全文获取类型
收费全文 | 120篇 |
免费 | 1篇 |
专业分类
化学工业 | 13篇 |
机械仪表 | 2篇 |
建筑科学 | 1篇 |
轻工业 | 37篇 |
水利工程 | 1篇 |
无线电 | 20篇 |
一般工业技术 | 10篇 |
冶金工业 | 23篇 |
自动化技术 | 14篇 |
出版年
2021年 | 1篇 |
2020年 | 2篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2013年 | 5篇 |
2012年 | 1篇 |
2011年 | 4篇 |
2010年 | 1篇 |
2008年 | 1篇 |
2007年 | 2篇 |
2006年 | 5篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 8篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 6篇 |
1996年 | 5篇 |
1994年 | 5篇 |
1993年 | 2篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1986年 | 6篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 6篇 |
1981年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 2篇 |
1967年 | 1篇 |
1965年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有121条查询结果,搜索用时 15 毫秒
11.
European Journal of Wood and Wood Products - 相似文献
12.
Chitins of various origins in DMA-LiCl solution have been reacted with excess 1,6-diisocyanatohexane (three or twelve equivalents per repeating unit) for 4-20 h. The resulting solutions were exposed to water vapor for 2 days and flexible and opaque materials were produced, which upon drying yielded powders whose main characteristics were insolubility in aqueous and organic solvents, remarkable crystallinity, typical infrared spectrum, high N/C ratio (0.287), and a high degree of substitution (0.29). Under the SEM structural features reminiscent of chitin were absent but no thermoplastic behavior was found by differential scanning calorimetry. Chitosan was similarly treated under heterogeneous conditions in anhydrous pyridine, and yielded reaction products with a lower degree of substitution (0.17). With partially hydrolysed chitosan, highly crystalline products were obtained. 相似文献
13.
14.
Yingxiao Xu Prasad Calyam David Welling Saravanan Mohan Alex Berryman Rajiv Ramnath 《中兴通讯技术(英文版)》2013,11(1):27-36
There are several motivations, such as mobility, cost, and security, that are behind the trend of traditional desktop users transitioning to thin-client-based virtual desktop clouds (VDCs). Such a trend has led to the rising importance of human-centric performance modeling and assessment within user communities that are increasingly making use of desktop virtualization. In this paper, we present a novel reference architecture and its easily deployable implementation for modeling and assessing objective user quality of experience (QoE) in VDCs. This architecture eliminates the need for expensive, time-consuming subjective testing and incorporates finite-state machine representations for user workload generation. It also incorporates slow-motion benchmarking with deep-packet inspection of application task performance affected by QoS variations. In this way, a "composite-quality" metric model of user QoE can be derived. We show how this metric can be customized to a particular user group profile with different application sets and can be used to a) identify dominant performance indicators and troubleshoot bottlenecks and b) obtain both absolute and relative objective user QoE measurements needed for pertinent selection of thin-client encoding configurations in VDCs. We validate our composite-quality modeling and assessment methodology by using subjective and objective user QoE measurements in a real-world VDC called VDPilot, which uses RDP and PCoIP thin-client protocols. In our case study, actual users are present in virtual classrooms within a regional federated university system. 相似文献
15.
Sandra P. van Tongeren Gerwin C. Raangs Gjalt W. Welling Hermie J. M. Harmsen Janneke Krooneman 《Microgravity science and technology》2006,18(3-4):219-222
Potentially pathogenic microbes and so-called technophiles may form a serious threat in advanced life support systems, such as the International Space Station (ISS). They not only pose a threat to the health of the crew, but also to the technical equipment and materials of the space station. The development of fast and easy to use molecular detection and quantification methods for application in manned spacecraft is therefore desirable and may also be valuable for applications on Earth. In this paper we present the preliminary results of the SAMPLE experiment in which we performed molecular microbial analysis on environmental samples of the ISS as part of an ESA-MAP project. 相似文献
16.
17.
PH Nibbering MM Welling PJ van den Broek KE van Wyngaarden EK Pauwels W Calame 《Canadian Metallurgical Quarterly》1998,19(12):1117-1121
Risk factors suggestive of relatively late exposure to EBV have been consistently associated with Hodgkin's disease (HD) in younger adults. In addition, evidence of EBV infection has been found in the Reed-Sternberg cells themselves in about one-third to one-half of all HD cases. However, no study yet published has correlated these childhood social environment risk factors with the presence of EBV in Hodgkin's tumor cells. We examined whether EBV-positive HD occurs in those patients whose childhood environment would predispose them to relatively late exposure to EBV. The study population consisted of 102 cases of mixed cellularity (MC; n = 25) or nodular sclerosing (n = 77) HD. Samples that tested positive for either EBV-encoded RNA or latent membrane protein or both were considered EBV-positive. Of the 102 cases, 83 completed a questionnaire regarding childhood social environment. The association with EBV-positivity was estimated by the odds ratio (OR) with 95% confidence intervals (CI). Twenty-two percent of the cases were EBV-positive. These cases were more likely to be MC (OR, 6.2; CI, 2.3-16.3) and male (OR, 3.4; CI, 1.3-9.0). History of infectious mononucleosis (IM) was not predictive of EBV-positivity, with only 3 of 14 such patients being EBV-positive (P = 0.82). Contrary to our hypothesis, no association between EBV and childhood environment risk factors was identified. The association of EBV with MC histology and male gender agrees with previous reports. The most intriguing finding was the dissociation between IM history and EBV-positivity, in that almost all of the cases with a history of IM were EBV-negative. 相似文献
18.
