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951.
Asif Khan Alam Zaib Irfan Ullah Shahid Khattak 《International Journal of Communication Systems》2020,33(6)
This paper presents link to system (L2S) interfacing technique for multiple input and multiple output (MIMO) iterative receivers. In L2S interfacing, usually the post detection signal to noise ratio (SNR)‐based frame error rate lookup tables (LUT) are used to predict the link level performance of receivers. While L2S interfacing for linear MIMO receivers can be conveniently implemented, it is more challenging for MIMO iterative receivers due to unavailability of the closed form SNR expressions. In this paper, we propose three methods for post detection SNR estimation for MIMO iterative receivers. The first is based on the QR decomposition of the channel matrix, the second relies on the residual noise calculation based on the soft symbols, and the third exploits the closed form SNR expressions for linear receivers. A link to system interface model for iterative receivers is developed for evaluating the reference curves for different modulation and coding schemes, and results are validated by comparing the simulated and predicted frame error rates. It is shown that linear and residual noise‐based SNR approximations result in a very good prediction performance whereas the performance of QR decomposition‐based method degrades for higher order modulations and coding schemes. This paper presents link to system interfacing technique for MIMO iterative receivers. A link to system interface model for iterative receivers is developed for evaluating the reference curves for different modulation and coding schemes, and results are validated by comparing the simulated and predicted frame error rates. Three post detection SNR evaluation schemes have been proposed for link to system interfacing all of which give good prediction performance especially at lower order modulation. 相似文献
952.
Salabat Khan Zijian Zhang Liehuang Zhu Mussadiq Abdul Rahim Sadique Ahmad Ruoyu Chen 《International Journal of Communication Systems》2020,33(15)
In classical public‐key infrastructure (PKI), the certificate authorities (CAs) are fully trusted, and the security of the PKI relies on the trustworthiness of the CAs. However, recent failures and compromises of CAs showed that if a CA is corrupted, fake certificates may be issued, and the security of clients will be at risk. As emerging solutions, blockchain‐ and log‐based PKI proposals potentially solved the shortcomings of the PKI, in particular, eliminating the weakest link security and providing a rapid remedy to CAs' problems. Nevertheless, log‐based PKIs are still exposed to split‐world attacks if the attacker is capable of presenting two distinct signed versions of the log to the targeted victim(s), while the blockchain‐based PKIs have scaling and high‐cost issues to be overcome. To address these problems, this paper presents a secure and accountable transport layer security (TLS) certificate management (SCM), which is a next‐generation PKI framework. It combines the two emerging architectures, introducing novel mechanisms, and makes CAs and log servers accountable to domain owners. In SCM, CA‐signed domain certificates are stored in log servers, while the management of CAs and log servers is handed over to a group of domain owners, which is conducted on the blockchain platform. Different from existing blockchain‐based PKI proposals, SCM decreases the storage cost of blockchain from several hundreds of GB to only hundreds of megabytes. Finally, we analyze the security and performance of SCM and compare SCM with previous blockchain‐ and log‐based PKI schemes. 相似文献
953.
Nan Wei Patrik Laiho Abu Taher Khan Aqeel Hussain Alina Lyuleeva Saeed Ahmed Qiang Zhang Yongping Liao Ying Tian Er‐Xiong Ding Yutaka Ohno Esko I. Kauppinen 《Advanced functional materials》2020,30(5)
In this work, a fast approach for the fabrication of hundreds of ultraclean field‐effect transistors (FETs) is introduced, using single‐walled carbon nanotubes (SWCNTs). The synthesis of the nanomaterial is performed by floating‐catalyst chemical vapor deposition, which is employed to fabricate high‐performance thin‐film transistors. Combined with palladium metal bottom contacts, the transport properties of individual SWCNTs are directly unveiled. The resulting SWCNT‐based FETs exhibit a mean field‐effect mobility, which is 3.3 times higher than that of high‐quality solution‐processed CNTs. This demonstrates that the hereby used SWCNTs are superior to comparable materials in terms of their transport properties. In particular, the on–off current ratios reach over 30 million. Thus, this method enables a fast, detailed, and reliable characterization of intrinsic properties of nanomaterials. The obtained ultraclean SWCNT‐based FETs shed light on further study of contamination‐free SWCNTs on various metal contacts and substrates. 相似文献
954.
955.
Jia Wenjuan Muhammad Khan Wang Shui-Hua Zhang Yu-Dong 《Multimedia Tools and Applications》2019,78(4):4045-4064
Multimedia Tools and Applications - Magnetic resonance imaging (MRI) is employed in medical treatment broadly, due to the quick development of computer technology. It is beneficial to classify the... 相似文献
956.
Mahmuda Mutahara Jeroen F. Warner Arjen E. J. Wals M. Shah Alam Khan Philippus Wester 《国际水资源开发杂志》2018,34(6):923-943
ABSTRACTThe article analyzes Tidal River Management in Bangladesh from a social learning perspective. Four cases were investigated using participatory assessment. Knowledge acquisition through transformations in the Tidal River Management process was explored as an intended learning outcome. The study finds that social learning occurred more prominently at the individual stakeholder level and less at the collective level. For Tidal River Management to be responsive and sustainable, especially in times of increased uncertainty and climate vulnerability, more attention needs to be paid to coordination and facilitation of multi-level learning that includes all stakeholders. 相似文献
957.
