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141.
We propose a tensor-optimized few-body model (TOFM) in the few-body framework with bare nucleon–nucleon interaction. The physical concept of TOFM comes from the tensor-optimized shell-model (TOSM), which is applicable for the study of medium and heavy nuclei. The TOSM wave function describes the deuteron-like tensor correlation and provides a good reproduction of the binding energy with the bare nucleon–nucleon interaction. Using the spirit of the TOSM approximation, we show the performance of TOFM for s-shell nuclei. It is found that the TOFM can account for the contribution of the tensor interaction very well and almost reproduces the total energy and various energy components as compared with rigorous few-body calculations. The relative correlation function is also provided to improve the performance of TOSM for the study of heavy nuclei. 相似文献
142.
Dr. Chihiro Maeda Shuichi Nomoto Koki Akiyama Dr. Takayuki Tanaka Prof. Tadashi Ema 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(63):15699-15705
Carbazole-based aza[7]helicenes and hetero[9]helicenes were successfully obtained via the intramolecular Scholl reaction of 3,6-bis(biphenyl-2-yl)carbazole congeners, while the reaction of 3,6-bis(naphthylphenyl)-appended carbazole gave a triple helicene via an unexpected simultaneous double aryl rearrangement. DFT calculations suggested that the rearrangement proceeded via an arenium cation intermediate. In addition, the reaction of methoxy-appended substrate gave an azahepta[8]circulene via the concurrent C−C bond formation. These helical dyes showed circularly polarized luminescence. The azahepta[8]circulene was further transformed into deeply saddle-distorted dibenzodiaza[8]circulenes as the first example of its solution-based synthesis and unambiguous structural determination. 相似文献
143.
Samantha Burrola Maya Horii Maria Jose Gonzalez-Guerrero John Christopher Bachman Frank A. Gomez 《Electrophoresis》2020,41(1-2):131-136
This paper describes the use of aluminum and zinc as anodic materials for a battery employing nickel (II) oxide (NiO) as cathode. Comparison of both materials resulted in the development of a compact, cost effective, and easy to use primary NiO/Al battery employing an alkaline electrolyte. The system features electrodes composed of powder forms of the active materials on modified paper substrates that are contained in a simple multilayer design utilizing thin laminated plastic materials to provide structure and flexibility to the battery as well as a paper separator. Various concentrations of potassium hydroxide (KOH) electrolyte were examined and maximum performance was observed at 6 M KOH. A maximum current density and power density of 1.94 mA/cm2 and 1 mW/cm2, respectively was achieved. This user-friendly device was able to produce a maximum capacity of 2.33 mAh/g when 2 mA/g was applied. This work demonstrates the viability of a paper-based battery featuring powder electrodes as a possible power source for microelectronic devices. 相似文献
144.
Dr. Kenichi Kato Katsuto Onishi Koki Maeda Masafumi Yagyu Dr. Shixin Fa Prof. Dr. Takahiro Ichikawa Prof. Dr. Motohiro Mizuno Dr. Takahiro Kakuta Prof. Dr. Tada-aki Yamagishi Prof. Dr. Tomoki Ogoshi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(21):6435-6439
Poly(ethylene oxide)s (PEOs) are useful polymers with good water solubility, biological compatibility, and commercial availability. PEOs with various end groups were threaded into pillar[5]arene rings in a mixture of water and methanol to afford pseudopolyrotaxanes. Corresponding polyrotaxanes were also constructed by capping COOH-terminated pseudopolyrotaxanes with bulky amines, in which multiple hydrogen bonds involving the pillar[5]arene OH groups were critically important to prevent dethreading. The number of threaded ring components could be rationally controlled in these materials, providing a simple and versatile method to tune the mechanical and thermal properties. Specifically, a polyrotaxane with a high-molecular-weight axle became elastic upon heating above the melting point of PEOs and exhibited temperature-dependent shape memory property because of the topological confinement and crosslinked hydrogen bonds. 相似文献
145.
Tetramethylammonium hydroxide (TMAH) thermochemolysis of 2-arylcoumaran lignin model compounds 总被引:1,自引:0,他引:1
Ken-ichi Kuroda Akiko Nakagawa-izumi Tatsuya Ashitani Koki Fujita 《Journal of Analytical and Applied Pyrolysis》2009,86(1):185-191
Phenolic 2-arylcoumarans 1–6 were used to examine the behaviors of β-5 subunits in lignin during tetramethylammonium hydroxide (TMAH) thermochemolysis. Products were monitored by gas chromatography/mass spectrometry. The process predominantly provided dimeric products with the opened hydrofuran ring. Substituent changes at the γ-position of ring A and at the 5-position of ring B had a large effect on the product compositions. 2-Arylcoumarans 1 and 6 with the γ-CH2OH substituent predominantly gave 2,3,3′,4′-tetramethoxystilbenes involving the elimination of the γ-CH2OH substituent, while 2–5 with the γ-CH3 substituent gave a mixture of 2,3,3′,4′-tetramethoxy-α-methylstilbenes and α-methoxy-α-(3′,4′-dimethoxyphenyl)-β-(2,3-dimethoxyphenyl)propanes. Substituent –CHCHCH3 on ring B remained unaffected. Substituents –CHCHCH2OH and –COOH on ring B produced the corresponding methyl ether and ester, respectively, by methylation. The –CHCHCHO substituent on ring B was converted to the –CHO substituent. 相似文献
146.
