全文获取类型
收费全文 | 1439篇 |
免费 | 71篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 499篇 |
金属工艺 | 17篇 |
机械仪表 | 15篇 |
建筑科学 | 52篇 |
矿业工程 | 1篇 |
能源动力 | 26篇 |
轻工业 | 297篇 |
水利工程 | 13篇 |
无线电 | 45篇 |
一般工业技术 | 201篇 |
冶金工业 | 157篇 |
原子能技术 | 6篇 |
自动化技术 | 177篇 |
出版年
2023年 | 18篇 |
2022年 | 105篇 |
2021年 | 94篇 |
2020年 | 45篇 |
2019年 | 35篇 |
2018年 | 48篇 |
2017年 | 41篇 |
2016年 | 62篇 |
2015年 | 30篇 |
2014年 | 75篇 |
2013年 | 100篇 |
2012年 | 84篇 |
2011年 | 118篇 |
2010年 | 100篇 |
2009年 | 73篇 |
2008年 | 77篇 |
2007年 | 60篇 |
2006年 | 40篇 |
2005年 | 44篇 |
2004年 | 24篇 |
2003年 | 30篇 |
2002年 | 20篇 |
2001年 | 11篇 |
2000年 | 17篇 |
1999年 | 23篇 |
1998年 | 9篇 |
1997年 | 20篇 |
1996年 | 7篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 7篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 7篇 |
1979年 | 3篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有1511条查询结果,搜索用时 15 毫秒
1.
Differential scanning calorimetry and hot stage microscopy have been used to study the interactions between sulphamethoxazole and the sugars maltose, glucose, sucrose and mannitol. Only the sulphamethoxazole-mannitol system appeared to be stable and presented a eutectic containing 90.3% sulphamethoxazole. Heats of fusion for sulphamethoxazole, mannitol and their eutectic were 33.4, 73.6 and 39.9 cal g respectively. 相似文献
2.
Given a graph G where a label is associated with each edge, we address the problem of looking for a maximum matching of G using the minimum number of different labels, namely the labeled maximum matching problem. It is a relatively new problem whose application is related to the timetabling problem. We prove it is NP-complete and present four different mathematical formulations. Moreover, we propose an exact algorithm based on a branch-and-bound approach to solve it. We evaluate the performance of our algorithm on a wide set of instances and compare our computational times with the ones required by CPLEX to solve the proposed mathematical formulations. Test results show the effectiveness of our procedure, that hugely outperforms the solver. 相似文献
3.
Monica L. Fernndez-Quintero Eugene F. DeRose Scott A. Gabel Geoffrey A. Mueller Klaus R. Liedl 《International journal of molecular sciences》2022,23(10)
Variable domains of camelid antibodies (so-called nanobodies or VHH) are the smallest antibody fragments that retain complete functionality and therapeutic potential. Understanding of the nanobody-binding interface has become a pre-requisite for rational antibody design and engineering. The nanobody-binding interface consists of up to three hypervariable loops, known as the CDR loops. Here, we structurally and dynamically characterize the conformational diversity of an anti-GFP-binding nanobody by using molecular dynamics simulations in combination with experimentally derived data from nuclear magnetic resonance (NMR) spectroscopy. The NMR data contain both structural and dynamic information resolved at various timescales, which allows an assessment of the quality of protein MD simulations. Thus, in this study, we compared the ensembles for the anti-GFP-binding nanobody obtained from MD simulations with results from NMR. We find excellent agreement of the NOE-derived distance maps obtained from NMR and MD simulations and observe similar conformational spaces for the simulations with and without NOE time-averaged restraints. We also compare the measured and calculated order parameters and find generally good agreement for the motions observed in the ps–ns timescale, in particular for the CDR3 loop. Understanding of the CDR3 loop dynamics is especially critical for nanobodies, as this loop is typically critical for antigen recognition. 相似文献
4.
