全文获取类型
收费全文 | 249篇 |
免费 | 10篇 |
专业分类
化学工业 | 61篇 |
金属工艺 | 3篇 |
机械仪表 | 6篇 |
建筑科学 | 10篇 |
能源动力 | 3篇 |
轻工业 | 23篇 |
水利工程 | 2篇 |
石油天然气 | 2篇 |
无线电 | 11篇 |
一般工业技术 | 39篇 |
冶金工业 | 37篇 |
自动化技术 | 62篇 |
出版年
2023年 | 6篇 |
2022年 | 18篇 |
2021年 | 21篇 |
2020年 | 6篇 |
2019年 | 9篇 |
2018年 | 5篇 |
2017年 | 8篇 |
2016年 | 8篇 |
2015年 | 7篇 |
2014年 | 11篇 |
2013年 | 16篇 |
2012年 | 13篇 |
2011年 | 20篇 |
2010年 | 6篇 |
2009年 | 13篇 |
2008年 | 16篇 |
2007年 | 5篇 |
2006年 | 8篇 |
2005年 | 14篇 |
2004年 | 10篇 |
2003年 | 3篇 |
2002年 | 7篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有259条查询结果,搜索用时 15 毫秒
131.
132.
The ability to keep track of locations in a dynamic, multimodal environment is crucial for successful interactions with other people and objects. The authors investigated the existence and flexibility of spatial indexing in adults and 6-month-old infants by adapting an eye-tracking paradigm from D. C. Richardson and M. J. Spivey (2000). Multimodal events were presented in specific locations, and eye movements were measured when the auditory portion of the stimulus was presented without its visual counterpart. Experiment 1 showed that adults spatially index auditory information even when the original associated locations move. Experiments 2 and 3 showed that infants are capable of both binding multimodal events to locations and tracking those locations when they move. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
133.
Koestner Richard; Lekes Natasha; Powers Theodore A.; Chicoine Emanuel 《Canadian Metallurgical Quarterly》2002,83(1):231
The present article includes separate meta-analyses showing that self-concordance and implementation intentions are significantly positively associated with goal progress. Study I confirmed the positive relations of both self-concordance and implementation intentions to weekend goal progress. Study 2 confirmed the positive relation of self-concordance with monthly progress on New Year's resolutions but failed to find a direct benefit for implementation intentions. Both studies, however, obtained a significant interaction effect indicating that goal self-concordance and implementation intentions combined synergistically to facilitate goal progress. The article also reports a meta-analysis and results from the 2 studies that demonstrated that goal progress was associated with improved affect over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
134.
In this paper, the relationship between the Bezout and the set-theoretic approaches to left coprimeness is studied. It is shown that left coprimeness in the set-theoretic sense implies left coprimeness in the Bezout sense. In addition to these results, we investigate whether some properties for linear left coprime realizations carry over to the nonlinear case, for example we examine the relations between two left coprime realizations of the same system. 相似文献
135.
Natasha D'Souza Denise I. Skonberg David A. J. Stone Paul B. Brown 《Journal of food science》2006,71(4):S337-S342
ABSTRACT: This study investigated the long-term effects of soybean meal (SBM)-based diets on rainbow trout quality. Two levels of SBM inclusion diets, 20% and 40%, were employed and compared with a fish meal control diet. Rainbow trout were fed one of the three diets for 6 mo, then harvested and filleted. Proximate composition, color, lipid oxidation and sensory quality of the fillets were evaluated. Thiobarbituric acid reactive substances (TBARS) and headspace propanal in ground fillets stored at 4 °C were measured over a 9-d period. Tristimulus color was measured on day 2 and day 13 of refrigerated storage. Sensory evaluation included discriminatory (difference) and affective (acceptance) testing. TBARS and propanal in the trout fed the highest (40%) SBM level were significantly lower than in the control and trout fed the 20% SBM diet. Significant differences in color were also recorded during refrigerated storage. Sensory difference testing revealed a significant difference between the trout fed the 40% SBM and the control. No significant differences were observed in the acceptability ratings of trout fillets from the three different dietary treatments. 相似文献
136.
Franklin NM Rogers NJ Apte SC Batley GE Gadd GE Casey PS 《Environmental science & technology》2007,41(24):8484-8490
Metal oxide nanoparticles are finding increasing application in various commercial products, leading to concerns for their environmental fate and potential toxicity. It is generally assumed that nanoparticles will persist as small particles in aquatic systems and that their bioavailability could be significantly greater than that of larger particles. The current study using nanoparticulate ZnO (ca. 30 nm) has shown that this is not always so. Particle characterization using transmission electron microscopy and dynamic light scattering techniques showed that particle aggregation is significant in a freshwater system, resulting in flocs ranging from several hundred nanometers to several microns. Chemical investigations using equilibrium dialysis demonstrated rapid dissolution of ZnO nanoparticles in a freshwater medium (pH 7.6), with a saturation solubility in the milligram per liter range, similar to that of bulk ZnO. Toxicity experiments using the freshwater alga Pseudokirchneriella subcapitata revealed comparable toxicity for nanoparticulate ZnO, bulk ZnO, and ZnCl2, with a 72-h IC50 value near 60 microg Zn/ L, attributable solely to dissolved zinc. Care therefore needs to be taken in toxicity testing in ascribing toxicity to nanoparticles per se when the effects may be related, at least in part, to simple solubility. 相似文献
137.
