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991.
At present, reducing carbon emissions is an urgent problem that needs to be solved in the cement industry. This study used three mineral admixtures materials: limestone powder (0–10%), metakaolin (0–15%), and fly ash (0–30%). Binary, ternary, and quaternary pastes were prepared, and the specimens’ workability, compressive strength, ultrasonic pulse speed, surface resistivity, and the heat of hydration were studied; X-ray diffraction and attenuated total reflection Fourier transform infrared tests were conducted. In addition, the influence of supplementary cementitious materials on the compressive strength and durability of the blended paste and the sustainable development of the quaternary-blended paste was analyzed. The experimental results are summarized as follows: (1) metakaolin can reduce the workability of cement paste; (2) the addition of alternative materials can promote cement hydration and help improve long-term compressive strength; (3) surface resistivity tests show that adding alternative materials can increase the value of surface resistivity; (4) the quaternary-blended paste can greatly reduce the accumulated heat of hydration; (5) increasing the amount of supplementary cementitious materials can effectively reduce carbon emissions compared with pure cement paste. In summary, the quaternary-blended paste has great advantages in terms of durability and sustainability and has good development prospects. 相似文献
992.
目的观察消肿愈溃散外敷治疗小儿疱疹性口炎的临床疗效。方法将213例疱疹性口炎患儿随机分为2组。治疗组115例予消肿愈溃散外涂,对照组98例予锡类散外涂。观察2组疗效及2组6~8岁患儿各45例用药后疼痛消退时间。结果治疗组痊愈率为66.1%,总有效率为99.5%;对照组痊愈率为39.1%,总有效率为59.1%,2组比较均有显著性差异(P均<0.01)。治疗组疼痛消失时间为(1.08±0.36)日,对照组为(2.06±0.53)日,2组比较有显著性差异(P<0.01)。结论消肿愈溃散治疗小儿疱疹性口炎疗效较好,止痛效果理想。 相似文献
993.
目的 评价Bio-oss骨粉在根尖吸收、根尖区溢脓惠牙病例的根管充填中应用的效果。方法 选取80例根尖吸收、根尖区溢脓的惠牙,根管预备后拍X线片,分别用传统根管填材料以及用Bio-oss骨粉糊荆进行根管充填。观察其疗效,随访。结果 应用Bio—oss骨粉糊荆作为根管充填材料的患者X线片示根尖有新生骨样组织生长,根尖区阴影减少,临床症状消失;传统材料充填的患者X线片示根尖区阴影无明显改变,治疗后复发率高。结论 Bio.oss骨粉在根尖吸收、根尖区溢脓惠牙病例根管充填中应用,可取得较好的临床效果。 相似文献
994.
Jií Svoboda Petr Boil Jakub Holzer Natlia Luptkov Milan Jarý Bohuslav Maek Petr Dym
ek 《Materials》2022,15(2)
Oxide-dispersion-strengthened (ODS) Fe-Al-Y2O3-based alloys (denoted as FeAlOY) containing 5 vol. % of nano-oxides have a potential to become top oxidation and creep-resistant alloys for applications at temperatures of 1100–1300 °C. Oxide dispersoids cause nearly perfect strengthening of grains; thus, grain boundaries with limited cohesive strength become the weak link in FeAlOY in this temperature range. One of the possibilities for significantly improving the strength of FeAlOY is alloying with appropriate elements and increasing the cohesive strength of grain boundaries. Nearly 20 metallic elements have been tested with the aim to increase cohesive strength in the frame of preliminary tests. A positive influence is revealed for Al, Cr, and Y, whereby the influence of Y is enormous (addition of 1% of metallic Y increases strength by a factor of 2), as it is presented in this paper. 相似文献
995.
The range of available aluminum alloy powders for laser powder bed fusion (LPBF) is restricted to mainly Al–Si based alloys. Currently aluminum alloy powders, designed for lightweight application, based on Al–Mg (5000 series), Al–Si–Mg (6000 series), or Al–Zn–Mg (7000 series), cannot be processed by LPBF without solidification cracks. This has an impact on the potential of LPBF for lightweight applications. In fusion welding, solidification cracks are eliminated by using filler materials. This study aims to transfer the known procedure to LPBF, by supplementing EN AW-5083 (AlMg4.5Mn0.7) with AlSi10Mg. EN AW-5083 and two modifications (+7 wt.% and +15 wt.% AlSi10Mg) were produced by LPBF and analyzed. It was found that, in EN AW-5083, the solidification cracks have a length ≥200 µm parallel to the building direction. Furthermore, the solidification cracks can already be eliminated by supplementing 7 wt.% AlSi10Mg. The microstructure analysis revealed that, by supplementing AlSi10Mg, the melt pool boundaries become visible, and the grain refines by 40% relative to the base alloy. Therefore, adding a low melting point phase and grain refinement are the mechanisms that eliminate solidification cracking. This study illustrates a practical approach to eliminate solidification cracks in LPBF. 相似文献
996.