Masanobu Nakayama Kenta Kanamori Koki Nakano Randy Jalem Ichiro Takeuchi Hisatsugu Yamasaki 《Chemical record (New York, N.Y.)》2019,19(4):771-778
Interest in all‐solid‐state Li‐ion batteries (LIBs) using non‐flammable Li‐conducting ceramics as solid electrolytes has increased, as safe and robust batteries are urgently desired as power sources for (hybrid) electric vehicles. However, the low Li‐ion conductivities of ceramics have hindered all‐solid‐state LIB commercialization; many researchers have attempted to develop fast Li‐ion conductors. We introduce two efficient high‐throughput computational approaches for materials exploration: (i) exhaustive search and (ii) informatics‐aided prediction. For demonstration, ~400 Li‐ and Zn‐containing oxide (Li?Zn?X?O) compounds of varied crystal structures are extracted from Materials Project datasets. We calculate the migration energies for Li‐ion conduction and the phase stabilities (decomposition energies) of these materials by simulation and apply Bayesian optimization to determine the material with the highest ionic conductivity. The results show much greater efficiency than a random search algorithm. 相似文献
147.
The catalytic enantioselective difluoromethylation of arylidene Meldrum's acids with (difluoromethyl)zinc reagent, easily prepared through zinc/iodide exchange reaction of difluoroiodomethane and diethylzinc with co-solvent such as pyridines, by a chiral phosphoramidite-Cu catalyst is shown to provide highly enantioselective sp [3]-difluoromethyl Michael addition product in good yields and high levels of enantioselectivity. 相似文献
148.
Z Horii M Ikeda M Hanaoka M Yamauchi Y Tamura 《Chemical & pharmaceutical bulletin》1967,15(11):1633-1640
149.
We report nuclear quadrupole resonance (NQR) studies on the chain Cu sites of PrBa2Cu4O8, a quasi-one-dimensional conductor with a nearly quarter-filled band. The nuclear spin-lattice relaxation rate 1/T1 shows a pronounced peak near 100 K caused by fluctuations of electric field gradient. Similar peak was observed for the spin-echo decay rate 1/T2, however, at a different temperature near 50 K. These results and broadening of the NQR spectrum at low temperatures indicate that slow charge fluctuations of either electronic or ionic origin freeze gradually at low temperatures. 相似文献
150.
Solid-state 13C and 1H spin diffusion NMR analyses of the microfibril structure for bacterial cellulose 总被引:1,自引:0,他引:1
Masuda K Adachi M Hirai A Yamamoto H Kaji H Horii F 《Solid state nuclear magnetic resonance》2003,23(4):198-212
To obtain further information about the cause for the rather large splitting of the C4 resonance line into the downfield (C4D) and upfield (C4U) lines in CP/MAS 13C NMR spectra for native cellulose, 13C and 1H spin diffusion measurements have been conducted by using different types of bacterial cellulose samples. In 13C spin diffusion measurements, the C4D resonance line is selectively inverted by the Dante π pulse sequence and the 13C spin diffusion is allowed to proceed from the C4D carbons to other carbons including the C4U carbons with use of the 13C4-enriched bacterial cellulose sample. The analysis based on the simple spin diffusion theory for the process experimentally observed reveals that the C4U carbons may be located at distances less than about 1 nm from the C4D carbons. In 1H spin diffusion measurements, poly(vinyl alcohol) (PVA) films in which ribbon assemblies of bacterial cellulose are dispersed are employed and the 1H spin diffusion process is examined from the water-swollen PVA continuous phase to the dispersed ribbon assemblies by the 13C detection through the 1H–13C CP technique. As a result, it is found that the C4D and C4U carbons are almost equally subjected to the 1H spin diffusion from the PVA phase, indicating that the C4U carbons are not localized in some limited area, e.g. in the surfacial region, but are distributed in the whole area in the microfibrils. These experimental results suggest that the C4U carbons may exist as structural defects probably due to conformational irregularity associated with disordered hydrogen bonding of the CH2OH groups in the microfibrils. 相似文献