全文获取类型
收费全文 | 391篇 |
免费 | 25篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 202篇 |
金属工艺 | 5篇 |
机械仪表 | 6篇 |
建筑科学 | 6篇 |
矿业工程 | 1篇 |
能源动力 | 5篇 |
轻工业 | 65篇 |
水利工程 | 4篇 |
无线电 | 26篇 |
一般工业技术 | 46篇 |
冶金工业 | 19篇 |
原子能技术 | 5篇 |
自动化技术 | 25篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 54篇 |
2021年 | 87篇 |
2020年 | 17篇 |
2019年 | 16篇 |
2018年 | 21篇 |
2017年 | 12篇 |
2016年 | 17篇 |
2015年 | 10篇 |
2014年 | 20篇 |
2013年 | 21篇 |
2012年 | 24篇 |
2011年 | 10篇 |
2010年 | 8篇 |
2009年 | 13篇 |
2008年 | 9篇 |
2007年 | 8篇 |
2006年 | 6篇 |
2005年 | 10篇 |
2004年 | 10篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 7篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1989年 | 1篇 |
排序方式: 共有417条查询结果,搜索用时 15 毫秒
91.
Magda Aleksandra Pawlicka Szymon Zmorzyski Sylwia Popek-Marciniec Agata Anna Filip 《International journal of molecular sciences》2022,23(20)
This study aimed to evaluate the safety and potential use of soy isoflavones in the treatment of skin problems, difficult-to-heal wounds and postoperative scars in women after the oncological treatment of breast cancer. The effects of different concentrations of genistein as a representative of soy isoflavonoids on MCF-7 tumor cells and BJ skin fibroblasts cultured in vitro were assessed. Genistein affects both healthy dermal BJ fibroblasts and cancerous MCF-7 cells. The effect of the tested isoflavonoid is closely related to its concentration. High concentrations of genistein destroy MCF-7 cancer cells, regardless of the exposure time, with a much greater effect on reducing cancer cell numbers at longer times (48 h). Lower concentrations of genistein (10 and 20 μM) increase the abundance of dermal fibroblasts. However, higher concentrations of genistein (50 μM and higher) are detrimental to fibroblasts at longer exposure times (48 h). Our studies indicate that although genistein shows high potential for use in the treatment of skin problems, wounds and surgical scars in women during and after breast cancer treatment, it is not completely safe. Introducing isoflavonoids to treatment requires further research into their mechanisms of action at the molecular level, taking into account genetic and immunological aspects. It is also necessary to conduct research in in vivo models, which will allow for eliminating adverse side effects of therapy. 相似文献
92.
Carmelina Daniela Anfuso Alessia Cosentino Aleksandra Agafonova Agata Zappal Giovanni Giurdanella Angela Trovato Salinaro Vittorio Calabrese Gabriella Lupo 《International journal of molecular sciences》2022,23(24)
The stria vascularis (SV) contributes to cochlear homeostasis and consists of three layers, one of which contains the blood-labyrinthic barrier (BLB), with a large number of bovine cochlear pericytes (BCPs). Cisplatin is a chemotherapeutic drug that can damage the SV and cause hearing loss. In this study, cell viability, proliferation rate, cytotoxicity and reactive oxygen species production were evaluated. The protein content of phospho-extracellular signal-regulated kinases (ERK) 1/2, total ERK 1/2, phospho-cytosolic phospholipase A2 (cPLA2), total cPLA2 and cyclooxygenase 2 (COX-2) and the release of prostaglandin E2 (PGE2) and vascular endothelial growth factor (VEGF) from BCPs were analyzed. Finally, the protective effect of platelet-derived growth factor (PDGF-BB) on BCPs treated with cisplatin was investigated. Cisplatin reduced viability and proliferation, activated ERK 1/2, cPLA2 and COX-2 expression and increased PGE2 and VEGF release; these effects were reversed by Dexamethasone. The presence of PDGF-BB during the treatment with cisplatin significantly increased the proliferation rate. No studies on cell regeneration in ear tissue evaluated the effect of the PDGF/Dex combination. The aim of this study was to investigate the effects of cisplatin on cochlear pericytes and propose new otoprotective agents aimed at preventing the reduction of their vitality and thus maintaining the BLB structure. 相似文献
93.
