全文获取类型
收费全文 | 751篇 |
免费 | 75篇 |
专业分类
电工技术 | 5篇 |
综合类 | 2篇 |
化学工业 | 286篇 |
金属工艺 | 9篇 |
机械仪表 | 2篇 |
建筑科学 | 50篇 |
矿业工程 | 4篇 |
能源动力 | 9篇 |
轻工业 | 146篇 |
水利工程 | 13篇 |
无线电 | 37篇 |
一般工业技术 | 84篇 |
冶金工业 | 119篇 |
原子能技术 | 2篇 |
自动化技术 | 58篇 |
出版年
2024年 | 6篇 |
2023年 | 17篇 |
2022年 | 53篇 |
2021年 | 60篇 |
2020年 | 28篇 |
2019年 | 29篇 |
2018年 | 28篇 |
2017年 | 18篇 |
2016年 | 24篇 |
2015年 | 33篇 |
2014年 | 26篇 |
2013年 | 54篇 |
2012年 | 40篇 |
2011年 | 43篇 |
2010年 | 33篇 |
2009年 | 34篇 |
2008年 | 36篇 |
2007年 | 28篇 |
2006年 | 20篇 |
2005年 | 32篇 |
2004年 | 17篇 |
2003年 | 16篇 |
2002年 | 17篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 9篇 |
1998年 | 16篇 |
1997年 | 8篇 |
1996年 | 11篇 |
1995年 | 7篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1985年 | 3篇 |
1983年 | 5篇 |
1981年 | 2篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1964年 | 2篇 |
1945年 | 1篇 |
排序方式: 共有826条查询结果,搜索用时 17 毫秒
51.
52.
53.
Guetmonde M Nieves C Vinderola G Reinheimer J de los Reyes-Gavilan CG 《The Journal of dairy research》2002,69(1):125-137
The influence of carbonation on the evolution of lactose, galactose and glucose in fermented milks with added probiotic bacteria (Lactobacillus casei, Lactobacillus acidophilus and/or Bifidobacterium bifidum) was evaluated and related to beta-galactosidase activity of starter strains. During incubation and first days of refrigeration, lactose hydrolysis resulting in the liberation of galactose and glucose occurred in CT (Streptococcus thermophilus/Lb. casei), AT (Str. thermophilus/Lb. acidophilus) and ABT fermented milks (Str. thermophilus/Lb. acidophilus/Bifid. bifidum). Levels of galactose were higher than those of glucose and could be related to the preferential consumption of glucose by actively growing bacteria. Through the incubation, lactose and monosaccharide levels were not affected by milk carbonation. However, during refrigerated storage the presence of this gas was associated with slightly lower content of lactose and higher levels of galactose and glucose in AT and ABT products but not in CT fermented milks. Through the refrigeration galactose was moderately utilised by Lb. acidophilus in AT products whereas the presence of Bifid. bifidum seems to prevent the consumption of this sugar in ABT fermented milks. Glucose remained constant, with minor variations in CT products but a continuous increase of this sugar occurred in carbonated AT and ABT fermented milks during storage. Beta-galactosidase activity displayed by Str. thermophilus strains was similar at pH 6.5 (initial pH of non-carbonated samples) and pH 6.3 (initial pH of carbonated samples) whereas Lb. acidophilus LaA3 showed greater beta-galactosidase activity at pH 6.3 than at higher pH values. Thus, the enhanced metabolic activity of Lb. acidophilus caused by the low initial pH of carbonated milk also promoted higher cellular beta-galactosidase activity that could have released greater amounts of galactose and glucose from lactose in AT and ABT fermented milks through the refrigerated period. In CT fermented milks, similar beta-galactosidase activity levels of Str. thermophilus at pH 6.5 and 6.3 together with the absence of beta-galactosidase activity in Lb. casei could explain the lack of differences on glucose and galactose content between carbonated and non-carbonated samples. 相似文献
54.
The preferences of 132 therapists-in-training for 16 client characteristics were investigated using a paired comparison methodology. Therapists most preferred to work with clients who were psychologically minded, shared similar attitudes and values, and had dissimilar personally troubling problems. They least preferred to work with clients who were not psychologically minded, had dissimilar attitudes and values, and were older. Order of preferences was not influenced by therapist sex, race, clinical experience, socioeconomic status, sexual orientation, or theoretical orientation. Limitations of this study as well as implications for further research and training are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
55.