Nano coatings for anti-corrosion and electromagnetic wave absorbing can simultaneously implement the functions of assimilating electromagnetic waves and reducing the corrosion of materials caused by corrosive environments, such as seawater. In this work, a composite material for both electromagnetic wave absorption and anti-corrosion was prepared by an in-situ chemical oxidation and surface coating method using carbonyl iron powder (CIP), graphene oxide (GO) and aniline (AN). The synthesized composite material was characterized by scanning electron microscopy (SEM), infrared spectroscopy (FT-IR) and XRD. The carbonyl iron powder-graphene oxide-polyaniline (CIP-GO-PANI) composite material was used as the functional filler, and the epoxy resin was the matrix body for preparing the anticorrosive wave-absorbing coating. The results show that CIP had strong wave-absorbing properties, and the anti-corrosion property was greatly enhanced after being coated by GO-PANI. 相似文献
997.
目的:观察参芪杀白汤为主联合化疗治疗白血病伴发脾周围炎患者临床疗效及患者脾肿大范围、疼痛程度、局部皮温及彩超脾周围炎相关表现的治疗前后改善情况。方法:在DA方案或VDCP±L-Asp方案化疗基础上,采用益气养阴,化瘀消癥中药,自拟参芪杀白汤内服、丹香解毒消癥散外敷治疗伴脾周围炎急性髓细胞白血病或急性淋巴细胞白血病。结果: 白血病疗效表明,观察组CR率69.0%,观察组46.3%; 总有效率观察组88.1%,明显优于对照组(68.3%,P<0.05); 脾周围炎治疗效果观察组痊愈率59.5%,对照组39.0%; 总有效率观察组92.9%,优于对照组(82.9%,P<0.05)。结论:益气养阴、化瘀消癥中药内服外用治疗急性白血病伴发脾周围炎可提高完全缓解率,既可清热解毒通络以止痛,又可软坚消癥治疗辅助治疗白血病,且未见明显不良反应。 相似文献
998.
The effect of ternary alloying elements (Mo and Ta) on the mechanical and superelastic properties of binary Ti-14Nb alloy fabricated by the mechanical alloying and spark plasma sintering was investigated. The materials were prepared in two ways: (i) by substituting Nb in base Ti-14Nb alloy by 2 at.% of the ternary addition, giving the following compositions: Ti-8Nb-2Mo and Ti-12Nb-2Ta and (ii) by adding 2 at.% of the ternary element to the base alloy. The microstructures of the materials consisted of the equiaxed β-grains and fine precipitations of TiC. The substitution of Nb by both Mo and Ta did not significantly affect the mechanical properties of the base Ti-14Nb alloy, however, their addition resulted in a decrease of yield strength and increase of plasticity. This was associated with the occurrence of the {332} <113> twinning that was found during the in-situ observations. The elevated concentration of interstitial elements (oxygen and carbon) lead to the occurrence of stress-induced martensitic transformation and twinning mechanisms at lower concentration of β-stabilizers in comparison to the conventionally fabricated materials. The substitution of Nb by Mo, and Ta caused the slight improvement of the superelastic properties of the base Ti-14Nb alloy, whereas their addition deteriorated the superelasticity. 相似文献
999.
目的:探究逍遥散联合恩替卡韦治疗肝郁脾虚型慢性乙型肝炎(CHB)的临床疗效。方法:选取慢性乙型肝炎患者100例,用随机数字表法将患者分为观察组和对照组,每组各50例。对照组给予恩替卡韦治疗,观察组给予恩替卡韦加逍遥散,比较两组患者的中医证候、血清病毒载量、肝脏硬度及不良反应等相关指标。结果:治疗3个月后,观察组的各项中医证候评分均低于对照组(P<0.05),临床疗效总有效率为92.00%高于对照组的76.00%(P<0.05)。治疗3个月后HBV-DNA转阴率观察组仍高于对照组,FS值小于对照组(P<0.05)。治疗6个月后,观察组的HBV-DNA转阴率高于对照组(P<0.05),FS值小于对照组(P<0.05)。两组患者均未出现严重的不良反应,总不良反应发生率比较,无统计学差异(P>0.05)。结论:逍遥散联合恩替卡韦治疗,能有效改善肝郁脾虚型CHB患者的临床证候,促进HBV-DNA阴转,降低肝脏硬度,且不良反应较少。 相似文献
1000.
目的制备盐酸小檗碱粉雾剂,肺部给药后考察其对于金黄色葡萄球菌肺炎的药效作用。方法通过正交试验优化喷雾干燥条件,制备盐酸小檗碱粉雾剂;对其肺部沉积、流动性、外观形态进行研究;并评价该制剂对金黄色葡萄球菌肺炎大鼠的药效作用。结果最终确定在130℃的进口温度、610L/h的气体体积流量下,以3m L/min的进料体积流量,通过喷雾干燥制备盐酸小檗碱粉雾剂。盐酸小檗碱粉雾剂肺部沉积率(FPF)76.4%,空气动力学直径为4.61μm。稳定指数(SI)≈1,充气能比(AR)=1.761,充气能量(AE10)=2.1 mJ10 mJ。对金黄色葡萄球菌的药效学评价,表面盐酸小檗碱粉雾剂可以有效改善肺炎大鼠的病理状态,显著降低肺炎大鼠白细胞、中性粒细胞的数量(P0.05),以及炎症因子(TNF-α、IL-1β及IL-6)的水平。结论盐酸小檗碱粉雾剂通过肺部给药可以直达病变部位,对金黄色葡萄球菌肺炎具有显著的治疗作用。 相似文献