全文获取类型
收费全文 | 672篇 |
免费 | 70篇 |
国内免费 | 36篇 |
专业分类
电工技术 | 62篇 |
综合类 | 105篇 |
化学工业 | 67篇 |
金属工艺 | 7篇 |
机械仪表 | 26篇 |
建筑科学 | 68篇 |
矿业工程 | 40篇 |
能源动力 | 52篇 |
轻工业 | 14篇 |
水利工程 | 108篇 |
石油天然气 | 42篇 |
武器工业 | 9篇 |
无线电 | 38篇 |
一般工业技术 | 39篇 |
冶金工业 | 40篇 |
原子能技术 | 3篇 |
自动化技术 | 58篇 |
出版年
2023年 | 2篇 |
2022年 | 17篇 |
2021年 | 26篇 |
2020年 | 13篇 |
2019年 | 18篇 |
2018年 | 22篇 |
2017年 | 22篇 |
2016年 | 24篇 |
2015年 | 17篇 |
2014年 | 31篇 |
2013年 | 26篇 |
2012年 | 63篇 |
2011年 | 59篇 |
2010年 | 30篇 |
2009年 | 36篇 |
2008年 | 34篇 |
2007年 | 45篇 |
2006年 | 34篇 |
2005年 | 46篇 |
2004年 | 27篇 |
2003年 | 26篇 |
2002年 | 21篇 |
2001年 | 22篇 |
2000年 | 30篇 |
1999年 | 13篇 |
1998年 | 13篇 |
1997年 | 15篇 |
1996年 | 10篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 1篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有778条查询结果,搜索用时 15 毫秒
1.
Simone Grassi Oscar Campuzano Mnica Coll Francesca Cazzato Georgia Sarquella-Brugada Riccardo Rossi Vincenzo Arena Josep Brugada Ramon Brugada Antonio Oliva 《International journal of molecular sciences》2021,22(8)
Inherited cardiomyopathies are frequent causes of sudden cardiac death (SCD), especially in young patients. Despite at the autopsy they usually have distinctive microscopic and/or macroscopic diagnostic features, their phenotypes may be mild or ambiguous, possibly leading to misdiagnoses or missed diagnoses. In this review, the main differential diagnoses of hypertrophic cardiomyopathy (e.g., athlete’s heart, idiopathic left ventricular hypertrophy), arrhythmogenic cardiomyopathy (e.g., adipositas cordis, myocarditis) and dilated cardiomyopathy (e.g., acquired forms of dilated cardiomyopathy, left ventricular noncompaction) are discussed. Moreover, the diagnostic issues in SCD victims affected by phenotype-negative hypertrophic cardiomyopathy and the relationship between myocardial bridging and hypertrophic cardiomyopathy are analyzed. Finally, the applications/limits of virtopsy and post-mortem genetic testing in this field are discussed, with particular attention to the issues related to the assessment of the significance of the genetic variants. 相似文献
2.
3.
Oscar Campuzano Olallo Sanchez-Molero Irene Mademont-Soler Helena Riuró Catarina Allegue Monica Coll Alexandra Pérez-Serra Jesus Mates Ferran Picó Anna Iglesias Ramon Brugada 《International journal of molecular sciences》2015,16(10):25773-25787
A leading cause of death in western countries is sudden cardiac death, and can be associated with genetic disease. Next-generation sequencing has allowed thorough analysis of genes associated with this entity, including, most recently, titin. We aimed to identify potentially pathogenic genetic variants in titin. A total of 1126 samples were analyzed using a custom sequencing panel including major genes related to sudden cardiac death. Our cohort was divided into three groups: 432 cases from patients with cardiomyopathies, 130 cases from patients with channelopathies, and 564 post-mortem samples from individuals showing anatomical healthy hearts and non-conclusive causes of death after comprehensive autopsy. None of the patients included had definite pathogenic variants in the genes analyzed by our custom cardio-panel. Retrospective analysis comparing the in-house database and available public databases also was performed. We identified 554 rare variants in titin, 282 of which were novel. Seven were previously reported as pathogenic. Of these 554 variants, 493 were missense variants, 233 of which were novel. Of all variants identified, 399 were unique and 155 were identified at least twice. No definite pathogenic variants were identified in any of genes analyzed. We identified rare, mostly novel, titin variants that seem to play a potentially pathogenic role in sudden cardiac death. Additional studies should be performed to clarify the role of these variants in sudden cardiac death. 相似文献
4.
