全文获取类型
收费全文 | 255篇 |
免费 | 11篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 72篇 |
金属工艺 | 1篇 |
机械仪表 | 12篇 |
建筑科学 | 12篇 |
能源动力 | 11篇 |
轻工业 | 49篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 26篇 |
一般工业技术 | 36篇 |
冶金工业 | 11篇 |
原子能技术 | 1篇 |
自动化技术 | 29篇 |
出版年
2024年 | 2篇 |
2023年 | 4篇 |
2022年 | 7篇 |
2021年 | 12篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 10篇 |
2017年 | 12篇 |
2016年 | 7篇 |
2015年 | 9篇 |
2014年 | 11篇 |
2013年 | 25篇 |
2012年 | 15篇 |
2011年 | 19篇 |
2010年 | 17篇 |
2009年 | 14篇 |
2008年 | 15篇 |
2007年 | 11篇 |
2006年 | 7篇 |
2005年 | 6篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 4篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1985年 | 1篇 |
1984年 | 5篇 |
1983年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有267条查询结果,搜索用时 15 毫秒
191.
Electrical Properties of Bioelectrodes 总被引:4,自引:0,他引:4
Onaral Banu Sun Hun H. Schwan Herman P. 《IEEE transactions on bio-medical engineering》1984,(12):827-832
This paper concentrates on the electrical properties of metal electrode?electrolyte interfaces with emphasis on contributions by Schwan's laboratory at the University of Pennsylvania and more recently by the Bio-Electrode Research Laboratory at Drexel University. We cover the fundamental aspects of electrical characterization studies in a wide dynamic range for the amplitude and frequency content under both linear and nonlinear conditions. 相似文献
192.
The author studies the realization of fully integrated MOS oscillators with multidecade tuning range and top speed exceeding 1 GHz. This fast operation requires the use of submicrometer fabrication technology. To overcome the analog circuit limitations of the latter, the design of the oscillator is simplified and, in turn, highly redundant digital and analog control capability is provided. A brief review of possible oscillator structures is given and it is found that the best approach for high-speed, wide-range specifications is the relaxation network of the constant-current charge type. Circuit techniques are presented to increase the speed of the latter, based on active use of parasitics and simplified feedback networks. NMOS and CMOS implementations are discussed and compared. The design and performance of an experimental submicrometer NMOS oscillator is presented. This device covers the 100-kHz-to-1-GHz frequency range and has a robust structure 相似文献
193.
Colour temperature and illumination level have affected the subjective impressions at an office setting. 2000 lx was preferred to 500 lx for impressions of comfort, spaciousness, brightness and saturation evaluation. A 4000 K colour temperature was preferred to 2700 K for impressions of ‘comfort and spaciousness’, while 2700 K was suggested for ‘relaxation’ and ‘saturation evaluation’. Test results indicate that, task–background contrast is more important and shall be studied for ‘perceived brightness’ evaluation. Participants liked the ‘mixed colour temperature mood’, the remote control and the flexibility in the lighting system and the majority offered to use it at offices. 相似文献
194.
P. Senthil Kumari A. R. Nadira Banu Kamal 《Automatic Control and Computer Sciences》2016,50(3):165-178
Cloud computing is currently emerging as a promising next-generation architecture in the Information Technology (IT) industry and education sector. The encoding process of state information from the data and protection are governed by the organizational access control policies. An encryption technique protects the data confidentiality from the unauthorized access leads to the development of fine-grained access control policies with user attributes. The Attribute-Based Encryption (ABE) verifies the intersection of attributes to the multiple sets. The handling of adding or revoking the users is difficult with respect to changes in policies. The inclusion of multiple encrypted copies for the same key raised the computational cost. This paper proposes an efficient Key Derivation Policy (KDP) for improvement of data security and integrity in the cloud and overcomes the problems in traditional methods. The local key generation process in proposed method includes the data attributes. The secret key is generated from the combination of local keys with the user attribute by a hash function. The original text is recovered from the ciphertext by the decryption process. The key sharing between data owner and user validates the data integrity referred MAC verification process. The proposed efficient KDP with MAC verification analyze the security issues and compared with the Cipher Text–Attribute-Based Encryption (CP-ABE) schemes on the performance parameters of encryption time, computational overhead and the average lifetime of key generation. The major advantage of proposed approach is the updating of public information and easy handling of adding/revoking of users in the cloud. 相似文献
195.
