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111.
Sung Chul Jee Ho Jae Lee Young Hoon Joo 《International Journal of Control, Automation and Systems》2012,10(4):841-848
This paper addresses sensor fault detection and isolation problems for continuous- and discrete-time linear time-invariant systems. To that end, we employ a bank consisting of the same number of observers as there are sensors. Both the observer gain and the residual gain are considered. Unlike earlier work, the design conditions with H ?/H ∞ performance are derived in terms of linear, rather than nonlinear, matrix inequalities. An illustrative example is provided to show the effectiveness of the proposed methodology. 相似文献
112.
Go Bong Choi Jong Woo Kim Jung Chul Suh Kwang Ho Jang Jong Min Lee 《Korean Journal of Chemical Engineering》2017,34(10):2584-2590
Pipe breaks in municipal water distribution networks may cause serious damage economically and socially. Existing methods for replacement scheduling of pipes do not provide practical indicators for replacing an individual deteriorated pipe. This work formulates the selection problem as the decision of preference ordering or ranking and proposes a bipartite ranking-based approach. The suggested approach also considers loss from broken pipes in terms of the costs associated with broken water main and its repair. We use rank aggregation method to integrate multiple ranks into replacement order of water mains. The suggested framework prioritizes current pipe sections for replacement based on the aggregated ranks. Multiple ranks given by the reliability of water pipe sections are aggregated and a cost effective policy for pipe replacement is derived. 相似文献
113.
Polyurethane (PU) grafted with several well-known pH indicators (alizarin yellow, bromocresol green, bromocresol purple, or thymol blue) via spacer is characterized for thermal, spectroscopic, mechanical, and shape memory properties, as well as for PU color change to aqueous solution with various pH values. The PU polymer frame is composed of 4,4′-methylenebis(phenylisocyanate) (MDI), which acts as a hard segment, poly(tetramethyleneglycol) (PTMG) as a soft segment, and a covalently linked pH indicator. The four different PU series studied in this work display characteristic color dependent upon the grafted indicator type. The PU series also exhibit a small degree of cross-linking due to the grafting agent used to covalently link the indicator to the PU frame. The tensile mechanical strength and the shape recovery of the indicator-grafted PU remain high after repeated tests compared to that of the plain linear PU. Regarding the tensile mechanical properties, the maximum stress and the strain increase to 424 and 1,880 %, respectively, for indicator-grafted PU compared to the linear PU. Furthermore, the shape recovery is observed to reach 98 % and improves after each test cycle. A reversible color change is observed after repeated exposure to aqueous solutions with varying pH values and is confirmed with UV-VIS spectra results. 相似文献
114.
Jun-Ho Bae Moon-Saeng Kim Beom-Cheol Hwang Chul Kim 《International Journal of Precision Engineering and Manufacturing》2010,11(2):299-307
In this paper, permanent magnets are used to remove magnetic sludge in the condenser of the power plant. To obtain the flow
characteristics and magnetic information that are needed for determining a proper design of the magnetic sludge removal apparatus,
we performed numerical simulations through the use of two commercial codes, ANSYS Workbench-Emag and CFX. We also performed
experiments on various kinds and sizes of magnets to obtain the magnetic information through a gauss meter. By analyzing the
results of simulations and experiments, the minimum magnetic force that is able to remove the any size of the magnetic sludge
in the condenser was calculated, and the design of the removal apparatus was confirmed. We made the test model which was confirmed
by the simulations and experiments for the tests of efficiency of the removal apparatus. After testing, the test results were
compared with those of numerical simulations and have good agreements. 相似文献
115.
Dong Hoon Oh Yi-Dong Yan Dong Wuk Kim Jong Oh Kim Chul Soon Yong 《Drug development and industrial pharmacy》2014,40(2):172-177
Objective: A novel flurbiprofen-loaded nanoemulsion which gave uniform emulsion droplets with a narrow size distribution was previously reported to be prepared using membrane emulsification method. The purpose of this study is to develop a novel flurbiprofen-loaded nanoparticle with a narrow size distribution and improved bioavailability.Method: The nanoparticle was prepared by solidifying nanoemulsion using sucrose as a carrier via spray drying method. Its physicochemical properties were investigated using SEM, DSC and PXRD. Furthermore, dissolution and bioavailability in rats were evaluated compared to a flurbiprofen-loaded commercial product.Results: The flurbiprofen-loaded nanoparticles with flurbiprofen/sucrose/surfactant mixture (1/20/2, weight ratio) gave good solidification and no stickiness. They associated with about 70?000-fold improved drug solubility and had a mean size of about 300 nm with a narrow size distribution. Flurbiprofen was present in a changed amorphous state in these nanoparticles. Moreover, the nanoparticles gave significantly shorter Tmax, and higher AUC and Cmax of the drug compared to the commercial product (p?0.05). In particular, they showed about nine-fold higher AUC of the drug than did the commercial productConclusion: These flurbiprofen-loaded nanoparticles prepared with sucrose by the membrane emulsification and spray drying method would be a potential candidate for orally delivering poorly water-soluble flurbiprofen with enhanced bioavailability. 相似文献
116.
