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81.
利用电感耦合等离子体-原子发射光谱法(ICP-AES)测定滇龙胆中重金属元素Cd和Pb,比较了干灰化法和湿化法2种样品处理方法对分析结果的影响,并测定了云南一些地区滇龙胆中的Cd和Pb含量。结果表明:采用电感耦合等离子体原子发射光谱法检测滇龙胆中的Cd和Pb,最低检出限(DL)分别为1.43ng·mL-1和1.16ng·mL-1;相对标准偏差(RSD)分别为4.37%和4.05%;回收率分别为96.25%和92.25%。利用湿法消解样品,精密度好,回收率高,优于干灰化法。干灰化法适合测定滇龙胆中Pb,但不适合测定Cd,其回收率仅为0.2%。用湿法消解样品,测定不同产地滇龙胆的Cd和Pb含量,结果表明:所测地区滇龙胆的Cd,Pb含量大大低于《中华人民共和国药典》(2005)规定的中药材重金属含量标准,符合GAP生产的要求。  相似文献   
82.
李利华 《光谱实验室》2010,27(5):1792-1795
用火焰原子吸收光谱法同时测定鱼腥草根部和叶子中Fe、Cu、Zn、Mn、Ca、Mg、Na和K8种微量元素的含量。方法的相对标准偏差为(RSD)1.16%,回收率为95.0%—110.0%。结果表明,鱼腥草根部和叶子中Fe、Mn、Ca、Mg、K、Na和Zn等人体必需的生命元素含量较高,各元素的含量均有差异。本试验为鱼腥草的进一步研究和综合开发利用提供了新的科学依据。  相似文献   
83.
分析经典选择重传自动请求重传(automatic repeat-request,ARQ)协议之后,利用量子力学中纠缠态的非定域关联性,提出了数据链路层的选择重传ARQ量子同步通信协议.该协议把链路分为准备阶段和发送阶段.在线路准备阶段完成EPR (Einstein-Podolsky-Rosen)关联对的分发,建立量子信道;在发送阶段完成数据帧和量子确认帧的传送.从吞吐量和信道利用率等方面比较分析了几种常见的数据链路层通信协议的性能.研究表明,该协议可以有效地提高数据链路层的最大吞吐量和信道利用率,改善选择重传ARQ协议的性能,在受时间瓶颈限制的通信中有着重要的应用价值.  相似文献   
84.
Lifetimes of high spin states in 129Cs axe measured using the Doppler shift attenuation method. The high spin states of 129 Cs axe populated following the fusion evaporation reaction 124 Sn(UB, 6n)129 Cs at a beam energy of 65 MeV. The reduced transition probabilities B(E2) and the transition quadrupole moments Qt in the negativeand positive-paxity bands are deduced. The experimental results indicate that the Qt values of the negative parity band are smaller than those of the positive parity bands, probably due to different γ-deformation driving effects of different proton orbitals. The Qt values exhibit a considerable increase near the band crossing region in these bands. This behavior demonstrates that nuclear shape changing results from the neutron or proton alignments. The signature splitting of the πh11/2 and πg7/2 bands shows the opposite changing trend after backbending due to the h11~2 neutron and h11/2 proton alignments, respectively.  相似文献   
85.
A surfactant ion-pair complex, [Ru(bpy)(2)L][Eu(NTA)(4)](2) (in which L = 1-docosyl-2-(2- pyridyl)benzimidazole, bpy = 2,2'-bipyridine, and NTA = 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedionato) has been synthesized. The surface pressure-area isotherm measurements show that the complex forms a stable Langmuir film at the air-water interface without adding any electrolytes into the subphase. The monolayers formed at the surface pressures of 5 mN m(-1) and 20 mN m(-1), have been successfully transferred onto glass and quartz substrates with the transfer ratios close to unity. The Langmuir-Blodgett films were studied by UV-visible, infrared, and emission spectroscopies, atomic force microscopy, and cyclic voltammetry. The optical, redox, and morphology properties of the LB films were found to be significantly affected by the target surface pressures used for the film depositions.  相似文献   
86.
