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排序方式: 共有2633条查询结果,搜索用时 31 毫秒
81.
Aminu Umar Kura Nooraini Mohd Ain Mohd Zobir Hussein Sharida Fakurazi Samer Hasan Hussein-Al-Ali 《International journal of molecular sciences》2014,15(4):5916-5927
Layered hydroxide nanoparticles are generally biocompatible, and less toxic than most inorganic nanoparticles, making them an acceptable alternative drug delivery system. Due to growing concern over animal welfare and the expense of in vivo experiments both the public and the government are interested to find alternatives to animal testing. The toxicity potential of zinc aluminum layered hydroxide (ZAL) nanocomposite containing anti-Parkinsonian agent may be determined using a PC 12 cell model. ZAL nanocomposite demonstrated a decreased cytotoxic effect when compared to levodopa on PC12 cells with more than 80% cell viability at 100 μg/mL compared to less than 20% cell viability in a direct levodopa exposure. Neither levodopa-loaded nanocomposite nor the un-intercalated nanocomposite disturbed the cytoskeletal structure of the neurogenic cells at their IC50 concentration. Levodopa metabolite (HVA) released from the nanocomposite demonstrated the slow sustained and controlled release character of layered hydroxide nanoparticles unlike the burst uptake and release system shown with pure levodopa treatment. 相似文献
82.
Hyeong Pil Kim Abd Rashid bin Mohd Yusoff Hyo Min Kim Hee Jae Lee Gi Jun Seo Jin Jang 《Nanoscale research letters》2014,9(1):150
We demonstrate that there is a new solution-processed electron transport layer, lithium-doped zinc oxide (LZO), with high-performance inverted organic photovoltaic device. The device exhibits a fill factor of 68.58%, an open circuit voltage of 0.86 V, a short-circuit current density of −9.35 cm/mA2 along with 5.49% power conversion efficiency. In addition, we studied the performance of blend ratio dependence on inverted organic photovoltaics. Our device also demonstrates a long stability shelf life over 4 weeks in air. 相似文献
83.
Uncrosslinked and chemically crosslinked ethylene‐vinyl acetate copolymers (EVAs) with 5–25 volume percentages of zeolite were prepared in a melt‐mixing process and then compression‐molded on a hot‐press machine according to standard test specifications. The mechanical properties measured by tensile test showed a reduction in tensile strength and elongation at break with increasing zeolite content. However, an increasing trend was observed for tensile modulus with addition of zeolite. Experimental results for ultimate stress were compared with those from Pukanszky equation. The experimental data showed a good fit to the Pukanszky model. The improvement in the interfacial interaction for crosslinked composites was also confirmed by this model. Morphological changes of EVA/zeolite composites were analyzed by scanning electron microscopy (SEM). The fractured surface of the composites indicated more complex morphology at higher zeolite loading. The influence of crosslinking induced by 2 wt% of dicumyl peroxide on the properties of EVA/zeolite composites was also investigated. The crosslinked composites showed better tensile properties than the uncrosslinked ones, a result which might be an indication of enhanced interaction between the EVA and zeolite. Density measurements, gel content determinations, and Fourier transform infrared analyses were also performed to evaluate the crosslink content of the composites. The changes in the properties of chemically crosslinked EVA/zeolite composites were observed. Meanwhile, SEM micrographs of the crosslinked EVA/zeolite composites showed better interfacial strength between zeolite and the EVA matrix as compared to that of the uncrosslinked composites. J. VINYL ADDIT. TECHNOL., 2012. © 2012 Society of Plastics Engineers 相似文献
84.
