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71.
K Yoshino M Fujiwara A Tanaka S Takahashi Y Nambu A Tomita S Miki T Yamashita Z Wang M Sasaki A Tajima 《Optics letters》2012,37(2):223-225
A high-speed quantum key distribution system was developed with the wavelength-division multiplexing (WDM) technique and dedicated key distillation hardware engines. Two interferometers for encoding and decoding are shared over eight wavelengths to reduce the system's size, cost, and control complexity. The key distillation engines can process a huge amount of data from the WDM channels by using a 1 Mbit block in real time. We demonstrated a three-channel WDM system that simultaneously uses avalanche photodiodes and superconducting single-photon detectors. We achieved 12 h continuous key generation with a secure key rate of 208 kilobits per second through a 45 km field fiber with 14.5 dB loss. 相似文献
72.
PHOTOCHROMISM AND LUMINESCENCE OF DOPANT CHROMOPHORES THROUGH TWO-PHOTON IONIZATION IN POLYMER FILMS
Two-photon ionization and recombination processes of an aromatic chromophore doped in polymer films werestudied and the features of these processes were discussed in relation to photofunctional polymers, An aromatic moleculehaving low ionization potential, e.g., N,N,N',N'-tetramethyl-p-phenylene diamine doped in poly(methyl methacrylate)(PMMA) film was easily photoionized by intense laser ligh excitation, giving a colored radical cation (photochromism) anda trapped electron in PMMA matrix. As a reversed process, the radical cation recombined with the trapped electron, showingdiscoloration and emitting luminescence, either isothermal luminescence (ITL), or thermoluminescence (TL). In this report,ITL and TL through the charge recombination process were studied and the luminescence was suggested as a mean of the read-out of photorecording. 相似文献
73.
D. Li K. Imasaki S. Miyamoto S. Amano T. Mochizuki 《International Journal of Infrared and Millimeter Waves》2006,27(2):165-171
The conventional cavity for a free-electron laser (FEL) oscillator usually forms an optical beam of Gaussian mode, which undergoes
transverse spread along the interaction region. The transverse divergence of an optical beam will induce reduction of the
FEL gain from three aspects: degenerating filling factor, causing diffraction loss and limiting the effective interaction
distance. Bessel optical beam has been experimentally demonstrated diffraction-free characteristics in its propagation, which
provides a possibility of improvement of FEL gain. In this paper, we present a conceptual design of a Bessel beam cavity for
the free-electron laser oscillator. This cavity generates nondiffracting optical beam in the wiggler, resulting in improving
the filling factor, decreasing the diffraction loss and elongating the effective interaction distance. 相似文献
74.
The concept of a binary feature tree (BFT) and the principle of its formation are described. A pattern is divided into sub-parts by comparing its similarity with other patterns. The BFT is established by sub-parts of a group of patterns and mapped into a three layered neural network which Sethi called an entropy network. The interconnection pattern between the first and hidden layers is formed according to the “AND“ relationship of node feature patterns determined by BFT. The interconnection pattern between the hidden and last layers is obtained by training. The advantage of the proposed network is that the scale is small because a feature neuron is adopted and the interconnection is local instead of full; therefore, it is easily implemented by either hardware or software. Two simulation examples show the success of the entropy network for pattern recognition. A feature extraction by an optical inner product method is also described.Presented at 1996 International Topical Meeting on Optical Computing (OC ‘96), April 21-25, Sendai, Japan. 相似文献
75.
Masahide Monde Tsuyoshi Uematsu Toshiki Toda Kazuhiko Ohnuma Yoshizumi Yasuda 《Optical Review》1995,2(2):132-134
To make holograms from computer graphic (CG) in a short time, a new holographic three dimensional (3D) printer is proposed here. This printer consists of galvanometer scanners, a micro computer and a laser, and uses a holographic contact duplicating method. Experiments have shown that a hologram of 39 × 41 mm can be obtained in 4 min.Presented at the International Commission for Optics Topical Meeting, Kyoto, 1994. 相似文献
76.
We describe spatial arrangement of polystyrene latex using a microscopic imaging system. A reduced photomask pattern is imaged on the particles in a water-filled cell so that polystyrene spheres align in a two-dimensional pattern. Calculating the forces exerted on the spheres by isolated line pattern, we investigated an optimum size for sphere diameter and the line width of the patterns. We are able to align spheres in real-time by this technique. 相似文献
77.
D. Li K. Imasaki M. Aoki S. Miyamoto S. Amano T. Mochizuki 《International Journal of Infrared and Millimeter Waves》2003,24(8):1301-1305
A gamma ray generation facility was developed through laser Compton scattering on an electron beam storage ring, for the purpose of researching nuclear transmutation. Theoretical analysis on gamma ray yield and energy spectrum was performed, as well as EGS4 simulation code was employed to simulate the interaction of gamma ray and Ge detector. The acquired experimental results are in agreement with theory. 相似文献
78.
79.
A large macrocyclic compound with six para-phenylene rings and six amide moieties, which are alternately secondary and tertiary, was synthesized. In a stepwise synthesis, the final cyclization step was successful because a combination of three tertiary amides, which prefer a cis conformation, and two linear secondary amides would arrange both amino and carboxyl ends close to each other, while various sizes of macrocyclic compounds including the target cyclic trimer were generated in one-pot synthesis where three secondary amide bonds were formed. 相似文献
80.
Megumi Mizuno Masahide Takahashi Yomei Tokuda Toshinobu Yoko 《Journal of Sol-Gel Science and Technology》2007,44(1):47-52
Organically-modified silicate-phosphate and silicate-phosphite copolymers were prepared through nonaqueous acid–base reaction.
The inductive effect of the organic substituent of the starting materials such as organically-modified chlorosilane and phosphorous
acid on the acid–base reaction was investigated by 31P NMR measurement and ab initio molecular orbital calculation. The condensation reaction takes place by nucleophilic addition
of phosphate ion (or phosphite ion) to chlorosilane through SN2 mechanism to form silicate-phosphate (or phosphite) network. The reactivity of the acid–base pair can be controlled by changing
the inductive effect of the organic substituents on the starting materials. 相似文献