全文获取类型
收费全文 | 5330篇 |
免费 | 476篇 |
国内免费 | 55篇 |
专业分类
电工技术 | 61篇 |
综合类 | 21篇 |
化学工业 | 1242篇 |
金属工艺 | 73篇 |
机械仪表 | 264篇 |
建筑科学 | 100篇 |
矿业工程 | 8篇 |
能源动力 | 330篇 |
轻工业 | 708篇 |
水利工程 | 64篇 |
石油天然气 | 30篇 |
武器工业 | 1篇 |
无线电 | 693篇 |
一般工业技术 | 1199篇 |
冶金工业 | 80篇 |
原子能技术 | 51篇 |
自动化技术 | 936篇 |
出版年
2024年 | 36篇 |
2023年 | 205篇 |
2022年 | 481篇 |
2021年 | 748篇 |
2020年 | 455篇 |
2019年 | 511篇 |
2018年 | 467篇 |
2017年 | 389篇 |
2016年 | 389篇 |
2015年 | 235篇 |
2014年 | 285篇 |
2013年 | 383篇 |
2012年 | 227篇 |
2011年 | 283篇 |
2010年 | 159篇 |
2009年 | 137篇 |
2008年 | 87篇 |
2007年 | 86篇 |
2006年 | 35篇 |
2005年 | 24篇 |
2004年 | 34篇 |
2003年 | 25篇 |
2002年 | 17篇 |
2001年 | 7篇 |
2000年 | 11篇 |
1999年 | 13篇 |
1998年 | 17篇 |
1997年 | 9篇 |
1996年 | 11篇 |
1995年 | 16篇 |
1994年 | 7篇 |
1993年 | 11篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 1篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 1篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 1篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1961年 | 1篇 |
排序方式: 共有5861条查询结果,搜索用时 0 毫秒
41.
Jing Li Zhibin Su Junxian Huang Weijie Feng Tingyang Wei Kun Meng Yaseen Muhammad 《应用聚合物科学杂志》2021,138(10):49967
This study reports the effect of polydopamine bionic coating and γ-methacryloxypropyltrimethoxysilane (KH570) composite modified polyacrylonitrile (PAN) fiber as a secondary modifier on the performance of styrene-butadiene-styrene (SBS) modified asphalt. Dynamic shear rheometer test indicated the complex shear modulu, storage modulus, and loss modulus of modified PAN (KD-PAN) incorporated SBS modified asphalt was increased by 12.4, 20.5, and 11.2%, respectively compared with PAN/SBS modified asphalt. The master curve of G* of fiber/SBS composite modified asphalt shows that the deformation resistance of KD-PAN/SBS modified asphalt is greater than that of PAN/SBS modified asphalt in the entire loading frequency range. The cone penetration test showed significantly enhanced shear strength of KD-PAN/SBS modified asphalt. The adhesion work test results and SEM images of interface between fiber and SBS modified asphalt revealed that the adhesion effect of KD-PAN and SBS modified asphalt is better than that of PAN and SBS modified asphalt. SEM and AFM images of fiber further showed that the fiber surface becomes rough after modification. The increased surface roughness of KD-PAN facilitated the adherence of SBS modified asphalt to it, which in turn led to the enhanced performance of KD-PAN/SBS composite modified asphalt at the same fiber content and temperature. 相似文献
42.
Mohsin Bilal Hasan Mujtaba Muhammad Arfan Jaffar 《Multimedia Tools and Applications》2016,75(11):6533-6548
We propose a modified particle swarm optimization (MPSO) based method for Pseudo De-convolution of the ill-posed inverse problem namely, the space-variant image degradation (SVD). In this paper, SVD is simulated by the pseudo convolution of different sub-regions of the image with different known blurring kernels and additive random noise with unknown variance. Two heuristic modifications are proposed in PSO: 1) Initialization of the swarm and 2) Mutation of the global best. Fuzzy logic is applied for the computation of regularization parameter (RP) to cater for the sensitivity of the problem. The computation of RP is crucial due to the additive noise in the SVD image. Thus mathematical morphology (MM) is applied for better extraction of spatial activity from the distorted image. The performance of the proposed method is evaluated with different test images and noise powers. Comparative analysis demonstrates the superiority of proposed restoration, in terms of quantitative measures, over well-known existing and state-of-the-art SVD approaches. 相似文献
43.
