全文获取类型
收费全文 | 388篇 |
免费 | 15篇 |
专业分类
电工技术 | 3篇 |
综合类 | 3篇 |
化学工业 | 70篇 |
金属工艺 | 3篇 |
机械仪表 | 16篇 |
建筑科学 | 11篇 |
能源动力 | 5篇 |
轻工业 | 65篇 |
水利工程 | 2篇 |
石油天然气 | 5篇 |
无线电 | 56篇 |
一般工业技术 | 40篇 |
冶金工业 | 76篇 |
自动化技术 | 48篇 |
出版年
2023年 | 7篇 |
2022年 | 8篇 |
2021年 | 21篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 7篇 |
2017年 | 14篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 3篇 |
2013年 | 20篇 |
2012年 | 11篇 |
2011年 | 18篇 |
2010年 | 15篇 |
2009年 | 16篇 |
2008年 | 8篇 |
2007年 | 20篇 |
2006年 | 10篇 |
2005年 | 5篇 |
2004年 | 12篇 |
2003年 | 9篇 |
2002年 | 8篇 |
2001年 | 7篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 20篇 |
1997年 | 10篇 |
1996年 | 14篇 |
1995年 | 16篇 |
1994年 | 3篇 |
1993年 | 7篇 |
1992年 | 8篇 |
1991年 | 11篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 7篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1972年 | 2篇 |
排序方式: 共有403条查询结果,搜索用时 31 毫秒
51.
A model of propositional-logic reasoning proposed by M. D. S. Braine, B. J. Reiser, and B. Rumain (1984) claims that inferences such as "p or q; not p /∴ q" are made spontaneously by readers at the moment both premises are available. This claim is inconsistent with some evidence in the text-processing literature that suggests that only those inferences necessary for textual coherence are made spontaneously. In the present study, participants read stories in which a logical inference was not necessary to maintain textual coherence, and inference making was assessed with on-line probes. Two experiments tested logical forms central to Braine et al's model, and both indicated that participants were making the logical inferences. Two further experiments replicated this result with stories that did not begin with thematic titles. These findings support Braine et al.'s prediction that some propositional-logic inferences are made routinely in texts that do not require them for coherence. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
52.
Examined the effects of instructions and modeling in the reflection-of-feeling training of individuals low in interpersonal-communication skills. Participants with low scores on R. Carkhuff's Communication Index (25 males and 25 females) were randomly assigned by sex to 1 of the 5 training groups so that there were 5 males and 5 females in each group. After viewing videotaped training material, each participant conducted a 15-min interview with a volunteer "client" and completed the Communication Index a second time. Interviews were scored for frequency of reflection-of-feeling responses and level of empathic communication displayed. Analysis of the reflection-of-feeling data indicated that instructions and instructions-plus-modeling were facilitative procedures. Ratings of written and verbal empathy demonstrated the effectiveness of the 2 combined conditions: instructions-plus-modeling and modeling-plus-instructions. Calculation of correlations among scores on criterion measures revealed a positive correlation between reflection-of-feeling scores and ratings of empathic communication. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
53.
An experimental 64-bit m.o.s. associative memory has been developed from a limit-case design study. Speeds in excess of 50 MHz are reported at a cost per bit that could approach eight times that for a conventional m.o.s. dynamic r.a.m. The design of the basic associative memory cell is described. 相似文献
54.
55.
Rasmussen SE Frederiksen H Struntze Krogholm K Poulsen L 《Molecular nutrition & food research》2005,49(2):159-174
The French have one of the lowest incidences of coronary heart disease in the Western world despite a diet with a relatively high fat content. This phenomenon that has puzzled researchers worldwide for more than a decade is known as the 'French paradox' and has been linked to the high consumption of red wine in France. Red wine is rich in the complex polyphenols, the proanthocyanidins, and these compounds have recently attracted attention as potential cardiac-protective compounds. The present review summarizes the literature on proanthocyanidins with focus on their chemical structure, the occurrence, the daily intake from foods, the bioavailability and metabolism, and the evidence for a protective effect against cardiovascular diseases. 相似文献
56.
Kirsi S. Mikkonen Susanna Heikkinen Annemai Soovre Marko Peura Ritva Serimaa Riku A. Talja Harry Helén Lea Hyvönen Maija Tenkanen 《应用聚合物科学杂志》2009,114(1):457-466
The development of packaging films based on renewable materials is an important and active area of research today. This is the first extensive study focusing on film‐forming properties of an agrobiomass byproduct, namely, oat spelt arabinoxylan. A plasticizer was needed for cohesive film formation, and glycerol and sorbitol were compared. The tensile properties of the films varied with the type and amount of the polyol. With a 10% (w/w) plasticizer content, the films containing glycerol had higher tensile strength than the films containing sorbitol, but with a 40% plasticizer content, the result was the opposite. Sorbitol‐plasticized films retained their tensile properties better than films with glycerol during 5 months of storage. The films were semicrystalline with similar crystallinity indices of 0.20–0.26. The largest crystallites (9.5 nm) were observed in the film with 40% glycerol. The softening of films with 40% (w/w) glycerol started at a significantly lower relative humidity (RH) than that of the corresponding sorbitol‐containing films. The films with sorbitol also had lower water vapor permeability (WVP) than the films with glycerol. The films plasticized with 10% (w/w) sorbitol had a WVP value of 1.1 g mm/(m2·d·kPa) at the RH gradient of 0/54%. The oxygen permeability of films containing 10% (w/w) glycerol or sorbitol was similar: 3 cm3·μm/(m2·d·kPa) at 50–75% RH. A higher plasticizer content resulted in more permeable films. Permeation of sunflower oil through the films was not detected. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
57.