Khamirul Amin Matori Loy Chee Wah Mansor Hashim Ismayadi Ismail Mohd Hafiz Mohd Zaid 《International journal of molecular sciences》2012,13(12):16812-16821
We report on a recycling project in which α-Al2O3 was produced from aluminum cans because no such work has been reported in literature. Heated aluminum cans were mixed with 8.0 M of H2SO4 solution to form an Al2(SO4)3 solution. The Al2(SO4)3 salt was contained in a white semi-liquid solution with excess H2SO4; some unreacted aluminum pieces were also present. The solution was filtered and mixed with ethanol in a ratio of 2:3, to form a white solid of Al2(SO4)3·18H2O. The Al2(SO4)3·18H2O was calcined in an electrical furnace for 3 h at temperatures of 400–1400 °C. The heating and cooling rates were 10 °C/min. XRD was used to investigate the phase changes at different temperatures and XRF was used to determine the elemental composition in the alumina produced. A series of different alumina compositions, made by repeated dehydration and desulfonation of the Al2(SO4)3·18H2O, is reported. All transitional alumina phases produced at low temperatures were converted to α-Al2O3 at high temperatures. The X-ray diffraction results indicated that the α-Al2O3 phase was realized when the calcination temperature was at 1200 °C or higher. 相似文献
85.
A. A. Nuraini A. K. A. Mohd Ihsan M. J. M. Nor N. Jamaluddin 《Journal of Mechanical Science and Technology》2012,26(8):2405-2411
This paper presents the results of vibro-acoustic modeling and simulation using the finite element and the boundary element methods for the free piston engine structure. A model of the engine was constructed through the use of finite element software to perform a normal mode analysis of the engine structure. The objective was to determine the mode shapes and the natural frequency that contribute to engine structure vibration. Theoretical development of the engine balance motion and frequency response was also conducted. From the simulation and finite element analysis, the force response pattern of the engine vibration was determined and then compared with its natural frequency. The vibration data were used as the input data for noise analysis using the boundary element method. The integration of the finite element and the boundary element determined the noise-frequency data of the engine structure toward the occurrence of engine noise. The information can be used by designers to analyze engine specifications and structure, especially at the preliminary design stage. 相似文献
86.
Georgios Papadopoulos Hanna Kurniawati Ahmed Shafeeq Bin Mohd Shariff Liang Jie Wong Nicholas M. Patrikalakis 《野外机器人技术杂志》2014,31(2):225-244
Over the past 10 years, significant scientific effort has been dedicated to the problem of three‐dimensional (3‐D) surface reconstruction for structural systems. However, the critical area of marine structures remains insufficiently studied. The research presented here focuses on the problem of 3‐D surface reconstruction in the marine environment. This paper summarizes our hardware, software, and experimental contributions on surface reconstruction over the past few years (2008–2011). We propose the use of off‐the‐shelf sensors and a robotic platform to scan marine structures both above and below the waterline, and we develop a method and software system that uses the Ball Pivoting Algorithm (BPA) and the Poisson reconstruction algorithm to reconstruct 3‐D surface models of marine structures from the scanned data. We have tested our hardware and software systems extensively in Singapore waters, including operating in rough waters, where water currents are around 1–2 m/s. We present results on construction of various 3‐D models of marine structures, including slowly moving structures such as floating platforms, moving boats, and stationary jetties. Furthermore, the proposed surface reconstruction algorithm makes no use of any navigation sensor such as GPS, a Doppler velocity log, or an inertial navigation system. 相似文献
87.
Ali Darejeh Siti Salwah Salim 《International journal of human-computer interaction》2016,32(8):613-642
Gamification is the use of video-game mechanics and elements in nongame contexts to enhance user engagement and performance. The purpose of this study is to conduct a systematic review to have an in-depth investigation into the existing gamification solutions targeted at solving user engagement problems in different categories of software. We carried out this systematic review by proposing a framework of gamifying process, which is the basis for comparison of existing gamification solutions. In order to report the review, the primary studies are categorized according to the following: a) gamified software and their platforms; b) elements of the gamifying process; c) gamification solutions in each software type; d) gamification solutions for software user engagement problems; e) gamification solutions in general; and f) effects of gamification on software user engagement and performance. Based on the search procedure and criteria, a total of 78 primary studies were extracted. Most of the studies focused on educational and social software, which were developed for web or mobile platforms. We concluded that the number of studies on motivating users to use software content, solving problems in learning software, and using real identity is very limited. Furthermore, few studies have been carried out on gamifying the following software categories: productivity software, cloud storage, utility software, entertainment software, search engine software, tool software, fitness software, software engineering, information worker software, and health-care software. In addition, a large number of gamification solutions are relatively simple and require improvement. Thus, for future studies, researchers can work on the items discovered in this review; they can improve the quality of the current gamified systems by using a wide variety of game mechanics and interface elements, utilizing a combination of contextual types of rewards and giving users the ability to use received rewards “in-game” and “out-game.” 相似文献
88.