Domenica Nigro Stefania Fortunato Stefania Lucia Giove Elisabetta Mazzucotelli Agata Gadaleta 《International journal of molecular sciences》2020,21(23)
Durum wheat (Triticum turgidum L. ssp. durum) is a minor crop grown on about 17 million hectares of land worldwide. Several grain characteristics determine semolina’s high end-use quality, such as grain protein content (GPC) which is directly related to the final products’ nutritional and technological values. GPC improvement could be pursued by considering a candidate gene approach. The glutamine synthetase (GS)/glutamate synthase (GOGAT) cycle represents a bottleneck in the first step of nitrogen assimilation. QTL for GPC have been located on all chromosomes, and several major ones have been reported on 2A and 2B chromosomes, where GS2 and Fd-GOGAT genes have been mapped. A useful and efficient method to validate a putative QTL is the constitution of near-isogenic lines (NILs) by using the marker found to be associated to that QTL. Here, we present the development of two distinct sets of heterogeneous inbred family (HIF)- based NILs segregating for GS2 and Fd-GOGAT genes obtained from heterozygous lines at those loci, as well as their genotypic and phenotypic characterizations. The results allow the validation of the previously identified GPC QTL on 2A and 2B chromosomes, along with the role of these key genes in GPC control. 相似文献
94.
T Kuroki K Yagita E Yabuuchi K Agata T Ishima Y Katsube T Endo 《Canadian Metallurgical Quarterly》1998,72(10):1050-1055
Microbiological contamination of hot spring bath water is a public health concern. A province-wide survey was carried out to determine the extent and distribution of both Legionella and free-living amoebae contamination. Among 30 samples of hot spring bath from 12 sites in Kanagawa, Japan, L. pneumophila was detected in 21 water samples from 11 sites, ranging from 10(1)-10(3) CFU/100 ml. Serogroups 3, 5 and 6 of L. pneumophila were predominantly isolated from the samples. Naegleria (46.7%), Platyamoeba (33.3%), Acanthamoeba (10.0%) and 2 other genera of free-living amoebae were detected in 22 samples from 11 sites. One or more genera of host amoebae of Legionella occurred in 17 samples (56.7%) from 9 sites. Another thing to be noted is that 13 water samples contained N. lovaniensis. Although N. lovaniensis is nonpathogenic, it is considered an indicator organism for places that are suitable for the growth of N. fowleri, a causative agent of primary amoebic meningoencephalitis in man. 相似文献
95.
M. Niraula K. Yasuda T. Ishiguro Y. Kawauchi H. Morishita Y. Agata 《Journal of Electronic Materials》2003,32(7):728-732
The growth characteristics and crystalline quality of thick (100) CdTe-epitaxial layers grown on (100) GaAs and (100) GaAs/Si
substrates in a metal-organic vapor-phase epitaxy (MOVPE) system for possible applications in x-ray imaging detectors were
investigated. High-crystalline-quality epitaxial layers of thickness greater than 100 μm could be readily obtained on both
types of substrates. The full width at half maximum (FWHM) values of the x-ray double-crystal rocking curve (DCRC) decreased
rapidly with increasing layer thickness, and remained around 50–70 arcsec for layers thicker than 30 μm on both types of substrates.
Photoluminescence (PL) measurement showed high-intensity excitonic emission with very small defect-related peaks from both
types of epilayers. Stress analysis carried out by performing PL as a function of layer thickness showed the layers were strained
and a small amount of residual stress, compressive in CdTe/GaAs and tensile in CdTe/GaAs/Si, remained even in the thick layers.
