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191.
The present study reports cytochemistry data about salivary glands of females (unfed, engorged, and at day three post-engorgement) and males (unfed, at day seven post-attachment, and at days three and seven post-detachment from the host) of the tick Rhipicephalus sanguineus. The results revealed nuclear changes in engorged females and at day three post-engorgement, and in males in all stages (except unfed). These changes were more prominent in females. Cytoplasmic changes were also observed in cells of all acini of males and females. In types II and III acini of engorged females, nuclear changes were observed in the shape (irregular, with blebs, fragmenting or fragmented), size (enlarged or reduced), and arrangement and condensation level of chromatin (marginal or as blebs). Changes were also detected in nucleoli, regarding their shape (fragmenting or fragmented), size (enlarged), and location (central, marginal or as blebs). Some nucleoli were also compacted or disorganized. In females at day three pos-engorgement, all acini exhibited similar changes to those observed in engorged females. RNA staining was stronger in cells of engorged females than those at day three post-engorgement. In males at day seven post-attachment, cells of types II, III, IV acini presented changes in the size of the nucleus and condensation level of chromatin similar to those of females. The shape of the nucleus was round, irregular or undergoing fragmentation, and the chromatin was located at the margin or throughout the nucleus. The changes in the nucleolus were similar to those of females, regarding size and organization, although round-shaped and in the central location. In males at day three post-detachment, cells of all acini exhibited nuclear changes similar to those of males at day seven post-attachment, in addition to the fragmentation of the nucleolus. At day seven post-detachment, changes were detected in all acini similar to the observed in males at day seven post-attachment. Regarding cytoplasmic RNA, staining was prominent in males at day seven post-attachment and weak in those at day seven post-detachment from the host. In females as well as males, different RNA staining patterns in the cytoplasm and nuclear changes characterized apoptotic cell death. 相似文献
192.
Dr. Kara M. Harmatys Dr. Juan Chen Danielle M. Charron Dr. Christina M. MacLaughlin Prof. Dr. Gang Zheng 《Angewandte Chemie (International ed. in English)》2018,57(27):8125-8129
Current biomimetics for medical applications use a single biomimetic approach to imitate natural structures, which can be insufficient for reconstructing structurally complex natural systems. Multipronged efforts may resolve these complexities. To achieve interesting nanostructure‐driven optical properties, a dual‐biomimetic system contained within a single nanoagent was engineered to recapitulate chlorosomes, efficient light‐harvesting organelles that have unique dye assemblies and tunable photonic properties. A series of chlorin dyes was synthesized, and these hydrophobic assemblies were stabilized inside a high‐density lipoprotein, a second biomimetic that enabled in vivo utility. This system resulted in tunable tumor imaging of intact (photoacoustic) and disrupted (activatable fluorescence) nanostructures. The successful demonstration of this multipronged biomimetic approach opens the door for reconstruction of complex natural systems for biomedical applications. 相似文献
193.
Kadarkarai Murugan Jagannathan Madhavan Christina Mary Samidoss Chellasamy Panneerselvam Al Thabiani Aziz Arumugam Malathi Aruliah Rajasekar Amuthavalli Pandiyan Suresh Kumar Abdullah A. Alarfaj Akon Higuchi Giovanni Benelli 《Journal of Cluster Science》2018,29(2):337-344
Anopheles stephensi is a mosquito vector of malaria, which is still considered a relevant public health problem due to increasing outdoor transmission, growing resistance to insecticides used to target vectors, and antiplasmodial drugs as well. Thus, there is a vital need to explore novel sources of effective compounds. In this study, the hydrothermal method was used for the synthesis of bismuth oxyiodide (BiOI) nanoflakes. Furthermore, the toxicity of BiOI nanoflakes was evaluated for the first time on A. stephensi, as well as in vivo against the malaria parasite Plasmodium berghei. The synthesis of BiOI nanoflakes was confirmed by various characterization techniques, including X-ray diffraction, Fourier transform-infrared spectroscopy, field emission scanning electron microscopy and transmission electron microscopy (HR-TEM). LC50 of BiOI nanoflakes on A. stephensi were 2.263 ppm (larva I), 3.414 ppm (II), 4.956 ppm (III), 6.983 ppm (IV) and 8.605 ppm (pupae). In vivo antiplasmodial experiments conducted on P. berghei infecting albino mice showed 27.2% of chemosuppression after 4 days of treatment with 300 mg/kg/day of BiOI, a lower performance if compared to chloroquine. Overall, our results suggested that hydrothermal synthesis of BiOI nanoflakes may be considered to develop newer and safer tools for malaria vector control. 相似文献
194.
