全文获取类型
收费全文 | 347篇 |
免费 | 32篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 86篇 |
金属工艺 | 3篇 |
机械仪表 | 5篇 |
建筑科学 | 20篇 |
能源动力 | 5篇 |
轻工业 | 77篇 |
水利工程 | 6篇 |
石油天然气 | 4篇 |
无线电 | 16篇 |
一般工业技术 | 56篇 |
冶金工业 | 44篇 |
原子能技术 | 1篇 |
自动化技术 | 53篇 |
出版年
2023年 | 1篇 |
2022年 | 16篇 |
2021年 | 27篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 13篇 |
2017年 | 8篇 |
2016年 | 9篇 |
2015年 | 17篇 |
2014年 | 17篇 |
2013年 | 28篇 |
2012年 | 13篇 |
2011年 | 24篇 |
2010年 | 18篇 |
2009年 | 20篇 |
2008年 | 20篇 |
2007年 | 16篇 |
2006年 | 9篇 |
2005年 | 7篇 |
2004年 | 4篇 |
2003年 | 7篇 |
2002年 | 4篇 |
2001年 | 7篇 |
2000年 | 9篇 |
1999年 | 6篇 |
1998年 | 15篇 |
1997年 | 11篇 |
1996年 | 11篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 3篇 |
排序方式: 共有379条查询结果,搜索用时 15 毫秒
71.
The drying of raw cured ham proceeds under natural convection. The aim of this work was to determine the effect of external resistance on the drying of frozen and salted Biceps femoris and Semimembranosus. Natural convection drying kinetics were obtained at 5, 10, 15, and 20°C. The De values obtained neglecting external resistance were underestimated. Activation energy, Ea, agreed with literature results. The use of a De value from literature and a calculated Ea allowed us to calculate De for the temperatures used in this study. The mass transfer coefficient (k) was estimated from a model taking external resistance and the calculated De into account. The k values agreed with the ones in literature; thus, under natural convection conditions, external mass transfer resistance must be considered. 相似文献
72.
Clemente C. Moredo Jr Tomoyasu Sakuno Toshinari Kawada 《The Journal of Adhesion》2013,89(1-4):183-195
Apitong (Dipterocarpus spp.) and Caribbean pine (Pinus caribaea Morelet) contain high amounts of extractives that contribute to poor bonding. To reduce, if not to eliminate, the effects of these extraneous substances, surfaces of small wood blocks were Soxhlet-extracted for 8 hours by different solvents. Wettability of the wood surfaces was then measured by droplet and dynamic methods using water and dilute NaOH as liquids. Tensile shear strengths of extracted wood bonded with aqueous vinyl polymer isocyanate (API), resorcinol formaldehyde (RF) and polyvinyl acetate (PVAc) resin adhesives were also measured. Results revealed that although Caribbean pine had much higher resin content than Apitong, the former had better wettability than the latter. Solvent extraction of the adherend with either hexane or ethanol-benzene (1:2) for 8 hours was not enough to improve its wettability but enough to improve its gluability. However, successive extraction with hexane, methanol and ethanol benzene rendered the wood satisfactorily wettable. Generally, a direct relationship between wettability and bond strength could not be observed. In a separate experiment to improve bonding strengths, test specimens were either overheated or autoclaved for 4 minutes at 125°C during the pressing period. Autoclave treatment was found to be useful in increasing the bond strengths of API, RF, PVAc and urea formaldehyde (UF)-bonded Apitong and Caribbean pine. 相似文献
73.
Massimo Concetti Lorenzo Fedele Giampiero Mercuri 《Reliability Engineering & System Safety》2009,94(1):63-77
The management of technical plant for productivity and safety is generally a complex activity, particularly when many plants distributed in the territory are considered (i.e. the more and more frequent case of outsourced plants maintenance by specialized companies), granted quality and cost results are required (i.e. the case of some rather innovative contract solutions) and the technology involved is heterogeneous and innovative (i.e. electro-mechanical plants).In order to efficiently achieve the above aims an “intelligent” maintenance-management system for the distant monitoring and controlling by a remote control center has been developed. The so-called GrAMS (granted availability management system) system is conceived to give to organizations involved in technical-industrial plants management the possibility to tend to a “well-known availability” and “zero-failures” management.In particular, this study deals with the diagnostic aspects and safety level of technical plants (such as elevators, thermo-technical plants, etc.), and with the involvement of ad hoc designed software analysis tools based on neural networks and reliability indicators.Part of the research dealing with the tele-maintenance intelligent system has been financed by the Italian High Institute for Safety (ISPESL) and led to the development of a pre-industrial prototype whose realization and testing is here described. 相似文献
74.