Complexity and trends analysis of hydrometeorological time series for a river streamflow: A case study of Songhua River Basin,China
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In China's national economic growth, an important role is being played by the Songhua River because of the river's abundant resources and natural conditions. Therefore, study of hydrometeorological time series is very important to understand the basin behaviour. This research uses the snow cover data derived from MODIS, streamflow, and meteorological records in the Songhua River Basin to evaluate similarity, complexity, and trends in the snow cover, temperature, precipitation, and streamflow. In this paper, we suggest a new method of ranking the statistics symbolic sequences to examine the degree of similarity (distance measurement) between meteorological stations and compare it with non‐parametric correlation methods and also investigate the deviations in the complexity of a hydrometeorological time series. Information‐based similarity index and multiscale entropy confirm that the hydrometeorological time series of different stations have self‐similarity and abundant complexity. Wavelet entropy is also used to investigate the basin behaviour by taking streamflow records and population. It is found that with the increase in population and urbanization, the complexity values are increased. The results also exhibit that due to increase in urbanization, it affects the hydrological process and nature of environment resulting in complex catchment behaviour. Furthermore, the streamflow trend results displayed significant decline (22.21 m3/s × year?1) in the Songhua River. The results also indicated that the seasonal snow cover trend has no impact on changes of the streamflow. However, the decline of the streamflow may be influenced by the significant human activity upstream of the Songhua River. 相似文献
958.
Muhammad Zubair Asghar Fazli Subhan Muhammad Imran Fazal Masud Kundi Adil Khan Shahboddin Shamshirband Amir Mosavi Peter Csiba Annamaria R. Varkonyi Koczy 《计算机、材料和连续体(英文)》2020,63(3):1093-1118
Emotion detection from the text is a challenging problem in the text analytics.
The opinion mining experts are focusing on the development of emotion detection
applications as they have received considerable attention of online community including
users and business organization for collecting and interpreting public emotions. However,
most of the existing works on emotion detection used less efficient machine learning
classifiers with limited datasets, resulting in performance degradation. To overcome this
issue, this work aims at the evaluation of the performance of different machine learning
classifiers on a benchmark emotion dataset. The experimental results show the
performance of different machine learning classifiers in terms of different evaluation
metrics like precision, recall ad f-measure. Finally, a classifier with the best performance
is recommended for the emotion classification. 相似文献
959.
Tahir Abbas Khan Sagheer Abbas Allah Ditta Muhammad Adnan Khan Hani Alquhayz Areej Fatima Muhammad Farhan Khan 《计算机、材料和连续体(英文)》2020,65(3):2591-2605
The prediction of human diseases, particularly COVID-19, is an extremely
challenging task not only for medical experts but also for the technologists supporting
them in diagnosis and treatment. To deal with the prediction and diagnosis of COVID-19,
we propose an Internet of Medical Things-based Smart Monitoring Hierarchical
Mamdani Fuzzy Inference System (IoMTSM-HMFIS). The proposed system determines
the various factors like fever, cough, complete blood count, respiratory rate, Ct-chest,
Erythrocyte sedimentation rate and C-reactive protein, family history, and antibody
detection (lgG) that are directly involved in COVID-19. The expert system has two input
variables in layer 1, and seven input variables in layer 2. In layer 1, the initial
identification for COVID-19 is considered, whereas in layer 2, the different factors
involved are studied. Finally, advanced lab tests are conducted to identify the actual
current status of the disease. The major focus of this study is to build an IoMT-based
smart monitoring system that can be used by anyone exposed to COVID-19; the system
would evaluate the user’s health condition and inform them if they need consultation with
a specialist for quarantining. MATLAB-2019a tool is used to conduct the simulation. The
COVID-19 IoMTSM-HMFIS system has an overall accuracy of approximately 83%.
Finally, to achieve improved performance, the analysis results of the system were shared
with experts of the Lahore General Hospital, Lahore, Pakistan. 相似文献
960.
Jianzhong Li DexiangMei Dong Deng Imran Khan Peerapong Uthansakul 《计算机、材料和连续体(英文)》2020,65(2):1571-1590
Non-orthogonal multiple access (NOMA) is one of the key 5G technology
which can improve spectrum efficiency and increase the number of user connections by
utilizing the resources in a non-orthogonal manner. NOMA allows multiple terminals to
share the same resource unit at the same time. The receiver usually needs to configure
successive interference cancellation (SIC). The receiver eliminates co-channel
interference (CCI) between users and it can significantly improve the system throughput.
In order to meet the demands of users and improve fairness among them, this paper
proposes a new power allocation scheme. The objective is to maximize user fairness by
deploying the least fairness in multiplexed users. However, the objective function
obtained is non-convex which is converted into convex form by utilizing the optimal
Karush-Kuhn-Tucker (KKT) constraints. Simulation results show that the proposed
power allocation scheme gives better performance than the existing schemes which
indicates the effectiveness of the proposed scheme. 相似文献