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121.
Magnetic phase transition in a heteromolecular hydrogen-bonded complex of nitronylnitroxide radicals
Hayakawa K Shiomi D Ise T Sato K Takui T 《The journal of physical chemistry. B》2005,109(19):9195-9197
An organic molecular acid-base complex has been synthesized from pyridine-substituted biradical 2 in a triplet (S = 1) ground state and a benzoic acid derivative of monoradical 3 with S = 1/2. The two constituent molecules are bound by an OH-N hydrogen bond in a crystalline solid state. The complex has been found to exhibit an antiferromagnetic phase transition at 5 K. The complex is the first example of a hydrogen-bonded heterospin, heteromolecular complex exhibiting a magnetic phase transition in purely organic molecule-based materials. 相似文献
122.
Akiyoshi Osaka Kanji Tsuru H. Iida Chikara Ohtsuki Satoshi Hayakawa Yoshinari Miura 《Journal of Sol-Gel Science and Technology》1997,8(1-3):655-661
Apatite derived by sol-gel routes through an amorphous state or derived biomimetically is likely to provide chemically and
biologically active surfaces. Thus apatite or apatite-composite particles were prepared by spray-pyrolysis of several solutions
as they were applicable to medical treatment. Calcium lactate and ammonium dihydrogen phosphate aqueous solutions stabilized
with ethylenediaminetetraacetic acid were sprayed ultrasonically and pyrolysed at 600°C to yield amorphous particles of apatite
while apatite-ferric oxide composite powders were prepared from the solutions of calcium lactate and ferric nitrate. Solutions
of calcium nitrate and titanium ethoxide in 0.5 N HNO3 were also spray-pyrolysed at 600°C to prepare calcium titanate and titanium oxide particles trapped on a Ti substrate. Apatite
could biomimetically be developed on the calcium titanate particles when they were soaked in an acellular simulated body fluid. 相似文献
123.
Tomoaki Sugiyama Hiroya Shiba Dr. Masashi Yoshikawa Prof. Dr. Hiroaki Wada Prof. Dr. Atsushi Shimojima Prof. Dr. Kazuyuki Kuroda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(11):2764-2772
The controlled synthesis of oligosiloxanes with well-defined structures is important for the bottom-up design of siloxane-based nanomaterials. This work reports the synthesis of various polycyclic and cage siloxanes by the hydrolysis and intramolecular condensation of monocyclic tetra- and hexasiloxanes functionalized with various alkoxysilyl groups. An investigation of monoalkoxysilylated cyclosiloxanes revealed that intramolecular condensation occurred preferentially between adjacent alkoxysilyl groups to form new tetrasiloxane rings. The study of dialkoxy- and trialkoxysilylated cyclotetrasiloxanes revealed multistep intramolecular condensation reactions to form cubic octasiloxanes in relatively high yields. Unlike conventional methods starting from organosilane monomers, intramolecular condensation enables the introduction of different organic substituents in controlled arrangements. So-called Janus cubes have been successfully obtained, that is, Ph4R4Si8O12, in which R=Me, OSiMe3, and OSiMe2Vi (Vi=vinyl). These findings will enable the creation of siloxane-based materials with diverse functions. 相似文献
124.
Tomoaki Nishizawa Nobuo Sugimoto Atsushi Shimizu 《Journal of Quantitative Spectroscopy & Radiative Transfer》2011,112(2):254-267
We developed backward and forward types of algorithms for estimating the vertical profiles of extinction coefficients at 532 nm for three component aerosols (water-soluble, dust, and sea salt) using three-channel Mie-scattering lidar data of the backscatter (β) at 532 and 1064 nm and the depolarization ratio (δ) at 532 nm. While the water-soluble and sea-salt particles were reasonably assumed to be spherical, the dust particles were treated as randomly oriented spheroids to account for their nonsphericity. The introduction of spheroid models enabled us to more effectively use the three-channel data (i.e., 2β+1δ data) and to reduce the uncertainties caused by the assumption of spherical dust particles in our previously developed algorithms. We also performed an extensive sensitivity study to estimate retrieval errors, which showed that the errors in the extinction coefficient for each aerosol component were smaller than 30% (60%) for the backward (forward) algorithm when the measurement errors were ±5%. We demonstrated the ability of the algorithms to partition aerosol layers consisting of three aerosol components by applying them to shipborne lidar data. Comparisons with sky radiometer measurements revealed that the retrieved optical thickness and angstrom exponent of aerosols using the algorithms developed in this paper agreed well with the sky radiometer measurements (within 6%). 相似文献
125.
