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951.
Wei Wang Chenzhe Li Hugo Rodrigue Fengpei Yuan Min‐Woo Han Maenghyo Cho Sung‐Hoon Ahn 《Advanced functional materials》2017,27(7)
The beam steering mechanism has been a key element for various applications ranging from sensing and imaging to solar tracking systems. However, conventional beam steering systems are bulky and complex and present significant challenges for scaling up. This work introduces the use of soft deployable reflectors combining a soft deployable structure with simple kirigami/origami reflective films. This structure can be used as a macroscale beam steering mechanism that is both simple and compact. This work first develops a soft deployable structure that is easily scalable by patterning of soft linear actuators. This soft deployable structure is capable of increasing its height several folds by expanding in a continuous and controllable manner, which can be used as a frame to deform the linearly stretchable kirigami/origami structures integrated into the structure. Experiments on the reflective capability of the reflectors are conducted and show a good fit to the modeling results. The proposed principles for deployment and for beam steering can be used to realize novel active beam steering devices, highlighting the use of soft robotic principles to produce scalable morphing structures. 相似文献
952.
Energy Harvesting: High‐Performance Piezoelectric,Pyroelectric, and Triboelectric Nanogenerators Based on P(VDF‐TrFE) with Controlled Crystallinity and Dipole Alignment (Adv. Funct. Mater. 22/2017)
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953.
Low‐Power Nonvolatile Charge Storage Memory Based on MoS2 and an Ultrathin Polymer Tunneling Dielectric
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Myung Hun Woo Byung Chul Jang Junhwan Choi Khang June Lee Gwang Hyuk Shin Hyejeong Seong Sung Gap Im Sung‐Yool Choi 《Advanced functional materials》2017,27(43)
Low‐power, nonvolatile memory is an essential electronic component to store and process the unprecedented data flood arising from the oncoming Internet of Things era. Molybdenum disulfide (MoS2) is a 2D material that is increasingly regarded as a promising semiconductor material in electronic device applications because of its unique physical characteristics. However, dielectric formation of an ultrathin low‐k tunneling on the dangling bond‐free surface of MoS2 is a challenging task. Here, MoS2‐based low‐power nonvolatile charge storage memory devices are reported with a poly(1,3,5‐trimethyl‐1,3,5‐trivinyl cyclotrisiloxane) (pV3D3) tunneling dielectric layer formed via a solvent‐free initiated chemical vapor deposition (iCVD) process. The surface‐growing polymerization and low‐temperature nature of the iCVD process enable the conformal growing of low‐k (≈2.2) pV3D3 insulating films on MoS2. The fabricated memory devices exhibit a tunable memory window with high on/off ratio (≈106), excellent retention times of 105 s with an extrapolated time of possibly years, and an excellent cycling endurance of more than 103 cycles, which are much higher than those reported previously for MoS2‐based memory devices. By leveraging the inherent flexibility of both MoS2 and polymer dielectric films, this research presents an important milestone in the development of low‐power flexible nonvolatile memory devices. 相似文献
954.
Superstructures: Enzyme‐Driven Hasselback‐Like DNA‐Based Inorganic Superstructures (Adv. Funct. Mater. 45/2017)
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955.
Phototransistors: High‐Performance UV–Vis–NIR Phototransistors Based on Single‐Crystalline Organic Semiconductor–Gold Hybrid Nanomaterials (Adv. Funct. Mater. 6/2017)
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956.
Strongly interacting amorphous poly(p-vinyl phenol) (PVPh) was added into semi-crystalline poly(ethylene oxide) (PEO) at 20 wt.% to generate dendritic lamellae of alternating birefringence colors, which intertwine roughly in the radial directions as periodic stripes. Optical and atomic-force microscopy analyses are performed on revealing lamellae assembly in highly dendritic PEO spherulites by crystallizing PEO/PVPh (80/20) at crystallization temperature (T c ) equals to 45 °C. The lamellae of two opposite colors in the same PEO spherulite quadrant are exactly of same geometry (of elongated plates, each being 0.2 μm in width and 2–5 μm in length), but they fan out +/?45o, respectively, as they grow away from the radial direction. The opposite colored-lamellae are radiating out in radial directions, interweaving each other to display alternating colors in radial alignment. However, such alternating colors can also be similarly seen in ring-banded spherulites in many polymers. The results presented in this study have demonstrated that the lamellae of alternating birefringent colors cannot only be seen in banded spherulites, but also in spherulites with radial dendrites. 相似文献
957.
