全文获取类型
收费全文 | 117篇 |
免费 | 6篇 |
专业分类
化学 | 64篇 |
晶体学 | 2篇 |
力学 | 9篇 |
数学 | 8篇 |
物理学 | 40篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 4篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2016年 | 2篇 |
2015年 | 4篇 |
2014年 | 8篇 |
2013年 | 7篇 |
2012年 | 6篇 |
2011年 | 9篇 |
2010年 | 12篇 |
2009年 | 5篇 |
2008年 | 8篇 |
2007年 | 6篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2003年 | 3篇 |
2000年 | 6篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 8篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1980年 | 1篇 |
排序方式: 共有123条查询结果,搜索用时 140 毫秒
61.
Horng‐Jyh Harn Yi‐Lin Chen Po‐Cheng Lin Yeung‐Leung Cheng Shin‐Chun Lee Tzyy‐Wen Chiou Hsueh‐Hui Yang 《中国化学会会志》2010,57(2):180-188
To explore the potential tumor markers for lung adenocarcinoma, two‐dimensional gel electrophoresis (2DE) coupled with nano‐LC/MS/MS was used to analyze the differentially expressed proteins in 10 surgical resected lung adenocarcinoma tissues. 16 proteins were significantly different between the cancer tissue and adjacent normal tissue. Galectin‐1, peroxiredoxin II (Prx II), proapolipoprotein, glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH), aldolase A, enolase 1, neuropolypeptide h3, Prx V, cyclophilin A, vimentin, protein disulfide isomerase (PDI), tropomyosin 3 (TPM 3), glutathione S‐transferase Pi (GST‐Pi), manganese superoxide dismutase (MnSOD), and cofilin 1 were up‐regulated in the cancer tissue. On the other hand, profilin was down‐regulated in the cancer tissue. Among these proteins, six proteins were validated by Western blot analysis. The identified proteins contributing to the spectrum of cancer progression may be used as potential diagnostic biomarkers for lung adenocarcinomas. 相似文献
62.
Chiy‐Rong Chen Yun‐Wen Liao Wen‐Ling Shih Chih‐Ying Tzeng Hsueh‐Ling Cheng Wei‐Tsung Kao Chi‐I Chang 《Helvetica chimica acta》2010,93(7):1355-1361
Two new cucurbitane triterpenes, (23E)‐7β‐methoxycucurbita‐5,23,25‐trien‐3β‐ol ( 1 ) and 23,25‐dihydroxy‐5β,19‐epoxycucurbit‐6‐ene‐3,24‐dione ( 2 ), and a new D : C‐friedooleanane triterpene, 3α‐[(E)‐feruloyloxy]‐D : C‐friedooleana‐7,9(11)‐dien‐29‐oic acid ( 3 ), together with two known D : C‐friedooleanane triterpenes, 3β‐[(E)‐feruloyloxy]‐D : C‐friedooleana‐7,9(11)‐dien‐29‐oic acid ( 4 ) and 3‐oxo‐D : C‐friedooleana‐7,9(11)‐dien‐29‐oic acid ( 5 ), were isolated from the stems of Momordica charantia. The structures of the new compounds 1 – 3 were determined by spectroscopic methods. 相似文献
63.
Kuang-Hua Hsueh Wei-Ting Chen Yung-Chuan Chu Lung-Chang Tsai Chi-Min Shu 《Journal of Thermal Analysis and Calorimetry》2012,109(3):1253-1260
With two active O?CO peroxide groups, 1,1-bis(tert-butylperoxy)cyclohexane (BTBPC) has a certain degree of thermal instability. It is usually used as an initiator in chemical processes, and therefore reckless operation may result in serious thermal accidents. This study focused on the runaway reactions of BTBPC alone and mixed with various concentrations of nitric acid (1, 2, 4, and 8?N). The essential thermokinetic parameters, such as exothermic onset temperature (T o), activation energy (E a), frequency factor (A), time to maximum rate under adiabatic condition (TMRad) and time to conversion limit (TCL), were evaluated by differential scanning calorimetry at the heating rate of 4?°C min?1, and a kinetics-based curve fitting method was used to assess the thermokinetic parameters. All the results indicated that BTBPC mixed with one more than 4?N nitric acid dramatically increased the degree of thermal hazard in the exothermic peak and became more dangerous. However, it was relatively safe for BTBPC mixed with less than 1?N nitric acid under 34.5?°C. 相似文献
64.
Kuang-Hua Hsueh Wei-Chun Chen Shang-Hao Liu Chi-Min Shu 《Journal of Thermal Analysis and Calorimetry》2014,118(3):1675-1683
Having two active peroxide groups, 1,1-bis(tert-butylperoxy)cyclohexane (BTBPC) has a certain degree of thermal instability. It is usually used as an initiator in a chemical process, and therefore, careless operation could result in severe accidents. This study emphasized the runaway reactions of BTBPC 70 mass% (4.5–5.2 mg), the relevant thermokinetic parameters, and the thermal safety parameters. Differential scanning calorimetry was used to evaluate the above-mentioned thermokinetic parameters, using four low heating rates (0.5, 1, 2, and 4 °C min?1) combined with kinetic simulation method. The results indicated that apparent exothermic onset temperature (T o), apparent activation energy (E a), and heat of decomposition (ΔH d) were ca. 118 °C, 156 kJ mol?1, and 1,080 kJ kg?1, respectively. In view of process loss prevention, at the low heating rates of 0.5, 1, 2, and 4 °C min?1, storing BTBPC 70 mass% below 27.27 °C is a more reassuring approach. 相似文献
65.