Nieves Sanjuán Gabriela Clemente José Bon Antonio Mulet 《European Food Research and Technology》2001,213(6):474-479
Different blanching treatments were applied to broccoli florets prior to dehydration in order to improve product quality. The pretreatments used were a conventional blanching in water at 99ǃ °C, and a stepwise blanching (a blanching at low temperature followed by a short blanching at high temperature after a holding time) using different temperatures for the first step (50, 55, 60, 65 and 70 °C). Five rehydration temperatures were used (25, 40, 55, 65 and 80 °C). Rehydration rate (Deff and We), chlorophyll content and texture of the rehydrated product were evaluated. Rehydration was modelled according to Fick's diffusion equation. A good agreement between the model and the experimental data was obtained when Deff and We values were identified for each temperature (average explained variance 96.9%). Samples stepwise blanched at 60 °C showed, on the average, the lowest We values. Stepwise blanching at 60-65 °C and rehydration at 25-55 °C were the combinations that gave the firmest product. Stepwise blanching at 50 °C together with the conventional blanching (99ǃ °C) and rehydration between 25 and 65 °C were the combinations that allowed preservation of the highest chlorophyll content. From these results, it seems difficult to obtain firm samples with a high chlorophyll content without additives. 相似文献
75.
Marianna Barbalinardo Marta Giannelli Ludovica Forcini Barbara Luppi Anna Donnadio Maria Luisa Navacchia Giampiero Ruani Giovanna Sotgiu Annalisa Aluigi Roberto Zamboni Tamara Posati 《International journal of molecular sciences》2022,23(12)
Skin disorders are widespread around the world, affecting people of all ages, and oxidative stress represents one of the main causes of alteration in the normal physiological parameters of skin cells. In this work, we combined a natural protein, fibroin, with antioxidant compounds extracted in water from pomegranate waste. We demonstrate the effective and facile fabrication of bioactive and eco-sustainable films of potential interest for skin repair. The blended films are visually transparent (around 90%); flexible; stable in physiological conditions and in the presence of trypsin for 12 days; able to release the bioactive compounds in a controlled manner; based on Fickian diffusion; and biocompatible towards the main skin cells, keratinocytes and fibroblasts. Furthermore, reactive oxygen species (ROS) production tests demonstrated the high capacity of our films to reduce the oxidative stress induced in cells, which is responsible for various skin diseases. 相似文献
76.
Veronica Conti Claudio Cantini Marco Romi Maria Michela Cesare Luigi Parrotta Stefano Del Duca Giampiero Cai 《International journal of molecular sciences》2022,23(10)
Future climate scenarios suggest that crop plants will experience environmental changes capable of affecting their productivity. Among the most harmful environmental stresses is drought, defined as a total or partial lack of water availability. It is essential to study and understand both the damage caused by drought on crop plants and the mechanisms implemented to tolerate the stress. In this study, we focused on four cultivars of tomato, an economically important crop in the Mediterranean basin. We investigated the biochemical mechanisms of plant defense against drought by focusing on proteins specifically involved in this stress, such as osmotin, dehydrin, and aquaporin, and on proteins involved in the general stress response, such as HSP70 and cyclophilins. Since sugars are also known to act as osmoprotectants in plant cells, proteins involved in sugar metabolism (such as RuBisCO and sucrose synthase) were also analyzed. The results show crucial differences in biochemical behavior among the selected cultivars and highlight that the most tolerant tomato cultivars adopt quite specific biochemical strategies such as different accumulations of aquaporins and osmotins. The data set also suggests that RuBisCO isoforms and aquaporins can be used as markers of tolerance/susceptibility to drought stress and be used to select tomato cultivars within breeding programs. 相似文献
77.