Po-Jung Jimmy Huang Natasha M. Evans Chang Lu Albert Zehan Li Thorsten Dieckmann Prof. Dr. Juewen Liu 《Chembiochem : a European journal of chemical biology》2023,24(23):e202300566
We recently reported that some adenosine binding aptamers can also bind caffeine and theophylline with around 20-fold lower affinities. This discovery led to the current work to examine the cross-binding of adenosine to theophylline aptamers. For the DNA aptamer for theophylline, cross-binding to adenosine was observed, and the affinity was 18 to 38-fold lower for adenosine based on assays using isothermal titration calorimetry and ThT fluorescence spectroscopy. The binding complexes were characterized using NMR spectroscopy, and both adenosine and theophylline showed an overall similar binding structure to the DNA theophylline aptamer, although small differences were also observed. In contrast, the RNA aptamer did not show binding to adenosine, although both aptamers have very similar relative selectivity for various methylxanthines including caffeine. After a negative selection, a few new aptamers with completely different primary sequences for theophylline were obtained and they did not show binding to adenosine. Thus, there are many ways for aptamers to bind theophylline and some can have cross-binding to adenosine. In biology, theophylline, caffeine, and adenosine can bind to the same protein receptors to regulate sleep, and their binding to the same DNA motifs may suggest an early role of nucleic acids in similar regulatory functions. 相似文献
138.
Zhen Zhang Natasha Ghezawi Bingrui Li Sirui Ge Sheng Zhao Tomonori Saito Diana Hun Peng-Fei Cao 《Advanced functional materials》2021,31(4):2006298
Self-healable elastomers are extremely attractive due to their ability to prolong product lifetime. An additional function that could further expand their applications is strong adhesion force to clean and dusty surfaces. This study reports a series of autonomous self-healable and highly adhesive elastomers (ASHA-Elastomer) that are fabricated via a simple, efficient, and scalable process. The obtained elastomers exhibit outstanding mechanical properties with elongation at break up to 2102% and toughness (modulus of toughness) of 1.73 MJ m–3. The damaged ASHA-Elastomer can autonomously self-heal with full recovery of functionalities, and the healing process is not affected by the presence of water. The elastomers are found to possess an ultrahigh adhesion force up to 3488 N m−1, greatly outperforming previously reported self-healing adhesive elastomers. Furthermore, the adhesion force of the ASHA-Elastomer is negligibly affected by dust on the surface, in stark contrast with regular adhesive polymers that have adhesion strengths extremely sensitive to dust. The successful development of high-toughness, autonomous self-healable, and ultra-adhesive elastomers will enable a wide range of applications with enhanced longevity and versatility, including their use in sealants, adhesives, and stretchable devices. 相似文献
139.
140.
Caroline C. C. Hulsker Mariëtte E. G. Kranendonk Thomas F. Eleveld Ad J. M. Gillis Cornelis P. van de Ven Natasha K. A. van Eijkelenburg Niels P. van der Kaaij Alida F. W. van der Steeg Leendert H. J. Looijenga 《International journal of molecular sciences》2021,22(17)
Background and case: An adolescent male presented with a second mediastinal tumor 1.5 years after treatment of a proven malignant germ-cell tumor in that location. The differential diagnosis included a recurrent germ-cell tumor or a non-germ cell malignancy. Serum tumor markers alpha-fetoprotein (AFP) and human chorionic gonadotrophin (HCG) were negative. The first biopsy was not informative, and the second biopsy gave a broad differential diagnosis including secondary non-germ cell malignancy using histology and immunohistochemistry. DNA methylation profiling, RNA sequencing, and targeted microRNA371a-3p profiling was subsequently performed, without a supportive result. After resection of the tumor the definitive diagnosis yielded two secondary non-germ cell malignancies in the form of a leiomyosarcoma and a solitary neuro endocrine carcinoma (NEC). In spite of the differences between the molecular profiles of the initial germ-cell tumor, the leiomyosarcoma and large-cell NEC are clonally related, as determined by the presence of identical chromosomal breakpoints. The copy number profiles suggest an initial polyploidization step, followed by various independent chromosomal gains and losses. This case demonstrates that germ-cell tumors must be evaluated carefully, including molecularly, in which the non-germ cell malignancy is negative for miR-371a-3p, both in tissue as well as in serum, in contrast to the primary tumor. We conclude that the patient presented with a primary type II mediastinal GCT and, a year and a half later, followed by a leiomyosarcoma and a large-cell NEC presenting as two secondary somatic-type malignancies clonally related to the original GCT. Conclusions: Malignant germ-cell tumors are known to recur as a somatic-type malignancy in very rare cases. This case report illustrates the challenges faced in defining the nature and clonality of the secondary somatic-type malignancies. 相似文献