全文获取类型
收费全文 | 84篇 |
免费 | 0篇 |
专业分类
化学 | 49篇 |
晶体学 | 4篇 |
力学 | 2篇 |
数学 | 11篇 |
物理学 | 18篇 |
出版年
2024年 | 1篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 4篇 |
2013年 | 10篇 |
2012年 | 5篇 |
2011年 | 5篇 |
2010年 | 4篇 |
2009年 | 6篇 |
2008年 | 4篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 3篇 |
排序方式: 共有84条查询结果,搜索用时 15 毫秒
1.
The authors consider the extended Hecke groups H(λq) generated by T(z) = -1 / z, S(z) = -1/(z + λq,) and R(z) = 1 / z with A, = 2 cos(π/q) for q≥3 an integer. In this paper, the even subgroup He(λq), the second commutator subgroup H (λq) and the principal congruence subgroups Hp(λq) of the extended Hecke groups H(λq) are studied. Also, relations between them are given. 相似文献
2.
Measurements of the elastic constant c33 for Tb-50% Ho, as a function of temperature and magnetic field, have been used to determine the magnetic phase diagram of the alloy. Evidence for the four phases:paramagnetic, spiral spin antiferromagnetic, fan and ferromagnetic are presented. The true ferromagnetic phase is only found below 100 K even in fields of up to 7 Tesla. 相似文献
3.
Sonochemical synthesis and electrochemical characterization of α-nickel hydroxide: precursor effects
F. Sinem Ertaş Recep Kaş Uğur Ünal Özgür Birer 《Journal of Solid State Electrochemistry》2013,17(5):1455-1462
Sonochemical degradation of urea was employed to synthesize alpha-nickel hydroxide from different nickel salts. Utilization of ultrasound yielded products with properties significantly different than the products obtained by thermal degradation of urea. The effect of intercalating chloride, nitrate, acetate, and sulfate anions on morphology and electrochemical performance was studied. The sulfate-intercalated sample had the smallest interlayer spacing when obtained by the sonochemical method, contradicting all the previous thermal synthesis results. The specific capacitance trend also differed from the literature values, and the value for the sulfate-intercalated sample was larger than that of acetate- and nitrate-intercalated samples. Ultrasonic synthesis increased the specific capacitance of the sulfate-intercalated sample significantly. This sample was also the most reversible and had the highest charge efficiency. 相似文献
4.
Sevim Hamamci Alisir Necmi Dege Recep Tapramaz 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(4):388-397
Three new diclofenac‐based copper(II) complexes, namely tetrakis{μ‐2‐[2‐(2,6‐dichloroanilino)phenyl]acetato‐κ2O:O′}bis(methanol‐κO)copper(II), [Cu2(μ‐dicl)4(CH3OH)2] ( 1 ), bis{2‐[2‐(2,6‐dichloroanilino)phenyl]acetato‐κ2O,O′}bis(1‐vinyl‐1H‐imidazole‐κN3)copper(II), [Cu(dicl)2(vim)2] ( 2 ), and bis{2‐[2‐(2,6‐dichloroanilino)phenyl]acetato‐κ2O,O′}bis(1H‐imidazole‐κN3)copper(II), [Cu(dicl)2(im)2] ( 3 ) [dicl is diclofenac (C14H10Cl2NO2), vim is 1‐vinylimidazole (C5H6N2) and im is imidazole (C3H4N2)], have been synthesized and characterized by elemental analysis, FT–IR spectroscopy, thermal analysis and single‐crystal X‐ray diffraction. X‐ray diffraction analysis shows that complex 1 consists of dimeric units in which the dicl ligand exhibits a bidentate syn,syn‐μ2 coordination mode linking two copper(II) centres. Complexes 2 and 3 have mononuclear units with the general formula [Cu(dicl)2L2] (L is vim or im) in which the CuII ions are octahedrally coordinated by two L and two dicl chelating ligands. The L and dicl ligands both occupy the trans positions of the coordination octahedron. The different coordination modes of dicl in the title complexes were revealed by Fourier transform IR (FT–IR) spectroscopy. The spin matching between the copper(II) centres in the dimeric [Cu2(μ‐dicl)4(CH3OH)2] units was also confirmed by magnetic data to be lower than the spin‐only value and electron paramagnetic resonance (EPR) spectra. The thermal properties of the complexes were investigated by thermogravimetric (TG) and differential thermal analysis (DTA) techniques. 相似文献
5.
