全文获取类型
收费全文 | 7432篇 |
免费 | 904篇 |
国内免费 | 480篇 |
专业分类
电工技术 | 167篇 |
综合类 | 237篇 |
化学工业 | 3763篇 |
金属工艺 | 239篇 |
机械仪表 | 266篇 |
建筑科学 | 170篇 |
矿业工程 | 6篇 |
能源动力 | 35篇 |
轻工业 | 940篇 |
水利工程 | 21篇 |
石油天然气 | 12篇 |
武器工业 | 5篇 |
无线电 | 587篇 |
一般工业技术 | 868篇 |
冶金工业 | 297篇 |
原子能技术 | 158篇 |
自动化技术 | 1045篇 |
出版年
2024年 | 60篇 |
2023年 | 348篇 |
2022年 | 1465篇 |
2021年 | 1389篇 |
2020年 | 559篇 |
2019年 | 466篇 |
2018年 | 308篇 |
2017年 | 277篇 |
2016年 | 356篇 |
2015年 | 307篇 |
2014年 | 379篇 |
2013年 | 462篇 |
2012年 | 349篇 |
2011年 | 351篇 |
2010年 | 236篇 |
2009年 | 226篇 |
2008年 | 197篇 |
2007年 | 184篇 |
2006年 | 132篇 |
2005年 | 145篇 |
2004年 | 115篇 |
2003年 | 76篇 |
2002年 | 88篇 |
2001年 | 73篇 |
2000年 | 44篇 |
1999年 | 43篇 |
1998年 | 30篇 |
1997年 | 24篇 |
1996年 | 27篇 |
1995年 | 19篇 |
1994年 | 24篇 |
1993年 | 14篇 |
1992年 | 10篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1956年 | 1篇 |
排序方式: 共有8816条查询结果,搜索用时 15 毫秒
1.
Penedo Frank J.; Dahn Jason R.; Gonzalez Jeffrey S.; Molton Ivan; Carver Charles S.; Antoni Michael H.; Roos Bernard A.; Schneiderman Neil 《Canadian Metallurgical Quarterly》2003,22(2):220
This study evaluated relations among optimism, perceived stress management skills (PSMS), and positive mood in 46 men who had surgical treatment for localized prostate cancer. The authors found that optimism, PSMS, and positive mood scores were positively correlated. Positive mood was unrelated to demographic and disease-related control variables. In a hierarchical regression model controlling for PSMS, the relationship between optimism and positive mood became nonsignificant, whereas PSMS remained a correlate of positive mood. Results suggest that the relationship between optimism and positive mood may be mediated by belief in being able to use stress management techniques effectively. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
2.
Javier Roca-Pardiñas Carmen Cadarso-Suárez María J. Lado 《Computational statistics & data analysis》2008,52(4):1958-1970
In many applications, the joint effect of two continuous covariates on the target binary response may vary across groups defined by levels of a given factor. A testing procedure that would enable this type of surface-by-factor interactions to be detected has been designed. To accomplish this goal, a logistic generalized additive model (GAM) with bivariate continuous interactions varying across groups defined by levels of a factor is considered. A local scoring algorithm based on local linear kernel smoothers was implemented to estimate the proposed logistic GAM. Bootstrap resampling techniques were used for the purpose of testing for factor-by-surface interactions. Given the high computational cost involved, binning techniques were used to speed up computation in the estimation and testing processes. The adequacy of the bootstrap-based test was assessed by means of a simulation study. If a factor-by-surface interaction is detected in the model, it is then established that the use of the odds-ratio curves is very useful in obtaining a direct interpretation of the fitted model. The benefits of using this methodology when analyzing real data are illustrated by applying the technique to the outputs produced by a computerized system dedicated to the early detection of breast cancer. 相似文献
3.
乳腺癌中着丝粒蛋白CenpG的差异表达 总被引:4,自引:0,他引:4
用间接免疫荧光(IIF)验证了着丝粒蛋白CenpG的一种抗血清;通过对31例乳腺癌组织块及每一例病人的癌旁正常(非癌性)组织块蛋白提取物进行免疫印迹(Western blot)分析,发现多数情况下(71%)癌组织中着丝粒蛋白CenpG(95kD)过表达;在两例乳腺癌组织中还发现了一种能被CenpG抗血清识别的43kD蛋白质成分。结果表明,新近发现和命名的CenpG(或者还有其他相关成分)的差异表达可能与细胞恶性增殖有关。 相似文献
4.
激光远距作用的机制与效应 总被引:1,自引:0,他引:1
本文定量分析激光远距作用的机理并对它们在治癌中的作用作简要的论述。 相似文献
5.
