全文获取类型
收费全文 | 1102篇 |
免费 | 88篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 7篇 |
综合类 | 3篇 |
化学工业 | 577篇 |
金属工艺 | 7篇 |
机械仪表 | 19篇 |
建筑科学 | 29篇 |
能源动力 | 27篇 |
轻工业 | 141篇 |
水利工程 | 4篇 |
石油天然气 | 1篇 |
无线电 | 83篇 |
一般工业技术 | 181篇 |
冶金工业 | 26篇 |
原子能技术 | 2篇 |
自动化技术 | 84篇 |
出版年
2024年 | 2篇 |
2023年 | 20篇 |
2022年 | 173篇 |
2021年 | 177篇 |
2020年 | 38篇 |
2019年 | 36篇 |
2018年 | 47篇 |
2017年 | 29篇 |
2016年 | 55篇 |
2015年 | 40篇 |
2014年 | 53篇 |
2013年 | 70篇 |
2012年 | 56篇 |
2011年 | 89篇 |
2010年 | 47篇 |
2009年 | 38篇 |
2008年 | 36篇 |
2007年 | 30篇 |
2006年 | 27篇 |
2005年 | 26篇 |
2004年 | 21篇 |
2003年 | 10篇 |
2002年 | 9篇 |
2001年 | 6篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有1191条查询结果,搜索用时 0 毫秒
181.
Patrizia Restani Francesca Uberti Chiara Tarantino Cinzia Ballabio Francesca Gombac Erica Bastiani Laura Bolognini Francesco Pavanello Roberta Danzi 《Food Analytical Methods》2012,5(3):480-486
The clarification or fining of wine removes undesirable substances such as proteins, phenols, and tannin compounds that would
cloud the wine and cause bitterness and astringency. Caseinates have useful fining properties, but their residues could present
a risk for allergic subjects. A commercial kit that was developed to detect caseinates in food has been examined for its applicability
to a wine matrix; it is sensitive to caseinates at concentrations as low as 1 ppm. The general characteristics of the caseinate
assay, described below in detail, are as follows. It is a sandwich enzyme-linked immunosorbent assay (ELISA): the microplate
is first coated with a specific anti-casein antibody; and after incubation with the wine sample, a secondary anti-casein antibody
conjugated with horseradish peroxidase is added to form a sandwich. The antibodies have been tested for their immunoreactivity
and the reproducibility of antigen recognition has been measured. An interlaboratory collaborative trial was organized to
evaluate the performance of this ELISA method and its ease of use by laboratories routinely dealing with wine/food analyses.
The results satisfy the criteria established by the International Organisation of Vine and Wine in the Compendium of International
Methods of Analysis MA-EAS1-07-ETCOL. 相似文献
182.
Marica Consolini Michela Sega Chiara Zanetti Marina Fusi Roberto Chignola Marco De Carli Corrado Rizzi Gianni Zoccatelli 《Food Analytical Methods》2012,5(2):234-243
Wheat α-amylase inhibitors (α-AIs) are known anti-nutritional factors, respiratory allergens, and they can sporadically cause
food allergy. α-AIs are therefore expected to reach the enteric mucosae in an immunologically active form, but information
on their stability to gastric digestion is not available. Resistance to pepsinolysis is nonetheless a key factor for any food
allergen. We therefore investigated whether α-AIs could resist pepsin digestion in simulated gastric fluids (SGF) and in emulsified
SGF, the latter simulating more realistically the multi-phase nature of stomach bolus. Since α-AIs comprise a huge family
of proteins, we investigated 0.19 α-AI as a prominent member. The digestion patterns were analyzed by immunoblotting using
anti-0.19 polyclonal antibodies and sera from wheat allergic patients sensitized to 0.19 α-AI. The results show that the immune
epitopes of α-AI are detectable up to 120 min of digestion in emulsifying conditions. Intra-molecular disulfide bonds and,
in particular, emulsification were found to be crucial factors for protein stability. The results show that 0.19 α-AI must
be considered a potential food allergen. 相似文献
183.
Chiara Tognoli Marco Saroglia Genciana Terova Rosalba Gornati Giovanni Bernardini 《Food chemistry》2011
The 5S ribosomal RNA is a very suitable target for easy, rapid and inexpensive fish species identification due to its structure, consisting of a conserved region followed by a species-specific noncoding region called ‘nontranscribed spacer’. We have exploited this species-specificity in length and sequence to discriminate among fish species which can be subjected to substitution in the fish markets. After sequencing and alignment of the corresponding portions of the 5S rRNAs of different fish species, we have designed the primer pairs necessary for PCR amplification on the DNA traits which most diverged and a primer pair on conserved regions. Our results have shown the feasibility, simplicity and reliability of the proposed approach for the detection of mislabelling or fraudulent substitution of fish species. 相似文献
184.
AbstractThis study considers the decay heat removal through passive systems (i.e., natural convection) in the pool-type experimental reactor MYRRHA (SCK?CEN). The low velocities associated with natural convection may cause a degradation of the thermal mixing in the upper plenum of the reactor: buoyancy dominated phenomena, such as stratification, buoyant jets or convective cells may occur. The large temperature gradients associated with these phenomena may induce thermal loads on the structure, compromising its integrity. The objectives of this work are, in order, (1) achieving an understanding of the fluid mechanics leading to the formation of thermal gradients in the upper plenum and (2) mitigating the temperature gradients the upper plenum’s geometry. The methodology chosen to address the problem is experimental. A ''two-dimensional'' water facility modeling a slab of the reactor's primary loop was designed. Simultaneous measurements of velocity and temperature were performed in the model's buffer tank using thermocouples and innovative optical imaging techniques. It was observed that vertical thermal gradients develop in the tank because of the combined effect of stratification and advection. Important reductions of local gradients were observed when changing porosity and position of upper plenum’s buffer plates. 相似文献
185.