Mohd Ikram Ramli Abu Bakar Sulong Norhamidi Muhamad Andanastuti Muchtar Mohd Yusuf Zakaria 《Ceramics International》2019,45(9):11648-11653
Composite biomaterials are in high demand in the medical field of today. The combination of bioactive wollastonite (WA) glass ceramic with the biocompatibility of alloy titanium (Ti6Al4V) could be a good candidate for implant applications. The rheological properties of Ti6Al4V/WA feedstock show a pseudoplastic behaviour with low activation energy. The feedstock was successfully injected as a green part with no defects. The green part was solvent debound for 6?h in heptane and thermal debound in an argon environment for 1?h. The brown part was successfully sintered at 1300?°C for 3?h with 5?°C/min heating and cooling rates. The average sintered density was 4.12?g/cm3; which is 97.5% from the theoretical density. The highest Young's modulus obtained was 18.10?GPa; which is in the range of human bone strength. EDX analysis shows that by increasing sintering temperature, the level of oxygen decreased. Cell viability test shown an absorbance increased with days increasing indicated that the cellular were proliferated on the composite Ti6Al4V/WA composite which also proved that the composite was non-toxic. This indicates that the Ti6Al4V/WA composite is suitable for bone implant applications. 相似文献
89.
Norazah Mohd Suki 《Electronic Commerce Research》2013,13(4):477-491
Shopping on the Internet enables consumers to search for information on products or services and make purchases through direct interaction with online retailers. This study investigates consumer shopping behaviour on the Internet based on four aspects, i.e. the Internet marketing environment, product characteristics, familiarity, and promotional offers. The impact of influencing factors was checked by questionnaire survey, which was then processed and evaluated. Two hundred randomly selected respondents (students and employees in a public higher learning institution in the Federal Territory of Labuan, Malaysia) participated in the survey. Multiple regression analysis was used as a statistical measure to determine the most influential relationship aspect among a series of independent variables of consumer shopping on the Internet. The results revealed that familiarity has a great influence on consumer shopping on the Internet, followed by promotional offers. The assimilation of these aspects, and the empirical examination of the factors that influence consumer shopping on the Internet, advanced understanding of these constructs and their link to dynamic technology deployment for shopping. The paper suggests managerially actionable implications, and future research directions. 相似文献
90.
This article investigates the tribological behavior of nanoparticles (NPs) of titanium dioxide anatase TiO2 (A), graphene, and TiO2 (A) + graphene added to the pure base oil group ΙΙ (PBO-GΙΙ). The morphology of these two nanostructures of TiO2 (A) and graphene was characterized by transmission electron microscopy (TEM). Oleic acid (OA) was blended as a surfactant into the formulation to help stabilize the NPs in the lubricant oil. A four-ball test rig was used to determine the tribological performance of six different samples, and an image acquisition system was used to examine and measure the wear scar diameter of the stationary balls. Field emission–scanning electron microscopy (FE-SEM) was used to examine the wear morphology. Energy-dispersive X-ray spectroscopy (EDX), element mapping, and Raman spectroscopy were employed to confirm the presence of (TiO2 (A) + graphene) and the formation of a tribolayer/film on the mating surfaces. Moreover, a 3D optical surface texture analyzer was utilized to investigate the scar topography and tribological performance. The experiments proved that adding (0.4?wt% TiO2 (A) + 0.2?wt% graphene) to the PBO-GΙΙ optimized its tribological behavior. These excellent results can be attributed to the dual additive effect and the formation of a tribofilm of NPs during sliding motion. Furthermore, the average reductions in the coefficient of friction (COF), wear scar diameter (WSD), and specific wear rate (SWR) were 38.83, 36.78, and 15.78%, respectively, for (0.4?wt% TiO2 (A) + 0.2?wt% graphene) nanolubricant compared to plain PBO-GΙΙ lubricant. 相似文献