全文获取类型
收费全文 | 66513篇 |
免费 | 1423篇 |
国内免费 | 310篇 |
专业分类
电工技术 | 1105篇 |
综合类 | 724篇 |
化学工业 | 8069篇 |
金属工艺 | 1575篇 |
机械仪表 | 1560篇 |
建筑科学 | 1432篇 |
矿业工程 | 473篇 |
能源动力 | 1070篇 |
轻工业 | 4164篇 |
水利工程 | 835篇 |
石油天然气 | 246篇 |
武器工业 | 6篇 |
无线电 | 4553篇 |
一般工业技术 | 7796篇 |
冶金工业 | 26416篇 |
原子能技术 | 630篇 |
自动化技术 | 7592篇 |
出版年
2023年 | 241篇 |
2022年 | 230篇 |
2021年 | 305篇 |
2020年 | 178篇 |
2019年 | 252篇 |
2018年 | 762篇 |
2017年 | 981篇 |
2016年 | 1369篇 |
2015年 | 1021篇 |
2014年 | 825篇 |
2013年 | 1432篇 |
2012年 | 2757篇 |
2011年 | 3365篇 |
2010年 | 1315篇 |
2009年 | 1479篇 |
2008年 | 1370篇 |
2007年 | 1423篇 |
2006年 | 1225篇 |
2005年 | 4132篇 |
2004年 | 3176篇 |
2003年 | 2704篇 |
2002年 | 1569篇 |
2001年 | 1437篇 |
2000年 | 894篇 |
1999年 | 1211篇 |
1998年 | 7942篇 |
1997年 | 5020篇 |
1996年 | 3405篇 |
1995年 | 2096篇 |
1994年 | 1642篇 |
1993年 | 1686篇 |
1992年 | 601篇 |
1991年 | 637篇 |
1990年 | 634篇 |
1989年 | 605篇 |
1988年 | 578篇 |
1987年 | 478篇 |
1986年 | 433篇 |
1985年 | 442篇 |
1984年 | 299篇 |
1983年 | 287篇 |
1982年 | 314篇 |
1981年 | 396篇 |
1980年 | 395篇 |
1979年 | 234篇 |
1978年 | 260篇 |
1977年 | 872篇 |
1976年 | 1670篇 |
1975年 | 225篇 |
1973年 | 172篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Correlation between instrumental texture and colour quality attributes with sensory analysis of selected cheeses as affected by fat contents
下载免费PDF全文
![点击此处可从《International Journal of Food Science & Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A. Półtorak J. Wyrwisz M. Moczkowska M. Marcinkowska‐Lesiak A. Stelmasiak U. Ulanicka M. Zalewska A. Wierzbicka Da‐Wen Sun 《International Journal of Food Science & Technology》2015,50(4):999-1008
This study evaluated several physical and sensory parameters of different types of cheese available in the Polish market. The measurements of textural properties were conducted in an Instron universal testing machine, while the colour properties of cheeses were measured using a Minolta chromameter. The chemical composition was determined by means of the near‐infrared spectroscopy (NIRs). Moreover, a trained sensory panel was invited to assess the cheese texture‐related properties. Generally, cheeses with reduced fat content were characterised by higher hardness, adhesiveness, cohesiveness and elasticity. Texture‐related parameters of cheese with canola oil were comparable to that of most of full‐fat cheeses. The correlation analysis between physical and sensory attributes related to cheese textural properties indicated the potential applications of TPA, shear and penetration tests (r = 0.766, r = 0.75 and r = 0.765, respectively) for the evaluation of sensory properties related to the hardness. Meanwhile, the elasticity of cheese obtained from sensory evaluation was strongly correlated with the elasticity determined from the shear test (r = 0.722) and moderately correlated with the elasticity from penetration test (r = 0.588), indicating a need to refine the method of penetration test. In addition, cheeses exhibited higher meltability during convection heating at 230 °C than microwave heating. The values of meltability for cheese with reduced fat content were lower than those of full‐fat cheese. 相似文献
12.
