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101.

In recent times, numerous Internet of Things (IoT) applications have begun to use biometric identity for authentication purposes. The integrity and confidentiality of biometric templates during storage and transmission is crucial as it contains key information on the physical identity of the users. Encryption is an effective template protection technique. However, most of the edge side gadgets in the IoT environment require lightweight encryption schemes due to constraints in available power and memory space. Conventional cryptosystems are expensive because of their complexity and multiple rounds for encryption. In the present work, a lightweight bio-cryptosystem is developed to ensure security while storing and transmitting biometric templates. The proposed bio-crypto architecture has three stages—key generation, confusion and diffusion. A two-dimensional logistic sine map is used for key generation. A novel method of diffusion using DNA encoding and ciphering is proposed to decrease the complexity of the encryption process considerably and achieve desirable integrity. Simulations and security analysis indicate that the proposed cryptosystem has sufficient level of security and robustness, involves lesser computational complexity and has the potential of satisfying the requirements of IoT applications.

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102.
In this work, a resolution improvement strategy has been presented for microwave tomography imaging in the dense and heterogeneous breasts. While improving the spatial resolution by reducing the size of pixels, the resultant image will be affected by spatial oscillation, and it will also lack to differentiate the dielectric values of low contrast tissue regions which are the unavoidable problems in the microwave tomography dense breast imaging. These difficulties are addressed as discrete ill-posed and ill-condition problems. In this paper, Enriched Conjugate Gradient Least Square (ECGLS) regularization method has been proposed and it is associated with the Distorted Born Iterative Method (DBIM) to improve the quality of high-resolution images of heterogeneous and dense type breasts. The Proposed-ECGLS (PECGLS) method introduces the span of enriched subspace with external penalization value to resolve the discrete ill-posed problem. The Gram-Schmidt factorization (or QR factorization) based step length and the external penalization value control the spatial oscillations and resolve the ill-condition problem with quick convergence. The performance of the Proposed-ECGLS method has been tested on heterogeneous and dense breast phantoms for synthetically embedded malignant along with differences in permittivity value of +8% to +10% in the fibrogland tissues. The results from the simulation studies depict that the Proposed-ECGLS has achieved up to 0.8276 of structural similarity in different level discretization error and it is better than the existing methods such as ECGLS and standard CGLS. This high-resolution microwave tomography imaging method will be helpful in malignant detection and fibroadenoma diagnosis in dense type breasts.  相似文献   
103.
Marble dust and basalt powder are industrial waste generated during the machining of marble stone and basalt rock. This paper presents an approach for the optimization of dry sliding wear parameters of aluminium 7075 reinforced with marble dust and basalt powder hybrid metal matrix composite using Taguchi based grey relational analysis. In this work, the composite is fabricated by stir casting technique and the wear parameters namely load, sliding velocity and sliding distance are optimized with consideration of multi responses such as wear rate and coefficient of friction. Experiments are conducted as per Taguchi's L9 orthogonal array. A grey relational analysis is carried out and grey relational grade is obtained. Based on the grey relational grade, optimum level of wear parameters has been identified by analysis of variance. The test results are validated by conducting the confirmation test. Experimental results have shown that the sliding velocity is the most effective factor among the control parameters on dry sliding wear, followed by the sliding distance and load. Finally, the micro structural investigations on the worn surfaces are performed by scanning electron microscope.  相似文献   
104.
105.
Wireless Personal Communications - This paper investigates the performance of an energy-harvesting (EH) relay network, where multiple sources communicate with a destination via multiple EH...  相似文献   
106.

Heterogeneous sensors are equipped with a limited battery source that is concerned with network lifetime problems. However, this problem can be tackled with the effective design of WSN-IoT by clustering and sleep scheduling mechanisms. This paper addresses this issue by presenting novel ideas involved in the WSN operations such as grid construction, cluster head selection, sleep scheduling, and data gathering by intelligent Agents (iAgents). An energy-efficient dual iAgents based Heterogeneous WSN (E2IA-HWSN) is proposed. iAgents are used in this paper to automatically collect the sensed data from IoT sensors. In this E2IA-HWSN, a 3?×?3 grid is built and each cell is sub-divided into four in which cluster heads (CH) are selected in each sub-division, followed by ring partitioning for selecting a CH present at the center. Multi-Objective Harris Hawks optimization (MO-HHO) algorithm is used to select CH and supernode, here to minimize the energy consumption of CH, the supernode takes responsibility to assign sleep schedules to devices. The scheduling slots are assigned only after a sensor reaches below the energy threshold. For scheduling, the Bayes rule-based Markov model (BR-MM) is applied with the determination of residual energy and sensed packet counts. Generator de Bits Pseudo Aleatorios (GBPA) eliminates redundant data in CH and then inter-cluster routing is performed in case of emergency events. If not, then the CH waits for the arrival of iagents, the trajectory of iAgents is dynamically predicted with Deep Policy Gradient (DDPG). The implementation is carried out in NS3.26 and the results show betterment to the well-known methods.