Inflammatory processes occur as a generic response of the immune system and can be triggered by various factors, such as infection with pathogenic microorganisms or damaged tissue. Due to the complexity of the inflammation process and its role in common diseases like asthma, cancer, skin disorders or Alzheimer's disease, anti-inflammatory drugs are of high pharmaceutical interest. Nature is a rich source for compounds with anti-inflammatory properties. Several studies have focused on the structural optimization of natural products to improve their pharmacological properties. As derivatization through total synthesis is often laborious with low yields and limited stereoselectivity, the use of biosynthetic, enzyme-driven reactions is an attractive alternative for synthesizing and modifying complex bioactive molecules. In this minireview, we present an outline of the biotechnological methods used to derivatize anti-inflammatory natural products, including precursor-directed biosynthesis, mutasynthesis, combinatorial biosynthesis, as well as whole-cell and in vitro biotransformation. 相似文献
58.
Adam S. Wilk Zhaoli Tang Courtney Hoge Laura C. Plantinga Janice P. Lea 《Hemodialysis international. International Symposium on Home Hemodialysis》2019,23(4):479-485
Introduction: Compared to traditional in‐center hemodialysis (HD), in‐center nocturnal dialysis (INHD) is characterized by longer sessions and nighttime administration, which may lead to better outcomes for some patients. Given the importance of patient choice in the decision to initiate INHD, we explored associations between patients’ psychosocial characteristics and their receipt of INHD. Methods: Among hemodialysis patients at a medium‐sized dialysis organization, we identified INHD patients as those for whom ≥80% of dialysis sessions were INHD sessions—starting at 6:30 pm or later and lasting ≥5 hours—over the 3 months (≥20 sessions total) after their first INHD session. We extracted dialysis session data from electronic medical records and psychosocial data from social worker assessments. We tested associations of patients’ psychosocial characteristics—as well as demographic and clinical characteristics—with INHD receipt among all hemodialysis patients (INHD and HD) in bivariate analyses and multivariable logistic regression models. Findings: Among 759 patients with complete data, we identified 47 (6.2%) as INHD patients. On average, these patients were more likely than HD patients to be employed (full‐time 10.6% vs. 5.2%; part‐time 17.0% vs. 4.2%; P < 0.001), and they were significantly less likely to require ambulatory assistance (14.9% vs. 39.6%, P < 0.001). In multivariable regressions, we found that part‐time employment (versus being unemployed) was associated with a 7.1 percentage‐point higher likelihood of being an INHD patient (P = 0.01), and the negative association with ambulatory assistance needs approached statistical significance (P = 0.056). No other psychosocial factors included in this main regression analysis were statistically significantly associated with INHD patient status. Discussion: Researchers comparing the outcomes of patients undergoing INHD versus other treatment modalities will need to account for differences in employment status—and other factors like requiring ambulatory assistance and age which may predict the ability to work—between INHD users and comparison patients to avoid bias in estimates. 相似文献
59.
Rebecca C. Feiner Isabell Kemker Lea Krutzke Ellen Allmendinger Daniel J. Mandell Norbert Sewald Stefan Kochanek Kristian M. Müller 《International journal of molecular sciences》2020,21(24)
The epidermal growth factor receptor (EGFR) plays a central role in the progression of many solid tumors. We used this validated target to analyze the de novo design of EGFR-binding peptides and their application for the delivery of complex payloads via rational design of a viral vector. Peptides were computationally designed to interact with the EGFR dimerization interface. Two new peptides and a reference (EDA peptide) were chemically synthesized, and their binding ability characterized. Presentation of these peptides in each of the 60 capsid proteins of recombinant adeno-associated viruses (rAAV) via a genetic based loop insertion enabled targeting of EGFR overexpressing tumor cell lines. Furthermore, tissue distribution and tumor xenograft specificity were analyzed with systemic injection in chicken egg chorioallantoic membrane (CAM) assays. Complex correlations between the targeting of the synthetic peptides and the viral vectors to cells and in ovo were observed. Overall, these data demonstrate the potential of computational design in combination with rational capsid modification for viral vector targeting opening new avenues for viral vector delivery and specifically suicide gene therapy. 相似文献
60.
Trisodium phosphate (TSP) has been reported to have antimicrobial activity and is approved by the U.S. Department of Agriculture for use in food processing applications. A novel (U.S. Patent 6,184,198), antimicrobial solution containing a blend of TSP, sodium bicarbonate, and sodium carbonate (TSP blend) has demonstrated effective inhibition of microbial contamination in a broad spectrum of applications. This high-resolution cold field emission scanning electron microcopy (LVSEM) investigation details structural changes and dry film formation in various classes of microbes as a mechanism for antimicrobial activity of this solution. The results showed that this TSP blend solution completely inhibited the growth of pathogenic E. coli O157:H7, and Salmonella bacteria, the mold Cryptococcus, as well as a Norwalk virus surrogate-feline calicivirus. Results by LVSEM confirmed that the antimicrobial effect was induced when encapsulating the target microbes in a high lubricity film that is formed around these organisms as the solution dries. The thickness of the film was estimated to be approximately 60 nm. 相似文献