The addition of reactive carbanions to (η4‐1,3‐diene)Fe(CO)3 complexes at ?78 °C and 25 °C produced putative homoallyl and allyl anion complexes, respectively. Reaction of the reactive intermediates with 2‐(phenylsulfonyl)‐3‐phenyloxaziridine afforded nucleophilic substituted (η4‐1,3‐diene)Fe(CO)3 complexes. 相似文献
66.
K.W. Liu S.J. Young S.J. Chang T.H. Hsueh Y.Z. Chen K.J. Chen H. Hung S.M. Wang Y.L. Wu 《Journal of Crystal Growth》2012,347(1):113-118
This study investigates how the thickness of Cr deposited on the Si substrate after the nitridation process influences the AIN buffer layer and the InN nanorods. Atomic force microscopy results reveal that different thicknesses of Cr form varying sizes of CrN nanoislands. The results of scanning electron microscopy and X-ray diffraction show that a Cr deposition thickness of 10 nm results in CrN nanoislands after the nitridation process, improving the quality and density of InN nanorods. A Cr layer that was too thick led to polycrystalline InN growth. The results of transmission electron microscopy indicate a baseball bat-like InN nanorod growth mechanism. 相似文献
67.
Shang‐En Wu S. Dhara Tao‐Hung Hsueh Yi‐Feng Lai Cheng‐Yu Wang Chuan‐Pu Liu 《Journal of Raman spectroscopy : JRS》2009,40(12):2044-2049
The optical properties of focused ion beam‐engraved, perfectly aligned and spatially controlled multi‐quantum‐well (MQW) InGaN/GaN nanopillars were investigated. Crystalline MQW nanopillars with a diameter of 30–95 nm and high aspect ratios (7:1–16:1) showed a maximum of three‐fold enhancement in emission intensity per unit active area. A light‐emitting contour map of Taiwan is drawn with a nanopillar structure to demonstrate the site control of the technique adopted in the present study. Raman scattering studies were used to characterize the newly created surfaces. Unknown peaks in GaN and InGaN nanostructures are identified for surface optical (SO) phonon modes with proper assignments of wave vectors using multiple excitations, and the SO mode for the ternary phase is reported for the first time. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
68.
Exact confined eigenstates in one-dimensional finite periodic systems with arbitrary symmetric basis
W.J. Hsueh 《Physics letters. A》2008,372(8):1319-1323
A set of eigenenergy equations for complete confinement of N periodic one-dimensional system with arbitrary symmetric potential in each cell is presented. Exact eigenenergies and their eigenfunctions are solved analytically. We find different solutions on the band edge states comparing early results solved by conventional methods. Our results show that higher band edge state of each bandgap is dependent on the confined length, but lower band edge state is independent of the length. Moreover, wavefunctions for lower band edge states are Bloch waves but those for other eigenstates, including higher band edge states, do not obey Bloch waves. 相似文献
69.
Hsueh‐Ju Liu Micah S. Ziegler T. Don Tilley 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(22):6722-6726
Reactivity studies of the thermally stable ruthenostannylene complex [Cp*(IXy)(H)2Ru Sn Trip] ( 1 ; IXy=1,3‐bis(2,6‐dimethylphenyl)imidazol‐2‐ylidene; Cp*=η5‐C5Me5; Trip=2,4,6‐iPr3C6H2) with a variety of organic substrates are described. Complex 1 reacts with benzoin and an α,β‐unsaturated ketone to undergo [1+4] cycloaddition reactions and afford [Cp*(IXy)(H)2RuSn(κ2‐O,O‐OCPhCPhO)Trip] ( 2 ) and [Cp*(IXy)(H)2RuSn(κ2‐O,C‐OCPhCHCHPh)Trip] ( 3 ), respectively. The reaction of 1 with ethyl diazoacetate resulted in a tin‐substituted ketene complex [Cp*(IXy)(H)2RuSn(OC2H5)(CHCO)Trip] ( 4 ), which is most likely a decomposition product from the putative ruthenium‐substituted stannene complex. The isolation of a ruthenium‐substituted stannene [Cp*(IXy)(H)2RuSn(Flu)Trip] ( 5 ) and stanna‐imine [Cp*(IXy)(H)2RuSn(κ2‐N,O‐NSO2C6H4Me)Trip] ( 6 ) complexes was achieved by treatment of 1 with 9‐diazofluorene and tosyl azide, respectively. 相似文献
70.
Implementation and Characterization of Flow Injection in Dissolution Dynamic Nuclear Polarization NMR Spectroscopy 下载免费PDF全文
The use of dissolution dynamic nuclear polarization (D ‐DNP) offers substantially increased signals in liquid‐state NMR spectroscopy. A challenge in realizing this potential lies in the transfer of the hyperpolarized sample to the NMR detector without loss of hyperpolarization. Here, the use of a flow injection method using high‐pressure liquid leads to improved performance compared to the more common gas‐driven injection, by suppressing residual fluid motions during the NMR experiment while still achieving a short injection time. Apparent diffusion coefficients are determined from pulsed field gradient echo measurements, and are shown to fall below 1.5 times the value of a static sample within 0.8 s. Due to the single‐scan nature of D ‐DNP, pulsed field gradients are often the only choice for coherence selection or encoding, but their application requires stationary fluid. Sample delivery driven by a high‐pressure liquid will improve the applicability of these types of D‐DNP advanced experiments. 相似文献