Two quantum secure direct communication (QSDC) protocols with quantum identification (QI) based on passive optical network (PON) architecture are proposed. One QSDC protocol can be implemented between two different optical network units just with simple configurations of PON by optical line terminal when they are in the same virtual private network after optical line terminal performing QI to the optical network units in the given PON architecture. The other QSDC protocol is also implemented between any two legitimated users in the virtual private network but with considerable reduction of workload of the optical line terminal. The security analysis shows that the proposed QSDC schemes with quantum identification are unconditionally secure and allow the legitimate users to exchange their secret information efficiently and to realize a quantum virtual private network in the PON networks ultimately.  相似文献   
87.
建立了气相色谱串联质谱(GC-MS)准确、快速测定香精香料中仲丁醇、富马酸二甲酯、咪唑和芝麻酚的分析方法.样品经甲醇超声提取15min后,通过Agilent DB-WAX(0.25mm×30m×0.25μm)色谱柱分离,质谱进行定性,外标法对于4种目标物质进行定量分析.实验结果表明,在0.5-20mg/L的范围内,4种物质具有较好的线性,各待测物质的线性相关系数均大于0.9990,检出限为0.02-0.12mg/L,在1,5mg/L和10mg/L 3个加标水平条件下,4种禁限用物质的平均回收率为88.0%-113.1%,相对标准偏差为0.32%-6.53%.该方法前处理简单,灵敏度高,线性相关性好,重复性佳,可以满足香精香料中4种物质的同时检测.  相似文献   
88.
喻利花  马冰洋  曹峻  许俊华 《物理学报》2013,62(7):76202-076202
通过非平衡磁控溅射的方法制备了不同V含量的(Zr,V)N复合薄膜, 采用EDS, XRD, XPS, 纳米压痕仪和摩擦磨损仪等对薄膜的化学成分、微结构、力学性能及摩擦性能进行了研究. 结果表明, V的加入虽未改变ZrN的fcc晶体结构, 但使薄膜的择优取向由ZrN的(200)面转变为(Zr,V)N的(111)面. 随着V含量增加, (Zr,V)N复合膜的硬度略有升高后缓慢降低, 并在含25.8 at.%V后迅速降低. 与此同时, 薄膜的常温摩擦系数亦有小幅降低. 高温摩擦研究表明, (Zr,V)N薄膜在300 ℃时出现V2O3, V2O5 在500 ℃后形成, 其含量也随温度的提高而增加. 薄膜的摩擦系数因V2O5 的形成而得到显著降低. 关键词: (Zr,V)N 薄膜 微结构 力学性能 摩擦性能  相似文献   
89.
Recently, individual reduced-symmetry metal nanostructures and their plasmonic properties have been studied extensively. However, little attention has been paid to the approach to fabricating ordered reduced-symmetry metal nanostructure arrays. In this paper, a novel perforated silver nanocap array with high surface-enhanced Raman scattering (SERS) activity and fluorescence suppression is reported. The array is fabricated by electron beam evaporating Ag onto the perforated barrier layer side of a hard anodization (HA) anodic aluminum oxide (AAO) template. The morphology and optical property of the perforated silver nanocap array are characterized by an atomic force microscope (AFM), a scanning electron microscope (SEM), and absorption spectra. The results of SERS measurements reveal that the perforated silver nanocap array offers high SERS activity and fluorescence suppression compared with an imperforated silver nanocap array.  相似文献   
90.
Abstract

The interaction of pioglitazone hydrochloride bound to tryptophan residues and tyrosine residues in bovine transferrin was investigated using synchronous fluorescence spectroscopy at various temperatures (298, 310, and 318?K). From binding constants and thermodynamic parameters, it was shown that 1:1 stable compound was formed by the electrostatic force interaction of pioglitazone hydrochloride bound to tryptophan residues and tyrosine residues in bovine transferrin. The extent of binding between pioglitazone hydrochloride and tryptophan residues in bovine transferrin was more than that between pioglitazone hydrochloride and tyrosine residues in bovine transferrin. At 310?K, the fluorescence quenching ratio number of tyrosine residues and tryptophan residues in bovine transferrin were 47.52% and 54.19%, respectively, which indicated that the fluorescence contribution of tryptophan residues was greater. At 310?K, pioglitazone hydrochloride-tyrosine residues(in bovine transferrin) binding rate were 55.60–73.82%, and the combined model was W?=??0.0315R2???0.1520R?+?0.7385. The value of Hill’s coefficients was greater than 1, which suggested that there was a positive cooperativity between pioglitazone hydrochloride and subsequent ligands. The results of molecular docking were consistent with that of experimental calculation.  相似文献   
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