全文获取类型
收费全文 | 222篇 |
免费 | 6篇 |
国内免费 | 13篇 |
专业分类
电工技术 | 1篇 |
综合类 | 14篇 |
化学工业 | 72篇 |
金属工艺 | 20篇 |
机械仪表 | 7篇 |
建筑科学 | 7篇 |
矿业工程 | 1篇 |
能源动力 | 2篇 |
轻工业 | 3篇 |
水利工程 | 2篇 |
武器工业 | 1篇 |
无线电 | 32篇 |
一般工业技术 | 71篇 |
冶金工业 | 4篇 |
自动化技术 | 4篇 |
出版年
2021年 | 2篇 |
2020年 | 7篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 6篇 |
2016年 | 7篇 |
2015年 | 6篇 |
2014年 | 9篇 |
2013年 | 10篇 |
2012年 | 14篇 |
2011年 | 24篇 |
2010年 | 28篇 |
2009年 | 25篇 |
2008年 | 18篇 |
2007年 | 30篇 |
2006年 | 20篇 |
2005年 | 14篇 |
2004年 | 9篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1994年 | 1篇 |
排序方式: 共有241条查询结果,搜索用时 0 毫秒
81.
烟草感染赤星病后有关酶动态的研究 总被引:8,自引:0,他引:8
本文研究11个烟草品种感染赤星病后过氧化物酶(POD)同工酶、多酚氧化酶(PPO)、硝酸还原酶(NR)和抗坏血酸氧化酶(AAO)活性的变化规律。结果表明:抗赤星病强的品种,PPO在接种36h内活性升高,以后下降;POD同工酶活性变幅大而快,接种初期活性稍有下降,然后增强,其中以阴极端2、4同工酶带增加较快,接种180h后就由弱酶带变为强带;NR活性变化不大;AAO活性提高。抗赤星病弱的品种,PPO活性低于对照;POD同工酶变化不大,呈下降趋势;NR活性变幅大;抗坏血酸氧化酶在接种初期活性下降,84h后回升。 相似文献
82.
采用阳极氧化铝箔的方法制备了孔径分布均匀的阳极氧化铝(AAO)模板,然后通过激光分子束外延(LMBE)的方法在这些孔洞里生长有序铁纳米阵列,根据控制生长的条件,生长出纳米线、纳米管,以及高度有序的量子点阵列,甚至得到纳米复制的新的复形模板.实验发现,虽然LMBE系统本身的高度可控性是这些不同类型的有序纳米阵列的前提,但不同材料在模板纳米孔洞里的不同生长趋向以及生长模式是探索可控生长的决定因素.这些可控参数的深入探讨为纳米阵列材料在微器件和纳米复制领域将有更直接的实际意义. 相似文献
83.
Guojun SONG Dong CHEN Zhi PENG Xilin SHE Jianjiang LI Ping HAN Institute of Polymer Materials Qingdao University Qingdao China 《材料科学技术学报》2007,(3)
Ni nanowires were prepared by electrodeposition in porous anodized aluminum oxide (AAO) template from a composite electrolyte solution. Well-ordered Ni nanowire arrays with controllable length were then made by the partial removal of AAO using a mixture of phosphoric acid and chromic acid (6 wt pct H3PO4: 1.8 wt pct H3CrO4). The images of Ni nanowire arrays were studied by scanning electron microscopy (SEM) to determine the relationship between etching time and the length of Ni nanowire arrays. The results indicate that the length of nanowires exposed from the template can be accurately controlled by controlling etching time. 相似文献
84.
85.
