全文获取类型
收费全文 | 715篇 |
免费 | 40篇 |
专业分类
电工技术 | 18篇 |
化学工业 | 270篇 |
金属工艺 | 6篇 |
机械仪表 | 14篇 |
建筑科学 | 11篇 |
矿业工程 | 2篇 |
能源动力 | 24篇 |
轻工业 | 78篇 |
水利工程 | 3篇 |
石油天然气 | 1篇 |
无线电 | 41篇 |
一般工业技术 | 170篇 |
冶金工业 | 7篇 |
原子能技术 | 13篇 |
自动化技术 | 97篇 |
出版年
2023年 | 13篇 |
2022年 | 30篇 |
2021年 | 23篇 |
2020年 | 11篇 |
2019年 | 17篇 |
2018年 | 22篇 |
2017年 | 18篇 |
2016年 | 23篇 |
2015年 | 23篇 |
2014年 | 23篇 |
2013年 | 32篇 |
2012年 | 63篇 |
2011年 | 49篇 |
2010年 | 36篇 |
2009年 | 45篇 |
2008年 | 45篇 |
2007年 | 41篇 |
2006年 | 33篇 |
2005年 | 20篇 |
2004年 | 17篇 |
2003年 | 18篇 |
2002年 | 16篇 |
2001年 | 12篇 |
2000年 | 9篇 |
1999年 | 7篇 |
1998年 | 5篇 |
1997年 | 7篇 |
1996年 | 8篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1989年 | 7篇 |
1988年 | 2篇 |
1986年 | 4篇 |
1985年 | 7篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 8篇 |
1981年 | 6篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1974年 | 3篇 |
1971年 | 1篇 |
1968年 | 1篇 |
1964年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有755条查询结果,搜索用时 0 毫秒
181.
Tomography-Based Multiscale Analyses of the 3D Geometrical Morphology of Reticulated Porous Ceramics
Jörg Petrasch Peter Wyss Rolf Stämpfli Aldo Steinfeld 《Journal of the American Ceramic Society》2008,91(8):2659-2665
X-ray microtomography with a digital resolution of 30 μm and synchrotron submicrometer tomography with a digital resolution of 350/700 nm are performed on catalyst-coated reticulate porous ceramic foa, 22[2] 121–45ms. Porosity, specific surface, pore-size distribution, two-point correlation function, and minimum size of a representative elementary volume are computed by image processing of the tomographic reconstructions on the mm-scale- and μm-scale-sized pores. Numerically determined porosities are experimentally validated by weighing, helium pycnometry, and mercury intrusion porosimetry. 相似文献
182.
183.
Michele Iovino Tullio Messana Giuseppe Lisco Aldo Vanacore Vito Angelo Giagulli Edoardo Guastamacchia Giovanni De Pergola Vincenzo Triggiani 《International journal of molecular sciences》2021,22(21)
Sodium appetite is an innate behavior occurring in response to sodium depletion that induces homeostatic responses such as the secretion of the mineralocorticoid hormone aldosterone from the zona glomerulosa of the adrenal cortex and the stimulation of the peptide hormone angiotensin II (ANG II). The synergistic action of these hormones signals to the brain the sodium appetite that represents the increased palatability for salt intake. This narrative review summarizes the main data dealing with the role of mineralocorticoid and ANG II receptors in the central control of sodium appetite. Appropriate keywords and MeSH terms were identified and searched in PubMed. References to original articles and reviews were examined, selected, and discussed. Several brain areas control sodium appetite, including the nucleus of the solitary tract, which contains aldosterone-sensitive HSD2 neurons, and the organum vasculosum lamina terminalis (OVLT) that contains ANG II-sensitive neurons. Furthermore, sodium appetite is under the control of signaling proteins such as mitogen-activated protein kinase (MAPK) and inositol 1,4,5-thriphosphate (IP3). ANG II stimulates salt intake via MAPK, while combined ANG II and aldosterone action induce sodium intake via the IP3 signaling pathway. Finally, aldosterone and ANG II stimulate OVLT neurons and suppress oxytocin secretion inhibiting the neuronal activity of the paraventricular nucleus, thus disinhibiting the OVLT activity to aldosterone and ANG II stimulation. 相似文献
184.
Ania Canseco-Rodriguez Valeria Masola Vincenza Aliperti Maria Meseguer-Beltran Aldo Donizetti Ana María Sanchez-Perez 《International journal of molecular sciences》2022,23(21)
Alzheimer’s Disease (AD) has currently no effective treatment; however, preventive measures have the potential to reduce AD risk. Thus, accurate and early prediction of risk is an important strategy to alleviate the AD burden. Neuroinflammation is a major factor prompting the onset of the disease. Inflammation exerts its toxic effect via multiple mechanisms. Amongst others, it is affecting gene expression via modulation of non-coding RNAs (ncRNAs), such as miRNAs. Recent evidence supports that inflammation can also affect long non-coding RNA (lncRNA) expression. While the association between miRNAs and inflammation in AD has been studied, the role of lncRNAs in neurodegenerative diseases has been less explored. In this review, we focus on lncRNAs and inflammation in the context of AD. Furthermore, since plasma-isolated extracellular vesicles (EVs) are increasingly recognized as an effective monitoring strategy for brain pathologies, we have focused on the studies reporting dysregulated lncRNAs in EVs isolated from AD patients and controls. The revised literature shows a positive association between pro-inflammatory lncRNAs and AD. However, the reports evaluating lncRNA alterations in EVs isolated from the plasma of patients and controls, although still limited, confirm the value of specific lncRNAs associated with AD as reliable biomarkers. This is an emerging field that will open new avenues to improve risk prediction and patient stratification, and may lead to the discovery of potential novel therapeutic targets for AD. 相似文献
185.
