全文获取类型
收费全文 | 363篇 |
免费 | 5篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 64篇 |
金属工艺 | 8篇 |
机械仪表 | 2篇 |
建筑科学 | 10篇 |
能源动力 | 4篇 |
轻工业 | 31篇 |
水利工程 | 3篇 |
无线电 | 32篇 |
一般工业技术 | 52篇 |
冶金工业 | 49篇 |
原子能技术 | 1篇 |
自动化技术 | 112篇 |
出版年
2023年 | 5篇 |
2022年 | 16篇 |
2021年 | 19篇 |
2020年 | 11篇 |
2019年 | 10篇 |
2018年 | 11篇 |
2017年 | 8篇 |
2016年 | 9篇 |
2015年 | 3篇 |
2014年 | 12篇 |
2013年 | 19篇 |
2012年 | 18篇 |
2011年 | 36篇 |
2010年 | 23篇 |
2009年 | 15篇 |
2008年 | 25篇 |
2007年 | 12篇 |
2006年 | 19篇 |
2005年 | 9篇 |
2004年 | 11篇 |
2003年 | 7篇 |
2002年 | 8篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 7篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1982年 | 6篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1977年 | 5篇 |
1969年 | 2篇 |
排序方式: 共有370条查询结果,搜索用时 15 毫秒
61.
62.
Golden Charles J.; Ariel Rona Notestine; McKay Stephen E.; Wilkening Greta N.; Wolf Brian A.; MacInnes William D. 《Canadian Metallurgical Quarterly》1982,50(2):291
Since the introduction of the Luria-Nebraska Neuropsychological Battery (LNNB), issues related to its understanding, interpretation, and validity have generated much interest. In response to P. A. Spiers's (see record 1981-24833-001) criticism of the battery, the authors suggest that the controversy appears to arise from a divergence in theoretical orientation on the role of quantitative versus qualitative assessment as well as from differences in the understanding of measurement methodology and validity. The present article discusses the theoretical basis from which the LNNB was constructed and describes the process of test interpretation. Previous and current research on use and validity of the battery is presented as it relates to the theoretical and methodological concerns. While basic philosophical differences with other theoretical systems are not likely to be resolved, the authors of the LNNB will continue to emphasize the integration of quantitative and qualitative approaches, both in the use of the LNNB and in the field of neuropsychology in general. It is concluded that the LNNB will continue to be revised on the basis of research findings and experience with the test in different patient populations. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
63.
Prosocial behavior is important for the functioning of society. This study investigates the extent to which environment shared by family members, nonshared environment, and genetics account for children's prosocial behavior. The prosocial behavior of twins (9,424 pairs) was rated by their parents at the ages of 2, 3, 4, and 7 and by their teachers at age 7. For parent ratings, shared environmental effects decreased from .47 on average at age 2 to .03 at age 7, and genetic effects increased from .32 on average to .61. The finding of weak shared environmental effects and large heritability at age 7 was largely confirmed through the use of teacher ratings. Using longitudinal genetic analyses, the authors conclude that genetic effects account for both change and continuity in prosocial behavior and nonshared environment contributes mainly to change. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
64.
In this first investigation of genetic and environmental influences on children's values, 271 German twin pairs (50.2% boys) reported their values at ages 7–11 years using the Portrait Values Questionnaire (Schwartz & Rubel, 2005). We distinguished between gender-neutral (conservation vs. openness to change) and gender-typed (self-transcendence vs. self-enhancement) values. Boys differed from girls in the importance given to gender-typed benevolence, achievement, and power values. Gender-neutral values showed moderate (.34) and gender-typed values showed higher (.49) heritability, with nonshared environment and error accounting for the remaining variance. For both sexes, substantial genetic effects accounted for the importance children gave to their respective gender-stereotypical end of the self-transcendence versus self-enhancement dimension. However, dramatic sex differences emerged in the gender-atypical end of the distribution. For girls, low self-transcendence (high gender-atypical values) showed a large (.76) group heritability. For boys, gender-atypical values (high self-transcendence) showed no heritability and a modest (.10) shared environment effect. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
65.
