全文获取类型
收费全文 | 831篇 |
免费 | 43篇 |
专业分类
电工技术 | 1篇 |
综合类 | 1篇 |
化学工业 | 337篇 |
金属工艺 | 54篇 |
机械仪表 | 17篇 |
建筑科学 | 19篇 |
矿业工程 | 8篇 |
能源动力 | 10篇 |
轻工业 | 51篇 |
水利工程 | 2篇 |
石油天然气 | 35篇 |
无线电 | 29篇 |
一般工业技术 | 147篇 |
冶金工业 | 80篇 |
原子能技术 | 19篇 |
自动化技术 | 64篇 |
出版年
2023年 | 14篇 |
2022年 | 98篇 |
2021年 | 86篇 |
2020年 | 19篇 |
2019年 | 19篇 |
2018年 | 27篇 |
2017年 | 25篇 |
2016年 | 38篇 |
2015年 | 17篇 |
2014年 | 27篇 |
2013年 | 35篇 |
2012年 | 30篇 |
2011年 | 40篇 |
2010年 | 36篇 |
2009年 | 21篇 |
2008年 | 23篇 |
2007年 | 23篇 |
2006年 | 27篇 |
2005年 | 17篇 |
2004年 | 8篇 |
2003年 | 10篇 |
2002年 | 17篇 |
2001年 | 10篇 |
1999年 | 6篇 |
1998年 | 11篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1994年 | 12篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1989年 | 4篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1985年 | 9篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1976年 | 6篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1973年 | 10篇 |
1972年 | 9篇 |
1971年 | 8篇 |
1970年 | 8篇 |
1969年 | 9篇 |
1968年 | 7篇 |
排序方式: 共有874条查询结果,搜索用时 15 毫秒
1.
Stekloplastik—Sertifikat Corporation Moscow. Translated from Khimicheskie Volokna, No. 2, pp. 58–59, March–April, 1994. 相似文献
2.
3.
Angelos Dimas Anastasia Politi Alexandra Bargiota Theodoros Panoskaltsis Nikolaos F. Vlahos Georgios Valsamakis 《International journal of molecular sciences》2022,23(15)
Fetal exposure in adverse environmental factors during intrauterine life can lead to various biological adjustments, affecting not only in utero development of the conceptus, but also its later metabolic and endocrine wellbeing. During human gestation, maternal bone turnover increases, as reflected by molecules involved in bone metabolism, such as vitamin D, osteocalcin, sclerostin, sRANKL, and osteoprotegerin; however, recent studies support their emerging role in endocrine functions and glucose homeostasis regulation. Herein, we sought to systematically review current knowledge on the effects of aforementioned maternal bone biomarkers during pregnancy on fetal intrauterine growth and metabolism, neonatal anthropometric measures at birth, as well as on future endocrine and metabolic wellbeing of the offspring. A growing body of literature converges on the view that maternal bone turnover is likely implicated in fetal growth, and at least to some extent, in neonatal and childhood body composition and metabolic wellbeing. Maternal sclerostin and sRANKL are positively linked with fetal abdominal circumference and subcutaneous fat deposition, contributing to greater birthweights. Vitamin D deficiency correlates with lower birthweights, while research is still needed on intrauterine fetal metabolism, as well as on vitamin D dosing supplementation during pregnancy, to diminish the risks of low birthweight or SGA neonates in high-risk populations. 相似文献
4.
Anastasia V. Poznyak Nikolay K. Sadykhov Andrey G. Kartuesov Evgeny E. Borisov Vasily N. Sukhorukov Alexander N. Orekhov 《International journal of molecular sciences》2022,23(13)
Aging is one of the most intriguing processes of human ontogenesis. It is associated with the development of a wide variety of diseases affecting all organs and their systems. The victory over aging is the most desired goal of scientists; however, it is hardly achievable in the foreseeable future due to the complexity and ambiguity of the process itself. All body systems age, lose their performance, and structural disorders accumulate. The cardiovascular system is no exception. And it is cardiovascular diseases that occupy a leading position as a cause of death, especially among the elderly. The aging of the cardiovascular system is well described from a mechanical point of view. Moreover, it is known that at the cellular level, a huge number of mechanisms are involved in this process, from mitochondrial dysfunction to inflammation. It is on these mechanisms, as well as the potential for taking control of the aging of the cardiovascular system, that we focused on in this review. 相似文献
5.