Brendan Frett Nicholas McConnell Anupreet Kharbanda Gunaganti Naresh Benjamin Rounseville Christina Warner John Chang Natalie Debolske Hong-yu Li 《Tetrahedron》2018,74(35):4592-4600
Carbon-carbon bonds are integral for pharmaceutical discovery and development. Frequently, CC bond reactions utilize expensive catalyst/ligand combinations and/or are low yielding, which can increase time and expenditures in pharmaceutical development. To enhance CC bond formation protocols, we developed a highly efficient, selective, and combinatorially applicable Friedel-Crafts acylation to acetylate the C-3 position of imidazo[1,2-a]pyridines. The reaction, catalyzed by aluminum chloride, is both cost effective and more combinatorial friendly compared to acetylation reactions requiring multiple, stoichiometric equivalents of AlCl3. The protocol has broad application in the construction of acetylated imidazo[1,2-a]pyridines with an extensive substrate scope. All starting materials are common and the reaction requires inexpensive, conventional heating methods for adaptation in any laboratory. Further, the synthesized compounds are predicted to possess GABA activity through a validated, GABA binding model. The developed method serves as a superior route to generate C-3 acetylated imidazo[1,2-a]pyridine building-blocks for combinatorial synthetic efforts. 相似文献
195.
Agnès Hagege Christina Troyer Manfred Grasserbauer Maurice J. F. Leroy 《Mikrochimica acta》1997,127(1-2):113-118
The behaviour of four biologically relevant selenium compounds (Se(VI), Se(IV), selenomethionine and selenocystine) in capillary zone electrophoresis (CZE) was investigated. Parameters which affect the separation, detection and sample introduction were investigated to improve the sensitivity of the analysis. Short-term repeatability was evaluated and detection limits were found to be in the g·l–1 range. 相似文献
196.
In a quest to develop an effective, scalable synthesis of (+)-spongistatin 1 ( 1), we devised a concise, third-generation scalable synthesis of (+)- 7, the requisite F-ring tetrahydropyran aldehyde, employing a proline-catalyzed cross-aldol reaction. Subsequent elaboration to (+)-EF Wittig salt (+)- 3, followed by union with advanced ABCD aldehyde (-)- 4, macrolactonization and global deprotection permitted access to >1.0 g of totally synthetic (+)-spongistatin 1 ( 1). 相似文献
197.
Molecular dynamics simulations were performed to study the translocation of single-stranded (ss) DNA through the nanoscale gap between the nanoscale electrodes of a proposed genomic sequencing device. An applied electric field forces the ssDNA to move in the direction of the nanoscale gap in platinum electrodes. A series of simulations utilizing eight different nanoscale gap distances as well as seven different nucleotide chain lengths were performed to determine the impact of these variables on the overall design of the sequencing device and the translocation behavior of ssDNA. The results clearly indicate a threshold value of the gap width below which the ssDNA will readily enter and traverse the nanoscale gap. Translocation velocities obtained for various chain lengths were consistent with simulated bulk data; however, successful translocation was inconsistent, possibly related to the sample's affinity for the metal electrodes. An attempt at overcoming this barrier was made through the implementation of shaped electrodes as well as pre-threading of the ssDNA sample. 相似文献
198.
