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81.
The average water surface slope in the lateral direction is taken into account as a local parameter ψ to study flow over a side weir. It was later shown that for smaller side weir lengths and side weir portions with no entrance and exit transition effects, ψ can be obtained from a numerical integral and also from the measurements of water surface elevations in the lateral direction. The effect of elemental weir length was further determined. Dividing the weir length into smaller computational segments has the effect of lowering the water surface to approach the measured profile, the downstream ends being coincident. The model was verified using experimental data. 相似文献
82.
Data-driven next-generation smart grid towards sustainable energy evolution: techniques and technology review 下载免费PDF全文
Faiaz Ahsan Nazia Hasan Dan Subrata K. Sarker Li Li S. M. Muyeen Md. Firoj Ali Zinat Tasneem Md. Mehedi Hasan Sarafat Hussain Abhi Md. Robiul Islam Md. Hafz Ahame Md. Manirul Islam Sajal K. Das Md. Faisal R. Badal Prangon Das 《电力系统保护与控制》2023,8(3):696-737
Meteorological changes urge engineering communities to look for sustainable and clean energy technologies to keep the environment safe by reducing CO2 emissions. The structure of these technologies relies on the deep integration of advanced data-driven techniques which can ensure efcient energy generation, transmission, and distribution. After conducting thorough research for more than a decade, the concept of the smart grid (SG) has emerged, and its practice around the world paves the ways for efcient use of reliable energy technology. However, many developing features evoke keen interest and their improvements can be regarded as the next-generation smart grid (NGSG). Also, to deal with the non-linearity and uncertainty, the emergence of data-driven NGSG technology can
become a great initiative to reduce the diverse impact of non-linearity. This paper exhibits the conceptual framework of NGSG by enabling some intelligent technical features to ensure its reliable operation, including intelligent control, agent-based energy conversion, edge computing for energy management, internet of things (IoT) enabled inverter, agent-oriented demand side management, etc. Also, a study on the development of data-driven NGSG is discussed to facilitate the use of emerging data-driven techniques (DDTs) for the sustainable operation of the SG. The prospects of DDTs in the NGSG and their adaptation challenges in real-time are also explored in this paper from various points of view including engineering, technology, et al. Finally, the trends of DDTs towards securing sustainable and clean energy evolution from the NGSG technology in order to keep the environment safe is also studied, while some major future issues are highlighted. This paper can ofer extended support for engineers and researchers in the context of data-driven technology and the SG. 相似文献
83.
Chee Chin Chu Zafarizal Aldrin Bin Azizul Hasan Siaw Kim Chua Kar Lin Nyam 《Journal of the American Oil Chemists' Society》2020,97(5):531-542
Pumpkin seed oil (PSO) with carnauba wax and beeswax was used to develop nanostructured lipid carriers (NLC) loaded with a UV filter, Uvinul® A Plus B. The aims of the study were to optimize the concentration of PSO to develop a stable NLC formulation, determine storage stability of the NLC with and without PSO, and the synergistic effect of PSO-NLC with UV filter for photoprotective properties. The physical properties of NLC were optimized based on the mean particle size, polydispersity index, and storage stability. The optimized NLC consisted 10% lipid phase (3.5% carnauba wax, 3.5% beeswax, and 3.0% PSO) and 90% aqueous phase. After optimization, Uvinul® A Plus B was added in the optimized PSO-NLC to produce a photoprotective formulation. Uvinul® A Plus B consisted of both UVA (Diethylamino Hydroxybenzoyl Hexyl Benzoate) and UVB (Ethylhexyl Methoxycinnamate) filters. The NLC produced with PSO and Uvinul® A Plus B had mean particle size of 135 ± 2 nm and showed good physical stability under storage time. Besides that, the NLC produced also proven to have positive effect in enhancing the entrapment efficiency and drug loading, which were 82.86 ± 0.15% and 55.41 ± 0.04%, respectively, and showed sun protection factor value of 16.61 ± 3.45. The results indicated the presence of synergistic effect among the PSO-NLC with Uvinul® A Plus B. 相似文献
84.