Aigli G. Vakrakou Anastasia Alexaki Maria-Evgenia Brinia Maria Anagnostouli Leonidas Stefanis Panos Stathopoulos 《International journal of molecular sciences》2022,23(15)
This article recapitulates the evidence on the role of mammalian targets of rapamycin (mTOR) complex pathways in multiple sclerosis (MS). Key biological processes that intersect with mTOR signaling cascades include autophagy, inflammasome activation, innate (e.g., microglial) and adaptive (B and T cell) immune responses, and axonal and neuronal toxicity/degeneration. There is robust evidence that mTOR inhibitors, such as rapamycin, ameliorate the clinical course of the animal model of MS, experimental autoimmune encephalomyelitis (EAE). New, evolving data unravel mechanisms underlying the therapeutic effect on EAE, which include balance among T-effector and T-regulatory cells, and mTOR effects on myeloid cell function, polarization, and antigen presentation, with relevance to MS pathogenesis. Radiologic and preliminary clinical data from a phase 2 randomized, controlled trial of temsirolimus (a rapamycin analogue) in MS show moderate efficacy, with significant adverse effects. Large clinical trials of indirect mTOR inhibitors (metformin) in MS are lacking; however, a smaller prospective, non-randomized study shows some potentially promising radiological results in combination with ex vivo beneficial effects on immune cells that might warrant further investigation. Importantly, the study of mTOR pathway contributions to autoimmune inflammatory demyelination and multiple sclerosis illustrates the difficulties in the clinical application of animal model results. Nevertheless, it is not inconceivable that targeting metabolism in the future with cell-selective mTOR inhibitors (compared to the broad inhibitors tried to date) could be developed to improve efficacy and reduce side effects. 相似文献
6.
Ioanna Nikitopoulou Aggeliki Katsifa Paraskevi Kanellopoulou Edison Jahaj Alice G. Vassiliou Zafeiria Mastora Ioanna Dimopoulou Stylianos E. Orfanos Vassilis Aidinis Anastasia Kotanidou 《International journal of molecular sciences》2022,23(14)
The pathogenesis of sepsis involves complex interactions and a systemic inflammatory response leading eventually to multiorgan failure. Autotaxin (ATX, ENPP2) is a secreted glycoprotein largely responsible for the extracellular production of lysophosphatidic acid (LPA), which exerts multiple effects in almost all cell types through its at least six G-protein-coupled LPA receptors (LPARs). Here, we investigated a possible role of the ATX/LPA axis in sepsis in an animal model of endotoxemia as well as in septic patients. Mice with 50% reduced serum ATX levels showed improved survival upon lipopolysaccharide (LPS) stimulation compared to their littermate controls. Similarly, mice bearing the inducible inactivation of ATX and presenting with >70% decreased ATX levels were even more protected against LPS-induced endotoxemia; however, no significant effects were observed upon the chronic and systemic transgenic overexpression of ATX. Moreover, the genetic deletion of LPA receptors 1 and 2 did not significantly affect the severity of the modelled disease, suggesting that alternative receptors may mediate LPA effects upon sepsis. In translation, ATX levels were found to be elevated in the sera of critically ill patients with sepsis in comparison with their baseline levels upon ICU admission. Therefore, the results indicate a role for ATX in LPS-induced sepsis and suggest possible therapeutic benefits of pharmacologically targeting ATX in severe, systemic inflammatory disorders. 相似文献
7.
