全文获取类型
收费全文 | 123篇 |
免费 | 47篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 21篇 |
金属工艺 | 4篇 |
机械仪表 | 2篇 |
轻工业 | 2篇 |
无线电 | 27篇 |
一般工业技术 | 91篇 |
冶金工业 | 12篇 |
自动化技术 | 10篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 11篇 |
2017年 | 3篇 |
2016年 | 12篇 |
2015年 | 14篇 |
2014年 | 14篇 |
2013年 | 9篇 |
2012年 | 13篇 |
2011年 | 9篇 |
2010年 | 3篇 |
2009年 | 7篇 |
2008年 | 2篇 |
2007年 | 13篇 |
2006年 | 8篇 |
2005年 | 1篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 7篇 |
1997年 | 1篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1976年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有170条查询结果,搜索用时 31 毫秒
121.
Electrocatalysis: Wafer Scale Phase‐Engineered 1T‐ and 2H‐MoSe2/Mo Core–Shell 3D‐Hierarchical Nanostructures toward Efficient Electrocatalytic Hydrogen Evolution Reaction (Adv. Mater. 44/2016)
下载免费PDF全文
![点击此处可从《Advanced materials (Deerfield Beach, Fla.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
122.
SrCl2 Derived Perovskite Facilitating a High Efficiency of 16% in Hole‐Conductor‐Free Fully Printable Mesoscopic Perovskite Solar Cells
下载免费PDF全文
![点击此处可从《Advanced materials (Deerfield Beach, Fla.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Hua Zhang Huan Wang Spencer T. Williams Dehua Xiong Wenjun Zhang Chu‐Chen Chueh Wei Chen Alex K.‐Y. Jen 《Advanced materials (Deerfield Beach, Fla.)》2017,29(15)
Despite the breakthrough of over 22% power conversion efficiency demonstrated in organic–inorganic hybrid perovskite solar cells (PVSCs), critical concerns pertaining to the instability and toxicity still remain that may potentially hinder their commercialization. In this study, a new chemical approach using environmentally friendly strontium chloride (SrCl2) as a precursor for perovskite preparation is demonstrated to result in enhanced device performance and stability of the derived hole‐conductor‐free printable mesoscopic PVSCs. The CH3NH3PbI3 perovskite is chemically modified by introducing SrCl2 in the precursor solution. The results from structural, elemental, and morphological analyses show that the incorporation of SrCl2 affords the formation of CH3NH3PbI3(SrCl2)x perovskites endowed with lower defect concentration and better pore filling in the derived mesoscopic PVSCs. The optimized compositional CH3NH3PbI3(SrCl2)0.1 perovskite can substantially enhance the photovoltaic performance of the derived hole‐conductor‐free device to 15.9%, outperforming the value (13.0%) of the pristine CH3NH3PbI3 device. More importantly, the stability of the device in ambient air under illumination is also improved. 相似文献
123.
I-Hsiang Chao Yu-Ting Yang Ming-Hsuan Yu Chiung-Han Chen Chwen-Haw Liao Bi-Hsuan Lin I-Chih Ni Wen-Chang Chen Anita W. Y. Ho-Baillie Chu-Chen Chueh 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(20):2207734
Two-dimensional (2D) tin (Sn)-based perovskites have recently received increasing research attention for perovskite transistor application. Although some progress is made, Sn-based perovskites have long suffered from easy oxidation from Sn2+ to Sn4+, leading to undesirable p-doping and instability. In this study, it is demonstrated that surface passivation by phenethylammonium iodide (PEAI) and 4-fluorophenethylammonium iodide (FPEAI) effectively passivates surface defects in 2D phenethylammonium tin iodide (PEA2SnI4) films, increases the grain size by surface recrystallization, and p-dopes the PEA2SnI4 film to form a better energy-level alignment with the electrodes and promote charge transport properties. As a result, the passivated devices exhibit better ambient and gate bias stability, improved photo-response, and higher mobility, for example, 2.96 cm2 V−1 s−1 for the FPEAI-passivated films—four times higher than the control film (0.76 cm2 V−1 s−1). In addition, these perovskite transistors display non-volatile photomemory characteristics and are used as perovskite-transistor-based memories. Although the reduction of surface defects in perovskite films results in reduced charge retention time due to lower trap density, these passivated devices with better photoresponse and air stability show promise for future photomemory applications. 相似文献
124.