Cabibbo Marcello Fava Alessandra Montanari Roberto Pakhomova Ekaterina Paoletti Chiara Richetta Maria Varone Alessandra 《Journal of Materials Science》2022,57(1):285-298
Journal of Materials Science - One of the big challenges for realizing future nuclear fusion reactors is the development of materials able to withstand the high thermal loads and particle fluxes... 相似文献
186.
Silvan Gantenbein Chiara Mascolo Caroline Houriet Robert Zboray Antonia Neels Kunal Masania André R. Studart 《Advanced functional materials》2021,31(52):2104574
Fiber-reinforced polymers are widely used as lightweight materials in aircraft, automobiles, wind turbine blades, and sports products. Despite the beneficial weight reduction achieved in such applications, these composites often suffer from poor recyclability and limited geometries. 3D printing of liquid crystal polymers into complex-shaped all-fiber materials is a promising approach to tackle these issues and thus increase the sustainability of current lightweight structures. Here, we report a spin-printing technology for the manufacturing of recyclable and strong all-fiber lightweight materials. All-fiber architectures are created by combining thick print lines and thin spun fibers as reinforcing elements in bespoke orientations. Through controlled extrusion experiments and theoretical analyses, we systematically study the spinning process and establish criteria for the generation of thin fibers and laminates with unprecedented mechanical properties. The potential of the technology is further illustrated by creating complex structures with unique all-fiber architectures and mechanical performance. 相似文献
187.
Antonio Brogi Chiara Renso Franco Turini 《Computer Languages, Systems and Structures》1999,25(4):417-242
We present a logic-based programming language that features meta-level composition operations over programs. Object programs are parameterised named collections of definite clauses which may contain formulae of the form A in Pexp, where A is a standard atomic formula and Pexp is a program expression obtained by applying composition operations over named object programs. The semantics of the language is presented in two different equivalent styles. An operational, top-down semantics is given by means of inference rules, while a denotational, bottom-up semantics is given via an immediate consequence operator associated with program expressions. A meta-programming implementation of the language is also presented by transforming the operational inference rules into meta-level axioms. Several programming examples are discussed to illustrate the expressive power of the language. 相似文献
188.
John Charles Rotondo Chiara Mazziotta Carmen Lanzillotti Mauro Tognon Fernanda Martini 《International journal of molecular sciences》2021,22(21)
Merkel cell polyomavirus (MCPyV) is a small DNA virus with oncogenic potential. MCPyV is the causative agent of Merkel Cell Carcinoma (MCC), a rare but aggressive tumor of the skin. The role of epigenetic mechanisms, such as histone posttranslational modifications (HPTMs), DNA methylation, and microRNA (miRNA) regulation on MCPyV-driven MCC has recently been highlighted. In this review, we aim to describe and discuss the latest insights into HPTMs, DNA methylation, and miRNA regulation, as well as their regulative factors in the context of MCPyV-driven MCC, to provide an overview of current findings on how MCPyV is involved in the dysregulation of these epigenetic processes. The current state of the art is also described as far as potentially using epigenetic dysregulations and related factors as diagnostic and prognostic tools is concerned, in addition to targets for MCPyV-driven MCC therapy. Growing evidence suggests that the dysregulation of HPTMs, DNA methylation, and miRNA pathways plays a role in MCPyV-driven MCC etiopathogenesis, which, therefore, may potentially be clinically significant for this deadly tumor. A deeper understanding of these mechanisms and related factors may improve diagnosis, prognosis, and therapy for MCPyV-driven MCC. 相似文献
189.
190.
Chiara Di Berardino Alessia Peserico Giulia Capacchietti Martina Crociati Maurizio Monaci Umberto Tosi Annunziata Mauro Valentina Russo Nicola Bernab Barbara Barboni 《International journal of molecular sciences》2021,22(22)
The use of assisted reproductive technologies (ART) still requires strategies through which to maximize individual fertility chances. In vitro folliculogenesis (ivF) may represent a valid option to convey the large source of immature oocytes in ART. Several efforts have been made to set up ivF cultural protocols in medium-sized mammals, starting with the identification of the most suitable gonadotropic stimulus. In this study, Equine Chorionic Gonadotropin (eCG) is proposed as an alternative to Follicle Stimulating Hormone (FSH) based on its long superovulation use, trans-species validation, long half-life, and low costs. The use of 3D ivF on single-ovine preantral (PA) follicles allowed us to compare the hormonal effects and to validate their influence under two different cultural conditions. The use of eCG helped to stimulate the in vitro growth of ovine PA follicles by maximizing its influence under FBS-free medium. Higher performance of follicular growth, antrum formation, steroidogenic activity and gap junction marker expression were recorded. In addition, eCG, promoted a positive effect on the germinal compartment, leading to a higher incidence of meiotic competent oocytes. These findings should help to widen the use of eCG to ivF as a valid and largely available hormonal support enabling a synchronized in vitro follicle and oocyte development. 相似文献