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991.
JingHua Tan Chenliang Chen Yiwu Liu Juying Wu Ding Wu Xiang Zhang Xiaoye He Zhihong She Ren He Hailiang Zhang 《RSC advances》2020,10(21):12475
Diffusion and sorption of five gases (H2, N2, O2, CO2, CH4) in hydrogenated nitrile butadiene rubber (HNBR) and ethylene–propylene–diene rubber (EPDM) have been investigated by molecular dynamics (MD) and grand canonical Monte Carlo (GCMC) simulations. The diffusion coefficients of gas molecules in HNBR and EPDM are well correlated with the effective penetrant diameter except for CO2. CO2 shows a lower diffusion coefficient due to its linear shape. Additionally, the favorable interaction between CO2 and HNBR is another factor for its lower diffusion coefficient in HNBR. HNBR shows lower diffusion coefficients than EPDM. This is because the polar –CN groups in HNBR chains increase interchain cohesion and result in tight intermolecular packing, low free volume and poor chain mobility, which decreases the diffusion coefficients of HNBR. The solubility coefficients of CH4, O2, N2 and H2 in HNBR are lower than those in EPDM, which is a result of the weak HNBR–penetrant interactions and low free volume of HNBR. However, the solubility coefficient of CO2 in HNBR is higher than in EPDM. This is attributed to the strong interaction between CO2 and HNBR. H2, O2, N2 and CH4 show lower permeability coefficients in HNBR than in EPDM, while CO2 has higher permeability coefficients in HNBR. These molecular details provide critical information for the understanding of structures and gas transport between HNBR and EPDM.Diffusion and sorption of five gases (H2, N2, O2, CO2, CH4) in HNBR and EPDM were explored by MD and GCMC simulations. 相似文献
992.
It is a great challenge to tune the porosity of porous materials. As most porous organic cages are soluble, solution processability can be a possible way to regulate the porosity of such materials. Herein, a triptycene-based cage (TC) is demonstrated to be stable in acid, base or boiling water. Meanwhile, its porosity can be tuned by adjusting the solution-state assembly processes. TC molecules crystallized slowly from solution exhibit nearly no porosity to nitrogen (off-state). While, after rapid precipitating from methanol/dichloromethane solution, the obtained TC (TC-rp) is in a porous state and exhibit a high BET surface area of 653 m2 g−1 (on-state).Here, a kind of triptycene-based cage is demonstrated to have good chemical stability in acid, base and boiling water. Moreover, its porosity can be tuned by varying the solution-state assembly processes. 相似文献
993.
Dual gate (DG) low-voltage transparent electric-double-layer (EDL) thin-film transistors (TFTs) with microporous-SiO2 for both top and bottom dielectrics have been fabricated, both dielectrics were deposited by plasma-enhanced chemical vapor deposition (PECVD) at room temperature. The threshold voltage of such devices can be modulated from −0.13 to 0.5 V by the top gate (TG), which switches the device from depletion-mode to enhancement-mode. High performance with a current on/off ratio (∼2.1 × 106), subthreshold swing (76 mV per decade), operating voltage (1.0 V), and field-effect mobility (∼2.6 cm2 V−1 s−1) are obtained. Such DG TFTs are promising for ion-sensitive field-effect transistors sensor applications with low-power consumptions.Dual gate (DG) low-voltage transparent electric-double-layer (EDL) thin-film transistors (TFTs) with microporous-SiO2 for both top and bottom dielectrics have been fabricated, both dielectrics were deposited by plasma-enhanced chemical vapor deposition (PECVD). 相似文献
994.
Selective photocatalytic reduction of CO2 has been regarded as one of the most amazing ways for re-using CO2. However, its application is still limited by the low CO2 conversion efficiency. This work developed a novel Pt/In2O3/g-C3N4 multifunctional catalyst, which exhibited high activity and selectivity to HCOOH during photocatalytic CO2 reduction under visible light irradiation owing to the synergistic effect between photocatalyst, thermocatalyst, and heterojunctions. Both In2O3 and g-C3N4 acted as visible photocatalysts, in which porous g-C3N4 facilitated H2 production from water splitting while the In2O3 nanosheets embedded in g-C3N4 pores favored CO2 fixation and H adsorption onto the Lewis acid sites. Besides, the In2O3/g-C3N4 heterojunctions could efficiently inhibit the photoelectron–hole recombination, leading to enhanced quantum efficiency. The Pt could act as a co-catalyst in H2 production from photocatalytic water splitting and also accelerated electron transfer to inhibit electron–hole recombination and generated a plasma effect. More importantly, the Pt could activate H atoms and CO2 molecules toward the formation of HCOOH. At normal pressure and room temperature, the TON of HCOOH in CO2 conversion was 63.1 μmol g−1 h−1 and could reach up to 736.3 μmol g−1 h−1 at 40 atm.A multifunctional Pt/In2O3/g-C3N4 catalyst exhibited high activity and selectivity to HCOOH during CO2 reduction owing to the synergy between visible-light harvesting, CO2 activation, HER, and photoelectron–hole separation via heterojunctions. 相似文献
995.
