全文获取类型
收费全文 | 1495篇 |
免费 | 112篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 536篇 |
金属工艺 | 20篇 |
机械仪表 | 32篇 |
建筑科学 | 38篇 |
矿业工程 | 1篇 |
能源动力 | 49篇 |
轻工业 | 382篇 |
水利工程 | 10篇 |
石油天然气 | 6篇 |
无线电 | 62篇 |
一般工业技术 | 206篇 |
冶金工业 | 83篇 |
原子能技术 | 11篇 |
自动化技术 | 168篇 |
出版年
2024年 | 6篇 |
2023年 | 19篇 |
2022年 | 60篇 |
2021年 | 114篇 |
2020年 | 46篇 |
2019年 | 56篇 |
2018年 | 41篇 |
2017年 | 48篇 |
2016年 | 57篇 |
2015年 | 57篇 |
2014年 | 58篇 |
2013年 | 119篇 |
2012年 | 87篇 |
2011年 | 111篇 |
2010年 | 88篇 |
2009年 | 93篇 |
2008年 | 93篇 |
2007年 | 62篇 |
2006年 | 51篇 |
2005年 | 39篇 |
2004年 | 36篇 |
2003年 | 30篇 |
2002年 | 22篇 |
2001年 | 23篇 |
2000年 | 16篇 |
1999年 | 19篇 |
1998年 | 16篇 |
1997年 | 11篇 |
1996年 | 7篇 |
1995年 | 9篇 |
1994年 | 9篇 |
1993年 | 11篇 |
1992年 | 11篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 8篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 9篇 |
1980年 | 6篇 |
1979年 | 4篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1971年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有1609条查询结果,搜索用时 31 毫秒
1.
Casalaro Giuseppina Lucia Cattivera Giulio Ciccozzi Federico Malavolta Ivano Wortmann Andreas Pelliccione Patrizio 《Software and Systems Modeling》2022,21(1):19-49
Software and Systems Modeling - Mobile robots operate in various environments (e.g. aquatic, aerial, or terrestrial), they come in many diverse shapes and they are increasingly becoming parts of... 相似文献
2.
3.
Jincy Joy Jessica Pereira Rachida Aid‐Launais Graciela Pavon‐Djavid Alok R Ray Didier Letourneur Anne Meddahi‐Pell Bhuvanesh Gupta 《Polymer International》2019,68(7):1367-1377
The work reported involved the fabrication of an electrospun tubular conduit of a gelatin and polycaprolactone (PCL) blend as an adventitia‐equivalent construct. Gelatin was included as the matrix for increased biocompatibility with the addition of PCL for durability. This is contrary to most of the literature available for biomaterials based on blends of gelatin and PCL where PCL is the major matrix. The work includes the assiduous selection of key electrospinning parameters to obtain smooth bead‐free fibres with a narrow distribution of pore size and fibre diameter. Few reports elucidate the optimization of all electrospinning parameters to fabricate tubular conduits with a focus on obtaining homogeneous pores and fibres. This stepwise investigation would be unique for the fabrication of gelatin–PCL electrospun tubular constructs. The fabricated microfibrous gelatin–PCL constructs had pores of size ca 50–100 μm reportedly conducive for cell infiltration. The measured value of surface roughness of 57.99 ± 17.4 nm is reported to be favourable for protein adhesion and cell adhesion. The elastic modulus was observed to be similar to that of the tunica adventitia of the native artery. Preliminary in vitro and in vivo biocompatibility tests suggest safe applicability as a biomaterial. Minimal cytotoxicity was observed using MTT assay. Subcutaneous implantation of the scaffold demonstrated acute inflammation which decreased by day 15. The findings of this study could enable the fabrication of smooth bead‐free microfibrous gelatin–PCL tubular construct as viable biomaterial which can be included in a bilayer or a trilayer scaffold for vascular tissue engineering. © 2019 Society of Chemical Industry 相似文献
4.
