首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   18篇
  免费   3篇
  国内免费   3篇
化学   17篇
物理学   7篇
  2022年   1篇
  2019年   2篇
  2016年   2篇
  2014年   4篇
  2012年   3篇
  2009年   1篇
  2006年   1篇
  2003年   1篇
  2002年   1篇
  2000年   3篇
  1995年   1篇
  1994年   1篇
  1991年   1篇
  1988年   1篇
  1983年   1篇
排序方式: 共有24条查询结果,搜索用时 15 毫秒
1.
基于棉涤线进样通道、过滤区、检测区和"开关元件",研制了一种新型3D纸基微流控分析器件,并应用于食盐中IO-3的测定。实验探讨并优化了该器件的制备和测定条件。在优化的测定条件下,显色测定灰度值与IO-3浓度在5~250μmol/L范围内呈线性关系,检出限为2.3μmol/L。该方法可应用于实际样品中IO-3的测定。  相似文献   
2.
液体光声池的结构性能研究   总被引:1,自引:0,他引:1  
  相似文献   
3.
建立了散射背景下测定人体血清中Zn^2+含量的激光热透镜光谱分析方法。比较了蛋白质微粒散射对于分光光度法和激光热透镜光谱分析法测定的影响。结果表明,激光热透镜光谱分析方法能够避免溶液中存留蛋白质微粒散射的影响。Zn^2+量在0~1.6μg/mL范围内呈线性关系(r=0.9986),检出限为1ng/mL。应用于人体血清中Zn^2+含量的测定,与原子吸收法测定结果基本一致。  相似文献   
4.
周健  闫宏涛 《分析试验室》1994,13(4):19-20,26
以耐尔蓝为显色剂,采用分光光度法进行铵的测定。选择了NaOH碱解蒸馏分离氨的条件,探讨了表面活性剂OP,SDS增敏增溶作用,分别测定了雨水,土壤,绿叶中铵含量,结果满意。  相似文献   
5.
By partially doping Pb to effectively suppress the superstructure in single-layered cuprate Bi_2Sr_2CuO_(6+δ)(Pb-Bi2201) and annealing them in vacuum or in high pressure oxygen atmosphere, a series of high quality Pb-Bi2201 single crystals are obtained with T_c covering from 17 K to non-superconducting in the overdoped region. High resolution angle resolved photoemission spectroscopy measurements are carried out on these samples to investigate the evolution of the Fermi surface topology with doping in the normal state. Clear and complete Fermi surfaces are observed and quantitatively analyzed in all of these overdoped Pb-Bi2201 samples. A Lifshitz transition from holelike Fermi surface to electron-like Fermi surface with increasing doping is observed at a doping level of ~0.35. This transition coincides with the change that the sample undergoes superconducting-to-non-superconducting states.Our results reveal the emergence of an electron-like Fermi surface and the existence of a Lifshitz transition in heavily overdoped Bi2201 samples. This provides important information in understanding the connection between the disappearance of superconductivity and the Lifshitz transition in the overdoped region.  相似文献   
6.
以钛酸四丁酯为原料,采用溶胶-微波法(Sol-Microwave Method)合成了镧和铈共掺型纳米TiO2粉体(La-Ce-TiO2),借助XRD、XPS和UV-Vis等测试手段对其进行了表征,并以甲基橙为模型污染物考察了掺杂量对样品光催化活性的影响规律.XRD分析表明,所得粉体均为锐钛矿相纳米TiO2,且稀土元素镧和铈掺杂后纳米TiO2特征衍射峰宽化,强度降低;XPS分析表明,镧和铈掺杂后样品表面存在大量的氧缺位;UV-Vis吸收光谱表明,所得粉体在400 nm以下均有连续宽化的吸收带,且La和Ce掺杂后样品对光的吸收显著增强,这足由于La(Ⅲ)-O荷移跃迁以及Ce(Ⅳ)f→d跃迁和Ce(Ⅳ)-O荷移跃迁所致;光催化实验表明,La和Ce共掺杂能显著提高纳米TiO2的光催化活性,其中当La(Ⅲ)和Ce(Ⅳ)掺杂量分别为2%和0.04%时,纳米TiO2光催化剂具有较高的催化活性,自然光照射下光催化氧化处理卷烟厂蒸叶车间废水,效果较好,废水COD去除率达到86.11%.  相似文献   
7.
以棉涤线作为分离载体,采用自制的微流控通道装置,研究并建立了一种新型棉涤线微流控通道分离方法。探讨了进样方式、微流控通道长度、微流控通道倾斜度以及展开剂对混合染料分离的影响。在优化条件下,方法应用于孔雀石绿和罗丹明B混合染料的分离,各组分色段清晰。表明棉涤线作为新的分离载体对混合物进行分离,操作简便,对分离环境要求低,具有一定的应用价值。  相似文献   
8.
Hongtao Yan 《中国物理 B》2022,31(8):87401-087401
The pseudogap state is one of the most enigmatic characteristics in the anomalous normal state properties of the high temperature cuprate superconductors. A central issue is to reveal whether there is a symmetry breaking and which symmetries are broken across the pseudogap transition. By performing high resolution laser-based angle-resolved photoemission measurements on the optimally-doped Bi2Sr1.6La0.4CuO6+δ superconductor, we report the observations of the particle-hole symmetry conservation in both the superconducting state and the pseudogap state along the entire Fermi surface. These results provide key insights in understanding the nature of the pseudogap and its relation with high temperature superconductivity.  相似文献   
9.
采用水热法制备了CdTe量子点(QDs),并采用静电层层自组装技术成功制备了CdTe QDs聚二烯丙基二甲基氯化铵(PDDA)固化多层膜,建立了该固化多层膜测定抗凝药物华法林(Warfarin,WF)的荧光分析新方法。结果表明,在0.1~10μmol/L范围内,相对荧光强度(F/F0)与华法林浓度(cWF)呈线性关系,相关系数(R2)和检出限(3σ/k)分别为0.9886和0.082μmol/L。该CdTe QDs/PDDA固化多层膜稳定性好、易储存、使用方便,可用于药物片剂中华法林含量的测定。  相似文献   
10.
High resolution laser-based angle-resolved photoemission measurements are carried out on an overdoped superconductor Bi_2Sr_2CaCu_2O_(8+)with a_(c )of 75 K.Two Fermi surface sheets caused by bilayer splitting are clearly identified with rather different doping levels:the bonding sheet corresponds to a doping level of 0.14,which is slightly underdoped while the antibonding sheet has a doping of 0.27 that is heavily overdoped,giving an overall doping level of 0.20 for the sample.Different superconducting gap sizes on the two Fermi surface sheets are revealed.The superconducting gap on the antibonding Fermi surface sheet follows a standard d-wave form while it deviates from the standard d-wave form for the bonding Fermi surface sheet.The maximum gap difference between the two Fermi surface sheets near the antinodal region is~2 meV.These observations provide important information for studying the relationship between the Fermi surface topology and superconductivity,and the layer-dependent superconductivity in high temperature cuprate superconductors.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号