全文获取类型
收费全文 | 2258篇 |
免费 | 93篇 |
国内免费 | 22篇 |
专业分类
化学 | 1616篇 |
晶体学 | 13篇 |
力学 | 86篇 |
综合类 | 1篇 |
数学 | 352篇 |
物理学 | 305篇 |
出版年
2024年 | 8篇 |
2023年 | 25篇 |
2022年 | 111篇 |
2021年 | 175篇 |
2020年 | 105篇 |
2019年 | 89篇 |
2018年 | 87篇 |
2017年 | 74篇 |
2016年 | 124篇 |
2015年 | 72篇 |
2014年 | 80篇 |
2013年 | 194篇 |
2012年 | 132篇 |
2011年 | 147篇 |
2010年 | 89篇 |
2009年 | 83篇 |
2008年 | 102篇 |
2007年 | 95篇 |
2006年 | 77篇 |
2005年 | 78篇 |
2004年 | 60篇 |
2003年 | 60篇 |
2002年 | 42篇 |
2001年 | 26篇 |
2000年 | 17篇 |
1999年 | 20篇 |
1998年 | 9篇 |
1997年 | 6篇 |
1996年 | 18篇 |
1995年 | 6篇 |
1994年 | 8篇 |
1993年 | 13篇 |
1992年 | 16篇 |
1991年 | 11篇 |
1990年 | 8篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 10篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 9篇 |
1982年 | 10篇 |
1980年 | 10篇 |
1979年 | 9篇 |
1978年 | 8篇 |
1976年 | 4篇 |
1975年 | 5篇 |
1974年 | 2篇 |
1971年 | 2篇 |
排序方式: 共有2373条查询结果,搜索用时 31 毫秒
971.
Rashid Waseem Anas Shamsi Taj Mohammad Md. Imtaiyaz Hassan Syed Naqui Kazim Anis Ahmad Chaudhary Hassan Ahmed Rudayni Mohammed Al-Zharani Faizan Ahmad Asimul Islam 《Molecules (Basel, Switzerland)》2022,27(3)
A sedentary lifestyle or lack of physical activity increases the risk of different diseases, including obesity, diabetes, heart diseases, certain types of cancers, and some neurological diseases. Physical exercise helps improve quality of life and reduces the risk of many diseases. Irisin, a hormone induced by exercise, is a fragmented product of FNDC5 (a cell membrane protein) and acts as a linkage between muscles and other tissues. Over the past decade, it has become clear that irisin is a molecular mimic of exercise and shows various beneficial effects, such as browning of adipocytes, modulation of metabolic processes, regulation of bone metabolism, and functioning of the nervous system. Irisin has a role in carcinogenesis; numerous studies have shown its impact on migration, invasion, and proliferation of cancer cells. The receptor of irisin is not completely known; however, in some tissues it probably acts via a specific class of integrin receptors. Here, we review research from the past decade that has identified irisin as a potential therapeutic agent in the prevention or treatment of various metabolic-related and other diseases. This article delineates structural and biochemical aspects of irisin and provides an insight into the role of irisin in different pathological conditions. 相似文献
972.
Nisa Najibah Mahleyuddin Said Moshawih Long Chiau Ming Hanis Hanum Zulkifly Nurolaini Kifli Mei Jun Loy Md. Moklesur Rahman Sarker Yaser Mohammed Al-Worafi Bey Hing Goh Shobna Thuraisingam Hui Poh Goh 《Molecules (Basel, Switzerland)》2022,27(1)
Coriandrum sativum (C. sativum), belonging to the Apiaceae (Umbelliferae) family, is widely recognized for its uses in culinary and traditional medicine. C. sativum contains various phytochemicals such as polyphenols, vitamins, and many phytosterols, which account for its properties including anticancer, anti-inflammatory, antidiabetic, and analgesic effects. The cardiovascular benefits of C. sativum have not been summarized before, hence this review aims to further evaluate and discuss its effectiveness in cardiovascular diseases, according to the recent literature. An electronic search for literature was carried out using the following databases: PubMed, Scopus, Google Scholar, preprint platforms, and the Cochrane Database of Systematic Reviews. Articles were gathered from the inception of the database until August 2021. Moreover, the traditional uses and phytochemistry of coriander were surveyed in the original resources and summarized. As a result, most of the studies that cover cardiovascular benefits and fulfilled the eligibility criteria were in vivo, while only a few were in vitro and clinical studies. In conclusion, C. sativum can be deemed a functional food due to its wide range of cardiovascular benefits such as antihypertensive, anti-atherogenic, antiarrhythmic, hypolipidemic as well as cardioprotective effects. 相似文献
973.
Madhuchandra Kenchegowda Mohamed Rahamathulla Umme Hani Mohammed Y. Begum Sagar Guruswamy Riyaz Ali M. Osmani Mysore P. Gowrav Sultan Alshehri Mohammed M. Ghoneim Areej Alshlowi Devegowda V. Gowda 《Molecules (Basel, Switzerland)》2022,27(1)
Cancer is a group of disorders characterized by uncontrolled cell growth that affects around 11 million people each year globally. Nanocarrier-based systems are extensively used in cancer imaging, diagnostics as well as therapeutics; owing to their promising features and potential to augment therapeutic efficacy. The focal point of research remains to develop new-fangled smart nanocarriers that can selectively respond to cancer-specific conditions and deliver medications to target cells efficiently. Nanocarriers deliver loaded therapeutic cargos to the tumour site either in a passive or active mode, with the least drug elimination from the drug delivery systems. This review chiefly focuses on current advances allied to smart nanocarriers such as dendrimers, liposomes, mesoporous silica nanoparticles, quantum dots, micelles, superparamagnetic iron-oxide nanoparticles, gold nanoparticles and carbon nanotubes, to list a few. Exhaustive discussion on crucial topics like drug targeting, surface decorated smart-nanocarriers and stimuli-responsive cancer nanotherapeutics responding to temperature, enzyme, pH and redox stimuli have been covered. 相似文献
974.
