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521.
Jyoti Prasad Chakraborty Deepak Kunzru 《Journal of Analytical and Applied Pyrolysis》2009,86(1):44-52
Pyrolysis of n-heptane was investigated in a tubular reactor in the temperature range of 793–953 K and pressure range of 0.1–2.93 MPa. At all conditions, the main products were methane, ethylene, ethane, propylene, 1-butene, 1-pentene and 1-hexene. With an increase in pressure, the selectivities of hydrogen, methane, ethylene and propylene decreased and that of propane, n-butane and 1-butene increased. To explain the product distribution at high pressure, the Rice–Kossiakoff theory was modified by including the bimolecular reactions of alkyl radicals with the parent hydrocarbon. The initial product selectivities, calculated using the modified R–K mechanism, were in good agreement with the experimental selectivities. The overall kinetics of n-heptane pyrolysis was determined by non-linear analysis. The optimum values of the kinetic parameters at each pressure were determined by minimizing the difference between the calculated and experimental conversions. At each pressure, the reaction order was close to unity and the activation energy ranged between 209 and 219 kJ mol−1. 相似文献
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Aromatic and hetero-aromatic acyl chlorides were efficiently cross-coupled with triarylbismuths as atom-efficient nucleophilic organometallic coupling reagents in sub-stoichiometric amounts using catalytic Pd(0)/C. Thus, the coupling reactions of various triarylbismuths with a variety of acyl chlorides furnished a plethora of both symmetrical/unsymmetrical aromatic and hetero-aromatic ketones in high yields. 相似文献
524.
Deepak Bandyopadhyay Jun Huan Jan Prins Jack Snoeyink Wei Wang Alexander Tropsha 《Journal of computer-aided molecular design》2009,23(11):785-797
Protein function prediction is one of the central problems in computational biology. We present a novel automated protein
structure-based function prediction method using libraries of local residue packing patterns that are common to most proteins
in a known functional family. Critical to this approach is the representation of a protein structure as a graph where residue
vertices (residue name used as a vertex label) are connected by geometrical proximity edges. The approach employs two steps.
First, it uses a fast subgraph mining algorithm to find all occurrences of family-specific labeled subgraphs for all well
characterized protein structural and functional families. Second, it queries a new structure for occurrences of a set of motifs
characteristic of a known family, using a graph index to speed up Ullman’s subgraph isomorphism algorithm. The confidence
of function inference from structure depends on the number of family-specific motifs found in the query structure compared
with their distribution in a large non-redundant database of proteins. This method can assign a new structure to a specific
functional family in cases where sequence alignments, sequence patterns, structural superposition and active site templates
fail to provide accurate annotation. 相似文献
525.
Deepak Bandyopadhyay Jun Huan Jan Prins Jack Snoeyink Wei Wang Alexander Tropsha 《Journal of computer-aided molecular design》2009,23(11):773-784
Protein function prediction is one of the central problems in computational biology. We present a novel automated protein structure-based function prediction method using libraries of local residue packing patterns that are common to most proteins in a known functional family. Critical to this approach is the representation of a protein structure as a graph where residue vertices (residue name used as a vertex label) are connected by geometrical proximity edges. The approach employs two steps. First, it uses a fast subgraph mining algorithm to find all occurrences of family-specific labeled subgraphs for all well characterized protein structural and functional families. Second, it queries a new structure for occurrences of a set of motifs characteristic of a known family, using a graph index to speed up Ullman’s subgraph isomorphism algorithm. The confidence of function inference from structure depends on the number of family-specific motifs found in the query structure compared with their distribution in a large non-redundant database of proteins. This method can assign a new structure to a specific functional family in cases where sequence alignments, sequence patterns, structural superposition and active site templates fail to provide accurate annotation. 相似文献
526.
Deepak Ajwani 《Discrete Applied Mathematics》2010,158(4):240-250
Many applications like pointer analysis and incremental compilation require maintaining a topological ordering of the nodes of a directed acyclic graph (DAG) under dynamic updates. All known algorithms for this problem are either only analyzed for worst-case insertion sequences or only evaluated experimentally on random DAGs. We present the first average-case analysis of incremental topological ordering algorithms. We prove an expected runtime of under insertion of the edges of a complete DAG in a random order for the algorithms of Alpern et al. (1990) [4], Katriel and Bodlaender (2006) [18], and Pearce and Kelly (2006) [23]. 相似文献
527.
Long‐Lived Excited States of Zwitterionic Copper(I) Complexes for Photoinduced Cross‐Dehydrogenative Coupling Reactions
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Dr. Bin Wang Dr. Deepak Prakash Shelar Xian‐Zhu Han Ting‐Ting Li Dr. Xiangguo Guan Prof. Dr. Wei Lu Dr. Kun Liu Prof. Dr. Yong Chen Prof. Dr. Wen‐Fu Fu Prof. Dr. Chi‐Ming Che 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(3):1184-1190
Four heteroleptic copper(I) complexes containing phenanthroline and monoanionic nido‐carborane‐diphosphine ligands have been prepared and structurally characterized by various spectroscopic techniques and X‐ray diffraction. These complexes exhibit intense absorptions in the visible range and excited‐state lifetimes on the microsecond scale. Their application in visible‐light‐induced cross‐dehydrogenative coupling reactions was investigated. Preliminary studies showed that one of the four copper(I) complexes is an efficient catalyst for photoinduced oxidative C?H functionalization using oxygen as oxidant. Furthermore, α‐functionalized tertiary amines were obtained in good‐to‐excellent yields by light irradiation (λ>420 nm) of a mixture of our CuI complex, tertiary amines, and a variety of nucleophiles (nitroalkane, acetone, or indoles) under aerobic conditions. Electron paramagnetic resonance measurements provided evidence for the formation of superoxide radical anions (O2??) rather than singlet oxygen (1O2) during these photocatalytic reactions. 相似文献
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