Min Zou Hengyu Wang P.R. Larson K.L. Hobbs M.B. Johnson O.K. Awitor 《Tribology Letters》2006,24(2):137-142
Surface nano-patterning with Ni nanodot arrays was investigated for adhesion and friction reduction of contacting interfaces. Self-assembled anodized aluminum oxide (AAO) templates in conjunction with thermal evaporation was used to fabricate nano-patterned surfaces with ordered Ni nanodot arrays on Si substrates. Surface morphology of the Ni nanodot-patterned surfaces (NDPSs) was characterized by scanning electron microscopy (SEM). Adhesion and friction studies on a Ni NDPS and a baseline smooth Si(100) surface were conducted using a TriboIndenter employing a diamond tip with 100 μm nominal radius of curvature. The results show that the ordered Ni nanodot-patterning reduced the adhesion forces and coefficients of friction up to 92 and 83%, respectively, compared to those of the smooth silicon surface. Surprisingly, the nanoscale multi-asperity contact between the diamond tip and inhomogeneous Ni NDPSs under low loads follows a continuum contact mechanics model. 相似文献
86.
Highly ordered ZnO nanowire arrays were fabricated by paired cell method into nanoporous anodic alumina oxide (AAO) template. ZnO nanowires were uniformly assembled into the ordered channels of the AAO template. TEM and selected-area electron diffraction patterns indicated that the ZnO nanowires grow as a single crystal. The factors influencing the final filled density of ZnO nanowires, including the solution concentration and the diffusing temperature are discussed briefly. In addition, the possible mechanism is also proposed to account for the growth of the ZnO nanowires in the AAO template. This result has established that this paired cell method makes it possible to grow single-crystalline ZnO nanowires in the AAO template under appropriate conditions. 相似文献
87.
采用简单的溶胶凝胶阳极氧化铝模板法制备了ITO纳米管.通过FE-SEM、HRTEM、XRD对其微观形貌、结构、相组成等进行了表征和分析,并测试了其对H_2的气敏特性.结果表明,所得纳米管是由10~20 nm晶粒组成的多晶结构,壁厚约为25 nm,平均直径约250 nm,与AAO (Anodic Aluminum Oxide)模板的直径相同.产物在550 ℃热处理后为立方铁锰矿结构的In_2O_3,Sn~(4+)已经掺杂到In_2O_3的晶格中.所得ITO纳米管常温下对氢气具有较好的敏感性及稳定性. 相似文献
88.
89.
Fe磁性纳米线阵列的制备与微波吸收性能研究 总被引:7,自引:0,他引:7
采用脉冲和直流电沉积方式,以FeSO4,(NH4)2SO4等混合溶液为电解液,在多孔阳极氧化铝模板(AAO模板)微孔内成功制备出Fe磁性纳米线阵列。用X射线衍射仪、扫描电镜及HP8510B网络分析仪对多孔AAO模板以及Fe磁性纳米线阵列的微观形貌、组织结构及微波吸收性能进行了测试。结果表明,沉积的纳米线为立方结构α=Fe,且纳米线阵列存在(110)择优取向性。Fe纳米线组装后的铝基AAO模板吸波材料具有良好的微波吸收效果,在2GHz~18GHz频段内的最大反射率为-4.8dB,大于-1dB的吸收带宽约为10GHz。 相似文献
90.
P. C. Stair C. Marshall G. Xiong H. Feng M. J. Pellin J. W. Elam L. Curtiss L. Iton H. Kung M. Kung H.-H. Wang 《Topics in Catalysis》2006,39(3-4):181-186
Nanostructured membrane structures have been fabricated by a combination of anodic aluminum oxidation (AAO) and atomic layer
deposition (ALD) for use as platforms for the synthesis of highly uniform heterogeneous catalysts. The ALD method makes it
possible to control pore diameters on the Angstrom scale even when the overall pore diameter is 10’s to 100’s of nanometers.
AAO membranes imbedded in an aluminum sealing ring have been tested for flow properties and found to follow Knudsen diffusion
behavior. Vanadia-coated membranes have been tested for the catalytic oxidative dehydrogenation of cyclohexane and show improved
selectivity at the same conversion compared to conventional powdered alumina supported vanadia catalysts. 相似文献