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151.
Chang Xin Zhang Chengyu Gao Lan Liu Xiao You Shengping Qi Wei Wang Kang Guo Xin Su Rongxin Lu Han He Zhimin 《天津大学学报(英文版)》2019,25(5):488-496
2,5-Furandicarboxylic acid(FDCA) is a potential biorenewable chemical for applications including plastics, polyamides, drugs, etc. The selective biosynthesis of FDCA from 5-hydroxymethylfurfural(HMF) by a specific enzyme poses a great challenge. In this study, we reported an efficient strategy to produce FDCA from HMF by the tandem biocatalysis of laccase(Cot A-TJ102@UIO-66-NH_2) and Novozym 435. For the first step, a nanoparticle metal–organic framework was synthesized as a carrier to immobilize Cot A-TJ102@UIO-66-NH_2, which was assigned for the production of 5-formyl-2-furancarboxylic acid(FFCA) and featured an enzyme loading of 255.54 mg/g, specific activity of 135.90 U/mg, and solid loading ratio of 99.65%. Under optimal conditions, an ideal FFCA yield of 98.5% was achieved, and the Cot A-TJ102@UIO-66-NH_2 presented a high recycling capacity after 10 cycles. For the second step, Novozym 435 was applied for the further conversion of FFCA into FDCA, presenting a high FDCA yield of 95.5% under the optimized conditions. Novozym 435 also exhibited a high recyclability after eight cycles. As a result, the tandem biocatalysis strategy provided a 94.2% FDCA yield from HMF, indicating its excellence as a method for FDCA production. 相似文献
152.
Objective: We aim to describe the environment iodine concentration in salt, water and soil along Zhejiang Province coast in the China foreland. It will be helpful for us to judge whether this area is insufficient in iodine and universal iodized salt is necessary or not. Methods: We collected iodized salt samples, drinking water samples (tap water in the towns, and well water or spring water in the villages), water samples from different sources (ditches, lakes, rivers) and soil samples through random sampling in June, 2005. Salt, water and soil iodine was detected by arsenic-cerium redox method. Statistical analysis was expressed as mean±SEMby Windows SPSS 13.0. Results: (1) The iodine concentration in salt was 27.9±4.33 mg/kg (n=108). (2) Seventy-five water samples were collected. The water iodine value was 0.6~84.8 μg/L (mean of 11.66 μg/L). The watershed along the Qiantang River has significantly higher iodine content than the water in Lin'an in mountain area (P<0.01). The iodine content and mean iodine content of tap water, well or spring water and natural water sources were 4.30±2.43 μg/L (n=34), 23.59±27.74 μg/L (n=19)and 12.72±10.72 μg/L (n=22) respectively. This indicated that among environmental water sources, the ditch iodine content was the highest with river water iodine being the lowest (P<0.01). (3) Soil iodine value was 0.11~2.93 mg/kg (mean of 1.32 mg/kg).Though there was no statistical difference of soil iodine in different districts (P=0.131), soil iodine content correlated positively with water iodine content. Conclusion: Iodine concentration in salt accords with national policy of adding iodine in salt. Foreland has more iodine in water than mountain area. The data reflected that water and soil iodine in foreland area was not high, which suggests universal iodized salt should be necessary. Environment iodine has relatively close association with pollution. 相似文献
153.
在不考虑月经周期的情况下连续灌喂氯地酚5天,每天50mg,第8天肌注hCG2000IU,对猕猴具有一定的卵泡超数发育作用,最多可使双侧卵巢共24个卵泡发育,最大卵泡直径5—6mm,但不同个体反应变化较大。FSH hCG超排方案(考虑或不考虑月经周期,连续肌注FSH6天,共80—90IU,第8天肌注hCG2500IU)比氯地酚效果较好,最多可使双侧卵巢共28个卵泡发育,卵泡最大直径10mm,另外在1只猕猴观察到5个卵泡破裂将卵排出。电刺激采得之猕猴精子经洗涤后与用以上两种超排方案以卵泡吸得之卵子一同输入兔输卵管进行受精,获得2个原核期受精卵和1个桑椹胚。 相似文献
154.
Luísa Faria Anne-Marie Fontaine 《European Journal of Psychology of Education - EJPE》1997,12(1):51-62
This study presents the building of an instrument to measure personal conceptions of intelligence based upon Dweck research, and some exploratory evidence. The instrument is directed to adolescents, has got more items than the original one and incorporates new aspects, such as the importance of effort and ability in relation with personal conceptions of intelligence. The results of a factor analysis evidenced the existence of two distinct factors — a static and a dynamic one — that explain together 31.7% of the total variance. The internal consistency of the scales evidenced alpha coefficients between .74 and .80. The results of a test-retest reliability study (with a month interval) proved to be better for the static scale than to the the dynamic one, as well as the results of an external validity study (correlations with grade point average). Some differential exploratory studies showed differences in personal conceptions of intelligence related to school grades (5th to 11th): the scores increased from the 5th to the 11th grade, showing that older students were less “static” (more “dynamic”), and also related to the socio-economic status (high vs. low): the higher SES subjects appeared less “static” (more “dynamic”) than the lower SES subjects. 相似文献
155.
学校科研管理的有效激励机制 总被引:2,自引:0,他引:2
激励机制是现代管理实践中提高管理效能的一项重要内容。在学校科研管理工作中积极推行激励机制,是确保科研工作规范、有序、健康发展和提升科研管理效益的基本手段,也是长久激发科研人员的内在工作动力及释放其创新潜能的必要条件。 相似文献
156.
157.
158.
水电建设项目受地质、地理位置,气候等一些自然或非自然因素的影响,不可避免地存在诸多风险因素,业界相继对风险识别、风险分析以及风险评价等做了深入研究,但鲜有人概括了水电建设项目前的常用的风险评价方法。通过对水电建设项目前存在的风险评价方法进行概括,在其中提出了一种新的改进的评价方法,并比较分析了各自的适用条件以及优缺点,能为水电建设项目合理选择使用评价方法提供了有效的参考依据,进而能使风险预测与客观实际相接近。 相似文献
159.
吕雪原 《齐齐哈尔师范高等专科学校学报》2011,(3):7-8,15
马克思主义中国化的过程,就是中国化的马克思主义理论形成、发展并不断创新的过程。这两个过程是完全一致的。理论在一个国家的实现程度,总是决定于理论满足这个国家的需要的程度。文章围绕马克思主义中国化的科学内涵及其实质、马克思主义中国化的历史进程和中国化马克思主义的主要启示来加深读者对马克思主义中国化和中国化的马克思主义的理解。 相似文献
160.