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91.
目的 研究TIG焊接过程中低氧铜扁线氢、氧含量对扁线焊接接头的影响.方法 以规格为3 mm×2 mm的无氧铜扁线和不同氢、氧含量的低氧铜扁线为研究对象,采用氩弧焊接(TIG)方式,系统研究了不同种类扁线母材及焊接接头的微观组织和焊后力学、电学性能.结果 无氧铜扁线经TIG焊接后,焊接接头处没有产生明显的气孔,焊接接头性能良好,其抗拉强度及塑性均与母材的相当.低氢低氧、低氢高氧扁线焊接接头出现少量的气孔,破断力值分别为678 N和654N.而高氢低氧、高氢高氧扁线焊接接头出现大量的大气孔,破断力值分别为208.7N和126N.不同氢氧含量的低氧铜扁线焊后导电率无明显变化.结论 低氧铜扁线焊接接头内部气孔的数量和尺寸受氢、氧含量的影响,相比之下氢元素的影响更大.  相似文献   
92.
    
The rapid development and progress in deep machine-learning techniques have become a key factor in solving the future challenges of humanity. Vision-based target detection and object classification have been improved due to the development of deep learning algorithms. Data fusion in autonomous driving is a fact and a prerequisite task of data preprocessing from multi-sensors that provide a precise, well-engineered, and complete detection of objects, scene or events. The target of the current study is to develop an in-vehicle information system to prevent or at least mitigate traffic issues related to parking detection and traffic congestion detection. In this study we examined to solve these problems described by (1) extracting region-of-interest in the images (2) vehicle detection based on instance segmentation, and (3) building deep learning model based on the key features obtained from input parking images. We build a deep machine learning algorithm that enables collecting real video-camera feeds from vision sensors and predicting free parking spaces. Image augmentation techniques were performed using edge detection, cropping, refined by rotating, thresholding, resizing, or color augment to predict the region of bounding boxes. A deep convolutional neural network F-MTCNN model is proposed that simultaneously capable for compiling, training, validating and testing on parking video frames through video-camera. The results of proposed model employing on publicly available PK-Lot parking dataset and the optimized model achieved a relatively higher accuracy 97.6% than previous reported methodologies. Moreover, this article presents mathematical and simulation results using state-of-the-art deep learning technologies for smart parking space detection. The results are verified using Python, TensorFlow, OpenCV computer simulation frameworks.  相似文献   
93.
94.
    
In today’s smart city transportation, traffic congestion is a vexing issue, and vehicles seeking parking spaces have been identified as one of the causes leading to approximately 40% of traffic congestion. Identifying parking spaces alone is insufficient because an identified available parking space may have been taken by another vehicle when it arrives, resulting in the driver’s frustration and aggravating traffic jams while searching for another parking space. This explains the need to predict the availability of parking spaces. Recently, deep learning (DL) has been shown to facilitate drivers to find parking spaces efficiently, leading to a promising performance enhancement in parking identification and prediction systems. However, no work reviews DL approaches applied to solve parking identification and prediction problems. Inspired by this gap, the purpose of this work is to investigate, highlight, and report on recent advances in DL approaches applied to predict and identify the availability of parking spaces. A taxonomy of DL-based parking identification and prediction systems is established as a methodology by classifying and categorizing existing literature, and by doing so, the salient and supportive features of different DL techniques for providing parking solutions are presented. Moreover, several open research challenges are outlined. This work identifies that there are various DL architectures, datasets, and performance measures used to address parking identification and prediction problems. Moreover, there are some open-source implementations available that can be used directly either to extend existing works or explore a new domain. This is the first short survey article that focuses on the use of DL-based techniques in parking identification and prediction systems for smart cities. This study concludes that although the deployment of DL in parking identification and prediction systems provides various benefits, the convergence of these two types of systems and DL brings about new issues that must be resolved in the near future.  相似文献   
95.
    
The COVID-19 pandemic has triggered a global humanitarian disaster that has never been seen before. Medical experts, on the other hand, are undecided on the most valuable treatments of therapy because people ill with this infection exhibit a wide range of illness indications at different phases of infection. Further, this project aims to undertake an experimental investigation to determine which treatments for COVID-19 disease is the most effective and preferable. The research analysis is based on vast data gathered from professionals and research journals, making this study a comprehensive reference. To solve this challenging task, the researchers used the HF AHP-TOPSIS Methodology, which is a well-known and highly effective Multi-Criteria Decision Making (MCDM) technique. The technique assesses the many treatment options identified through various research papers and guidelines proposed by various countries, based on the recommendations of medical practitioners and professionals. The review process begins with a ranking of different treatments based on their effectiveness using the HF-AHP approach and then evaluates the results in five different hospitals chosen by the authors as alternatives. We also perform robustness analysis to validate the conclusions of our analysis. As a result, we obtained highly corroborative results that can be used as a reference. The results suggest that convalescent plasma has the greatest rank and priority in terms of effectiveness and demand, implying that convalescent plasma is the most effective treatment for SARS-CoV-2 in our opinion. Peepli also has the lowest priority in the estimation.  相似文献   
96.
97.
    