The relationship between heart failure (HF), sleep-disordered breathing and cardiac arrhythmias is complex and poorly understood. Whereas the frequency of predominantly obstructive sleep apnea in HF patients is low and similar or moderately higher to that observed in the general population, central sleep apnea (CSA) has been observed in approximately 50% of HF patients, depending on the methods used to detect CSA and patient selection. Despite this high prevalence, it is still unclear whether CSA is merely a marker or an independent risk factor for an adverse prognosis in HF patients and whether CSA is associated with an increased risk for supraventricular as well as ventricular arrhythmias in HF patients. The current review focuses on the relationship between CSA and atrial fibrillation as the most common atrial arrhythmia in HF patients, and on the relationship between CSA and ventricular tachycardia and ventricular fibrillation as the most frequent cause of sudden cardiac death in HF patients. 相似文献
5.
Effect of different size of planer joint enlargement as a noninvasive and practical strategy for seismic retrofit of gravity load designed external reinforced concrete beam‐column connections was experimentally investigated. The joint region was enlarged using steel angles that are mounted using prestressed cross‐ties. Reverse cyclic load tests on five half‐scale control and retrofitted external RC beam‐column connections were conducted. Three different size of planer joint enlargement being 180, 140, and 90 mm were considered for retrofitted specimens. The performance of the retrofitted specimens is compared with that of the control gravity load designed beam‐column connections, in terms of load–displacement hysteresis curve, energy dissipation and ductility capacities, and global strength and stiffness degradation behavior. The experimental results showed that increasing the size of planer joint enlargement significantly enhances the seismic capacity of the retrofitted connections, in terms of strength, stiffness, energy dissipation, and ductility capacity and also planer joint enlargement can relocate beam plastic hinges to outside the joint panel. 相似文献
6.
突发性水污染事故的应急处理 总被引:9,自引:1,他引:9
近年来,我国城市水源地突发性污染事件日益增加,如何保护水源地生态环境安全和城市供水系统安全,以及如何快速、有效地处理突发性水污染事故已成为亟需解决的问题。介绍了突发性水污染事故应急处理的一般程序,重点讨论了应急措施、处理技术及区域污染物的处理方法。对于危及城市自来水厂区域的突发性污染事故,若在其处理能力范围内,可采用强化混凝、三级处理、备用水源地取水、开启与邻近城市间的备用供水管网等应急处理方法向城市供水;对于自来水厂取水口等遭受污染的水域,可采用吸附、化学沉淀、化学氧化、强化消毒等方法对不同污染物进行治理或隔离。 相似文献
7.
8.
通过对铜吊车梁直角式突变支座双向荷载的静力和疲劳试验,研究了突变支座各板件的应力状态;讨论了荷载循环次数对突变点附近腹板应力的影响;对这种吊车梁的疲劳破坏特征也作了较详细的描述,提出了设计施工中应当采取的技术措施。 相似文献
9.
10.
通过某地区电网分析了光伏电站对送出输电线路相电流差突变量选相元件和序分量选相元件的影响。光伏电站的容量相对于系统容量很小,在送出主变中性点接地的系统中,当送出输电线路发生接地故障时,光伏电站侧零序等值阻抗远小于其正、负序等值阻抗,故障电流主要成分为零序电流,因而三相故障电流幅值、相位相近,致使选相元件误选相。以某地区光伏电站并网为例,在PSCAD/EMTDC中分别搭建了基于相电流差突变量和基于序分量的选相元件的仿真模型,并对两种选相元件进行测试。仿真结果表明两种选相元件的动作性能均受到严重影响。 相似文献