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951.
952.
基于西北地区143个气象站点的气象数据,采用FAO-56 Penman-Monteith公式计算潜在蒸发量,并结合降水量计算西北地区1989—2019年干燥度指数(AI),采用Mann-Kendall趋势分析、小波分析、偏微分方程等方法来揭示其变化趋势、变化周期和气候因子对AI的贡献率。结果表明: 1989—2019年,西北地区AI整体呈不显著的减小趋势,其中,青海呈显著减小趋势,新疆呈不显著的上升趋势;研究区AI在2010年发生了突变,AI变化存在1个17年的主周期。西北地区AI呈现出由东南部向中部、西北部向中部增加的空间格局。西北地区AI变化的倾向率为-1.267·(10 a)-1,其中,甘肃、宁夏、陕西、青海和新疆AI变化的倾向率分别为-1.17、-0.41、-0.49、-1.77和-2.73·(10 a)-1。青海小灶火、新疆库尔勒、阿克苏和吐鲁番地区干旱风险发生的可能性较高。降水量和实际水汽压是影响甘肃、宁夏、青海、陕西AI变化的主要气侯因子,影响新疆AI变化的主要气侯因子为潜在蒸散、太阳辐射和平均气温。 相似文献
953.
孢子植物物种多样性丰富, 是自然生态系统的重要组成部分。孢子植物的传播通常被认为主要依靠风、水、弹力等非生物媒介, 而动物的作用往往被忽略。本文主要概述了: (1)孢子植物对动物传播的适应: 一方面孢子植物可为动物提供食物、庇护所、繁殖场所等, 另一方面孢子植物也可产生视觉、嗅觉等方面的线索来吸引动物, 从而促进动物传播其繁殖体。(2)动物对孢子植物的传播模式: 包括体内传播(消化道和组织寄生)和体外传播两种, 这些模式都能对孢子植物繁殖体进行有效传播。由于动物间形态或生活习性的不同, 以致传播距离存在差异, 最短距离为0.1 cm, 最长距离可从北半球至南半球。(3)动物对孢子植物传播的生态与进化意义; 由于某些孢子植物繁殖体的结构特点或萌发的需求, 以致其繁殖体只能通过动物的传播才能得以定殖, 因此动物与孢子植物之间存在密不可分的关系。目前, 动物对孢子植物的传播研究主要是描述性的内容以及研究单方面的传播途径, 建议在今后的研究中考虑动物对孢子植物传播的有效性以及多途径同时传播对孢子植物定殖的影响, 同时应更加关注孢子植物和动物互惠关系的形成、维持机制及将来的进化趋势。 相似文献
954.
Bethany M. Henrick Lucie Rodriguez Tadepally Lakshmikanth Christian Pou Ewa Henckel Aron Arzoomand Axel Olin Jun Wang Jaromir Mikes Ziyang Tan Yang Chen Amy M. Ehrlich Anna Karin Bernhardsson Constantin Habimana Mugabo Ylva Ambrosiani Anna Gustafsson Stephanie Chew Heather K. Brown Petter Brodin 《Cell》2021,184(15):3884-3898.e11
955.
MAGE-C2/CT10 promotes growth and metastasis through upregulating c-Myc expression in prostate cancer
Molecular and Cellular Biochemistry - Prostate cancer (PC) is the most common reproductive cancer in men and the third leading cause of cancer death among men worldwide. Recently targeted therapy... 相似文献
956.
Wang ZJ Zhou YJ Zhao YX Liu YY Shi DM Liu XL Yu M Gao F 《Obesity (Silver Spring, Md.)》2012,20(1):141-146
Obesity is a major risk factor for developing coronary artery disease. The impact of obesity on prognosis among those with established coronary disease is less clear. The objective of this study was to evaluate the effect of obesity on repeat revascularization in patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stents (DES). We examined 6,083 patients who were divided into three groups according to BMI: normal (BMI 18.5-24.9 kg/m(2), n = 1,592); overweight (BMI 25-29.9 kg/m(2), n = 3,026) and obese (BMI >30 kg/m(2), n = 1,465). The follow-up focused on clinical-driven repeat revascularization, including target lesion revascularization (TLR) and nonTLR. Median follow-up was 26 months (interquartile range 20-32). There was no significant difference in the incidence of TLR among normal, overweight, and obese patients (6.3% vs. 6.1% vs. 7.1%; P = 0.423). In contrast, the incidence of nonTLR was significantly higher in obese patients compared with normal and overweight (8.4% vs. 6.0% vs. 5.8%, P = 0.003). Multivariate analysis showed that obesity was an independent predictor of nonTLR during follow-up (hazard ratio = 1.39; 95% confidence interval = 1.06-1.83; P = 0.019), along with diabetes and hypercholesterolemia. Concomitant use of statins was independently associated with decreased risk of nonTLR (hazard ratio = 0.75; 95% confidence interval = 0.62-0.92; P = 0.005). In conclusion, among patients undergoing PCI with DES, obesity was not associated with TLR, but was associated with a higher risk of nonTLR. 相似文献
957.