Wide variability exists with respect to how breast cancer survivors respond to common psychological and psychosocial challenges of their disease, ranging from posttraumatic stress disorder to posttraumatic growth. This cross-sectional study examined contextual, disease-related, and intraindividual predictors of posttraumatic growth in 224 randomly selected breast cancer survivors. A series of hierarchical regression analyses found that age at diagnosis, marital status, employment, education, perceived intensity of disease, and active coping accounted for 34%, 35%, and 28% of the variance in growth in relationships with others, new possibilities, and appreciation for life. These findings suggest that a more comprehensive model of growth will be helpful in understanding the various factors that play a role in breast cancer survivors' perception of psychological and psychosocial growth. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
6.
7.
Conventional cancer therapies, the second leading cause of death worldwide, result in serious side effects and, at best, merely extend the patient''s lifespan by a few years. Searching for effective prevention is of high priority in both basic and clinical sciences. In recent decades natural products have been considered to be an important source of cancer chemopreventive agents. Red wine polyphenols, which consisted of various powerful antioxidants such as flavonoids and stilbenes, have been implicated in cancer prevention and that promote human health without recognizable side effects. Since resveratrol, a major component of red wine polyphenols, has been studied and reviewed extensively for its chemopreventive activity to interfere with the multi-stage carcinogenesis, this review focuses on recent progress in studies on cancer chemopreventive activities of red wine polyphenol extracts and fractions as well as other red wine polyphenols, like procyanidin B5 analogues and myricetin. 相似文献
8.
Yu. I. Petunin E. A. Djomina D. A. Klyushin M. Yu. Savkina 《Cybernetics and Systems Analysis》2006,42(3):449-455
Spline regression is used to analyze the influence of radiation on the cancer probability in a group of participants of Chernobyl
accident mitigation, depending on the exposure dose. A new method is proposed to approximate modified polygons by linear splines
with two nodes. An algorithm for the identification of a transition point is outlined.
__________
Translated from Kibernetika i Sistemnyi Analiz, No. 3, pp. 168–176, May–June 2006. 相似文献
9.
Ioannis D. Moscholios Michael D. Logothetis 《International Journal of Communication Systems》2006,19(1):67-93
We consider a single link loss system of quasi‐random input, described by the Engset multirate loss model (EnMLM). Blocked calls may once reattempt to be connected to the system requiring less bandwidth; then the system is described by the single retry model for finite sources (f‐SRM). The EnMLM and the f‐SRM are extended with the single threshold finite source model (f‐STM), where calls may attempt to be connected to the system with less bandwidth requirements, according to the link occupancy, before blocking occurs. We focus on CBP equalization in the EnMLM, f‐SRM and f‐STM, under the bandwidth reservation (BR) policy. For this analysis, we apply two approximate methods, the Roberts' method and the method of reverse transition rates (RTR), which lead to a recursive CBP calculation. We evaluate the accuracy of the above models under the BR policy by comparing the analytical with simulation CBP results, based on the relative approximation errors (RAE). The results are highly satisfactory because they show that the proposed models (formulas) lead to small RAE. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
10.
Maria Buuales Maria Cristina Ballesteros-Briones Manuela Gonzalez-Aparicio Sandra Hervas-Stubbs Eva Martisova Uxua Mancheo Ana Ricobaraza Sara Lumbreras Cristian Smerdou Ruben Hernandez-Alcoceba 《International journal of molecular sciences》2021,22(8)
Immune checkpoint inhibitors (ICIs) have demonstrated remarkable efficacy in a growing number of malignancies. However, overcoming primary or secondary resistances is difficult due to pharmacokinetics issues and side effects associated with high systemic exposure. Local or regional expression of monoclonal antibodies (mAbs) using gene therapy vectors can alleviate this problem. In this work, we describe a high-capacity adenoviral vector (HCA-EFZP-aPDL1) equipped with a mifepristone-inducible system for the controlled expression of an anti-programmed death ligand 1 (PD-L1) blocking antibody. The vector was tested in an immune-competent mouse model of colorectal cancer based on implantation of MC38 cells. A single local administration of HCA-EFZP-aPDL1 in subcutaneous lesions led to a significant reduction in tumor growth with minimal release of the antibody in the circulation. When the vector was tested in a more stringent setting (rapidly progressing peritoneal carcinomatosis), the antitumor effect was marginal even in combination with other immune-stimulatory agents such as polyinosinic-polycytidylic acid (pI:C), blocking mAbs for T cell immunoglobulin, mucin-domain containing-3 (TIM-3) or agonistic mAbs for 4-1BB (CD137). In contrast, macrophage depletion by clodronate liposomes enhanced the efficacy of HCA-EFZP-aPDL1. These results highlight the importance of addressing macrophage-associated immunoregulatory mechanisms to overcome resistance to ICIs in the context of colorectal cancer. 相似文献