Savaş Sönmezoğlu Sevilay Şenkul Recep Taş Güven Çankaya Muzaffer Can 《Solid State Sciences》2010,12(5):706-711
We have formed conjugated polymeric aniline–thiophene organic material on p-Si substrate by adding polyaniline–poly-3-methyl thiophene blend solution in acetonitrile on top of a p-Si substrate and then evaporating the solvent. It has been seen that the forward bias current–voltage (I–V) characteristics of polyaniline–poly-3-methyl thiophene blend/p-Si/Al with a barrier height value of 0.60 eV and an ideality factor value of 3.37 showed rectifying behaviour at room temperature. The polyaniline–poly-3-methyl thiophene blend/p-Si/Al Schottky barrier diode showed non-ideal I–V behaviour with the value of ideality factor greater than unity that could be ascribed to the interfacial layer, interface states and series resistance. Furthermore, Cheung's functions and modified Norde's function were used to extract the diode parameters including ideality factor, barrier height and series resistance. It has been seen that there is a good agreement between the barrier height values from all methods. However, the values of series resistance obtained from Cheung's functions is higher than the values obtained from Norde's functions. The energy distribution of interface states density, determined from forward bias current–voltage (I–V) characteristic technique at room temperature, increases exponentially with bias from 2.81 × 1016 cm?2 eV?1 in (0.73–Ev) eV to 1.14 × 1017 cm?2 eV?1 in (0.48–Ev) eV. 相似文献
6.
7.
Historical textiles in the Topkap? Museum, which are called silk kaftans and brocades by art historians from the sixteenth and nineteenth were characterized by scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM–EDX) and high-performance liquid chromatography with diode array detection for identification of metal threads and dyestuffs. In the most Ottoman textiles, metal threads, especially belonging to the sultans, were used as the gold gild. Although the chemical composition of the samples on the surface may easily be obtained by SEM–EDX, the thickness of the thin gold layer on metal threads cannot be obtained directly. Hence, the goal of this project is to describe whether metal threads are gilded or not and to measure coating thickness. A new method was developed for measuring the thickness of gold layer, and the modeling was reformed. The SEM–EDX results were interpreted in accordance with the theoretical models. The coating thickness of metal threads was subsequently measured in ancient textiles. The thickness, depth, and valuable metal composition in the threads of the artistic objects were obtained by this approach. Dye analysis was used to characterize the presence of indigotin, carminic acid, ellagic acid, and luteolin in the historical textiles. 相似文献
8.
9.
Suo Z Yang X Deliorman M Cao L Avci R 《Langmuir : the ACS journal of surfaces and colloids》2012,28(2):1351-1359
Capturing pathogens on a sensor surface is one of the most important steps in the design of a biosensor. The efficiency of a biosensor at capturing pathogens has direct bearing on its sensitivity. In this work we investigated the capturing of Escherichia coli on substrates modified with antibodies targeting different types of fimbriae: K88ab (F4), K88ac (F4), K99 (F5), 987P (F6), F41, and CFA/I. The results suggest that all these fimbriae can be used for the efficient immobilization of living E. coli cells. The immobilization efficiency was affected by the purity and clone type of the antibody and the fimbriae expression level of the bacteria. For a specific fimbriae type, a higher immobilization efficiency was often observed with the monoclonal antibodies. Immunoimmobilization was utilized in an antibody microarray immersed in a mixed culture of pathogens to demonstrate the rapid and simultaneous label-free detection of multiple pathogens within less than 1 h using a single test. The capture rate of living pathogens exceeds a single bacterium per 100 × 100 μm(2) area per 0.5 h of incubation for a bulk concentration of 10(5) cfu/mL. 相似文献
10.
Van Ham R Van Vaeck L Adriaens A Adams F Hodges B Gianotto A Avci R Appelhans A Groenewold G 《Talanta》2006,69(1):91-96
The feasibility of static secondary ion mass spectrometry (S-SIMS) for the detection of molecule specific information from complex materials, such as natural clay and soil samples, has been investigated. Ion trap (IT), as well as triple quadrupole (TQ) instruments, have been used for mass analysis. Secondary ion images have been acquired using time-of-flight (TOF) S-SIMS. The generation of molecular adduct ions from thin and thick layers on the mineral substrates has been investigated using KBr as a simple model system. Results show that molecular adducts of KBr can be indeed detected from the spiked materials. However, the concentrations of the spiking solutions have to be significantly larger than expected from the surface area measured by gas adsorption techniques. In addition imaging analysis has evidenced that the detection of adduct ions in the mass spectra directly relates to the presence of local micro-crystallites. 相似文献