The low temperature oxidation of a Montana subbituminous coal was investigated using round bottom 100 ml flasks in constant temperature baths. The experiments were carried out in normal and oxygen enriched air at 30°C, 45°C and 70°C with particle sizes ranging from 4 mesh to 100 mesh. Periodic analysis of gas samples from the flasks provided the rate data. The reactivity of the as received coal was compared with that of the same coal dried (i) in high pressure steam and (ii) in hot water
A rate equation has been proposed incorporating the effects of oxygen diffusion and surface reaction. For higher oxygen concentration and smaller particle sizes, the zero order surface reaction was found to be controlling. The temperature dependency of the reaction rate was found to be well represented by the Arrhenius equation. The activation energy varied slightly under various conditions between 15 to 20 kca)/g mole
The reactivity of the hot water dried coal was found to be similar to that of the as received coal. Steam dried coal however, was found to be much less reactive. 相似文献
A rate equation has been proposed incorporating the effects of oxygen diffusion and surface reaction. For higher oxygen concentration and smaller particle sizes, the zero order surface reaction was found to be controlling. The temperature dependency of the reaction rate was found to be well represented by the Arrhenius equation. The activation energy varied slightly under various conditions between 15 to 20 kca)/g mole
The reactivity of the hot water dried coal was found to be similar to that of the as received coal. Steam dried coal however, was found to be much less reactive. 相似文献
85.
86.
Improved catalytic activity by catalase immobilization using γ‐cyclodextrin and electrospun PCL nanofibers 下载免费PDF全文
Nanofibrous structures are promising for biocatalyst immobilization due to their large surface area which facilitates the enzyme attachment, stability, ease of separation, and fine porous structure. There is limited research available on the change in enzyme activity following interaction with cyclodextrin. In this study, catalase enzyme was immobilized into nanofibrous structures by various techniques, with and without γ‐CD addition, and the enzymatic activity of catalase was evaluated. In addition, catalase‐γ‐CD complex containing PEO polymer solution was electrospun in between PCL nanofibrous layers as a newly developed technique. The enzyme immobilized nanofibrous structures were characterized by SEM, XRD, and FT‐IR analysis methods. Among all the activity tests, best enzyme activity was recorded with catalase‐γ‐CD physical mixture encapsulated PCL nanofibrous layers. Moreover, the test results indicated that the use of cyclodextrin in immobilization process considerably improves the catalytic activity of the enzyme. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44404. 相似文献
87.
Oktay H. Ozturk Yesim Can Zafer Yonden Sedat Motor Gonul Oktay Hasan Kaya Mutay Aslan 《Lipids》2013,48(12):1217-1226
Although hypocholesterolemia is a reported finding in sickle cell disease (SCD), low-density lipoprotein (LDL)/high-density lipoprotein (HDL) subfractions and HDL-associated enzymes have not been determined in SCD patients. Blood was collected from 38 hemoglobin (Hb)A volunteers and 45 homozygous HbSS patients who had not received blood transfusions in the last 3 months. Serum lipids were measured by automated analyzer while LDL and HDL subfraction analysis was done by continuous disc polyacrylamide gel electrophoresis. Serum levels of cholesteryl ester transfer protein (CETP), lecithin-cholesterol acyltransferase (LCAT), apolipoprotein B (apoB) and apolipoprotein A-1 (apoA-I) were determined by enzyme-linked immunosorbent assay (ELISA). Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) levels were significantly decreased, while TG levels were significantly increased in SCD patients compared to controls. A significant decrease in intermediate-density lipoprotein (IDL)-C, IDL-B, IDL-A and LDL-1 fractions were seen in SCD patients, while no significant difference was observed in small dense LDL particles. A significant decrease was seen in HDL-large, HDL-intermediate and HDL-small fractions in SCD patients versus controls. Levels of LCAT and ApoA-1 protein measured in SCD patients were significantly lower while no significant difference was observed in CETP and ApoB protein levels compared to controls. The reduction observed in LDL- and HDL-C in SCD patients was reflected as significantly decreased IDL, LDL-1 and HDL-subfractions. Decreased HDL subfractions may possibly lead to the reduced ApoA-1 and LCAT protein levels observed in SCD patients. 相似文献
88.
