全文获取类型
收费全文 | 1380篇 |
免费 | 90篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 460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 | 176篇 |
出版年
2023年 | 7篇 |
2022年 | 77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1471条查询结果,搜索用时 78 毫秒
971.
972.
Giosuè Scognamiglio Anna De Chiara Maurizio Di Bonito Fabiana Tatangelo Nunzia Simona Losito Annamaria Anniciello Rossella De Cecio Crescenzo D’Alterio Stefania Scala Monica Cantile Gerardo Botti 《International journal of molecular sciences》2016,17(5)
In normal cell physiology, programmed death 1 (PD-1) and its ligand, PD-L1, play an immunoregulatory role in T-cell activation, tolerance, and immune-mediated tissue damage. The PD-1/PD-L1 pathway also plays a critical role in immune escape of tumor cells and has been demonstrated to correlate with a poor prognosis of patients with several types of cancer. However, recent reports have revealed that the immunohistochemical (IHC) expression of the PD-L1 in tumor cells is not uniform for the use of different antibodies clones, with variable specificity, often doubtful topographical localization, and with a score not uniquely defined. The purpose of this study was to analyze the IHC expression of PD-L1 on a large series of several human tumors to correctly define its staining in different tumor tissues. 相似文献
973.
Claudia Bernal Marzia Marciello Monica Mesa Ligia Sierra Gloria Fernandez-Lorente Cesar Mateo Jose M. Guisan 《International Dairy Journal》2013,28(2):76-82
β-galactosidase from Kluyveromyces lactis was covalently immobilised on a Glyoxyl Sepharose (GS) support by multi-point attachment. The enzyme immobilisation process was very efficient; the supports immobilised almost all the protein responsible for the catalytic activity in a short period of time, retaining approximately 82% of the activity in the case of the optimal immobilised preparations. Stability of the GS derivatives varied as a function of enzyme-support incubation time. The optimal immobilised preparation was produced after 2 h of incubation with the support at alkaline pH. This derivative, obtained by multi-point covalent attachment, was 100-fold more stable at pH 7 and 50 °C than the cyanogen bromide Sepharose derivative obtained by a one-point covalent immobilisation method. Stabilisation was also observed under a wide range of experimental conditions. This method allowed the immobilisation of 9000 IU enzyme g?1 of support, resulting in highly active and stable derivatives suitable for industrial processes. 相似文献
974.
Expanding a multilingual media monitoring and information extraction tool to a new language: Swahili
Ralf Steinberger Sylvia Ombuya Mijail Kabadjov Bruno Pouliquen Leo Della Rocca Jenya Belyaeva Monica de Paola Camelia Ignat Erik van der Goot 《Language Resources and Evaluation》2011,45(3):311-330
The Europe Media Monitor (EMM) family of applications is a set of multilingual tools that gather, cluster and classify news in currently fifty languages and that extract named entities and quotations (reported speech) from twenty languages. In this paper, we describe the recent effort of adding the African Bantu language Swahili to EMM. EMM is designed in an entirely modular way, allowing plugging in a new language by providing the language-specific resources for that language. We thus describe the type of language-specific resources needed, the effort involved, and ways of boot-strapping the generation of these resources in order to keep the effort of adding a new language to a minimum. The text analysis applications pursued in our efforts include clustering, classification, recognition and disambiguation of named entities (persons, organisations and locations), recognition and normalisation of date expressions, as well as the identification of reported speech quotations by and about people. 相似文献
975.