Ki-Young Shin Yong Hoon Rim Youn Soo Kim Hyo Shin Kim Jae Woong Han Chang Hyun Choi Kyung Suk Lee Joung Hwan Mun 《Journal of Mechanical Science and Technology》2010,24(9):1901-1909
Gait analysis using 3D motion capture systems provides joint kinematic and kinetic analysis results such as joint relative
angles and moments that can be use used to evaluate the degrees of pathological gait patterns. However, the complex data produced
using these 3D motion capture systems can only analyzed by experts, because the gait analysis is highly coupled to the kinematics
of each joint. Therefore, several Several previous studies using gait analysis have relied on the data compression technique
to represent gait deviation from the average normal profiles as a single value. Even though it is important to evaluate gait
pathologies at the joint level, all these previous studies have just used a single value to evaluate the pathological gait
pattern. Using just one variable for evaluation of a gait is limited in terms of determining which joint movement patterns
are getting better during rehabilitation. Therefore, in this study, a method suitable for evaluating gait deviation during
a gait was developed to provide three indices for the hip, knee and ankle joints. In addition, to validate the proposed method
in clinical cases, experimental tests were conducted on thirty thirty-six normal walkers and six patients with cerebral palsy.
Furthermore, to validate the proposed method in regards to rehabilitation, experimental tests were conducted on three classified
walking groups with imposed ankle equinus constraints. The JNI for the hip joint, knee joint and ankle were 8.78 (±3.70),
2.92 (±3.25) and 8.79 (±4.38), respectively, in the normal walking group. However, these values were significantly different
for the pathological walking group with cerebral palsy. The JNI of the hip joint, knee joint and ankle joint were 203.73 (±171.59),
81.23 (±52.13) and 248.39 (±149.99), respectively, for this group. There were also differences between any two of the three
classified groups with imposed ankle equinus constraints. In particular, the JNI of the ankle joint was statistically different
at the p<0.01 level, and this parameter clearly increased as the degree of the imposed ankle equinus was increased. These
results demonstrate that the proposed JNI can be used as a scalar factor to evaluate the angular deviation of each joint in
normal and patient groups. In addition, this approach can be adapted to evaluate rehabilitation and pre/post surgery. 相似文献
117.
Response surface methodology was used for optimizing the ratio of vegetable oil and carbon black and occluded volume fraction of rubber in the compound. Central composite design for two variables was chosen as the experimental design. The data obtained from measurement of properties was fitted as a two variable second-order equation, and were plotted as contours using software developed from MATLAB v.5.1. From contours it is observed that at the ratio of 0.06 of vegetable oil and carbon black, there is maximum coupling, and a further increment in vegetable oil and carbon black ratio shows less coupling and more plasticizing effect. The ultimate failure properties like tensile and tear strength and elongation decreases with an increase in occluded volume fraction, reaches a minima at the central region, followed by an increase, whereas 300% modulus and hardness decreases throughout.© 2001 John Wiley & Sons, Inc, J Appl Polym Sci 82: 997-1005, 2001 相似文献
118.
Yu-Jin Hong Ig-Jae Kim Sang Chul Ahn Hyoung-Gon Kim 《Simulation Modelling Practice and Theory》2010,18(4):446-455
We propose a new method to recognize a user’s activities of daily living with accelerometers and RFID sensor. Two wireless accelerometers are used for classification of five human body states using decision tree, and detection of RFID-tagged objects with hand movements provides additional instrumental activity information. Besides, we apply our activity recognition module to the health monitoring system. We derive linear regressions for each activity by finding the correlations between the attached accelerometers and the expended calories calculated from gas exchange analyzer under different activities. Finally, we can predict the expended calories more efficiently with only accelerometer sensor depend on the recognized activity. We implement our proposed health monitoring module on smart phones for better practical use. 相似文献
119.
Preparation of dual‐layer acetylated methyl cellulose hollow fiber membranes via co‐extrusion using thermally induced phase separation and non‐solvent induced phase separation methods
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Hanna Jang Du‐Hyun Song Hye‐Jin Lee Seong‐Han Lim In‐Chul Kim Young‐Nam Kwon 《应用聚合物科学杂志》2015,132(43)
Dual‐layer acetylated methyl cellulose (AMC) hollow fiber membranes were prepared by coupling the thermally induced phase separation (TIPS) and non‐solvent induced phase separation (NIPS) methods through a co‐extrusion process. The TIPS layer was optimized by investigating the effects of coagulant composition on morphology and tensile strength. The solvent in the aqueous coagulation bath caused both delayed liquid–liquid demixing and decreased polymer concentration at the membrane surface, leading to porous structure. The addition of an additive (triethylene glycol, (TEG)) to the NIPS solution resolved the adhesion instability problem of the TIPS and NIPS layers, which occurred due to the different phase separation rates. The dual‐layer AMC membrane showed good mechanical strength and performance. Comparison of the fouling resistance of the AMC membranes with dual‐layer polyvinylidene fluoride (PVDF) hollow fiber membranes fabricated with the same method revealed less fouling of the AMC than the PVDF hollow fiber membrane. This study demonstrated that a dual‐layer AMC membrane with good mechanical strength, performance, and fouling resistance can be successfully fabricated by a one‐step process of TIPS and NIPS. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42715. 相似文献
120.