Uniform Luminous Perovskite Nanofibers with Color‐Tunability and Improved Stability Prepared by One‐Step Core/Shell Electrospinning
下载免费PDF全文
![点击此处可从《Small (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Ping‐Chun Tsai Jung‐Yao Chen Ender Ercan Chu‐Chen Chueh Shih‐Huang Tung Wen‐Chang Chen 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(22)
A one‐step core/shell electrospinning technique is exploited to fabricate uniform luminous perovskite‐based nanofibers, wherein the perovskite and the polymer are respectively employed in the core and the outer shell. Such a coaxial electrospinning technique enables the in situ formation of perovskite nanocrystals, exempting the needs of presynthesis of perovskite quantum dots or post‐treatments. It is demonstrated that not only the luminous electrospun nanofibers can possess color‐tunability by simply tuning the perovskite composition, but also the grain size of the formed perovskite nanocrystals is largely affected by the perovskite precursor stoichiometry and the polymer solution concentration. Consequently, the optimized perovskite electrospun nanofiber yields a high photoluminescence quantum yield of 30.9%, significantly surpassing the value of its thin‐film counterpart. Moreover, owing to the hydrophobic characteristic of shell polymer, the prepared perovskite nanofiber is endowed with a high resistance to air and water. Its photoluminescence intensity remains constant while stored under ambient environment with a relative humidity of 85% over a month and retains intensity higher than 50% of its initial intensity while immersed in water for 48 h. More intriguingly, a white light‐emitting perovskite‐based nanofiber is successfully fabricated by pairing the orange light‐emitting compositional perovskite with a blue light‐emitting conjugated polymer. 相似文献
125.
Because the microworld can create a learning environment that allows learners to interact with the real world, the view of the microworld has been widely used in education and training. In this study, the simulated transactional interactive concurrent system (STICS) was used to provide an environment that simulates the stock market trading of the Taiwan Stock Exchange; the goal is to explore the effectiveness of using STICS in enhancing the financial literacy of students. This study adopts a quasi-experimental design approach and divides students into two groups. The intervention group was made up of 42 students who learned financial knowledge aided by STICS, with a comparison group consisting of 43 students who learned with traditional lecturing and dictating methods. The study found that learners who used the STICS as an aid to learn financial knowledge had significantly better learning effectiveness than those who did not use STICS, in terms of motivation, attitude, and achievement. The intervention group also made significant improvements in average scores in learning motivation and achievement after 8 weeks of experimental teaching and learning. 相似文献
126.
Chueh HS Tsai WK Chang CC Chang SM Su KH Chen JC 《Computer methods and programs in biomedicine》2008,92(3):289-293
A beam-hardening effect is a common problem affecting the quantitative aspects of X-ray computed tomography (CT). We have developed two statistical reconstruction algorithms for poly-energetic X-ray CT that can effectively reduce the beam-hardening effect. Phantom tests were used to evaluate our approach in comparison with traditional correction methods. Unlike previous methods, our algorithm utilizes multiple energy-corresponding blank scans to estimate the attenuation map for a particular energy spectrum. Therefore, our algorithm is an energy-selective reconstruction. In addition to benefits over other statistical algorithms for poly-energetic reconstruction, our algorithm has the advantage of not requiring prior knowledge of the object material, the energy spectrum of the source and the energy sensitivity of the detector. The results showed an improvement in coefficient of variation, uniformity and signal-to-noise ratio; overall, this novel approach produces a better beam-hardening correction. 相似文献
127.