De Cremer David; Brockner Joel; Fishman Ariel; van Dijke Marius; van Olffen Woody; Mayer David M. 《Canadian Metallurgical Quarterly》2010,95(2):291
Prior research has shown that procedural fairness interacts with outcome fairness to influence employees’ work attitudes (e.g., organizational commitment) and behaviors (e.g., job performance, organizational citizenship behavior), such that employees’ tendencies to respond more positively to higher procedural fairness are stronger when outcome fairness is relatively low. In the present studies, we posited that people’s uncertainty about their standing as organizational members would have a moderating influence on this interactive relationship between procedural fairness and outcome fairness, in that the interactive relationship was expected to be more pronounced when uncertainty was high. Using different operationalizations of uncertainty of standing (i.e., length of tenure as a proxy, along with self-reports and coworkers’ reports), we found support for this hypothesis in 4 field studies spanning 3 different countries. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
66.
Montanaro MA Rimoldi OJ Igal RA Montenegro S Tarrés MC Martínez SM Brenner RR 《Lipids》2003,38(8):827-832
Both diabetes mellitus type 1 and diabetes mellitus type 2 are widespread diseases that alter carbohydrate and lipid metabolism.
e Stilmann-Salgado (eSS) rats are experimental animals that spontaneously evolve to a state similar to that of young people
affected by non-insulin-dependent diabetes mellitus (NIDDM; type 2). Using 6-mon-old eSS rats that, according to the literature
[Martinez, S.M., Tarrés, M.C., Montenegro, S, Milo, R., Picena, J.C., Figueroa, N., and Rabasa, S.R. (1988) Spontaneous Diabetes
in eSS Rats, Acta Diabetol. Lat. 25, 303–313], had already developed insulin resistance, we investigated the changes evoked on Δ9, Δ6, and Δ5 liver desaturases.
The abundance of mRNA and enzymatic activities were measured, as well as the FA composition of liver microsomal lipids. Compared
to control rats, the mRNA content and activity of SCD-1 (stearoyl CoA-desaturase, isoform of the Δ9 desaturase) were significantly
higher, urase, isoform of the Δ9 desaturase) were significantly higher, whereas the mRNA and activities of Δ6 and Δ5 desaturases
were not significantly modified. Correspondingly, the proportion of 18∶1n−9 and the ratios of 18∶1n−9/18∶0 and 16∶1/16∶0 in
lipids were significantly increased, whereas the proportion of 20∶4n−6 was unaltered. These effects were found while glycemia
was constant or increased. The results are completely opposite those described in insulin-dependent diabetes mellitus (type
1), in which a depression of all the desaturases is found. They suggest that in eSS rats, the activities of the desaturases
were not modified by an insulin-resistance effect. Moreover, we suggest that the enhancement of SCD-1 activity might be considered
as another typical sign of the NIDDM syndrome, because it has also been found in other animal models of NIDDM, for example,
the ones evoked by the sucrose-rich diet and in the Zucker rat. 相似文献
67.
The decomposition of N2O, and the catalytic reduction by NH3 of N2O and N2O + NO, have been studied on Fe-BEA, -ZSM-5 and -FER catalysts. These catalysts were prepared by classical ion exchange and characterized by TPR after various activation treatments. Fe-FER is the most active material in the catalytic decomposition because “oxo-species” reducible at low temperature, appearing upon interaction of FeII-zeolite with N2O (-oxygen), are formed in largest amounts with this material. The decomposition of N2O is promoted by addition of NH3, and even more with NH3 + NO in the case of Fe-FER and -BEA. It is proposed that the NO-promoted reduction of N2O originated from the fast surface reaction between -oxygen O* and NO* to yield NO2*, which in turn reacts immediately with NH3. 相似文献
68.