Richard O. Sinnott Christopher Bayliss Andrew Bromage Gerson Galang Yikai Gong Philip Greenwood Glenn Jayaputera Davis Marques Luca Morandini Ghazal Nogoorani Hossein Pursultani Muhammad Sarwar William Voorsluys Ivo Widjaja 《Journal of Grid Computing》2016,14(4):603-618
Big data technologies and a range of Government open data initiatives provide the basis for discovering new insights into cities; how they are planned, how they managed and the day-to-day challenges they face in health, transport and changing population profiles. The Australian Urban Research Infrastructure Network (AURIN – www.aurin.org.au) project is one example of such a big data initiative that is currently running across Australia. AURIN provides a single gateway providing online (live) programmatic access to over 2000 data sets from over 70 major and typically definitive data-driven organizations across federal and State government, across industry and across academia. However whilst open (public) data is useful to bring data-driven intelligence to cities, more often than not, it is the data that is not-publicly accessible that is essential to understand city challenges and needs. Such sensitive (unit-level) data has unique requirements on access and usage to meet the privacy and confidentiality demands of the associated organizations. In this paper we highlight a novel geo-privacy supporting solution implemented as part of the AURIN project that provides seamless and secure access to individual (unit-level) data from the Department of Health in Victoria. We illustrate this solution across a range of typical city challenges in localized contexts around Melbourne. We show how unit level data can be combined with other data in a privacy-protecting manner. Unlike other secure data access and usage solutions that have been developed/deployed, the AURIN solution allows any researcher to access and use the data in a manner that meets all of the associated privacy and confidentiality concerns, without obliging them to obtain ethical approval or any other hurdles that are normally put in place on access to and use of sensitive data. This provides a paradigm shift in secure access to sensitive data with geospatial content. 相似文献
44.
This paper proposes the design of anti-windup compensator gain for stability of actuator input constrained state delay systems using constrained pole-position of the closed-loop. Based on Delay-Dependent Lyapunov-Krasovskii functionals and local sector conditions, a new LMI characterization is derived that ensures closed-loop asymptotic stability of constrained state delay systems while accounting upper bound fixed state delay and largest lower bound of the system’s pole-position in the formulation of anti-windup gain. Besides, at saturation, the method significantly nullifies the inherent slow dynamics present in the system. It is shown in the comparative numerical examples that the LMI formulation draws stability with improved time-domain performance. 相似文献
45.
Masoom Alam Xinwen Zhang Mohammad Nauman Tamleek Ali Muhammad Ali Sajid Anwar Quratulain Alam 《Multimedia Tools and Applications》2013,66(2):283-302
Service Oriented Architecture with underlying technologies like web services and web service orchestration opens new vistas for integration among business processes operating in heterogeneous environments. However, such dynamic collaborations require a highly secure environment at each respective business partner site. Existing web services standards address the issue of security only on the service provider platform. The partner platforms to which sensitive information is released have till now been neglected. Remote Attestation is a relatively new field of research which enables an authorized party to verify that a trusted environment actually exists on a partner platform. To incorporate this novel concept in to the web services realm, a new mechanism called WS-Attestation has been proposed. This mechanism provides a structural paradigm upon which more fine-grained solutions can be built. In this paper, we present a novel framework, Behavioral Attestation for Web Services, in which XACML is built on top of WS-Attestation in order to enable more flexible remote attestation at the web services level. We propose a new type of XACML policy called XACML behavior policy, which defines the expected behavior of a partner platform. Existing web service standards are used to incorporate remote attestation at the web services level and a prototype is presented, which implements XACML behavior policy using low-level attestation techniques. 相似文献
46.