T. Ohtsuki K. Shikano H. Yuki K. Hirose K. Takamiya 《Czechoslovak Journal of Physics》2006,56(1):D425-D432
In order to achieve a progressive experimental program, a new system for radioisotope production has been developed at one
of the beam-courses of a multipurpose Cyclotron of K=110 MeV. The upgraded beam-course is useful for the study of the nuclear physics and chemistry of heavy elements, radiopharmaceutical
studies, the production of radioactive tracers, activation analysis using charged particles, etc. Several topics are demonstrated
in the field of radioanalytical and nuclear studies. 相似文献
126.
In order to observe and estimate the flow of fluid in three-dimensional space, the pulsed Doppler method has been used widely.
However, the velocity information acquired is only the velocity component in the beam direction of the wave even if an observation
plane is formed by beam scanning. Accordingly, it is difficult to know the velocity distribution in the observation plane
in tree-dimensional flow. In this paper, the new idea for processing the velocity distribution in the beam direction on an
observation plane for transposing to flux distribution (flow function method) has been introduced. Further, the flow in an
observation domain is divided into two kinds of flows, viz., the base flow which indicates the directivity of the flow in
the observation domain and the vortex which is considered a two-dimensional flow. By applying the theory of a stream function
to the two-dimensional flow, and by using the physical feature of a streamline to the base flow, the velocity component v
which intersects perpendicularly to the beam direction is estimated. The flow velocity distribution in a scanning plane (observation
plane) can be known from these two components of velocity, viz., beam direction componentu and perpendicular component to the beam directionv. The principle was explained by an example of the blood flow measurement in normal and abnormal heart chamber, by the ultrasonic
Doppler method. 相似文献
127.
128.
Yuko Takao Tomoaki Masuoka Koji Yamamoto Tadashi Mizutani Fukashi Matsumoto Kazuyuki Moriwaki Koichi Hida Toshiyuki Iwai Takatoshi Ito Takumi Mizuno Toshinobu Ohno 《Tetrahedron letters》2014
Novel fluorinated subnaphthalocyanine derivatives were newly designed and synthesized as donor materials for low molecular organic photovoltaic cells using fullerene as an acceptor. They were designed to have the low-lying HOMO energy levels for improvement of open circuit voltage without any expense of short-circuit current density. The HOMO/LUMO energy levels of hexafluoro-, heptafluoro-, dodecafluoro-, tridecafluoro- and the parent subnaphthalocyanine estimated based on the photoelectron spectroscopy were −5.69/−3.93, −5.67/−3.90, −5.96/−4.19, −5.92/−4.11 and −5.30/−3.58 eV, respectively, showing that frontier orbital energy levels can be effectively tuned by fluorination. 相似文献
129.
130.
Kozo Matsumoto Tomoaki Chijiiwa Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2014,52(20):2986-2990
An ionic liquid, 1‐ethyl‐3‐(3‐ethyl‐3‐oxetanylmethyl)imidazolium bis(trifluoromethanesulfonyl)imide (OXImTFSI), was synthesized, and its cationic polymerization was examined. The heating of a mixture of 1‐ethylimidazole and 3‐chloromethyl‐3‐ethyloxetane at 90 °C for 48 h yielded 1‐ethyl‐3‐(3‐ethyl‐3‐oxetanylmethyl)imidazolium chloride, which was transformed to a room‐temperature ionic liquid, OXImTFSI, by ion exchange with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). This ionic liquid was polymerized using boron trifluoride ethyl ether complex as a catalyst to give polyOXImTFSI. Five percent weight loss temperature (Td5) of polyOXImTFSI evaluated by thermal gravimetric analysis was 409 °C, indicating the high thermal stability. Glass transition temperature (Tg) of the polymer evaluated by differential scanning calorimetry was ?19 °C, indicating the high flexibility of the material. Ionic conductivity of polyOXImTFSI was determined to be 1.86 × 10?8 S/cm at 23 °C, which was far lower than that of the OXImTFSI monomer (5.05 × 10?4 S/cm). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2986–2990 相似文献