献   
17.
Targeting protein kinases in cancer therapy with irreversible small-molecule inhibitors is moving to the forefront of kinase-inhibitor research and is thought to be an effective means of overcoming mutation-associated drug resistance in epidermal growth factor receptor kinase (EGFR). We generated a detection technique that allows direct measurements of covalent bond formation without relying on kinase activity, thereby allowing the straightforward investigation of the influence of steric clashes on covalent inhibitors in different resistant kinase mutants. The obtained results are discussed together with structural biology and biochemical studies of catalytic activity in both wild-type and gatekeeper mutated kinase variants to draw conclusions about the impact of steric hindrance and increased catalytic activity in drug-resistant kinase variants.  相似文献   
18.
Numerous controlled trials have demonstrated the efficacy of specific immunotherapy, although its mechanism is not completely understood. Few studies have addressed the effects of immunotherapy on the release of mediators. We measured in vitro sulphidoleukotriene (sLT) and histamine release after specific stimulus (Dermatophagoides pteronyssinus or Lollium perenne) in a group of patients under immunotherapy (n = 35) and compared the results with those obtained in a group of allergic patients without immunotherapy (n = 57). SLT quantification was carried out by cellular stimulation allergen test (CAST)-ELISA and we measured the amount of histamine release using a fluorometric method. We found a significant (p < 0.05) reduction of allergen-specific mediator release on the group of patients under immunotherapy treatment. When we studied the group of patients sensitive to D. pteronyssinus we also observed a significant reduction in sLT release after the in vitro stimulus with anti-IgE. In vitro sLT production could be a good marker for follow-up immunotherapy. This study provides more evidence to support the immunological and cellular changes induced by immunotherapy.  相似文献   
19.
Recent studies suggest that variations of the vitamin D receptor (VDR) gene are related to bone mineral density (BMD). In this study, we examined the effect of vitamin D3 supplementation on BMD at the femoral neck in relation to VDR genotype. We analyzed 81 women, age 70 years and over, who participated in a placebo-controlled clinical trial on the effect of vitamin D3 supplementation (400 IU daily for at least 2 years) on BMD and fracture incidence. VDR genotype was based on the presence (b) or absence (B) of the BsmI restriction site. Mean BMD of the right and left femoral neck was measured at baseline and after 1 and 2 years. Dietary calcium, body mass index, and years since menopause were assessed at baseline while biochemical markers were measured at baseline and after 1 year. There was no difference among the BB, Bb, and bb genotype for baseline measurements of BMD at the femoral neck (mean and SD, g/cm2: 0.70 (0.10), 0.71 (0.12), and 0.69 (0.10), respectively), nor for any of the biochemical indices. The mean increase of BMD in the vitamin D group relative to the placebo group, expressed as percentage of baseline BMD, was significantly higher (p = 0.03) in the BB (delta BMD: 4.4%, p = 0.04) and Bb genotype (delta BMD: 4.2%, p = 0.007) compared with the bb genotype (delta BMD: -0.3%, p = 0.61). No significant changes were found for any of the other measured parameters. The VDR genotype-dependent effect of vitamin D supplementation in these elderly subjects suggest a functional involvement of VDR gene variants in determining BMD.  相似文献   
20.
Farmers' varieties of sorghum from three communities in different regions of northern Bénin were analysed for their food quality and agro‐morphological properties, and also for their genetic diversity using amplified fragment length polymorphism (AFLP). Farmers' varieties of sorghum differed greatly with respect to their morphology and agronomic and food traits. Most of the varieties had long (>200 cm) stems (87%), loose panicles (79%) and a red or pink colour (52%). Most were susceptible to drought (54%) and to attacks by striga (79%), insects (99%) and birds (77%). Farmers evaluated the quality of the seeds for preparing porridges as being high for 60% of the varieties and 26% of the varieties were regarded as suitable for making beverages. Late‐maturing, large‐seeded, red or pink varieties are preferred by farmers for porridges and beverages. Gene diversity among varieties within regions, as measured by neutral markers, was similar for the three regions (0.211–0.240). However, across regions the short (<150 cm) stem varieties showed relatively high genetic diversity compared with long or medium stem varieties (0.378 vs 0.184–0.216 for long–medium stem varieties). Genetic differentiation (Fst) among regions and among stem lengths of varieties was significant and ranged between 0.086 and 0.135. Grain colour, stem length and panicle shape varied significantly with the region/stem length and correlated with the genetic differentiation of regions. No relationship could be detected between the genetic differentiation of the varieties and their food quality as expressed by the farmers. Implications of the findings for crop conservation and breeding are discussed. Copyright © 2006 Society of Chemical Industry  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