N,N-Dimethylacetamide/lithium chloride (DMAc/LiCl) treated silica is used as a reinforcing filler in nitrile rubber (NBR). Effect of the treatment on aggregate morphology and dispersion of silica in the matrix is investigated using XPS, SEM, and AFM. Binding energy levels of O1s and Si2p electrons in DMAc/LiCl treated silica have shifted significantly from 532.49 to 530.98 eV and 103.19 to 101.33 eV respectively. SEM observations have revealed a reduction in the agglomerate size of silica-a desirable feature for realizing better processing properties of silica filled rubber compounds. Data from AFM observations have also shown better dispersion of DMAc/LiCl treated silica. Mooney viscosity of masterbatches, measured at 100°C over a period of 7 days, has not exhibited any storage hardening which is an indication of easier processability. At 125°C, Mooney data exhibited a reduction in scorch time as a function of DMAc/LiCl concentration. However, MDR data at 160°C have not shown much changes in the scorch time while NBR with high nitrile content exhibited longer cure times. Higher crosslink density of vulcanizates indicate that DMAc/LiCl treatment of silica could effectively reduce filler-filler interactions and networking in silica filled rubber compounds thereby enabling mixing and processing operations energy efficient.  相似文献   
98.
    
This study aimed to synthesize experimental composites reinforced with various concentrations (0, 40, 50, and 60 wt%) of nano-hydroxyapatite grafted glass fibers. The release of monomers, residual monomers, and in-vitro bioactivity of composite groups were evaluated after 1, 7, and 28 days. Compressive strength/ modulus, cell viability (by direct and indirect method), and bacterial adhesion were evaluated. The results showed that bis-GMA was released from all samples. TEGDMA released from 50 and 60 wt% samples on day 1 and UDMA showed negligible release. Compressive strength values of 40 wt% sample were higher than other experimental groups. New apatite layer was formed, whereby both direct and indirect methods demonstrated cell viability. The numbers of active colonies grown were least for 60 wt% sample while their number increased over time. The nano-hydroxyapatite/glass fibers have potential to be used as filler in dental composites and experimental composites were found to be biocompatible and comparable with commercial material.  相似文献   
99.
    
Corrosion of reinforced concrete (RC) structures is one of the significant causes of deterioration of reinforced concrete (RC) structures. Chlorination is a major process governing the initiation and advancement of the injurious corrosion of steel bars. Now, several researches on the chlorination of concrete structures have been ongoing around the world. Present article reviews several recently performed chlorination studies, and from results of a field survey evaluates the effect of chloride content on the probability of corrosion and the influence of concrete compressive strength on the chloride content and penetration, also evaluates the effect of concrete cover over the chloride content of the RC structures at rebar depth and on the probability of corrosion.  相似文献   
100.
Targeting of G-protein coupled receptors (GPCRs) like somatostatin-14 (SST-14) could have a potential interest in delivery of anti-cancer agents to tumor cells. Attachment of SST to different nano-carriers e.g. polymeric nanoparticles is limited due to the difficulty of interaction between SST itself and those nano-carriers. Furthermore, the instability problems associated with the final formulation. Attaching of SST to gold nanoparticles (AuNPs) using the positive and negative charge of SST and citrate-AuNPs could be considered a new technique to get stable non-aggregated AuNPs coated with SST. Different analyses techniques have been performed to proof the principle of coating between AuNPs and SST. Furthermore, cellular uptake studies on HCC-1806, HELA and U-87 cell lines has been investigated to show the ability of AuNPs coated SST to enter the cells via SST receptors. Dynamic light scattering (DLS) indicated a successful coating of SST on the MUA-AuNPs surface. Furthermore, all the performed analysis including DLS, SDS-PAGE and UV-VIS absorption spectra indicated a successful coating of AuNPs with SST. Cellular uptake studies on HCC-1806, HELA and U-87 cell lines showed that the number of AuNPs-SST per cell is signiflcantly higher compared to citrate-AuNPs when quantified using inductively coupled plasma spectroscopy. Moreover, the binding of AuNPs-SST to cells can be suppressed by addition of antagonist, indicating that the binding of AuNPs-SST to cells is due to receptor-specific binding. In conclusion, AuNPs could be attached to SST via adsorption to get stable AuNPs coated SST. This new formulation has a potential to target SST receptors localized in many normal and tumor cells.  相似文献   
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