Mahdi N. Mahyari Hasan Karimi Hasan Naseh Mehran Mirshams 《Journal of Mechanical Science and Technology》2010,24(10):1997-2006
The focus of the present study is to investigate the effectiveness of installing vortex breakers at the outlet of launch vehicle
tanks on postponing vortex formation and decreasing the critical height of propellants while discharging. Analytical results
in the absence of a vortex breaker show that the effects of the Weber and Reynolds numbers in the flow field can be ignored
for values greater than 720 and 1.1 × 105, respectively; and critical height can be considered as a function of Froude number under aforementioned conditions. The
analytical criteria are verified by two-dimensional, axis symmetrical, transient and two-phase numerical model. Eventually,
some experiments are conducted to examine the effectiveness of the applied vortex breakers in reduction of the critical height
of propellant. Experimental results show that a 30% decrease can be achieved in critical height by using a particular type
of vortex breaker. Additionally, the carried out simulations for an existing two-stage launch vehicle indicate a 13% increase
in orbital altitude, which in turn proves the considerable improvement in launch vehicle mass/energetic capabilities. 相似文献
89.
SPARCL: an effective and efficient algorithm for mining arbitrary shape-based clusters 总被引:3,自引:3,他引:0
Vineet Chaoji Mohammad Al Hasan Saeed Salem Mohammed J. Zaki 《Knowledge and Information Systems》2009,21(2):201-229
Clustering is one of the fundamental data mining tasks. Many different clustering paradigms have been developed over the years,
which include partitional, hierarchical, mixture model based, density-based, spectral, subspace, and so on. The focus of this
paper is on full-dimensional, arbitrary shaped clusters. Existing methods for this problem suffer either in terms of the memory
or time complexity (quadratic or even cubic). This shortcoming has restricted these algorithms to datasets of moderate sizes.
In this paper we propose SPARCL, a simple and scalable algorithm for finding clusters with arbitrary shapes and sizes, and
it has linear space and time complexity. SPARCL consists of two stages—the first stage runs a carefully initialized version
of the Kmeans algorithm to generate many small seed clusters. The second stage iteratively merges the generated clusters to
obtain the final shape-based clusters. Experiments were conducted on a variety of datasets to highlight the effectiveness,
efficiency, and scalability of our approach. On the large datasets SPARCL is an order of magnitude faster than the best existing
approaches. 相似文献
90.
Ahmad Feyz Dizaji Hossein Ali Sepiani Farzad Ebrahimi Akbar Allahverdizadeh Hasan Ali Sepiani 《Journal of Mechanical Science and Technology》2009,23(8):2299-2307
An initial-boundary value problem that is Duffing’s oscillator with time varying coefficients will be studied. Using Banach’s
fixed-point theorem, the existence of periodic solution of the equation will be predicted. The method applied in this paper
is the Schauder second fixed point theorem, which includes the response of structures under vibratory force systems. As an
example, the dynamics of nonlinear simply supported rectangular thin plate under influence of a relatively moving mass is
studied. By expansion of the solution as a series of mode functions, the governing equations of motion are reduced to an ordinary
differential equation for time development vibration amplitude, which is Duffing’s oscillator. Finally, a parametric study
is developed, after that some numerical examples are solved, and the validity of the present analysis is clearly shown.
This paper was recommended for publication in revised form by Associate Editor Maenghyo Cho
Hossein Ali Sepiani received his B.S. degree in Mechanical Engineering from University of Kashan, Iran, in 2003. He then received his M.S. degree
from University of Tehran, in 2006. Currently, Hossein is continuing his research at University of Tehran. His research interests
include new materials (FGMs, Nano-materials, SMAs, SMPs, etc), Composites (Woven Fabrics and Fiber Metal Laminates), Smart
Materials (Shape Memory Alloy, Magnet/Electro-rheological and Piezoelectric Sensors and Actuators), Intelligent structures
(Structures integrated with smart materials), Vibration and control of Intelligent Structures and their application.
Ahmad Feyz Dizaji got his B.S. degree from University of Tehran, Iran, in 1970. Then he continued his study in U.S. and received his PhD. degree
from Michigan State University in 1983, in Applied Mathematics under the supervision of Professor Shui-ni Chow and Professor
J. Mallet-Paret. Since then he has been a member of the Faculty of Engineering in University of Tehran, teaching mathematics
in both undergraduate and graduate levels. 相似文献