RA Damhof JW Drijfhout AJ Scheffer JB Wilterdink GW Welling S Welling-Wester 《Canadian Metallurgical Quarterly》1993,130(1-2):187-193
To locate T cell determinants of glycoprotein D (gD) of herpes simplex virus type 1 (HSV-1), proliferation assays of lymphocytes obtained from 10 healthy HSV-seropositive individuals were performed using 34 overlapping gD peptides as antigens. Despite large differences between individual responses to the peptides both in number of stimulating peptides and gD regions, three regions (1-54, 110-214, and 290-314) induced a response in 50% or more of the HSV-seropositives. T cells were less frequently stimulated by peptides of region 210-294. No correlation was found between serological data and proliferative responses to the peptides. The diversity in T cell response to the peptides suggests a lack of immunodominance, implying that a single peptide/region of gD, or a combination of peptides, will not be sufficient to serve as a basis for a future HSV-1 vaccine. 相似文献
19.
Intuition may be considered a common factor in psychotherapy, characterizing both psychotherapist and client functioning. After reviewing existing models for intuition, the author proposes a 5-phase model to explain intuition on the basis of the cognitive functions of pattern discovery and recognition. It is argued that intuition should not be viewed as a single phenomenon; rather, the phenomena labeled as intuition can be understood as belonging to different phases of a single process. These phases consist of early knowledge representations that demonstrate the creative role that intuition may play in the construction of knowledge. The author illustrates this model by presenting examples from the practice of psychotherapy. Finally, the author discusses the possibilities of promoting intuitive insight, the fallibility of intuition, and the role intuition may play in integrative decision making. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
20.
Transesophageal echocardiographic predictors for maintenance of sinus rhythm after electrical cardioversion of atrial fibrillation 总被引:1,自引:0,他引:1
PM Verhorst O Kamp RC Welling MJ Van Eenige CA Visser 《Canadian Metallurgical Quarterly》1997,79(10):1355-1359
The aim of this study was to assess the value of transesophageal echocardiography (TEE) in patients with atrial fibrillation in predicting restoration and maintenance of sinus rhythm after electrical cardioversion. TEE was performed in 62 patients with atrial fibrillation before their first elective cardioversion. Clinical variables evaluated were: age, gender, duration, and etiology of atrial fibrillation. TEE variables included: left atrial (LA) length, width, and size, LA annulus size, as well as presence of LA spontaneous contrast, thrombus and mitral regurgitation, LA appendage size and flow, and left ventricular function. Based on initial outcome of cardioversion, patients were grouped into patients who remained in atrial fibrillation and in whom sinus rhythm was restored. The latter group of patients was followed for 1 year, and grouped into patients who reverted to atrial fibrillation and in whom sinus rhythm was maintained. Successful cardioversion was achieved in 50 of 62 patients (81%). None of the clinical or TEE variables were related to initial outcome. At 1-year follow-up, 29 of 50 patients (58%) who underwent successful cardioversion continued to have sinus rhythm. The following variables were related to maintenance of sinus rhythm: duration of atrial fibrillation (6.7 +/- 7.3 vs 2.0 +/- 2.4 months; p < 0.005); LA length (6.2 +/- 0.7 vs. 5.5 +/- 1.0 cm; p < 0.008); width (5.1 +/- 0.5 vs. 4.5 +/- 0.7 cm; p < 0.002); size (26.4 +/- 5.0 vs 19.8 +/- 6.5 cm2; p < 0.0005); annulus size (4.0 +/- 0.2 vs 3.7 +/- 0.3 cm; p < 0.0005); presence of LA spontaneous contrast (13 [62%] vs 4 [14%]; p < 0.002), and LA appendage flow (19 +/- 8 vs 36 +/- 15 cm/s; p < 0.0005). In multivariate logistic regression analysis, LA annulus size, but especially LA appendage flow, were significantly associated with maintenance of sinus rhythm. Thus, in TEE-guided electrical cardioversion of atrial fibrillation, variables often used to assess thromboembolic risk may also be used to predict 1-year outcome of cardioversion. 相似文献