Maria Luisa Calabr Nayana Lazzari Giulia Rigotto Marco Tonello Antonio Sommariva 《International journal of molecular sciences》2020,21(23)
The mechanisms by which neoplastic cells disseminate from the primary tumor to metastatic sites, so-called metastatic organotropism, remain poorly understood. Epithelial–mesenchymal transition (EMT) plays a role in cancer development and progression by converting static epithelial cells into the migratory and microenvironment-interacting mesenchymal cells, and by the modulation of chemoresistance and stemness of tumor cells. Several findings highlight that pathways involved in EMT and its reverse process (mesenchymal–epithelial transition, MET), now collectively called epithelial–mesenchymal plasticity (EMP), play a role in peritoneal metastases. So far, the relevance of factors linked to EMP in a unique peritoneal malignancy such as pseudomyxoma peritonei (PMP) has not been fully elucidated. In this review, we focus on the role of epithelial–mesenchymal dynamics in the metastatic process involving mucinous neoplastic dissemination in the peritoneum. In particular, we discuss the role of expression profiles and phenotypic transitions found in PMP in light of the recent concept of EMP. A better understanding of EMP-associated mechanisms driving peritoneal metastasis will help to provide a more targeted approach for PMP patients selected for locoregional interventions involving cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. 相似文献
5.
6.
María Clara Verdi Constanza Melian Patricia Castellano Graciela Vignolo Mariana Blanco Massani 《International Journal of Food Science & Technology》2020,55(1):267-275
The effectiveness of antimicrobial mixtures against Listeria innocua 7, used as a L. monocytogenes surrogate, was investigated in broth and a food system. Synergistic effects were found for nisin (Nis), potassium sorbate (PS), calcium propionate (CP) and sodium lactate (SL), Nis + PS being the most effective binary mixture that exhibited listericidal activity in broth. To assess the effect of adding lactocin AL705 (AL705) to Nis + organic acid salt combinations, tridimensional isobolograms were generated. Sub-MIC combinations of the antimicrobials exerted bactericidal activity against L. innocua 7 after AL705 addition to the binary mixtures. However, when applied on Sardo cheese contaminated with L. innocua 7 (initial inoculum 4.45 ± 0.06 CFU g−1), only Nis + PS + AL705 produced count reductions respect to the control, reaching 3.04 ± 0.35 CFU g−1 counts after 15 days at 15 °C. Ternary combinations containing AL705 showed potential to reduce antimicrobial usages for L. innocua 7 inhibition. 相似文献
7.
The fission yeast Schizosaccharomyces pombe is an important model organism for the study of fundamental questions in eukaryotic cell and molecular biology. A plethora of cellular processes are membrane associated and/or dependent on the proper functioning of cellular membranes. Phospholipids are not only the basic building blocks of cellular membranes; they also serve as precursors to numerous signaling molecules. In this review, we describe the biosynthetic pathways leading to major S. pombe phospholipids, how these pathways are regulated, and what is known about degradation and turnover of fission yeast phospholipids. This review also addresses the synthesis, regulation and the role of water-soluble phospholipid precursors. The last chapter of the review is devoted to the use of S. pombe for the biotechnological production of value-added lipid molecules. 相似文献
8.
Non-pinched, minimum energy solutions are important class of distillation designs that offer the potential advantage of a better trade-off between capital investment and operating costs. In this paper, two important tasks associated with non-pinched distillation designs are studied. Thus the novel contributions of this work to the literature are
- (1) A comprehensive methodology for finding non-pinched minimum energy designs.
- (2) Understanding of the reasons for the existence of non-pinched distillation designs.
9.
Rafael Gallego Lucia Comino Alberto Ruiz‐Cabello 《International journal for numerical methods in engineering》2006,66(12):1913-1933
In this paper, the material constant sensitivity boundary integral equation is presented, and its numerical solution proposed, based on boundary element techniques. The formulation deals with plane problems with general rectilinear anisotropy. Expressions for the computation of sensitivities for displacements, tractions, strains and stresses are derived, both for boundary and interior points. The sensitivities can be computed with respect to the bulk material properties or to the properties of part of the domain (inclusions, coatings, etc.). To assess the accuracy of the proposed approach, the computed results are compared to analytical ones derived from exact solutions obtained by complex potential theory, when possible, or finite difference derivatives otherwise. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
10.