Medeni Soysal K. Berker Loğoğlu Mashar Tekin Ersin Esen Ahmet Saracoğlu Banu Oskay Acar Ezgi Can Ozan Tuğrul K. Ateş Hakan Sevimli Müge Sevinç İlkay Atıl Savaş Özkan Mehmet Ali Arabacı Seda Tankız Talha Karadeniz Duygu Önür Sezin Selçuk A. Aydın Alatan Tolga Çiloğlu 《Multimedia Tools and Applications》2014,72(3):2787-2832
Concept detection stands as an important problem for efficient indexing and retrieval in large video archives. In this work, the KavTan System, which performs high-level semantic classification in one of the largest TV archives of Turkey, is presented. In this system, concept detection is performed using generalized visual and audio concept detection modules that are supported by video text detection, audio keyword spotting and specialized audio-visual semantic detection components. The performance of the presented framework was assessed objectively over a wide range of semantic concepts (5 high-level, 14 visual, 9 audio, 2 supplementary) by using a significant amount of precisely labeled ground truth data. KavTan System achieves successful high-level concept detection performance in unconstrained TV broadcast by efficiently utilizing multimodal information that is systematically extracted from both spatial and temporal extent of multimedia data. 相似文献
196.
Broder GR Ranasinghe RT She JK Banu S Birtwell SW Cavalli G Galitonov GS Holmes D Martins HF Macdonald KF Neylon C Zheludev N Roach PL Morgan H 《Analytical chemistry》2008,80(6):1902-1909
Microparticles incorporating micrometer-sized diffractive bar codes have been modified with oligonucleotides and immunoglobulin Gs to enable DNA hybridization and immunoassays. The bar codes are manufactured using photolithography of a chemically functional commercial epoxy photoresist (SU-8). When attached by suitable linkers, immobilized probe molecules exhibit high affinity for analytes and fast reaction kinetics, allowing detection of single nucleotide differences in DNA sequences and multiplexed immunoassays in <45 min. Analysis of raw data from assays carried out on the diffractive microparticles indicates that the reproducibility and sensitivity approach those of commercial encoding platforms. Micrometer-sized particles, imprinted with several superimposed diffraction gratings, can encode many million unique codes. The high encoding capacity of this technology along with the applicability of the manufactured bar codes to multiplexed assays will allow accurate measurement of a wide variety of molecular interactions, leading to new opportunities in diverse areas of biotechnology such as genomics, proteomics, high-throughput screening, and medical diagnostics. 相似文献
197.
In this study, we aimed to investigate the removal of basic dyes, including Safranin T (ST), Nile Blue A (NBA), and Brilliant Cresyl Blue (BCB), from aqueous solution with a sulfonated phenol–formaldehyde resin. This sulfonated resin was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The adsorption properties of this resin were investigated under different adsorption conditions with different initial dye concentrations, contact times, and pH values. The adsorption equilibrium data were analyzed with Langmuir and Freundlich models. The adsorption behaviors of ST, NBA, and BCB onto the sulfonated resol‐type phenol–formaldehyde resin were better described by the Freundlich model. The adsorption capacities of the sulfonated resol resin for ST, NBA, and BCB decreased in the following order: NBA > BCB > ST. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
198.