186.
Marco Alfonso Perrone Alberto Aimo Sergio Bernardini Aldo Clerico 《International journal of molecular sciences》2023,24(1)
The term “inflammageing” was introduced in 2000, with the aim of describing the chronic inflammatory state typical of elderly individuals, which is characterized by a combination of elevated levels of inflammatory biomarkers, a high burden of comorbidities, an elevated risk of disability, frailty, and premature death. Inflammageing is a hallmark of various cardiovascular diseases, including atherosclerosis, hypertension, and rapid progression to heart failure. The great experimental and clinical evidence accumulated in recent years has clearly demonstrated that early detection and counteraction of inflammageing is a promising strategy not only to prevent cardiovascular disease, but also to slow down the progressive decline of health that occurs with ageing. It is conceivable that beneficial effects of counteracting inflammageing should be most effective if implemented in the early stages, when the compensatory capacity of the organism is not completely exhausted. Early interventions and treatments require early diagnosis using reliable and cost-effective biomarkers. Indeed, recent clinical studies have demonstrated that cardiac-specific biomarkers (i.e., cardiac natriuretic peptides and cardiac troponins) are able to identify, even in the general population, the individuals at highest risk of progression to heart failure. However, further clinical studies are needed to better understand the usefulness and cost/benefit ratio of cardiac-specific biomarkers as potential targets in preventive and therapeutic strategies for early detection and counteraction of inflammageing mechanisms and in this way slowing the progressive decline of health that occurs with ageing. 相似文献
187.
Bioactive glasses (BG) show great promise for bone tissue engineering based on their key properties, e.g., biocompatibility, biodegradability, osteoconductivity as well as osteogenic and angiogenic potential, which make them excellent candidates for bone tissue scaffolds and bone substitute materials. Recent work has shown that dissolution products of bioactive glasses have the potential to induce angiogenesis in addition to their known effect of influencing gene expression and promoting osteoblastic differentiation. One of the most interesting features of BG is their ability to bond both to soft and hard tissues, depending on their composition. To intensify the positive impact of BG for medical applications, there are considerable research efforts on using bioactive glass based platforms as carriers for the encapsulation, delivery and controlled release of bioactive molecules and therapeutic drugs. Different types of bioactive glasses have been considered in combination with different therapeutic drugs, hormones, growth factors and peptides. Using bioactive glasses as drug delivery system combines thus the effectiveness of therapeutic drugs (or bioactive/signaling molecules) with the intrinsic advantages of this inorganic biomaterial. Considering research carried out in the last 15?years, this review presents the different chemical compositions and morphologies of bioactive glasses used as carrier for bioactive molecules and therapeutic drugs and discusses the expanding potential of BG with drug delivery capability focusing in the field of bone tissue engineering. 相似文献
188.
189.
Marco Sangermano Giulio Malucelli Ezio Amerio Roberta Bongiovanni Aldo Priola Anna Di Gianni Brigitte Voit Giancarlo Rizza 《大分子材料与工程》2006,291(5):517-523
Summary: Titania‐containing coatings were prepared by cationic photopolymerization of an epoxy resin either by dispersion of preformed TiO2 nanoparticles or by their in‐situ generation through a sol‐gel dual‐cure process. The kinetics of photopolymerization was evaluated by real‐time FT‐IR, studying the effect of the TiO2 concentration. The properties of cured films were investigated, showing an increase of hydrophilicity on the surface of the coatings with increasing TiO2 content. TEM analysis demonstrated that it is possible to achieve a significantly better control of the dispersion of the inorganic particles within the organic matrix by in‐situ generation of TiO2, thus completely avoiding macroscopic phase separation and obtaining homogeneous, transparent coatings.
190.
Dr. Antonella Virgilio Prof. Veronica Esposito Dr. Giuseppe Citarella Prof. Luciano Mayol Prof. Aldo Galeone 《Chembiochem : a European journal of chemical biology》2012,13(15):2219-2224
Several anti‐HIV aptamers adopt DNA quadruplex structures. Among these, “Hotoda's aptamer” (base sequence TGGGAG) was one of the first to be discovered. Although it has been the topic of some recent research, no detailed structural investigations have been reported. Here we report structural investigations on this aptamer and analogues with related sequences, by using UV, CD, and NMR spectroscopy as well as electrophoretic techniques. The addition of a 3′‐end thymine has allowed us to obtain a single, investigable quadruplex structure. Data clearly point to the presence of an A‐tetrad. Furthermore, the effects of the incorporation of an 8‐methyl‐2′‐deoxyguanosine at the 5′‐end of the G‐run were investigated. 相似文献