Jana Dulle Silke Nemeth Ekaterina V. Skorb Torsten Irrgang Jürgen Senker Rhett Kempe Andreas Fery Daria V. Andreeva 《Advanced functional materials》2012,22(15):3128-3135
This paper proposes a sonochemical approach to the nanostructuring of Al/Ni catalyst with high content of accessible Ni centers and a high reusability. The surface and bulk composition as well as pore size distribution of this catalyst are controlled synergistically by adjusting the ultrasound intensity in aqueous solution. Sonochemical activation of Al/Ni alloy leads to formation of mesoporous Al/Ni metallic based frameworks with surface area up to 125 m2 g?1, and regular distribution of nickel active center in the porous matrix. One of the opportunities of porous Al/Ni catalyst is that due to a time‐resolved controllable formation of protective oxide layer it can be stored and handled under air in comparison to traditional Raney catalysts which need inert conditions. The Al/Ni catalyst is characterized by scanning electron microscopy (SEM), electron diffraction spectroscopy (EDS), X‐ray photoelectron spectroscopy (XPS), confocal scanning fluorescence microscopy (CSFM), solid‐state NMR experiments, and powder X‐ray diffraction analysis (PXRD). The catalytic activity was investigated for the hydrogenation of acetophenone. 相似文献
8.
Juan S. Rocha-Ortiz Jianchang Wu Jonas Wenzel Andreas J. Bornschlegl Jose Dario Perea Salvador Leon Anastasia Barabash Anna-Sophie Wollny Dirk M. Guldi Jiyun Zhang Alberto Insuasty Larry Lüer Alejandro Ortiz Andreas Hirsch Christoph J. Brabec 《Advanced functional materials》2023,33(44):2304262
Dumbbell-shaped systems based on PAHs-BODIPY-triarylamine hybrids TM-(01-04) are designed as novel and highly efficient hole-transporting materials for usage in planar inverted perovskite solar cells. BODIPY is employed as a bridge between the PAH units, and the effects of the conjugated π-system's covalent attachment and size are investigated. Fluorescence quenching, 3D fluorescence heat maps, and theoretical studies support energy transfer within the moieties. The systems are extremely resistant to UVC 254 nm germicidal light sources and present remarkable thermal stability at degradation temperatures exceeding 350 °C. Integrating these systems into perovskite solar cells results in outstanding power conversion efficiency (PCE), with TM-02-based devices exhibiting a PCE of 20.26%. The devices base on TM-01, TM-03, and TM-04 achieve PCE values of 16.98%, 17.58%, and 18.80%, respectively. The long-term stability of these devices is measured for 600 h, with initial efficiency retention between 94% and 86%. The TM-04-based device presents noticeable stability of 94%, better than the reference polymer PTAA with 91%. These findings highlight the exciting potential of dumbbell-shaped systems based on PAHs-BODIPY-triarylamine derivatives for next-generation photovoltaics. 相似文献
9.
Ya. A. Kamenchuk S. I. Pisareva L. N. Andreeva F. G. Unger 《Chemistry and Technology of Fuels and Oils》2006,42(1):39-42
Precipitation of sediment caused by external factors — temperature and solvent — is due to the spin nature of the contaminants
formed during use of the oil. These paramagnetic contaminants also lead to aging of oils. Their total elimination restores
the properties of used oil to the level of the base oil, but requires sufficient energy effects.
__________
Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 1, pp. 29–31, January–February, 2006. 相似文献
10.
Achim Streit Piotr Bala Alexander Beck-Ratzka Krzysztof Benedyczak Sandra Bergmann Rebecca Breu Jason Milad Daivandy Bastian Demuth Anastasia Eifer André Giesler Björn Hagemeier Sonja Holl Valentina Huber Nadine Lamla Daniel Mallmann Ahmed Shiraz Memon Mohammad Shahbaz Memon Michael Rambadt Morris Riedel Mathilde Romberg Bernd Schuller Tobias Schlauch Andreas Schreiber Thomas Soddemann Wolfgang Ziegler 《电信纪事》2010,65(11-12):757-762
UNICORE is a European Grid Technology with more than 10 years of history. Originating from the Supercomputing domain, the latest version UNICORE 6 has turned into a general-purpose Grid technology that follows established standards and offers a rich set of features to its users. The paper starts with an architectural insight into UNICORE 6, highlighting the workflow features, standards and the different clients. Next, the current state of advancement is presented by describing recent developments. The paper closes with an outlook on future planned developments. 相似文献