A metal chelate polymer (MCP) of PVAc‐AgNO3 was prepared by adding AgNO3 salts into the PVAc matrix and was coated on to PET substrate to form PVAc‐AgNO3/PET films. These films were then treated with NaBH4 aqueous solution to become the reduced metallized conductive films (RMCF) of PVAc‐AgNO3/PET. The electromagnetic interference shielding effectiveness (EMI/SE) and the characteristics of these films were investigated. The SE value was measured by the far‐field transmission line method. The surface resistivity (Rs) of RMCF with a AgNO3 content of 15 wt % was found to be below 5 Ω/sq, and the SE value exceeded 20 dB over the frequency range 50–900 MHz. The Rs of RMCF with a AgNO3 content of 30 wt % was less than 1 Ω/sq, and the SE value even reached 33 dB at 550–650 MHz. It was confirmed by X‐ray and scanning electronmicroscope (SEM) analysis that the conducting network, as formed by closely deposited silver atoms on the reduced coating surface, was the dominant pathway for effective electron propagation that contributed to the excellent conductivity of these RMCF (PVAc‐AgNO3/PET). © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 270–273, 2004 相似文献
128.
Metabolism studies were conducted on 4-methylaminorex (4,5-dihydro-4-methyl-5-phenyl-2-oxazolamine [4-MAX]), a potent central nervous system stimulant that has emerged as a drug of abuse under the name "EU4EA", "EU4Euh", and "Ice". Tritiated norephedrine was cyclized with cyanogen bromide to form 3H-4-MAX, which was administered to rats at a dose of 10 mg/kg orally and intravenously. Radioactivity was excreted almost entirely in urine (40% of the dose was excreted by 24 h), primarily as the parent drug (60% of the total excretions were as the parent compound). Three metabolites were identified by high-performance liquid chromatography-tandem mass spectrometry with thermospray ionization: norephedrine, 5-phenyl-4-methyl-2-oxazolidinone, and 2-amino-5-(p-hydroxyphenyl)-4-methyl-2-oxazoline. Stability studies showed that 4-MAX in aqueous solution degraded very slightly to norephedrine upon standing. There was no evidence for glucuronide or sulfate conjugation. These results suggest that the metabolic fate of 4-MAX is similar to that of the amphetamines in that it is eliminated primarily unchanged but undergoes some slight oxidative deamination and aromatic hydroxylation. Hydrolytic degradation back to the synthetic precursor can also occur. There was no evidence for the hydrolysis of the oxazolamine ring to form a urea that has been reported for the demethylated congener aminorex. This suggests that 4-methyl substitution of the oxazoline ring may inhibit metabolism similar to the alpha-methyl substitution of beta-phenylethylamines. 相似文献
129.
The integration of semiporous membranes into poly(dimethylsiloxane) (PDMS) microfluidic devices is useful for mass transport control. Several methods such as plasma oxidation and manual application of PDMS prepolymer exist to sandwich such membranes into simple channel structures, but these methods are difficult to implement with reliable sealing and no leakage or clogging for devices with intricate channel features. This paper describes a simple but robust strategy to bond semiporous polyester and polycarbonate membranes between layers of PDMS microchannel structures effectively without channel clogging. A thin layer of PDMS prepolymer, spin-coated on a glass slide, is transferred to PDMS substrates with channel features as well as to the edges of the semiporous membrane by stamping. This thin PDMS prepolymer serves as "mortar" to strongly bond the two PDMS layers and seal off the crevices generated from the thickness of the membranes. This bonding method enabled the fabrication of an 8x12 criss-crossing microfluidic channel array with 96 combinations of fluid interactions. The capability of this device for bioanalysis was demonstrated by measuring responses of cells to different color fluorescent reagents. 相似文献
130.
Chang MT Chou LJ Chueh YL Lee YC Hsieh CH Chen CD Lan YW Chen LJ 《Small (Weinheim an der Bergstrasse, Germany)》2007,3(4):658-664
Very dense and uniformly distributed nitrogen-doped tungsten oxide (WO(3)) nanowires were synthesized successfully on a 4-inch Si(100) wafer at low temperature. The nanowires were of lengths extending up to 5 mum and diameters ranging from 25 to 35 nm. The highest aspect ratio was estimated to be about 200. An emission peak at 470 nm was found by photoluminescence measurement at room temperature. The suggested growth mechanism of the nanowires is vapor-solid growth, in which gaseous ammonia plays a significant role to reduce the formation temperature. The approach has proved to be a reliable way to produce nitrogen-doped WO(3) nanowires on Si in large quantities. The direct fabrication of WO(3)-based nanodevices on Si has been demonstrated. 相似文献