全文获取类型
收费全文 | 1162篇 |
免费 | 47篇 |
学科分类
工业技术 | 1209篇 |
出版年
2023年 | 12篇 |
2022年 | 26篇 |
2021年 | 34篇 |
2020年 | 26篇 |
2019年 | 32篇 |
2018年 | 24篇 |
2017年 | 25篇 |
2016年 | 24篇 |
2015年 | 18篇 |
2014年 | 42篇 |
2013年 | 49篇 |
2012年 | 42篇 |
2011年 | 69篇 |
2010年 | 66篇 |
2009年 | 42篇 |
2008年 | 52篇 |
2007年 | 46篇 |
2006年 | 36篇 |
2005年 | 37篇 |
2004年 | 22篇 |
2003年 | 18篇 |
2002年 | 22篇 |
2001年 | 19篇 |
2000年 | 20篇 |
1999年 | 33篇 |
1998年 | 59篇 |
1997年 | 37篇 |
1996年 | 27篇 |
1995年 | 23篇 |
1994年 | 19篇 |
1993年 | 21篇 |
1992年 | 18篇 |
1991年 | 11篇 |
1990年 | 8篇 |
1989年 | 15篇 |
1988年 | 20篇 |
1987年 | 13篇 |
1986年 | 14篇 |
1985年 | 10篇 |
1984年 | 13篇 |
1982年 | 5篇 |
1980年 | 4篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1972年 | 3篇 |
1969年 | 3篇 |
1965年 | 3篇 |
1939年 | 3篇 |
1938年 | 3篇 |
排序方式: 共有1209条查询结果,搜索用时 0 毫秒
1.
2.
Lauren P.D. Nandhakumar N. 《IEEE transactions on pattern analysis and machine intelligence》1997,19(5):417-430
The ability to determine the viewing parameters of objects from their projections has enabled well established tomographic techniques to be employed in the 3D reconstruction of objects from images obtained via modalities where the orientation of the objects cannot be controlled. A method is described for the determination of the viewing parameters of randomly acquired projections of asymmetric objects. It extends upon the common lines algorithm by determining the relative orientation of projections from the location of lines of intersection among the Fourier transforms of the projections in 3D Fourier space. A new technique for finding the lines of intersection in the presence of translational displacement, and for subsequently finding the translational displacement, is presented. The complete algorithm is described and its efficacy is demonstrated using real data. A new technique for dealing with noise is also discussed 相似文献
3.
Industries in the US continue to lose ground in international competition. If IS is to help change that trend, it will have to become more creative. Creativity improvement programs are being introduced in other areas of the company— now is the time for IS organizations to follow suit. 相似文献
4.
Nusslock Robin; Abramson Lyn Y.; Harmon-Jones Eddie; Alloy Lauren B.; Hogan Michael E. 《Canadian Metallurgical Quarterly》2007,116(1):105
On the basis of the behavioral approach system (BAS) dysregulation theory of bipolar disorder, this study examined the relation between occurrence of a BAS activation-relevant life event--goal striving--and onset of hypomanic and depressive episodes and symptoms. In particular, the authors examined the relation between preparing for and completing final exams (a goal-striving event) and onset of bipolar spectrum episodes and symptoms in college students with bipolar II disorder or cyclothymia (i.e., "soft" bipolar spectrum conditions). One hundred fifty-nine individuals with either a bipolar spectrum disorder (n=68) or no major affective psychopathology (controls; n=91) were further classified on the basis of whether they were college students (i.e., completed final exams). Consistent with the BAS dysregulation theory, preparing for and completing final exams was associated with an increase in hypomanic but not depressive episodes and symptoms in individuals with a soft bipolar spectrum diagnosis. Furthermore, self-reported BAS sensitivity moderated the presence of certain hypomanic symptoms during final exams. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
5.
Bouchard Thomas J.; Arvey Richard D.; Keller Lauren M.; Segal Nancy L. 《Canadian Metallurgical Quarterly》1992,77(1):89
Responds to the points made by R. Cropanzano and K. James (see record 1991-00462-001) concerning the article by R. D. Arvey et al (1989). The authors acknowledge that the Arvey et al study is based on a single design, makes use of a small and special sample, and, as such, is vulnerable to threats of internal and external validity. Nevertheless, after providing a more comprehensive conceptual and empirical context for the study, and after reviewing a number of the issues raised by Cropanzano and James, the authors conclude that it is not premature to accept the idea that work attitudes are partially genetically influenced. Indeed, the authors use behavioral genetic theory, together with data gathered in the Arvey et al study, to make specific point predictions regarding the outcomes of an array of studies that easily can be undertaken. Finally, the authors acknowledge that the comments and issues raised by Cropanzano and James, along with the interchange, can offer directions for future research in this important area. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
6.
Flynn P.J. Jain A.K. 《IEEE transactions on pattern analysis and machine intelligence》1991,13(10):1066-1075
BONSAI, a model-based 3D object recognition system, is described. It identifies and localizes 3D objects in range images of one or more parts that have been designed on a computer-aided-design (CAD) system. Recognition is performed via constrained search of the interpretation tree, using unary and binary constraints (derived automatically from the CAD models) to prune the search space. Attention is focused on the recognition procedure, but the model-building, image acquisition, and segmentation procedures are also outlined. Experiments with over 200 images demonstrate that the constrained search approach to 3D object recognition has an accuracy comparable to that of previous systems 相似文献
7.