Laura Mannarino Lara Paracchini Federica Pezzuto Gheorghe Emilian Olteanu Laura Moracci Luca Vedovelli Irene De Simone Cristina Bosetti Monica Lupi Rosy Amodeo Alessia Inglesi Maurizio Callari Serena Penpa Roberta Libener Sara Delfanti Antonina De Angelis Alberto Muzio Paolo Andrea Zucali Paola Allavena Giovanni Luca Ceresoli Sergio Marchini Fiorella Calabrese Maurizio DIncalci Federica Grosso 《International journal of molecular sciences》2022,23(10)
5.
Ornella Rondinone Alessio Murgia Jole Costanza Silvia Tabano Margherita Camanni Luigi Corsaro Laura Fontana Patrizia Colapietro Luciano Calzari Silvia Motta Carlo Santaniello Tatjana Radaelli Enrico Ferrazzi Silvano Bosari Davide Gentilini Silvia Maria Sirchia Monica Miozzo 《International journal of molecular sciences》2022,23(10)
6.
Juan F. Zapata-Acevedo Valentina García-Prez Ricardo Cabezas-Prez Monica Losada-Barragn Karina Vargas-Snchez Rodrigo E. Gonzlez-Reyes 《International journal of molecular sciences》2022,23(12)
Laminin, a non-collagenous glycoprotein present in the brain extracellular matrix, helps to maintain blood–brain barrier (BBB) integrity and regulation. Neuroinflammation can compromise laminin structure and function, increasing BBB permeability. The aim of this paper is to determine if neuroinflammation-induced laminin functional changes may serve as a potential biomarker of alterations in the BBB. The 38 publications included evaluated neuroinflammation, BBB disruption, and laminin, and were assessed for quality and risk of bias (protocol registered in PROSPERO; CRD42020212547). We found that laminin may be a good indicator of BBB overall structural integrity, although changes in expression are dependent on the pathologic or experimental model used. In ischemic stroke, permanent vascular damage correlates with increased laminin expression (β and γ subunits), while transient damage correlates with reduced laminin expression (α subunits). Laminin was reduced in traumatic brain injury and cerebral hemorrhage studies but increased in multiple sclerosis and status epilepticus studies. Despite these observations, there is limited knowledge about the role played by different subunits or isoforms (such as 411 or 511) of laminin in maintaining structural architecture of the BBB under neuroinflammation. Further studies may clarify this aspect and the possibility of using laminin as a biomarker in different pathologies, which have alterations in BBB function in common. 相似文献
7.
Andreea Campu Ilinca Muresan Ana-Maria Craciun Simona Cainap Simion Astilean Monica Focsan 《International journal of molecular sciences》2022,23(14)
Acute myocardial infarction (AMI) is considered as one of the main causes of death, threating human lives for decades. Currently, its diagnosis relies on electrocardiography (ECG), which has been proven to be insufficient. In this context, the efficient detection of cardiac biomarkers was proposed to overcome the limitations of ECG. In particular, the measurement of troponins, specifically cardiac troponin I (cTnI) and cardiac troponin T (cTnT), has proven to be superior in terms of sensitivity and specificity in the diagnosis of myocardial damage. As one of the most life-threatening conditions, specific and sensitive investigation methods that are fast, universally available, and cost-efficient to allow for early initiation of evidence-based, living-saving treatment are desired. In this review, we aim to present and discuss the major breakthroughs made in the development of cTnI and cTnT specific biosensor designs and analytical tools, highlighting the achieved progress as well as the remaining challenges to reach the technological goal of simple, specific, cheap, and portable testing chips for the rapid and efficient on-site detection of cardiac cTnI/cTnT biomarkers in order to diagnose and treat cardiovascular diseases at an incipient stage. 相似文献
8.