Naveed Aslam Mirza Hikmat Ullah Khan Khalid Iqbal Saqib Iqbal Muhammad Imran 《New Review of Hypermedia and Multimedia》2013,19(4):335-345
ABSTRACTThe quality of user-generated content over World Wide Web media is a matter of serious concern for both creators and users. To measure the quality of content, webometric techniques are commonly used. In recent times, bibliometric techniques have been introduced to good effect for evaluation of the quality of user-generated content, which were originally used for scholarly data. However, the application of bibliometric techniques to evaluate the quality of YouTube content is limited to h-index and g-index considering only views. This paper advocates for and demonstrates the adaptation of existing Bibliometric indices including h-index, g-index and M-index exploiting both views and comments and proposes three indices hvc, gvc and mvc for YouTube video channel ranking. The empirical results prove that the proposed indices using views along with the comments outperform the existing approaches on a real-world dataset of YouTube. 相似文献
47.
Muhammad Waseem Rizwan Ahmed Muhammad Irfan Shahid Qamar 《Quantum Information Processing》2013,12(12):3649-3664
We present a scheme for the implementation of three-qubit Grover’s algorithm using four-level superconducting quantum interference devices (SQUIDs) coupled to a superconducting resonator. The scheme is based on resonant, off-resonant interaction of the cavity field with SQUIDs and application of classical microwave pulses. We show that adjustment of SQUID level spacings during the gate operations, adiabatic passage, and second-order detuning are not required that leads to faster implementation. We also show that the marked state can be searched with high fidelity even in the presence of unwanted off-resonant interactions, level decay, and cavity dissipation. 相似文献
48.
Targeting spam control on middleboxes: Spam detection based on layer-3 e-mail content classification
This paper proposes a spam detection technique, at the packet level (layer 3), based on classification of e-mail contents. Our proposal targets spam control implementations on middleboxes. E-mails are first pre-classified (pre-detected) for spam on a per-packet basis, without the need for reassembly. This, in turn, allows fast e-mail class estimation (spam detection) at receiving e-mail servers to support more effective spam handling on both inbound and outbound (relayed) e-mails. In this paper, the naïve Bayes classification technique is adapted to support both pre-classification and fast e-mail class estimation, on a per-packet basis. We focus on evaluating the accuracy of spam detection at layer 3, considering the constraints on processing byte-streams over the network, including packet re-ordering, fragmentation, overlapped bytes, and different packet sizes. Results show that the proposed layer-3 classification technique gives less than 0.5% false positive, which approximately equals the performance attained at layer 7. This shows that classifying e-mails at the packet level could differentiate non-spam from spam with high confidence for a viable spam control implementation on middleboxes. 相似文献
49.
Mohd Saberi Mohamad Sigeru Omatu Safaai Deris Muhammad Faiz Misman Michifumi Yoshioka 《Artificial Life and Robotics》2009,13(2):410-413
A microarray machine offers the capacity to measure the expression levels of thousands of genes simultaneously. It is used
to collect information from tissue and cell samples regarding gene expression differences that could be useful for cancer
classification. However, the urgent problems in the use of gene expression data are the availability of a huge number of genes
relative to the small number of available samples, and the fact that many of the genes are not relevant to the classification.
It has been shown that selecting a small subset of genes can lead to improved accuracy in the classification. Hence, this
paper proposes a solution to the problems by using a multiobjective strategy in a genetic algorithm. This approach was tried
on two benchmark gene expression data sets. It obtained encouraging results on those data sets as compared with an approach
that used a single-objective strategy in a genetic algorithm.
This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January
31–February 2, 2008 相似文献
50.
Mohd Saberi Mohamad Sigeru Omatu Safaai Deris Muhammad Faiz Misman Michifumi Yoshioka 《Artificial Life and Robotics》2009,13(2):414-417
Gene expression technology, namely microarrays, offers the ability to measure the expression levels of thousands of genes
simultaneously in biological organisms. Microarray data are expected to be of significant help in the development of an efficient
cancer diagnosis and classification platform. A major problem in these data is that the number of genes greatly exceeds the
number of tissue samples. These data also have noisy genes. It has been shown in literature reviews that selecting a small
subset of informative genes can lead to improved classification accuracy. Therefore, this paper aims to select a small subset
of informative genes that are most relevant for cancer classification. To achieve this aim, an approach using two hybrid methods
has been proposed. This approach is assessed and evaluated on two well-known microarray data sets, showing competitive results.
This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January
31–February 2, 2008 相似文献