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951.
Thibaud Brochet Jrme Lapuyade-Lahorgue Alexandre Huat Sbastien Thureau David Pasquier Isabelle Gardin Romain Modzelewski David Gibon Juliette Thariat Vincent Grgoire Pierre Vera Su Ruan 《Entropy (Basel, Switzerland)》2022,24(4)
In this paper, we propose to quantitatively compare loss functions based on parameterized Tsallis–Havrda–Charvat entropy and classical Shannon entropy for the training of a deep network in the case of small datasets which are usually encountered in medical applications. Shannon cross-entropy is widely used as a loss function for most neural networks applied to the segmentation, classification and detection of images. Shannon entropy is a particular case of Tsallis–Havrda–Charvat entropy. In this work, we compare these two entropies through a medical application for predicting recurrence in patients with head–neck and lung cancers after treatment. Based on both CT images and patient information, a multitask deep neural network is proposed to perform a recurrence prediction task using cross-entropy as a loss function and an image reconstruction task. Tsallis–Havrda–Charvat cross-entropy is a parameterized cross-entropy with the parameter . Shannon entropy is a particular case of Tsallis–Havrda–Charvat entropy for . The influence of this parameter on the final prediction results is studied. In this paper, the experiments are conducted on two datasets including in total 580 patients, of whom 434 suffered from head–neck cancers and 146 from lung cancers. The results show that Tsallis–Havrda–Charvat entropy can achieve better performance in terms of prediction accuracy with some values of . 相似文献
952.
Considering mass and stiffness of piezoelectric layers and damage effects of composite layers, nonlinear dynamic equations of damaged piezoelectric smart laminated plates are derived. The derivation is based on the Hamilton's principle, the higher- order shear deformation plate theory, von Karman type geometrically nonlinear straindisplacement relations, and the strain energy equivalence theory. A negative velocity feedback control algorithm coupling the direct and converse piezoelectric effects is used to realize the active control and damage detection with a closed control loop. Simply supported rectangular laminated plates with immovable edges are used in numerical computation. Influence of the piezoelectric layers' location on the vibration control is in- vestigated. In addition, effects of the degree and location of damage on the sensor output voltage are discussed. A method for damage detection is introduced. 相似文献
953.
954.
一种消象旋传动机构的设计与精度分析 总被引:1,自引:1,他引:0
本文提出了一种消象旋机构的结构形式.并对齿轮传动的结构方式做了重点介绍.通过对齿轮传动进行精度分析,可以得出传动过程中齿轮精度及传动误差对棱镜消旋系统正象精度的影响. 相似文献
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956.
在不同的恒定频率下,研究了PCC(沉淀碳酸钙)/PEG200(聚乙二醇,平均分子量为200)分散体系的剪切变稀和剪切增稠的流变性能.随着动态剪切应力的升高,复数粘度开始不随应力而改变,而后出现明显的剪切变稀,当复数粘度达到最小值后出现强烈的剪切增稠.在固定频率5 rad/s下研究了模量以及滞后角的正切与应力幅度的关系,在低的应力下储能模量开始几乎与应力幅度无关,继而快速下降.滞后角的正切从0.6升高到92,表明体系发生了从弹性到粘性的转变,尤其在发生剪切增稠后滞后角的正切快速增大.从Lissajous图分别探索了在剪切变稀区和剪切增稠区的能量与最大应变的关系.应变周期内的消耗的能量与最大应变幅度指数关系得到了确认.在剪切变稀区指数为1.91,而在剪切增稠区由于形成了粒子簇激增至3.97.以上现象运用\粒子簇"理论得到了定性的解释. 相似文献
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959.
Jing Xu Fei Teng Baiqi Wang Xinxuan Ruan Yifan Ma Dingyuan Zhang Yan Zhang Zhijun Fan Hua Jin 《Molecules (Basel, Switzerland)》2022,27(11)
This study investigated the effects of microwave modification, alkali polyphenol (ferulic acid) covalently combined modification, and microwave-alkali polyphenol covalently combined modification on the gel properties of soy protein emulsions. The results showed that the properties of soy protein emulsions were improved significantly by the three modification methods. After three kinds of modification, the viscoelasticity of soy protein emulsion gel increased, and a gel system with stronger elasticity was formed. The texture, water-holding, and hydration properties of the emulsion gel increased significantly. The SEM and ClSM results showed that the modified soy protein emulsion gel had a more compact and uniform porous structure, and the oil droplets could be better embedded in the network structure of the gel. Among the three modification methods, the microwave-alkali method polyphenol covalently combining the compound modification effect was best, and the microwave modification effect was least effective compared to the other two methods. Our obtained results suggested that for gel property modification of soy protein emulsion gels, microwave pretreatment combined with the covalent binding of polyphenols by an alkaline method is an effective method. 相似文献
960.
利用改进的Hummers法氧化鳞片石墨,获得富含羟基和羧基的氧化石墨烯量子点(GOQDs)。通过透射电子显微镜、X射线衍射、红外光谱及拉曼光谱测试表征其理化性质。此外,利用鸡卵清蛋白(OVA)作为模式抗原,构筑GOQDs/OVA纳米疫苗并评估其载量、安全性、免疫效力等。结果显示,GOQDs/OVA纳米疫苗直径在5 nm左右,具有高度的水分散性和稳定性。其对OVA的最大负载量约为500 mg·g-1,在pH=5.5和7.4环境下24 h的释放率分别为74.65%和56.93%,表现出pH刺激响应释放性能。当GOQDs浓度在500 μg·mL-1以下时,不会引起溶血、细胞损伤、重要组织发生病变等现象。免疫后,与OVA单独免疫对照组相比,GOQDs/OVA纳米疫苗可以诱导产生高水平的免疫球蛋白G(IgG)、免疫球蛋白G1(IgG1)及免疫球蛋白G2a(IgG2a)抗体,提高白细胞介素(IL)-1β、IL-2、IL-4和IL-6、肿瘤坏死因子-α(TNF-α)和γ干扰素(IFN-γ)的分泌,同时促进脾中辅助性(CD4+)和细胞毒性(CD8+)T淋巴细胞百分比的增加。 相似文献