Claudia Terezia Socol Alexandra Chira Maria Antonia Martinez-Sanchez Maria Angeles Nuez-Sanchez Cristina Maria Maerescu Daniel Mierlita Alexandru Vasile Rusu Antonio Jose Ruiz-Alcaraz Monica Trif Bruno Ramos-Molina 《International journal of molecular sciences》2022,23(9)
Obesity and colorectal cancer (CRC) are among the leading diseases causing deaths in the world, showing a complex multifactorial pathology. Obesity is considered a risk factor in CRC development through inflammation, metabolic, and signaling processes. Leptin is one of the most important adipokines related to obesity and an important proinflammatory marker, mainly expressed in adipose tissue, with many genetic variation profiles, many related influencing factors, and various functions that have been ascribed but not yet fully understood and elucidated, the most important ones being related to energy metabolism, as well as endocrine and immune systems. Aberrant signaling and genetic variations of leptin are correlated with obesity and CRC, with the genetic causality showing both inherited and acquired events, in addition to lifestyle and environmental risk factors; these might also be related to specific pathogenic pathways at different time points. Moreover, mutation gain is a crucial factor enabling the genetic process of CRC. Currently, the inconsistent and insufficient data related to leptin’s relationship with obesity and CRC indicate the necessity of further related studies. This review summarizes the current knowledge on leptin genetics and its potential relationship with the main pathogenic pathways of obesity and CRC, in an attempt to understand the molecular mechanisms of these associations, in the context of inconsistent and contradictory data. The understanding of these mechanisms linking obesity and CRC could help to develop novel therapeutic targets and prevention strategies, resulting in a better prognosis and management of these diseases. 相似文献
9.
Alessandro Di Minno Monica Gelzo Marianna Caterino Michele Costanzo Margherita Ruoppolo Giuseppe Castaldo 《International journal of molecular sciences》2022,23(9)
Metabolomics helps identify metabolites to characterize/refine perturbations of biological pathways in living organisms. Pre-analytical, analytical, and post-analytical limitations that have hampered a wide implementation of metabolomics have been addressed. Several potential biomarkers originating from current targeted metabolomics-based approaches have been discovered. Precision medicine argues for algorithms to classify individuals based on susceptibility to disease, and/or by response to specific treatments. It also argues for a prevention-based health system. Because of its ability to explore gene–environment interactions, metabolomics is expected to be critical to personalize diagnosis and treatment. Stringent guidelines have been applied from the very beginning to design studies to acquire the information currently employed in precision medicine and precision prevention approaches. Large, prospective, expensive and time-consuming studies are now mandatory to validate old, and discover new, metabolomics-based biomarkers with high chances of translation into precision medicine. Metabolites from studies on saliva, sweat, breath, semen, feces, amniotic, cerebrospinal, and broncho-alveolar fluid are predicted to be needed to refine information from plasma and serum metabolome. In addition, a multi-omics data analysis system is predicted to be needed for omics-based precision medicine approaches. Omics-based approaches for the progress of precision medicine and prevention are expected to raise ethical issues. 相似文献
10.
Guillermo Bentabol-Ramos Rocio Saenz de Santa Maria-Garcia Monica Vidal-Diaz Ibon Eguiluz-Gracia Almudena Testera-Montes 《International journal of molecular sciences》2022,23(9)
Asthma is a heterogeneous disease in terms of both phenotype and response to therapy. Therefore, there is a great need for clinically applicable tools allowing for improved patient classification, and selection for specific management approaches. Some interventions are highly helpful in selected patients (e.g., allergen immunotherapy or aspirin desensitization), but they are costly and/or difficult to implement. Currently available biomarkers measurable in peripheral blood or exhaled air display many limitations for asthma phenotyping and cannot identify properly the specific triggers of the disease (e.g., aeroallergens or NSAID). The united airway concept illustrates the relevant epidemiological and pathophysiological links between the upper and lower airways. This concept has been largely applied to patient management and treatment, but its diagnostic implications have been less often explored. Of note, a recent document by the European Academy of Allergy and Clinical Immunology proposes the use of nasal allergen challenge to confirm the diagnosis of allergic asthma. Similarly, the nasal challenge with lysine acetylsalicylate (L-ASA) can be used to identify aspirin-sensitive asthma patients. In this review, we will summarize the main features of allergic asthma and aspirin-exacerbated respiratory disease and will discuss the methodology of nasal allergen and L-ASA challenges with a focus on their capacity to phenotype the inflammatory disease affecting both the upper and lower airways. 相似文献