Tamilselvan SUBRAMANI Suresh RAO Kamatchiammal SENTHILKUMAR Soundararajan PERIASAMY Noorjahan Banu ALITHEEN 《Biocell》2013,37(3):71-76
The present study demonstrates that the expression of c-Jun and c-Fos are elevated in gingival fibroblast cells treated with angiotensin II and cyclosporine. The healthy human gingival tissues were collected and gingival fibroblasts were isolated and cultured. We used RT-PCR and Western blot analysis to identify the expression of c-Jun and c-Fos in cyclosporine and angiotensin II treated human gingival fibroblast cells. We found that angiotensin II in combination with cyclosporine induces c-Jun and c-Fos expressions significantly; however, the angiotensin II antagonist losartan inhibits the expression of c-Jun and c-Fos (p < 0.01). The data suggest that angiotensin II in combination with cyclosporine modulates the expression of c-Jun and c-Fos in human gingival fibroblast cells. 相似文献
199.
Cotar AI Badescu D Oprea M Dinu S Banu O Dobreanu D Dobreanu M Ionac A Flonta M Straut M 《International journal of molecular sciences》2011,12(12):9504-9513
Infective endocarditis (IE) is a serious, life-threatening disease with highly variable clinical signs, making its diagnostic a real challenge. A diagnosis is readily made if blood cultures are positive, but in 2.5 to 31% of all infective endocarditis cases, routine blood cultures are negative. In such situations, alternative diagnostic approaches are necessary. Coxiella burnetii and Bartonella spp. are the etiological agents of blood culture-negative endocarditis (BCNE) most frequently identified by serology. The purpose of this study is to investigate the usefulness of molecular assays, as complementary methods to the conventional serologic methods for the rapid confirmatory diagnostic of Q fever endocarditis in patients with BCNE. Currently, detection of C. burnetii by culture or an antiphase I IgG antibody titers >800 represents a major Duke criterion for defining IE, while a titers of >800 for IgG antibodies to either B. henselae or B. quintana is used for the diagnosis of endocarditis due to Bartonella spp. We used indirect immunofluorescence assays for the detection of IgG titers for C. burnetii, B. henselae and B. quintana in 57 serum samples from patients with clinical suspicion of IE. Thirty three samples originated from BCNE patients, whereas 24 were tested before obtaining the blood cultures results, which finally were positive. The results of serologic testing showed that nine out of 33 BCNE cases exhibited antiphase I C. burnetii IgG antibody titer >800, whereas none has IgG for B. henselae or B. quintana. Subsequently, we used nested-PCR assay for the amplification of C. burnetii DNA in the nine positive serum samples, and we obtained positive PCR results for all analyzed cases. Afterwards we used the DNA sequencing of amplicons for the repetitive element associated to htpAB gene to confirm the results of nested-PCR. The results of sequencing allowed us to confirm that C. burnetii is the causative microorganism responsible for BCNE. In conclusion, the nested PCR amplification followed by direct sequencing is a reliable and accurate method when applied to serum samples, and it may be used as an additional test to the serological methods for the confirmatory diagnosis of BCNE cases determined by C. burnetii. 相似文献
200.
Derya Alkan Figen Tokatli Banu Ozen 《Journal of the American Oil Chemists' Society》2012,89(2):261-268
The aim of this research was to characterize the extra virgin olive oil samples from different locations in the Aegean coastal
area of Turkey in terms of their phenolic compositions for two consecutive years to show the classification of oil samples
with respect to harvest year and geography. Forty seven commercial olive oil samples were analyzed with HPLC–DAD, and 17 phenolic
compounds were quantified. Hydroxytyrosol, tyrosol, vanillic acid, p-coumaric acid, ferulic acid, cinnamic acid, luteolin and apigenin were the characteristic phenols observed in all oil samples
for two harvest years. Syringic acid, vanillin and m-coumaric acid were the phenolic compounds appeared in the olive oil depending on the harvest year. Partial least square-discriminant
analysis (PLS-DA) of data revealed that oils from the north Aegean and south Aegean areas had different phenolic profiles.
The phenolic compounds, which played significant roles in the discrimination of the olive oils, were tyrosol, oleuropein aglycon,
cinnamic acid, apigenin and hydroxytyrosol to tyrosol ratio. The Aegean coastal region is the largest olive oil producer and
exporter of Turkey. This study shows that the olive oils from different parts of the region have their own defining characteristics
that can be used in the authentication studies and geographical labeling of Turkish olive oils. 相似文献