Lavinia Mareri Luigi Parrotta Giampiero Cai 《International journal of molecular sciences》2022,23(10)
Land plants are constantly subjected to multiple unfavorable or even adverse environmental conditions. Among them, abiotic stresses (such as salt, drought, heat, cold, heavy metals, ozone, UV radiation, and nutrient deficiencies) have detrimental effects on plant growth and productivity and are increasingly important considering the direct or indirect effects of climate change. Plants respond in many ways to abiotic stresses, from gene expression to physiology, from plant architecture to primary, and secondary metabolism. These complex changes allow plants to tolerate and/or adapt to adverse conditions. The complexity of plant response can be further influenced by the duration and intensity of stress, the plant genotype, the combination of different stresses, the exposed tissue and cell type, and the developmental stage at which plants perceive the stress. It is therefore important to understand more about how plants perceive stress conditions and how they respond and adapt (both in natural and anthropogenic environments). These concepts were the basis of the Special Issue that International Journal of Molecular Sciences expressly addressed to the relationship between environmental stresses and plants and that resulted in the publication of 5 reviews and 38 original research articles. The large participation of several authors and the good number of contributions testifies to the considerable interest that the topic currently receives in the plant science community, especially in the light of the foreseeable climate changes. Here, we briefly summarize the contributions included in the Special Issue, both original articles categorized by stress type and reviews that discuss more comprehensive responses to various stresses. 相似文献
78.
Ian Stoppa Casimiro Luca Gigliotti Nausicaa Clemente Deepika Pantham Chiara Dianzani Chiara Monge Chiara Puricelli Roberta Rolla Salvatore Sutti Filippo Ren Renzo Boldorini Elena Boggio Umberto Dianzani 《International journal of molecular sciences》2022,23(13)
Background: ICOS and its ligand ICOSL are immune receptors whose interaction triggers bidirectional signals that modulate the immune response and tissue repair. Aim: The aim of this study was to assess the in vivo effects of ICOSL triggering by ICOS-Fc, a recombinant soluble form of ICOS, on skin wound healing. Methods: The effect of human ICOS-Fc on wound healing was assessed, in vitro, and, in vivo, by skin wound healing assay using ICOS−/− and ICOSL−/− knockout (KO) mice and NOD-SCID-IL2R null (NSG) mice. Results: We show that, in wild type mice, treatment with ICOS-Fc improves wound healing, promotes angiogenesis, preceded by upregulation of IL-6 and VEGF expression; increases the number of fibroblasts and T cells, whereas it reduces that of neutrophils; and increases the number of M2 vs. M1 macrophages. Fittingly, ICOS-Fc enhanced M2 macrophage migration, while it hampered that of M1 macrophages. ICOS−/− and ICOSL−/− KO, and NSG mice showed delayed wound healing, and treatment with ICOS-Fc improved wound closure in ICOS−/− and NSG mice. Conclusion: These data show that the ICOS/ICOSL network cooperates in tissue repair, and that triggering of ICOSL by ICOS-Fc improves cutaneous wound healing by increasing angiogenesis and recruitment of reparative macrophages. 相似文献
79.
Bornmann Lutz Mutz Rüdiger Haunschild Robin de Moya-Anegon Felix de Almeida Madeira Clemente Mirko Stefaner Moritz 《Scientometrics》2021,126(11):9305-9331
Scientometrics - In over five years, Bornmann, Stefaner, de Moya Anegon, and Mutz (2014b) and Bornmann, Stefaner, de Moya Anegón, and Mutz (2014c, 2015) have published several releases of the... 相似文献
80.
Carbon dioxide (CO2), a vital molecule of the carbon cycle, is a critical component in living organisms’ metabolism, performing functions that lead to the building of compounds fundamental for the life cycle. In all living organisms, the CO2/bicarbonate (HCO3−) balancing is governed by a superfamily of enzymes, known as carbonic anhydrases (CAs, EC 4.2.1.1). CAs catalyze the pivotal physiological reaction, consisting of the reversible hydration of the CO2 to HCO3− and protons. Opportunistic and pathogenic fungi can sense the environmental CO2 levels, which influence their virulence or environmental subsistence traits. The fungal CO2-sensing is directly stimulated by HCO3− produced in a CA-dependent manner, which directly activates adenylyl cyclase (AC) involved in the fungal spore formation. The interference with CA activity may impair fungal growth and virulence, making this approach interesting for designing antifungal drugs with a novel mechanism of action: the inhibition of CAs linked to the CO2/HCO3−/pH chemosensing and signaling. This review reports that sulfonamides and their bioisosteres as well as inorganic anions can inhibit in vitro the β- and α-CAs from the fungi, suggesting how CAs may be considered as a novel “pathogen protein” target of many opportunistic, pathogenic fungi. 相似文献