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107.
In this research, the hydrothermal method was used for synthesising cellulose acetate (CA) templated nanorods like CuS fibres using vegetable extract (Brassica oleracea var. italica). These extracts act as a reducing agent in the presence of CA. Surprisingly, when the same reaction was carried out in the absence of CA and broccoli extract, structural morphology disappeared and was found as agglomerated. In the presence of cellulose templated extract mediated CuS has revealed as nanorods like fibres and was confirmed by field emission scanning electron microscope analysis. Their crystallinity property of CuS nanoparticles (NPs) and cellulose templated biosynthesised CuS NPs was analysed and compared using X‐ray diffraction technique. The biological activities of the obtained product were examined for antibacterial assessment against two bacterial strains that include two‐gram negative strains (E.Coli and S. aureus). The nanostructured product found to exhibit excellent antibacterial agent against all the strains. Biosynthesised nanostructure showed its efficacy against A549 lung cancer cells which might attribute to a larger surface to volume ratio of nanorods like fibres. The authors observation suggest that CuS nanorods like fibres can significantly reduce the cell growth with IC50 value of 31.2 μg/ml.Inspec keywords: nanomedicine, copper compounds, X‐ray diffraction, nanorods, nanofabrication, antibacterial activity, DNA, toxicology, microorganisms, molecular biophysics, cancer, cellular biophysics, biomedical materials, nanoparticles, lung, field emission scanning electron microscopy, polymers, crystal growth from solutionOther keywords: A549 lung cancer cells, hydrothermal method, structural morphology, crystallinity property, CuS nanoparticles, two‐gram negative strains, CuS nanorods, cytotoxicity effects, DNA cleavage properties, cellulose acetate, Brassica oleracea var. italica, field emission scanning electron microscope, X‐ray diffraction, antibacterial agent, hydrothermal biosynthesis, CuS  相似文献   
108.
The aim of the present study is to evaluate the effect of hot water extract of black tea in regenerating β cells in streptozotocin‐induced diabetic mice. Light microscopic examination of pancreatic sections of streptozotocin‐induced diabetic mice showed the acinar cells to be small, shrunken, and with deteriorated β cells. The dose of streptozotocin not only altered the function of β cells but also damaged the acinar region. The changes in acinar cells were coarsening of endoplasmic reticulation suggesting alteration in their secretory function. The control pancreatic tissue showed well‐defined granulated islets and dark β cells when stained with chrome hematoxylin and phloxine. Interestingly, pancreatic sections of diabetic mice fed with black‐tea extract showed regeneration of β cells and acinar region appeared normal with increased numbers of β cells. To understand the probable mechanism of action of black‐tea extract, we analyzed inducible nitric oxide synthase (iNOS) expression by immunohistochemistry and the results showed an increased iNOS levels in streptozotocin‐induced diabetic pancreas, and such high iNOS levels were inhibited in black‐tea extract treated mice. According to histological results obtained, it can be concluded that the black‐tea extract helps in regeneration of damaged pancreas and protects pancreatic β cells by its antioxidant action against nitrosative stress in streptozotocin‐induced diabetes. Microsc. Res. Tech., 2009. © 2009 Wiley‐Liss, Inc.  相似文献   
109.
This paper proposes the use of electrochemical impedance spectroscopy (EIS) to estimate the cathode flow rate in a fuel cell system. Through experimental testing of an eight-cell, hydrogen-fueled polymer electrolyte stack, it shows that the ac impedance measurements are highly sensitive to the airflow rates at varying current densities. The ac impedance magnitude at 0.1 Hz allows the distinction of airflow rates (stoichiometry of 1.5–3.0) at current densities as low as 0.1 A/cm2. Using experimental data and regression analysis, a simple algebraic equation that estimates the airflow rate using impedance measurements at a frequency of 0.1 Hz is developed. The derivation of this equation is based on the operating cell voltage equation that accounts for all the irreversibilities.  相似文献   
110.

2-benzyl-amino-4-P-tolyl-6,7-di-hydro 5H-cyclo-penta –[b]pyridine–3 carbo–nitrile—BAPTDHCPCAN crystal is grown by solution growth evaporation method and analysed for XRD, Unit Cell, Dielectric analysis, UV, Tauc’s plot and fluorescence and mechano studies. The single crystalline XRD data portrays the monoclinic nature of BAPTDHCPCAN with space group P21/c and a, b, c as 8.6828 Å, 17.7283 Å, 12.0403 Å with β as 94.254°. Chemical formula of crystal as C23H21N3. The crystalline dimension is 14?×?12x7 mm3. The dielectric properties of the BAPTDHCPCAN have larger value at low range of frequencies. The phase matching effectiveness is analyzed and found to be 66 mV. The influx value of macro and thin film of BAPTDHCPCAN crystal is 4.2125 microns and 4.4336 microns as mid value before nano shaped influx. Absorption spectral two peaks centered at 248 nm at 325 nm, the band gap of crystal is calculated as 5.0 eV by photonic enhancement and the fluorescence represented emission for 399 nm. The BAPTDHCPCAN crystal is found to have represented –ve photoconductive nature. The BAPTDHCPCAN crystal specimen in of RISE [Reverse Indentation Size Effect] consequence with n greater than 2.

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