Hee‐Chang Eun Young‐Ho Lee Heon‐Soo Chung Keun‐Hyeok Yang 《The Structural Design of Tall and Special Buildings》2006,15(4):445-466
An objective of this study is to establish the shear strength of reinforced concrete deep beam with web opening. Eighteen beams were tested with the variables of the steel ratio and strength of longitudinal bars, concrete strength, and shear span‐to‐depth ratio. It was observed that the opening is strengthened by longitudinal bars but the load‐carrying capacity of deep beams with openings can be largely improved by the increase in concrete strength. Modifying the softened truss model derived by Mau and Hsu and utilizing the results of this experiment carried out with the variables of concrete strength, cross‐section size, shear‐span‐to‐depth ratio, and the strength and steel ratio of longitudinal bars, this study proposes an improved model to predict the shear strength. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
958.
CIPEA(China International Practice Exhibition of Architecture),详见《室内设计与装修》2005年04期)组委会办公室位于南京市中心区。对于这个280m^2的室内,功能上的要求是办公和展示,造价上是简装,甲方似乎除了这两个要求外并没有再提其他,因为毕竟对于尚在校学习、还没有一个建成项目的我们来说,甲方与其提出什么苛求,不如营造一个宽松的气氛。而我们却捏了一把汗,因为这儿将有我们崇拜的国内外最著名的建筑大师到来…… 相似文献
959.
B.I. Choi H.S. Nham S.B. Woo J.C. Kim S.Y. Kwon 《International Journal of Thermophysics》2008,29(5):1578-1588
A new low frost-point humidity generator (LFPG) has been designed, and its performance has been tested, in order to extend
the calibration capabilities to the low frost-point range at KRISS. The water vapor–gas mixture is generated by saturating
air with water vapor over a surface of an ice-coated saturator under the conditions of constant temperature and pressure.
This LFPG covers a range of frost point from − 99 °C to − 40 °C. The temperature of the saturator, which is controlled by
thermoelectric devices and a two-stage mechanical refrigeration system, is stable within 5 mK, and the difference between
the saturator temperature and the frost point generated at the saturator outlet is less than 20 mK. This stability is achieved
by using oxygen-free high-conductivity copper materials as the saturator body, and applying a precision PID temperature control
system. The performance of this new LFPG system is compared with the KRISS standard two-temperature generator in the frost-point
range ( − 80 to − 40) °C, and its performance is tested with a quartz crystal microbalance (QCM), which was built at KRISS,
to − 91 °C. 相似文献
960.
The characterization of PCDDs, PCDFs and coplanar PCBs during the past 50 years in Gwangyang Bay, South Korea 总被引:1,自引:1,他引:0
Kim YS Eun H Cho HS Kim KS Watanabe E Baba K Katase T 《Journal of hazardous materials》2008,154(1-3):756-765
The PCDD/DFs and coplanar PCBs (co-PCBs) in sediment samples from Gwangyang Bay in South Korea was investigated. The total concentration of dioxins and their toxic equivalent quantity (TEQ; calculated with the WHO 2005 Toxic Equivalency Factors) value in the surface sediment of the outer site (261 pg g(-1) TOC, 4.4 pg-TEQ g(-1)) were 3-fold higher than the inner site (90 pg g(-1) TOC, 1.1 pg-TEQ g(-1)) in the Bay. The dioxin in the sediment samples was found to come from a mixture of the impurities of pentachlorophenol (PCP), chloronitrofen (CNP) and combustion based on the result of hierarchical cluster analysis (HCA). These dioxin sources have been influenced by the characterization associated with this region which was both an agricultural-centered and industrial-centered area. According to principal component analysis (PCA) related to the Kow values for the congener-specific composition of co-PCBs in the sediment core, the Kanechlor (KC)-500 and the atmospheric deposition were identified as the possible sources. The maximum burden in the sediment core was 1.3 kg for 1967-1974 and the total burdens of PCDD/DFs and co-PCBs in the sediment core were estimated to be 6.6 kg during the past 50 years. The cumulative burdens of dioxin are still increasing in Gwangyang Bay. 相似文献