Furthermore, the resistivity of the layers on the GaAs substrate was found to be lower than that of layers on GaAs/Si possibly
because of the difference of the activation of incorporated impurity from the substrates because of the different kinds of
stress existing on them. A heterojunction diode was then fabricated by growing a CdTe epilayer on an n+-GaAs substrate, which exhibited a good rectification property with a low value of reverse-bias leakage current even at high
applied biases. 相似文献
96.
Pawel Stoch Małgorzata Ciecińska Agata Stoch Łukasz Kuterasiński Ireneusz Krakowiak 《Ceramics International》2018,44(1):728-734
In the paper process of sintering of hospital incineration ash as a counterpart of low-level active waste with borosilicate glass frit is presented. It is shown that low porosity glass-ceramic waste-form can be obtained at a temperature range of 850–900 °C. In the sinter, the main crystal phases are wollastonite and aegirine-augite pyroxenes which have a large isomorphous capacity of binding hazardous elements. The crystal phases are fully encapsulated by the glass that provides additional protection against environmental influence. Thus, multibarrier material can be obtained at a temperature considerably lower than vitrification. This, in turn, can improve the economics of immobilization process. 相似文献
97.
Agata Błachnio Aneta Przepiórka Patrycja Rudnicka 《International journal of human-computer interaction》2013,29(11):775-787
In recent years, Facebook has become the most popular of social networking sites (SNSs). Due to its increasing popularity and rising number of its users, the phenomenon of Facebook has aroused academic interest as well. There has been a growing number of studies on this subject. The aim of this article is to present the main trends in Facebook research and to provide an overview of major empirical findings. Among the most intensively explored topics in Facebook research, studies that concentrate on personality and individual differences among users, the role of self-efficacy, and motivation for using that specific SNS were identified. There is also a growing trend in empirical studies that focuses on testing advanced theoretical models of Facebook usage determinants. Technology acceptance model, presented in this article, is one of the most often used among them. This kind of approach may serve as a suggestion for a methodological conceptualization in the future confirmatory research on Facebook. 相似文献
98.
The influence of two PVAs of the same molecular weight (13,000–23,000) and different degree of hydrolysis equal to 88% and 98% on breakage and coalescence of toluene droplets in the liquid/liquid dispersion were considered for PVA concentration range 0.001–0.01%. Analysis of experimental results shows that drop coalescence is significant only in the system containing 0.001% PVA. Drop coalescence for polymer concentration range 0.002–0.01% is strongly limited. Therefore, population balance was solved using breakage and coalescence expressions with assumed partially mobile drop interfaces for the lowest PVA concentration. For c ≥ 0.002% drop size distributions were properly predicted using only breakage model. Multifractal formalism was used to take into account intermittent character of turbulence and explain drop behavior. Larger drop size reduction by PVA of lower degree of hydrolysis observed experimentally was confirmed by the model. 相似文献
99.
ABSTRACT An inexpensive and easy-to-build vacuum furnace capable of reaching temperatures in the 1000°C-1350°C region (with modifications the upper limit can be extended) at pressures of 10?7 torr has been constructed. This furnace has been found to be very useful in the preparation of melts where sample purity and safe working conditions are considerations. 相似文献
100.
Agata Skwarek Mariusz Pluska Andrzej Czerwinski Krzysztof Witek 《Materials Science and Engineering: B》2012,177(15):1286-1291
This paper describes variations in whisker growth on the surface of tin-rich, lead-free alloys soldered on a Cu layer depending on the laminate used for the printed circuit board, which can be either glass-epoxy or paper-phenol. The structure of the glass-epoxy laminate surface is characterized by spatial nonuniformity caused by the regular structure formed by regions of glass fibers and resin in the top layer of the laminate. The higher value of thermal expansion of the resin than of the glass fiber means that the area of the resin expands more than that of the glass fiber. This causes local compressive stress in the solder layer and as a result promotes whisker growth in the area of the alloy soldered on the Cu layer over the glass fiber. This effect does not occur on the surface of an alloy soldered on Cu layer over a paper-phenol laminate. 相似文献