Roos PH Venkatachalam A Manz A Waentig L Koehler CU Jakubowski N 《Analytical and bioanalytical chemistry》2008,392(6):1135-1147
Numerous structurally and enzymatically similar cytochromes P450 (CYPs) are involved in the metabolism of xenobiotics and
are present in different amounts and with different enzyme profiles in human tissues and cells. Analysis of their adaptively
regulated and individually variable patterns is a peculiar analytical challenge. We developed a laser ablation inductively
coupled plasma mass spectrometry (LA-ICP-MS) based method for concomitant detection and semiquantitative determination of
electrophoretically separated and blotted CYPs. The first results are given here for the two enzymes CYP1A1 and CYP2E1. Specific
monoclonal antibodies directed against the enzymes were differentially labelled with europium via a covalently linked chelator
and with iodine, respectively. Analysis of the modified antibodies shows that both europium and iodine are coupled to the
heavy and the light chains of the antibodies. Also, the antibodies maintained their antigen-binding properties after labelling
as demonstrated by LA-ICP-MS-analysed immunoblots. The method allowed us to detect specifically and concomitantly both CYP
enzymes in complex biological samples, i.e. microsomes of rat liver and minipig duodenum, which are characterized by different
levels and proportions of the two CYP enzymes. A strong CYP1A1 signal is found in liver microsomes of 3-methylcholanthrene-treated
rats, while it is (nearly) absent in liver microsomes of rats treated with isonocotinic acid hydrazide (isoniazid). The constitutively
expressed CYP2E1 is found in microsomes of both treatment groups. Duodenal microsomes of minipigs orally exposed to polycyclic
aromatic hydrocarbons show a clear CYP1A1 signal. Low levels of CYP2E1 can also be detected in these microsomes. The LA-ICP-MS
method allows concomitant determination of CYPs, thereby exhibiting sensitivity similar to that of conventional chemoluminescence
detection via peroxidase-labelled secondary antibodies. The latter method allows readout of a single CYP protein in a 1D separation.
Although the results presented here are only for labelling by use of the elements iodine and europium, the same strategy can
be applied also for other lanthanide elements in combination with chelating compounds, so LA-ICP-MS of western blots offers
a new capability to be applied for highly multiplexed CYP determinations via labelled antibodies. 相似文献
199.
Oliver Staller Christina Mitterbauer Katharina Mayr 《Central European Journal of Chemistry》2008,6(4):535-541
In this paper we report a method to determine tensile strengths and Young’s modulus of cubic biaxial textured metal tapes
used as substrate materials for coated conductors (CC). Simplicity, rapidity and reproducibility of the procedure are important
for the evaluation of continuous in-house productions. Our approach is based on the EN 10002-1 B tensile test method. A key
role for satisfactory results is the sample preparation of 100–250 μm thick tapes, which will be described in detail. Copper
(E-Cu57) can be successfully transformed to cubic biaxial textured substrates. Best results were achieved by annealing between
750°C and 850°C in reducing atmosphere. Best FWHM values for the ψ scan are 5.51° and for the ϕ scan are 4.5°. Pole figure
analysis verified the sharp {001} <100> texture of the tape. Vickers hardness measurements (HV 0.1) for the cold worked material
yielded values of 135 and for the annealed tape, values of 37. The ultimate tensile yield strength Rm of the textured substrate
is 150 MPa and thus significantly lower than that for the cold worked material (413 MPa). Cubic biaxial substrates could be
manufactured from Isotan CuNi44 (WM49) bars. Best results were achieved by annealing at 1200°C in reducing atmosphere. Pole
figure analysis verified the {001} <100> texture with other low intensity texture components. Vickers hardness measurements
(HV 0.1) for the cold worked material yielded values of 236 and for the annealed tape values of 92. The ultimate tensile yield
strength R
m of the textured substrate is 300 MPa and thus significantly lower than that for the cold worked material (723 MPa).
相似文献
200.
Christina Conroy 《Acta Analytica》2008,23(4):367-372
In his “Space, supervenience and substantivalism”, Le Poidevin proposes a substantivalism in which space is discrete, implying
that there are unmediated spatial relations between neighboring primitive points. This proposition is motivated by his concern
that relationism suffers from an explanatory lacuna and that substantivalism gives rise to a vicious regress. Le Poidevin
implicitly requires that the relationist be committed to the “only x and y” principle regarding spatial relations. It is not obvious that the relationist is committed to this principle in such a context.
An additional motivation for Le Poidevin's argument, that space should be considered to be discrete, is that he believes that
substantivalists are committed to a vicious regress. I show that the regress is in fact not of the vicious variety. These
two main arguments show that Le Poidevin's suggestion that we drop the density postulate for space is unnecessary.
相似文献
Christina ConroyEmail: |