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   318篇
  免费   30篇
  国内免费   3篇
电工技术   5篇
综合类   19篇
化学工业   91篇
金属工艺   4篇
机械仪表   11篇
建筑科学   7篇
能源动力   18篇
轻工业   23篇
水利工程   1篇
石油天然气   1篇
无线电   34篇
一般工业技术   52篇
冶金工业   4篇
原子能技术   8篇
自动化技术   73篇
  2023年   3篇
  2022年   20篇
  2021年   14篇
  2020年   11篇
  2019年   11篇
  2018年   21篇
  2017年   25篇
  2016年   15篇
  2015年   18篇
  2014年   16篇
  2013年   24篇
  2012年   22篇
  2011年   30篇
  2010年   17篇
  2009年   16篇
  2008年   19篇
  2007年   6篇
  2006年   3篇
  2005年   6篇
  2004年   2篇
  2003年   11篇
  2002年   6篇
  2001年   6篇
  1999年   4篇
  1998年   1篇
  1997年   1篇
  1996年   2篇
  1995年   1篇
  1993年   1篇
  1992年   2篇
  1989年   3篇
  1988年   1篇
  1987年   1篇
  1985年   2篇
  1984年   1篇
  1983年   2篇
  1982年   1篇
  1980年   3篇
  1972年   2篇
  1943年   1篇
排序方式: 共有351条查询结果,搜索用时 0 毫秒
151.

Definition of the problem

Because determining a patient’s decision-making competence has far-reaching ethical and legal implications, the concept of competence must be clearly understood. The criteria for competence are commonly defined in terms of mental abilities; more basic questions as to whether competence refers to an inherent ability or to an ethical judgment are rarely discussed in more detail.

Arguments

A central aspect of this distinction between ability and judgment concerns the significance of ethical considerations relating to paternalism and its legitimacy. Where competence is conceived as inherent ability, such considerations follow a determination of competence; where it is conceived as ethical judgment, these matters become constitutive of understanding and determining competence.