Ugur Gezer Ebru E. Y?rüker Metin Keskin Cemil Burak Kulle Yoganiranjana Dharuman Stefan Holdenrieder 《International journal of molecular sciences》2015,16(12):29654-29662
Circulating nucleic acids (CNAs) are under investigation as a liquid biopsy in cancer as potential non-invasive biomarkers, as stable structure in circulation nucleosomes could be valuable sources for detection of cancer-specific alterations in histone modifications. Our interest is in histone methylation marks with a focus on colorectal cancer, one of the leading cancers respective the incidence and mortality. Our previous work included the analysis of trimethylations of lysine 9 on histone 3 (H3K9me3) and of lysine 20 on histone 4 (H4K20me3) by chromatin immuno- precipitation-related PCR in circulating nucleosomes. Here we asked whether global immunologic measurement of histone marks in circulation could be a suitable approach to show their potential as biomarkers. In addition to H3K9me3 and H4K20me3 we also measured H3K27me3 in plasma samples from CRC patients (n = 63) and cancer free individuals (n = 40) by ELISA-based methylation assays. Our results show that of three marks, the amounts of H3K27me3 (p = 0.04) and H4K20me3 (p < 0.001) were significantly lower in CRC patients than in healthy controls. For H3K9me3 similar amounts were measured in both groups. Areas under the curve (AUC) in receiver operating characteristic (ROC) curves indicating the power of CRC detection were 0.620 for H3K27me3, 0.715 for H4K20me3 and 0.769 for the combination of both markers. In conclusion, findings of this preliminary study reveal the potential of blood-based detection of CRC by quantification of histone methylation marks and the additive effect of the marker combination. 相似文献
13.
14.
15.
Alfredo M. Gravagnuolo Eden Morales‐Narváez Charlene Regina Santos Matos Sara Longobardi Paola Giardina Arben Merkoçi 《Advanced functional materials》2015,25(38):6084-6092
Class I hydrophobin Vmh2, a peculiar surface active and versatile fungal protein, is known to self‐assemble into chemically stable amphiphilic films, to be able to change wettability of surfaces, and to strongly adsorb other proteins. Herein, a fast, highly homogeneous and efficient glass functionalization by spontaneous self‐assembling of Vmh2 at liquid–solid interfaces is achieved (in 2 min). The Vmh2‐coated glass slides are proven to immobilize not only proteins but also nanomaterials such as graphene oxide (GO) and quantum dots (QDs). As models, bovine serum albumin labeled with Alexa 555 fluorophore, anti‐immunoglobulin G antibodies, and cadmium telluride QDs are patterned in a microarray fashion in order to demonstrate functionality, reproducibility, and versatility of the proposed substrate. Additionally, a GO layer is effectively and homogeneously self‐assembled onto the studied functionalized surface. This approach offers a quick and simple alternative to immobilize nanomaterials and proteins, which is appealing for new bioanalytical and nanobioenabled applications. 相似文献
16.
Morampudi Mahesh Kumar Prasad Munaga V. N. K. Raju U. S. N. 《Multimedia Tools and Applications》2020,79(27-28):19215-19237
Multimedia Tools and Applications - Rapid advancement in technology has led to the use of biometric authentication in every field. In particular, from the past few years, iris recognition systems... 相似文献
17.
The Journal of Supercomputing - Deep learning algorithms have yielded remarkable results in medical diagnosis and image analysis, besides their contribution to improvements in a number of fields... 相似文献
18.
J Comas I Rodríguez-Roda M Poch K V Gernaey C Rosen U Jeppsson 《Water science and technology》2006,53(4-5):303-311
Wastewater treatment plant operators encounter complex operational problems related to the activated sludge process and usually respond to these by applying their own intuition and by taking advantage of what they have learnt from past experiences of similar problems. However, previous process experiences are not easy to integrate in numerical control, and new tools must be developed to enable re-use of plant operating experience. The aim of this paper is to investigate the usefulness of a case-based reasoning (CBR) approach to apply learning and re-use of knowledge gained during past incidents to confront actual complex problems through the IWA/COST Benchmark protocol. A case study shows that the proposed CBR system achieves a significant improvement of the benchmark plant performance when facing a high-flow event disturbance. 相似文献
19.
In this paper, implementation of the Benchmark Simulation Model No 2 (BSM2) within Matlab-Simulink is presented. The BSM2 is developed for plant-wide WWTP control strategy evaluation on a long-term basis. It consists of a pre-treatment process, an activated sludge process and sludge treatment processes. Extended evaluation criteria are proposed for plant-wide control strategy assessment. Default open-loop and closed-loop strategies are also proposed to be used as references with which to compare other control strategies. Simulations indicate that the BM2 is an appropriate tool for plant-wide control strategy evaluation. 相似文献
20.
From an experimental and theoretical investigation of the continuity of influent inorganic suspended solids (ISS) along the links connecting the primary settling tank (PST), fully aerobic or N removal activated sludge (AS) and anaerobic and aerobic sludge digestion unit operations, it was found that the influent wastewater (fixed) ISS concentration is conserved through primary sludge anaerobic digestion, activated sludge and aerobic digestion unit operations. However, the measured ISS flux at different stages through a series of wastewater treatment plant (WWTP) unit operations is not equal to the influent ISS flux, because the ordinary heterotrophic organisms (OHO) biomass contributes to the ISS flux by differing amounts depending on the active fraction of the VSS solids at that stage. 相似文献