In this paper, a general idea of Presic type $L$-fuzzy fixed point results using some weakly contractive conditions in the setting of metric space is initiated. Stability of $L$-fuzzy mappings and associated new concepts are proposed herein to complement their corresponding notions related to crisp multi-valued and single-valued mappings. Illustrative nontrivial examples are provided to support the assertions of our main results. 相似文献
975.
Mohammed Seaïd 《PAMM》2004,4(1):494-495
We propose a robust multigrid solver for the isotropic transport equation in three space dimensions. Discrete‐ordinates and Galerkin method are used for angle and space discretizations, respectively. The fully discrete problem is formulated as a compact linear system of algebraic equations with a dense iterate matrix. Using a hierarchy of nested meshes our multigrid algorithm employes the Atkinson‐Brakhage approximate inverse as a smoother while a Krylov subspace method is used to solve the coarse problem. Numerical results and comparisons are shown for a transport problem with thermal source. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
976.
977.
Ali Boudjada Olivier Hernandez Jean Meinnel Mohammed Mani Werner Paulus 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1106-1108
In the structure of triiodomesitylene (1,3,5‐triiodo‐2,4,6‐trimethylbenzene), C9H9I3, at 293 K, the benzene ring is found to be significantly distorted from ideal D6h symmetry; the average endocyclic angles facing the I atoms and the methyl groups are 123.8 (3) and 116.2 (3)°, respectively. The angle between the normal to the molecular plane and the normal to the (100) plane is 5.1°. No disorder was detected at 293 K. The thermal motion was investigated by a rigid‐body motion tensor analysis. Intra‐ and intermolecular contacts are described and topological differences compared with the isomorphous compounds trichloromesitylene and tribromomesitylene are discussed. 相似文献
978.
Mohammed Nazrul Islam Tsutomu Sasaki Masaaki Imai Satya Prasad Majumder Yoshinori Namihira 《Optics Communications》1999,160(4-6):219-224
The performance of a coherent optical continuous-phase frequency shift keying (CPFSK) system is evaluated theoretically including the combined effect of fiber chromatic dispersion, non-zero laser line width and receiver noises. The system limitations imposed by chromatic dispersion and laser phase noise are depicted. The system performance can be improved by shifting the zero-dispersion wavelength to the operating wavelength of the system and this shifting can be achieved efficiently by using a suitable combination of different types of optical fibers. Dispersion shifting characteristics are demonstrated using four kinds of fibers, namely: standard single-mode fiber (SMF), dispersion shifted fiber (DSF), dispersion compensated fiber (DCF) and large core fiber (LCF). The effect of dispersion shifting on the system performance is evaluated in terms of transmission distance and bit rate. 相似文献
979.
Mathematical simulation of nonlinear physical and abstract systems is a very vital process for predicting the solution behavior of fractional partial differential equations(FPDEs)corresponding to different applications in science and engineering. In this paper, an attractive reliable analytical technique, the conformable residual power series, is implemented for constructing approximate series solutions for a class of nonlinear coupled FPDEs arising in fluid mechanics and fluid flow, which are often designed to demonstrate the behavior of weakly nonlinear and long waves and describe the interaction of shallow water waves. In the proposed technique the n-truncated representation is substituted into the original system and it is assumed the(n-1) conformable derivative of the residuum is zero. This allows us to estimate coefficients of truncation and successively add the subordinate terms in the multiple fractional power series with a rapidly convergent form. The influence, capacity, and feasibility of the presented approach are verified by testing some real-world applications. Finally, highlights and some closing comments are attached. 相似文献
980.
Mohammad Y. Alshahrani Kholoud M. Alshahrani Munazzah Tasleem Arshiya Akeel Tahani M. Almeleebia Irfan Ahmad Mohammed Asiri Najla A. Alshahrani Nadiyah M. Alabdallah Mohd Saeed 《Molecules (Basel, Switzerland)》2021,26(19)
Minichromosome maintenance complex component 7 (MCM7) is involved in replicative licensing and the synthesis of DNA, and its overexpression is a fascinating biomarker for various cancer types. There is currently no effective agent that can prevent the development of cancer caused by the MCM7 protein. However, on the molecular level, inhibiting MCM7 lowers cancer-related cellular growth. With this purpose, this study screened 452 biogenic compounds extracted from the UEFS Natural Products dataset against MCM protein by using the in silico art of technique. The hit compounds UEFS99, UEFS137, and UEFS428 showed good binding with the MCM7 protein with binding energy values of −9.95, −8.92, and −8.71 kcal/mol, which was comparatively higher than that of the control compound ciprofloxacin (−6.50). The hit (UEFS99) with the minimum binding energy was picked for molecular dynamics (MD) simulation investigation, and it demonstrated stability at 30 ns. Computational prediction of physicochemical property evaluation revealed that these hits are non-toxic and have good drug-likeness features. It is suggested that hit compounds UEFS99, UEFS137, and UEFS428 pave the way for further bench work validation in novel inhibitor development against MCM7 to fight the cancers. 相似文献