Investigation of cell wall composition related to stem lodging resistance in wheat (Triticum aestivum L.) by FTIR spectroscopy 总被引:1,自引:0,他引:1
We explored the rapid qualitative analysis of wheat cultivars with good lodging resistances by Fourier transform infrared resonance (FTIR) spectroscopy and multivariate statistical analysis. FTIR imaging showing that wheat stem cell walls were mainly composed of cellulose, pectin, protein, and lignin. Principal components analysis (PCA) was used to eliminate multicollinearity among multiple peak absorptions. PCA revealed the developmental internodes of wheat stems could be distributed from low to high along the load of the second principal component, which was consistent with the corresponding bands of cellulose in the FTIR spectra of the cell walls. Furthermore, four distinct stem populations could also be identified by spectral features related to their corresponding mechanical properties via PCA and cluster analysis. Histochemical staining of four types of wheat stems with various abilities to resist lodging revealed that cellulose contributed more than lignin to the ability to resist lodging. These results strongly suggested that the main cell wall component responsible for these differences was cellulose. Therefore, the combination of multivariate analysis and FTIR could rapidly screen wheat cultivars with good lodging resistance. Furthermore, the application of these methods to a much wider range of cultivars of unknown mechanical properties promises to be of interest. 相似文献
958.
Zhang‐Yan Peng Tong‐Han Lan Lei Yang Hu Chao Mei Jia Hua Ping Xu Yong Jie Che Xiang Lin 《Cell biology international》2012,36(11):973-979
Ion current fluctuation of voltage‐dependent potassium channel in LβT2 cells has been investigated by autocorrelation function and DFA (detrended fluctuation analysis) methods. The calculation of the autocorrelation function exponent and DFA exponent of the sample was based on the digital signals or the 0–1 series corresponding to closing and opening of channels after routine evolution, rather than the sequence of sojourn times. The persistent character of the correlation of the time series was evident from the slow decay of the autocorrelation function. DFA exponent α was significantly greater than 0.5. The main outcome has been the demonstration of the existence of memory in this ion channel. Thus, the ion channel current fluctuation provided information about the kinetics of the channel protein. The result suggests the correlation character of the ion channel protein non‐linear kinetics indicates whether the channel is open or not. 相似文献
959.
探讨孢子丝菌病不典型的临床表现.孢子丝菌病是皮肤科常见的一种深部真菌病,典型的皮肤科特征是慢性肉芽肿、溃疡性损害、炎性结节等.而部分孢子丝菌病的患者由于各种各样的原因导致皮损丧失特征性临床表现,给皮肤科医生尤其是临床经验尚不丰富的年轻医师于该病的诊断带来了一定的困难.本文所讨论的8例患者均为就诊于我科门诊并已确诊为孢子丝菌病病例,皮损与典型的孢子丝菌病皮损表现不相符,希望皮肤科医师在以后的临床工作中遇到一些不典型皮损但是综合患者病史、生活环境、诊治过程等情况可考虑到此种疾病,及时给予明确的诊断,使患者能够得到及时、有效的治疗. 相似文献
960.
Kashin-Beck disease is an endemic osteoarthropathy in China which may lead to skeletal deformation and dwarfism. We have analysed articular cartilage from two patients and found an accumulation of the precursor molecule, pro-pN-collagen II (pN, peptide attached at the amino-terminus) which was not present in extracts of control fetal cartilage. In addition, collagen II isolated from the same tissue by limited pepsin digestion had a decreased electrophoretic mobility, increased proline hydroxylation and decreased thermal stability. Previously, a genetic defect in pro-pN-collagen-I processing has been described in calf and sheep (dermatosparaxis) and man (Ehlers-Danlos, type VII) which caused an extreme fragility of the skin [Lenaers, A., Ansay, M., Nusgens, B.V. & Lapière, C.M. (1971) Eur. J. Biochem. 23, 533-541; Helle, O. & Nes, N.J. (1972) Acta Vet. Scand. 13, 443-445; Lichtenstein, J.R., Martin, G.R., Kohn, L.D., Byers, P.H. & McKusick, V.A. (1973) Science 182, 298-300]. Accordingly, one may assume that the impaired conversion of pro-pN-collagen II to collagen II and the structural alteration of collagen II, presumably caused by fulvic acid and other environmental factors, play an important role in the pathogenesis of Kashin-Beck disease. 相似文献