Conclusion

Despite the observed tendency to understand competence ideally as an inherent ability, actual practice suggests that, to the contrary, competence is conceived as a matter of ethical judgment. These conflicting tendencies may account for associated conceptual controversies, especially with regard to risk-relative evaluations. Moreover, conceived as judgment, determinations of competence need not adhere rigidly to definitions of autonomy, and so are better able to deal with the inherent ambiguity of this notion.
  相似文献   
152.
153.
To unravel the controlling mechanisms of gene regulation, in this paper we present the application of sophisticated soft computing methods applied on an important problem from Bioinformatics—inferring gene regulatory networks (GRN) from time series gene expression microarray data. The main questions addressed in this paper are: (a) what knowledge can be derived from different models? (b) Would an integrated approach be more suitable to reveal about the controls of gene regulation? To reduce the number of genes in addition to apply the appropriate clustering methods, here we have also considered the valuable inputs from the biological experiments. To infer the GRN we have applied: three computational intelligence methods—Least Angle Regression (LARS), Expectation Maximization (EM) with Kalman Filter (KF), and an Evolving Fuzzy Neural Network (EFuNN). The methods are applied on time series microarray data of Schizosaccharomyces pombe yeast cell-cycle genes. Each method reveals some new aspects of the problem and it is agreed that to infer the GRN and to understand the processes behind gene regulation it is more suitable to adopt such integrative approach as ours through which some new knowledge is discovered, such as: using LARS we hypothesize—first, an exoglucanase gene exg1 is now implicated to be tied with MCB cluster regulation and second, a mannosidase with histone linked mannoses. A new quantitative prediction is that the time delay of the interaction between two genes seems to be approximately 30 min, or 0.17 cell cycles. Using the method of EM with KF, 25 cell cycle-regulated key genes were successfully clustered into three functionally co-regulated groups. We have also identified two genes namely Cdc22 and Suc22 that indeed interact with each other and are the potential candidates as a control in Ribonucleotide reductase (RNR) activity. Based on the EFuNN results and integrating knowledge from EM-KF method, we hypothesize that interaction between Suc22, Cdc22 and Mrc1 may be mediated by two other genes namely Cds1 and Spd1. The methods discussed and applied here can be used to analyze any kind of short time series of many interacting variables for inferring the regulatory network. Researchers should take such integrative computational intelligence approach seriously to understand the complex phenomenon of gene regulation and thus to simulate the development of the cell.  相似文献   
154.
Summary The miscibility behaviour of sulfonylated poly(2,6-dimethyl-1,4-phenylene oxide) of the different degree of sulfonylation blended with poly(styrene-co-maleic anhydride) or poly(-methylstyrene-co-maleic anhydride) was studied. The critical degree of sulfonylation for phase separation in these blends was found to be 55 mole % and 66 mole %, respectively. The miscibility behaviour was analyzed on the basis of the mean field treatment and studied by DSC.Dedicated to Professor Dragutin Fle in honor of his 70th birthday  相似文献   
155.
In proteomics, effective methods are needed for identifying the relatively limited subset of proteins displaying significant changes in abundance between two samples. One way to accomplish this task is to target for identification by MS/MS only the "interesting" proteins based on the abundance ratio of isotopically labeled pairs of peptides. We have developed the software and hardware tools for online LC-FTICR MS/MS studies in which a set of initially unidentified peptides from a proteome analysis can be selected for identification based on their distinctive changes in abundance following a "perturbation". We report here the validation of this method using a mixture of standard proteins combined in different ratios after isotopic labeling. We also demonstrate the application of this method to the identification of Shewanella oneidensis peptides/proteins exhibiting differential abundance in suboxic versus aerobic cell cultures.  相似文献   
156.
This paper presents a method of numerical solution of boundary value problems governed by a set of ordinary differential equations. The highest derivative is chosen as the unknown function. Governing equations are transformed into a set of integral equations. The kernels of integral equations turn out to be influence functions for deflection and/or bending moments of a corresponding beam, and can, therefore, be computed using well-known methods of structural analysis. Finally, the unknown function (highest derivative) is approximated in a defined manner and the solution is obtained through numerical integration.  相似文献   
157.
A new solid‐state sensor for potentiometric determination of surfactants with a layer of multi‐walled carbon nanotubes was prepared. As a sensing material, 1,3‐didecyl‐2‐methylimidazolium–tetraphenylborate ion‐pair was used. The investigated sensor showed a Nernstian response for both dodecylbenzenesulphonate (DBS, 57.6 mV/decade of activity between 5 × 10?7 to 1 × 10?3 M) and sodium lauryl sulfate (LS, 58.4 mV/decade of activity between 2 × 10?7 to 2 × 10?3 M). It responded in 8–10 s for each ten‐fold concentration change in the range of 1 × 10?6 to 3 × 10?3 M. The detection limits for DS and DBS were 2 × 10?7 and 3 × 10?7 M, respectively. The sensor revealed a stable response (signal drift 2.6 mV/h) and exhibited satisfactory selectivity performances for LS over most of the anions generally used in surfactant‐based commercial detergents. The main application of this sensor was the end‐point determination in potentiometric titrations of anionic surfactants. The (diisobutyl phenoxy ethoxy ethyl)dimethyl benzyl ammonium chloride (Hyamine), cetyltrimethylammonium bromide, hexadecylpyridinium chloride monohydrate (HDPC) and 1,3‐didecyl‐2‐methylimidazolium chloride were tested as potential cationic titrants, and all exhibited analytically usable titration curves with well‐defined equivalence points. The standard solution of HDPC was used as a cationic titrant by all potentiometric titrations. The operational life‐time of the sensor described was prolonged to more than 3 months.  相似文献   
158.
Independent living of older adults is one of the main challenges linked to the ageing population. Especially those living with diseases like COPD, MCI or frailty, need more support in everyday life and this is by itself a big societal challenge with impact in multiple sectors. In this paper we present eWALL, an innovative open-source eHealth platform that aims to address these challenges by means of an advanced cloud-based infrastructure. eWALL is designed in an innovative manner and achieved technical breakthroughs in eHealth platforms, while prioritizing user and market needs that are often abandoned and are the major reason for technically sound solutions that fail. We consider this as an opportunity and we aim to change the eHealth systems’ experience for older adults and break the barriers for the penetration of ICT solutions.  相似文献   
159.
Forschung im Ingenieurwesen - PGE – Produktgenerationsentwicklung – ist ein am IPEK entwickelter Ansatz, der erstmals eine zutreffende Charakterisierung von...  相似文献   
160.
This paper describes a meta-analysis of previously published studies on the shrinkage strain of recycled aggregate concrete (RAC). The study aims at providing an analytic expression for the shrinkage strain of RAC to be used in conjunction with the existing fib Model Code 2010 shrinkage prediction model. For this purpose, a database of experimental results on the shrinkage of RAC and companion natural aggregate concrete (NAC), produced with the same water-cement ratio, was compiled using strict selection criteria. Results from 19 studies entered into the database, consisting of 125 shrinkage curves (39 NAC and 86 RAC) with a total of 424 data points. A comparison of RAC and companion NAC revealed that, on average, RAC displays a larger shrinkage strain. This difference increases with increasing recycled concrete aggregate (RCA) content and with decreasing compressive strength. Applying the fib Model Code 2010 shrinkage prediction model revealed that, relative to its performance on NAC, the shrinkage strain of RAC is underestimated. Finally, a correction coefficient for the shrinkage strain of RAC, \(\xi _{{\mathrm{cs}},{\mathrm{RAC}}}\), to be used in conjunction with the fib Model Code 2010 model, was proposed in the form of a bivariate power function with RAC compressive strength and RCA replacement ratio as variables.  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