Joyce Maria Gomes da Costa Eric Keven Silva Ariel Antonio Campos Toledo Hijo Viviane Machado Azevedo Soraia Vilela Borges 《Drying Technology》2013,31(3):346-354
The effect of water content on the glass transition temperature of Swiss cheese bioaroma microencapsulated with a spray dryer was determined using differential scanning calorimetry (DSC) while mass loss was determined by thermogravimetric analysis (TGA). The sorption isotherm behavior was assessed at 15–45°C. Data were fitted with different sorption models. The bioaroma microparticles were produced via spray drying in a matrix with a 1:1 ratio (w/w) of maltodextrin 20DE and modified corn starch (Capsul). The isotherms displayed Type II behavior, and the best fit was obtained by the Guggenheim–Anderson–de Boer (GAB) model (coefficient of determination R² ≥ 0.98). The DSC analysis showed that the increased equilibrium moisture content caused a significant reduction in the Tg of the microparticles. The samples stored at intermediate humidity showed thermal stability and the samples with equilibrium moisture content of 17.92% showed a lower mass loss. 相似文献
69.
Carina Levin Ariel Koren Annie Rebibo-Sabbah Maya Levin Naama Koifman Benjamin Brenner Anat Aharon 《International journal of molecular sciences》2021,22(18)
Beta thalassemia major (βT) is a hereditary anemia characterized by transfusion-dependency, lifelong requirement of chelation, and organ dysfunction. MicroRNA (miRNA) can be packed into extracellular vesicles (EVs) that carry them to target cells. We explored EV-miRNA in βT and their pathophysiologic role. Circulating EVs were isolated from 35 βT-patients and 15 controls. EV miRNA was evaluated by nano-string technology and real-time quantitative polymerase chain reaction (RT-qPCR). We explored effects of EVs on cell culture proliferation, apoptosis, and signal transduction. Higher amounts of small EV (exosomes) were found in patients than in controls. The expression of 21 miRNA was > two-fold higher, and of 17 miRNA < three-fold lower in βT-EVs than control-EVs. RT-qPCR confirmed differential expression of six miRNAs in βT, particularly miR-144-3p, a regulator of erythropoiesis. Exposure of endothelial, liver Huh7, and pancreatic 1.1B4 cells to βT-EVs significantly reduced cell viability and increased cell apoptosis. βT-EV-induced endothelial cell apoptosis involved the MAPK/JNK signal-transduction pathway. In contrast, splenectomized βT-EVs induced proliferation of bone marrow mesenchymal stem cells (BM-MSC). In summary, the miR-144-3p was strongly increased; βT-EVs induced apoptosis and decreased endothelial, pancreatic, and liver cell survival while supporting BM-MSC proliferation. These mechanisms may contribute to βT organ dysfunction and complications. 相似文献
70.
Dr. Betul Kacar Dr. Amanda K. Garcia Dr. Ariel D. Anbar 《Chembiochem : a European journal of chemical biology》2021,22(1):114-119
Our understanding of life in the universe comes from one sample, life on Earth. Current and next-generation space missions will target exoplanets as well as planets and moons in our own solar system with the primary goal of detecting, interpreting and characterizing indications of possible biological activity. Thus, understanding life's fundamental characteristics is increasingly critical for detecting and interpreting potential biological signatures elsewhere in the universe. Astrobiologists have outlined the essential roles of carbon and water for life, but we have yet to decipher the rules governing the evolution of how living organisms use bioessential elements. Does the suite of life's essential chemical elements on Earth constitute only one possible evolutionary outcome? Are some elements so essential for biological functions that evolution will select for them despite low availability? How would this play out on other worlds that have different relative element abundances? When we look for life in the universe, or the conditions that could give rise to life, we must learn how to recognize it in extremely different chemical and environmental conditions from those on Earth. We argue that by exposing self-organizing biotic chemistries to different combinations of abiotic materials, and by mapping the evolutionary history of metalloenzyme biochemistry onto geological availabilities of metals, alternative element choices that are very different from life's present-day molecular structure might result. A greater understanding of the paleomolecular evolutionary history of life on Earth will create a predictive capacity for detecting and assessing life's existence on worlds where alternate evolutionary paths might have been taken. 相似文献