8.
A Region Ensemble for 3-D Face Recognition 总被引:1,自引:0,他引:1
Faltemier T.C. Bowyer K.W. Flynn P.J. 《Information Forensics and Security, IEEE Transactions on》2008,3(1):62-73
In this paper, we introduce a new system for 3D face recognition based on the fusion of results from a committee of regions that have been independently matched. Experimental results demonstrate that using 28 small regions on the face allow for the highest level of 3D face recognition. Score-based fusion is performed on the individual region match scores and experimental results show that the Borda count and consensus voting methods yield higher performance than the standard sum, product, and min fusion rules. In addition, results are reported that demonstrate the robustness of our algorithm by simulating large holes and artifacts in images. To our knowledge, no other work has been published that uses a large number of 3D face regions for high-performance face matching. Rank one recognition rates of 97.2% and verification rates of 93.2% at a 0.1% false accept rate are reported and compared to other methods published on the face recognition grand challenge v2 data set. 相似文献
9.
E. Fay D. J. Flynn J. R. Lundehn P. J. Chapman R. D. Mason 《Journal für Verbraucherschutz und Lebensmittelsicherheit》2007,17(3):61-77
Pflanzenschutzmittel müssen seit 1993 in den Mitgliedstaaten der Europ?ischen Gemeinschaft nach der Richtlinie 91/414/EWG
des Rates bewertet und zugelassen werden. Das Programm zur Bewertung von alten Wirkstoffen (welche vor Juli 1993 auf dem Markt
waren) beinhaltet mehrere Schritte und Stufen, die früher über einen Zeitraum von bis zu 10 Jahren zu bew?ltigen waren; heute
sind dafür jedoch 15 Jahre vorgesehen. Das Programm wurde seit 1996 von der Europ?ischen Kommission mit Unterstützung des
ECCO-Teams(European Community Co-Ordination) koordiniert. Das ECCO-Team bestand aus zwei Gruppen: eine im Pesticides Safety Directorate – PSD in York (Gro?britannien)
und eine im Bundesamt für Verbraucherschutz und Lebensmittelsicherheit (BVL) bzw. vor November 2002 in der Biologischen Bundesanstalt
für Land- und Forstwirtschaft in Braunschweig. Sie unterstüzten das Programm zur Bewertung von Wirkstoffen im Namen der Kommission
in technischer und administrativer Hinsicht und zeichneten sich insbesondere für das ECCO Peer Review Programm (Expertenprüfungen)
verantwortlich. Im November 2003 übernahm die Europ?ische Beh?rde für Lebensmittelsicherheit (EFSA) die Verantwortung für
die wissenschaftliche überprüfung der von den Mitgliedstaaten erstellten Bewertungen durch Experten. Das ECCO-Team leistete
jedoch weiterhin der Europ?ischen Kommission Unterstützung bei der Durchführung anderer Verfahrensaspekte, vor allem im Bereich
der Managementaufgaben der Europ?ischen Kommission. Insgesamt war das Programm au?erordentlich erfolgreich. Es wurden für
162 Wirkstoffen zwischen 1996 und 2003 der Inhalt der von den Mitgliedstaaten erstellten Bewertungsberichte durch eine Expertengruppe
diskutiert und füberprüft, was ma?geblich eine Entscheidungsfindung zur Akzeptabilitf?t dieser Wirkstoffe auf Gemeinschaftsebene
erm?glicht hat. 相似文献
10.
J Kaufman B Birmaher D Brent U Rao C Flynn P Moreci D Williamson N Ryan 《Canadian Metallurgical Quarterly》1997,36(7):980-988
OBJECTIVE: To describe the psychometric properties of the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime version (K-SADS-PL) interview, which surveys additional disorders not assessed in prior K-SADS, contains improved probes and anchor points, includes diagnosis-specific impairment ratings, generates DSM-III-R and DSM-IV diagnoses, and divides symptoms surveyed into a screening interview and five diagnostic supplements. METHOD: Subjects were 55 psychiatric outpatients and 11 normal controls (aged 7 through 17 years). Both parents and children were used as informants. Concurrent validity of the screen criteria and the K-SADS-PL diagnoses was assessed against standard self-report scales. Interrater (n = 15) and test-retest (n = 20) reliability data were also collected (mean retest interval: 18 days; range: 2 to 36 days). RESULTS: Rating scale data support the concurrent validity of screens and K-SADS-PL diagnoses. Interrater agreement in scoring screens and diagnoses was high (range: 93% to 100%). Test-retest reliability kappa coefficients were in the excellent range for present and/or lifetime diagnoses of major depression, any bipolar, generalized anxiety, conduct, and oppositional defiant disorder (.77 to 1.00) and in the good range for present diagnoses of posttraumatic stress disorder and attention-deficit hyperactivity disorder (.63 to .67). CONCLUSION: Results suggest the K-SADS-PL generates reliable and valid child psychiatric diagnoses. 相似文献