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51.
《Proceedings of the Combustion Institute》2023,39(3):3519-3528
Ammonia is a highly promising energy carrier for achieving a carbon-neutral society. The co-combustion of solid particle clouds–ammonia, in particular, is considered an efficient and feasible method of reducing carbon dioxide emissions. Understanding turbulent flame stabilization and extinguishment processes during the two-phase hybrid-mixture co-combustion of solid particle clouds–ammonia is essential for the co-combustion technology to be used in combustors. To the best of our knowledge, this is the first study to describe the turbulent flame propagation limits and associated mechanism on the co-combustion of solid particle clouds–ammonia–air. Turbulent flame propagation experiments on silica particle clouds–ammonia–air mixing combustion and polymethylmethacrylate (PMMA) particle cloud–ammonia–air co-combustion were conducted in this work using a novel fan-stirred constant-volume vessel to clarify the turbulent flame propagation limits and associate mechanism of solid particle cloud–ammonia–air co-combustion. Results showed that adding inert silica particles contracted the turbulent flame propagation limits of premixed ammonia–air mixtures. However, adding PMMA particles expanded and then contracted the turbulent flame propagation limits of a premixed ammonia–air mixture as the ammonia equivalence ratio increased from lean to rich. In the solid particle cloud–ammonia–air co-combustion, reactive particles induce two types of effects on the turbulent flame propagation limits of premixed ammonia–air mixtures: The local equivalence ratio increment effect is caused by adding volatile matter from preheated particles in the preheat zone of the flame front, and the heat sink negative effect is induced by the unburned particles. 相似文献
52.
本文研究时标上的具有线性收获项的Nicholson’s blowflies模型,运用压缩映射不动点定理获得存在唯一概周期正解的充分条件.此外,通过利用Liapunov函数研究概周期正解的全局渐近稳定性. 相似文献
53.
Yu Ping Wang Chung-Tsun Shieh Xianbiao Wei 《Mathematical Methods in the Applied Sciences》2020,43(15):8841-8855
In this paper, the authors study partial inverse nodal problems for differential pencils on a star-shaped graph. We firstly show that the potential on each edge can be uniquely determined by twin-dense nodal subsets on some interior intervals under certain conditions. Without any nodal information on some potential on the fixed edge, we may add some spectral information to guarantee these uniqueness theorems. We still consider the case of arbitrary intervals having the internal vertex. In particular, we pose and solve a new partial inverse nodal problem for differential pencils on the star-shaped graph from the Weyl m-function and the theory concerning densities of zeros of entire functions. 相似文献
54.
The dissipative part of the linear magnetic dynamic susceptibility of dipolar spin glasses is considered. Due to the transition of the system (at enough high concentration of the magnetic dipoles) from a paramagnetic phase to a magnetic dipolar one, an anomalous temperature dependence of the dissipative part of the magnetic susceptibility is found. Some considerations related to the experimental results for LiHoxY 1?xF4 are made. 相似文献
55.
Singly Bonded Monoadduct rather than Methanofullerene: Manipulating the Addition Pattern of Trimetallic Nitride Clusterfullerene through One Endohedral Metal Atom Substitution 下载免费PDF全文
Song Wang Dr. Jing Huang Congli Gao Fei Jin Prof. Dr. Qunxiang Li Prof. Dr. Suyuan Xie Prof. Dr. Shangfeng Yang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(24):8309-8315
Bingel–Hirsch reactions of trimetallic nitride clusterfullerenes (NCFs) generally yield methanofullerene (cyclopropane) adducts instead of singly bonded derivatives, which have been reported for monometallofullerenes. Herein, we report the synthesis and characterization of the Bingel–Hirsch derivative of a mixed metal nitride clusterfullerene (MMNCF) TiY2N@Ih‐C80. Surprisingly, in contrast to the reported Bingel–Hirsch cyclopropane adducts of the analogous NCF Y3N@Ih‐C80, the Bingel–Hirsch derivative of TiY2N@Ih‐C80 is the first singly bonded monoadduct (labeled as TiY2N@C80‐Mono) to be reported, which was determined unambiguously by single‐crystal X‐ray crystallography. Besides, the reactivity of TiY2N@Ih‐C80 was found to be significantly improved relative to that of Y3N@Ih‐C80. Upon substituting one endohedral yttrium (Y) atom of Y3N@Ih‐C80 with titanium (Ti), the Bingel–Hirsch derivative changes from the cyclopropane to the singly bonded monoadduct, revealing that not only the reactivity but also the addition pattern of NCFs can be manipulated simultaneously through one endohedral metal atom substitution. 相似文献
56.
Xianshu Cai Yue Zhao Dr. Jun Zhang Dr. Wenwen Zi Dr. Shuo Tao Feng Jiao Prof. Hongbin Du 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(35):e202201075
Large and extra-large pore zeolites have been widely applied in industrial areas as catalysts, adsorbents, etc. Among them, silica and/or aluminosilicate zeolites have been attracted great attention due to their excellent hydrothermal stability and strong acidity. However, a great deal of zeolite structures are still not available in the form of silica and/or aluminosilicate. Herein, we report the synthesis of pure silica and aluminosilicate large-pore zeolites, denoted as NUD-14 and Al-NUD-14, respectively, by using a designed cation 1-ethyl-4-phenylpyridinium as an organic structure-directing agent (OSDA). NUD-14 has an intersecting 12×11×11-member ring pore system, which is isostructural to the germanosilicate PUK-16 zeolite with a POS topology. The OSDAs can be completely removed from the framework by calcination. NUD-14 and Al-NUD-14 possess excellent acid and hydrothermal stabilities, superior to the germanosilicate POS zeolite. The incorporation of Al into the zeolite framework makes the Al-NUD-14 zeolite possess medium and strong acidities. The successful synthesis of NUD-14 consisting of a rare odd-member ring pore structure may provide a platform for interesting size- and shape-selective catalytic applications. 相似文献
57.
Y. X. Guo Y. F. Liu C. W. Zou Z. M. Qi Y. Y. Wang Y. Q. Xu X. L. Wang F. Zhang R. Zhou 《Applied Physics A: Materials Science & Processing》2014,115(4):1245-1250
To investigate the effects of oxygen pressure on the structural and phase transition properties for VO2/c-sapphire, highly orientated VO2 thin films were grown on (0001) sapphire substrates by pulsed laser deposition (PLD) with different oxygen pressures. The crystal structure, morphology and component of the films were systematically investigated. The temperature-dependent resistance (R-T) measurement was conducted, which showed the distinct phase transition characteristic for the prepared films. The results indicate that the oxygen pressure plays an important role for the VO2 film preparation. The film grown at 1.7 Pa has lower phase transition temperature, higher film strain, and smaller grain size than that at 5.4 Pa, while no obvious crystal phase transition is observed. The experiment suggests that even a small change in oxygen pressure can influence the structure, morphology and phase-transition behavior of VO2 films obviously, and its potential causes are mainly attributed to the reduction of the kinetic energy to the substrate for target atoms caused by the oxygen pressure, the resulting grain aggregation and interfacial stress. 相似文献
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