排序方式: 共有17条查询结果,搜索用时 15 毫秒
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以钌(Ⅱ)多吡啶配合物[Ru(bipy)2DAFND](Cl O4)2(Ru-DAFND,bipy=2,2'-联吡啶,DAFND=4,5-二氮杂芴-9-对硝基苯腙)为指示剂,采用锁相放大技术构建了基于荧光猝灭原理的光纤DNA传感器,研究了传感器的性能。以p H 7.1的Tris缓冲溶液为介质,在2.6×10-8~5.4×10-6mol/L范围,ct DNA浓度与传感器光学敏感膜的相对滞后相移(Δφ)有较好的线性关系,检出限为8.4×10-9mol/L,响应时间为70 s。通过研究溶液p H值和干扰物对传感器性能的影响,表明该传感系统具有较好的重复性和稳定性。 相似文献
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采用密度泛函(DFT)中的B3LYP方法,选择CEP-31g基组,优化并得到了MgnLa(n=2- 6)小团簇的基态平衡结构,计算出了掺杂团簇的基态结构的平均键长、对称性、费米能级、能级间隙、束缚能、总能的二阶差分.结果表明,随着团簇原子数的增加,La原子更容易趋于团簇表面位置. 与未掺杂Mg团簇相比,La原子多采用取代其稳定基态结构的一个Mg原子形成掺杂团簇的稳定结构. 从有限的结果看,其中 Mg3La和 Mg6La的结构更为稳定. 相似文献
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On the basis of the double-well ratchet potential which can be calculated theoretically and implemented experimentally, the influences of the time delay, the coupling constant, and the asymmetric parameter of the potential on the performance of a delayed feedback ratchet consisting of two Brownian particles coupled mutually with a linear elastic force are investigated. The centre-of-mass velocity of two coupled Brownian particles, the average effective diffusion coefficient, and the Pe number are calculated. It is found that the parameters are affected by not only the time delay and coupling constant but also the asymmetric parameter of the double-well ratchet potential. It is also found that the enhancement of the current may be obtained by varying the coupling constant of the system for the weak coupling case. It is expected that the results obtained here may be observed in some physical and biological systems. 相似文献
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The Onsager reciprocity relation and generalized efficiency of a thermal Brownian motor 总被引:1,自引:0,他引:1 下载免费PDF全文
Based on a general model of Brownian motors, the Onsager
coefficients and generalized efficiency of a thermal Brownian motor
are calculated analytically. It is found that the Onsager
reciprocity relation holds and the Onsager coefficients are not
affected by the kinetic energy change due to the particle's motion.
Only when the heat leak in the system is negligible can the
determinant of the Onsager matrix vanish. Moreover, the influence of
the main parameters characterizing the model on the generalized
efficiency of the Brownian motor is discussed in detail. The
characteristic curves of the generalized efficiency varying with
these parameters are presented, and the maximum generalized
efficiency and the corresponding optimum parameters are determined.
The results obtained here are of general significance. They are used
to analyze the performance characteristics of the Brownian motors
operating in the three interesting cases with zero heat leak,
zero average drift velocity or a linear response relation, so that
some important conclusions in current references are directly
included in some limit cases of the present paper. 相似文献
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A novel compound of 1,2-dis(1,3-diphenylpropan-2-yl)disulfane(C30H30S2,Mr=454.27)was synthesized in ethanol with 1,3-diphenyl-2-propanone as raw materials,giving high yield of product(90%).Its structure was determined by IR,1H NMR,MS,elemental analysis and X-ray diffraction.The crystal belongs to monoclinic,space group C2 with a=18.727(3),b=6.5179(9),c=13.7576(18),β=131.0610(10)o,V=1266.2(3)3,Z=2,Dc=2.136 g/cm3,μ=1.078 mm-1,F(000)=843,R=0.0490 and wR=0.1247 for 3211 observed reflections with I>2(I).X-ray analysis reveals that the molecule is not symmetrical.There exist no classical hydrogen bonds andπ-πstacking interactions.Moreover,the thermal stability of compound 3 was investigated. 相似文献
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《高等学校化学学报》是中华人民共和国教育部主办的化学学科综合性学术期刊 除重点报道我国高等学校师生基础研究和应用研究方面具有创造性的研究成果外 还积极报道中国科学院及其他研究机构所属研究人员的最新成果。 栏目设置 .学术论文报道学术水平高社会效益或经济效益大并具有创新性的研究成果。全文 《高等学校化学学报》2000,21(4):534
《高等学校化学学报》是中华人民共和国教育部主办的化学学科综合性学术期刊,除重点报道我国高等学校师生基础研究和应用研究方面具有创造性的研究成果外,还积极报道中国科学院及其他研究机构所属研究人员的最新成果。1 栏目设置1.1 学术论文 报道学术水平高、社会效益或经济效益大并具有创新性的研究成果。全文(包括图、表、参考文献、中英文摘要及关键词等)一般在6000字左右。1.2 研究快报 及时报道重要研究领域和学科发展前沿的领先成果(来稿时请附发表快报理由,刊登后仍可发表论文),全文限3000字以内,不列中文摘要,英文摘要内容应… 相似文献
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为提高化学镀Ni-W-P镀层的耐蚀性和耐磨性,拓宽其应用,采用电化学方法和热处理等手段,研究了镀液中添加剂硝酸铈(Ce(NO3)3)的质量分数和热处理对化学镀Ni-W-P镀层的沉积速度、孔隙率、失重腐蚀速度、腐蚀电位、腐蚀电流、交流阻抗、显微硬度、摩擦系数等性能的影响。结果表明:添加1.0 wt%Ce(NO3)3时,所得镀层的沉积速度最大(36.5 g/m2·h),孔隙率最低(0.8个/cm2),耐腐蚀性能最好。镀层的组织均匀、致密、无缺陷和非晶态结构是其耐蚀性能高的重要原因。100~600℃热处理后,镀层硬度和耐磨性有所提高,而400℃热处理之后,合金显微硬度高达1100 HV,是镀态的1.8倍。 相似文献