Web 2.0, Language Resources and standards to automatically build a multilingual Named Entity Lexicon
Antonio Toral Sergio Ferrández Monica Monachini Rafael Mu?oz 《Language Resources and Evaluation》2012,46(3):383-419
This paper proposes to advance in the current state-of-the-art of automatic Language Resource (LR) building by taking into consideration three elements: (1) the knowledge available in existing LRs, (2) the vast amount of information available from the collaborative paradigm that has emerged from the Web 2.0 and (3) the use of standards to improve interoperability. We present a case study in which a set of LRs for different languages (WordNet for English and Spanish and Parole-Simple-Clips for Italian) are extended with Named Entities (NE) by exploiting Wikipedia and the aforementioned LRs. The practical result is a multilingual NE lexicon connected to these LRs and to two ontologies: SUMO and SIMPLE. Furthermore, the paper addresses an important problem which affects the Computational Linguistics area in the present, interoperability, by making use of the ISO LMF standard to encode this lexicon. The different steps of the procedure (mapping, disambiguation, extraction, NE identification and postprocessing) are comprehensively explained and evaluated. The resulting resource contains 974,567, 137,583 and 125,806 NEs for English, Spanish and Italian respectively. Finally, in order to check the usefulness of the constructed resource, we apply it into a state-of-the-art Question Answering system and evaluate its impact; the NE lexicon improves the system’s accuracy by 28.1%. Compared to previous approaches to build NE repositories, the current proposal represents a step forward in terms of automation, language independence, amount of NEs acquired and richness of the information represented. 相似文献
976.
Felicia Stefania Falvella Marta Caporale Stefania Cheli Antonia Martinetti Rosa Berenato Claudia Maggi Monica Niger Francesca Ricchini Ilaria Bossi Maria Di Bartolomeo Elisa Sottotetti Francesca Futura Bernardi Filippo de Braud Emilio Clementi Filippo Pietrantonio 《International journal of molecular sciences》2015,16(4):8884-8895
Fluoropyrimidines, the mainstay agents for the treatment of colorectal cancer, alone or as a part of combination therapies, cause severe adverse reactions in about 10%–30% of patients. Dihydropyrimidine dehydrogenase (DPD), a key enzyme in the catabolism of 5-fluorouracil, has been intensively investigated in relation to fluoropyrimidine toxicity, and several DPD gene (DPYD) polymorphisms are associated with decreased enzyme activity and increased risk of fluoropyrimidine-related toxicity. In patients carrying non-functional DPYD variants (c.1905+1G>A, c.1679T>G, c.2846A>T), fluoropyrimidines should be avoided or reduced according to the patients’ homozygous or heterozygous status, respectively. For other common DPYD variants (c.496A>G, c.1129-5923C>G, c.1896T>C), conflicting data are reported and their use in clinical practice still needs to be validated. The high frequency of DPYD polymorphism and the lack of large prospective trials may explain differences in studies’ results. The epigenetic regulation of DPD expression has been recently investigated to explain the variable activity of the enzyme. DPYD promoter methylation and its regulation by microRNAs may affect the toxicity risk of fluoropyrimidines. The studies we reviewed indicate that pharmacogenetic testing is promising to direct personalised dosing of fluoropyrimidines, although further investigations are needed to establish the role of DPD in severe toxicity in patients treated for colorectal cancer. 相似文献
977.
978.
Domenico De Berardis Michele Fornaro Nicola Serroni Daniela Campanella Gabriella Rapini Luigi Olivieri Venkataramanujam Srinivasan Felice Iasevoli Carmine Tomasetti Andrea De Bartolomeis Alessandro Valchera Giampaolo Perna Monica Mazza Marco Di Nicola Giovanni Martinotti Massimo Di Giannantonio 《International journal of molecular sciences》2015,16(1):1111-1130
Agomelatine, a melatonergic antidepressant with a rapid onset of action, is one of the most recent drugs in the antidepressant category. Agomelatine’s antidepressant actions are attributed to its sleep-promoting and chronobiotic actions mediated by MT1 and MT2 receptors present in the suprachiasmatic nucleus, as well as to its effects on the blockade of 5-HT2c receptors. Blockade of 5-HT2c receptors causes release of both noradrenaline and dopamine at the fronto-cortical dopaminergic and noradrenergic pathways. The combined actions of agomelatine on MT1/MT2 and 5-HT2c receptors facilitate the resynchronization of altered circadian rhythms and abnormal sleep patterns. Agomelatine appeared to be effective in treating major depression. Moreover, evidence exists that points out a possible efficacy of such drug in the treatment of bipolar depression, anxiety disorders, alcohol dependence, migraines etc. Thus, the aim of this narrative review was to elucidate current evidences on the role of agomelatine in disorders other than major depression. 相似文献
979.
980.