目的比较经动脉与静脉采血行血液稀释式自体血回输的效果。方法将行血液稀释式自体血回输的择期手术患者189例按时间先后分为对照组(97例)和观察组(92例)。对照组行静脉采血,观察组经动脉采血,监测两组患者采血前后血压、心率、SpO2变化;比较两组采血时间、一次穿刺采血成功率。结果两组患者采血前、采血后15min、30min平均动脉压、心率、SpO2变化比较,差异无统计学意义(均P>0.05);观察组一次穿刺采血成功率显著高于对照组,采血时间显著短于对照组(P<0.05,P<0.01)。结论经动脉采血可在保证安全的前提下,缩短采血时间,提高一次采血成功率。 相似文献
996.
Hark Chuan Tan Chye Khoon Poh Yanli Cai Wilson Wang 《Journal of orthopaedic research》2013,31(6):983-990
Orthopedic metallic prosthetic implants are commonly made of cobalt chromium (CoCr) alloys. However, such metal‐based implants are susceptible to fibrous capsule formation on the implant surface after implantation. At the bone‐implant interface, this capsule can prevent implant integration, resulting in loosening and failure. Minimizing the development of such a capsule on the CoCr surface would improve direct bone‐implant bonding leading to long‐term implant functionality. We evaluated the anti‐fibrosis effect of bone morphogenic protein‐7 (BMP‐7) peptide covalently bonded to CoCr alloy. This peptide, a biomimetic derivation of the knuckle epitope of BMP‐7, was conjugated at the N‐terminus with a cysteine amino acid. X‐ray photoelectron spectroscopy (XPS) and probe binding assay were used to evaluate different stages of grafting and surface functionalization using polydopamine coating. Cellular functions were studied using fibroblast attachment, cell proliferation, and MTT assays. Fibroblasts were grown on functionalized and pristine CoCr substrates, and the efficacy of BMP‐7 peptide on anti‐fibrosis was analyzed via gene expression and protein expression of fibrosis markers ACTA2, Collagen 1A1, and fibronectin. The peptide functionalized substrates showed significant reduction of fibrosis markers expression after 1 week of incubation compared to controls. BMP‐7 signaling pathway activation was shown by the presence of phosphorylation of Smad1/5/8. These findings may contribute to the improvement of CoCr implants in orthopedic surgery applications. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 983–990, 2013 相似文献
997.
998.
C. Wu A.L. Tan D.A.E. Maze A.J.A. Holland 《Burns : journal of the International Society for Burn Injuries》2013
Background
Scalds and contact burns in children may occur as the result of spillage of hot food and drinks, including instant hot noodles. This study sought to determine the frequency of noodle burns in children and investigate the thermal properties of instant hot noodles.Methods
Data on instant hot noodle burns in children were retrieved from the New South Wales Severe Burn Injury Database between 2005 and 2010. Five widely available brands of instant hot noodles, including three cup and two packet varieties, were prepared following the manufacturer's instructions. For each preparation the initial temperature after cooking was recorded, together with the time to cool to 50 °C.Results
291 children sustained instant hot noodle burns over the 6 year study period, representing 5.4% of all children referred to our burns unit. Over a third received inadequate first aid. Cup noodles cooked with boiling water reached the highest temperature of over 80 °C and took the longest time to cool to 50 °C: on average 52.3 min. Cup noodles in smaller, narrower containers achieved higher post-cooking temperatures compared to noodles in wider, bowel shaped containers. Packet noodles cooked in a Microwave oven attained lower peak temperatures and shorter cooling times compared to cup noodles.Conclusions
Although relatively uncommon in children, instant hot noodle burns often received inadequate first aid. When cooked according to manufacturer's instructions, noodles generally exceeded temperatures sufficient to cause a burn. Consumers and parents need to be aware of the risks of burn when preparing these foods. 相似文献999.
1000.
Min-Hoe Chew Poh-Koon Koh Melinda Tan Kiat-Hon Lim Loi Carol Choong-Leong Tang 《World journal of surgery》2013,37(10):2468-2475