Fernando Rosa-Velardo Clara Segura David de Frutos-Escrig 《Electronic Notes in Theoretical Computer Science》2005,137(1):151
We propose a general method for the treatment of history-dependent runtime errors. When one has to control this kind of errors, a tagged version of the language is usually defined, in which tags capture only the necessary information of the history of processes. We will characterize such tagged languages as being quotients of the reachability tree defined by the computations of the original language. From this fact we can conclude that the property characterized by each tagged language is indeed a property of the original one. In this way, we can work in a common framework, instead of defining an ad hoc semantics for each property. In particular, we could still use the analysis machinery existing in the calculus in order to prove that or other related properties. We have applied this methodology to the study of resource access control in a distributed π-calculus, called Dπ. In particular, we have proved that the tagged version of Dπ is indeed a tagging according to our definition. 相似文献
56.
Hill Clara E.; Helms Janet E.; Spiegel Sharon B.; Tichenor Victoria 《Canadian Metallurgical Quarterly》1988,35(1):27
We developed a measure of client reactions to therapist interventions. The 21 categories of the measure were divided into 14 positive and 7 negative reactions, which differed significantly from each other on client helpfulness ratings. Preliminary validity data indicated that therapist intentions were related to client reactions more for successful cases than unsuccessful cases, pretreatment symptomatology was highly predictive of which reactions the clients reported, there were some predictable changes in reactions across time in treatment, and within-case correlations of reactions with client-rated session depth and smoothness indicated some similarities across cases. We discuss the case-specific nature of client reactions, methodological issues, and the need for greater therapist awareness of client reactions. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
57.
Hill Clara E.; Thompson Barbara J.; Cogar Mary C.; Denman Daniel W. 《Canadian Metallurgical Quarterly》1993,40(3):278
Therapists and clients reported on their own and their perceptions of each other's covert processes in long-term therapy. Therapists had a match rate of .45 for client reactions, with therapists rating match on therapeutic work reactions as helpful. Although 65% of clients left somethimg unsaid (primarily because of avoidance), only 27% of therapists were able to match what clients left unsaid. Of the clients, 46% had secrets (often sexual), primarily because of shame or insecurity. Clients had a match rate of .50 for therapist intentions, with therapists rating match on exploratory and restructuring intentions as helpful and both clients and therapists rating match on assessment intentions as not helpful. Thus, awareness of the other's covert processes had an effect on therapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
58.
Hayes Jeffrey A.; McCracken Janet E.; McClanahan Mary K.; Hill Clara E.; Harp Jennifer S.; Carozzoni Paul 《Canadian Metallurgical Quarterly》1998,45(4):468
A consensual qualitative research strategy was used to examine data from 127 interviews conducted with 8 psychologists immediately following their sessions of brief therapy with 8 clients. Analyses revealed 3 domains relevant to countertransference: origins (including categories of family issues, needs and values, therapy specific issues, and cultural issues), triggers (including categories of content of client material, therapist comparing client with others, change in therapy structure or procedures, therapist assessing progress of therapy, therapist perception of client, and emotions), and manifestations (including categories of approach, avoidance, negative feelings, and treatment planning). The frequency of categories within and across cases was classified, and relationships among categories from the 3 domains were detected, generating hypotheses for future empirical research. Implications for practice, training, and continued research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
59.
Hill Clara E.; Nutt-Williams Elizabeth; Heaton Kristin J.; Thompson Barbara J.; Rhodes Renee H. 《Canadian Metallurgical Quarterly》1996,43(2):207
Twelve experienced therapists completed a questionnaire, and 8 of the 12 were then interviewed about their experiences with a therapeutic impasse that ended in the termination of therapy. Data were analyzed using a qualitative methodology. Results indicated that most of the clients were anxious and depressed with personality disorders and interpersonal problems. Therapists perceived impasses as having a profound negative impact on both clients and therapists. Variables associated with impasses in a majority of the cases were a client history of interpersonal problems, a lack of agreement between therapists and clients about the tasks and goals of therapy, interference in the therapy by others, transference, possible therapist mistakes, and therapist personal issues. Implications for training, practice, and research are provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
60.