除谱－多波长线性回归分光光度法测定邻硝基酚中的微量对硝基酚

提出了用除谱－多波长线性回归分光光度法测定强干扰基体中微量组分的原理和实验方法。利用本法能测出邻硝基酚中０．１７％的对硝基酚。除谱线性回归的相关系数大于０．９８６。测定误差小于２．５％，７次平行测定的标准偏差为２．２％。     

E.Dinc的双除数因子-比光谱导数法的错误性

E .Dinc等人曾提出双除数因子 比光谱导数法 ,并应用于两种三元混合体系的同时测定。实际上 ,双除数因子 比光谱导数法是完全错误的 ,它不能成功应用于三元混合体系的同时测定。文章从理论上和实践上证明了E .Dinc方法的错误性。     

反相高效液相色谱法测定尿中α-萘酚、β-萘酚、对硝基酚和间硝基酚

利用反相高效液相色谱法建立了同时检测人尿样中的α-萘酚、β-萘酚、对硝基酚和间硝基酚的新方法。采用DiamonsilTMC18（150mm×4.6mm,5μm）色谱柱分离,以V（甲醇）∶V（乙酸铵缓冲液）=58∶42为流动相,流速为0.75mL/min,柱温为35℃,于波长280nm处检测。当α-萘酚、β-萘酚、对硝基酚和间硝基酚的浓度分别在0.120—19.44、0.106—19.44、0.479—27.80μg/mL和0.439—27.80μg/mL范围内与峰面积呈良好线性关系,RSD分别为3.7%—4.3%、2.4%—3.6%、2.7%—4.9%和2.9%—3.6%（n=5）。本法用于尿中4种物质的同时测定,回收率分别为98.8%、103.8%、97.5%和105.0%,结果满意。     

CPA矩阵分光光度法同时测定三种酚

在无水乙醇介质中，对乙酰胺基酚，对氨基酚、对硝基酚三者的紫外吸收光谱相互严重重叠，用一般的光度分析手段无法同时测定。本文首次采用CPA矩阵法，不经分离直接测定了上述三组分的含量，实验结果表明：当选取216、234、260、292、312nm5个波长点作为CPA矩阵程序的最佳波长点时，该法对样品中各组分的平均回收率在100.2%－103.5%之间，结果较满意，与现行分析方法相比，本方法具有简便、快速的优点。本法已用于扑热息痛合成物中三组分含量的测定。     

5‘—硝基水杨基荧光酮双波长标准加入分光光度法同时测定？…

在０．３－０．９ｍｏｌ／Ｌ硫酸介质中，在溴化十六烷基三甲铵存在下，５’－硝基水杨基荧光酮与锗和钼形成最大吸收波长分别为５１３和５３３ｎｍ的红色配合物，其吸收光谱严重重叠。基于此，本文采用双波长标准加入法对该混合物的显色体系进行了研究，建立了同时分光光度测定锗和钼的新方法，并与等吸收双波长法作了比较。     

导数光谱在二维联用数据解析中的应用

利用导数光谱能增大组分的光谱差异，从而提高二维联用数据解析的分辨率，通过将二维数据对波长求导，以解析光谱相近的同系物体系。并将其应用于实际的间硝基苯酚与邻硝基苯酚二组分体系的解析．获得了令人满意的结果，光谱重合性好，证实该法可行。     

高效液相色谱法测定工业废水中的硝基酚

采用反相高效液相色谱法,Nucleosil(R)C18柱(250×4.6mm,5μm),以甲醇∶水=60∶40(V∶V,pH值约为3)流动相,采用紫外检测器,检测波长280nm,在室温条件下测定工业废水中硝基酚类的含量.在0.02598-0.1299 mg/mL范围内邻硝基苯酚钠浓度与峰面积线性关系良好,线性相关系数为0.9992,平均回收率为94.36%,精密度RSD为3%;在0.02573-0.1286 mg/mL范围内对硝基苯酚钠浓度与峰面积线性关系良好,线性相关系数为0.9996,平均回收率为96.54%,精密度RSD为5%;间硝基苯酚钠在0.02515-0.1257 mg/mL浓度范围内,峰面积与浓度呈现良好的线性关系,线性相关系数为97.34%,平均回收率为103.08%.此方法操作简便,适用于生产质量控制.     

5′-硝基水杨基荧光酮双波长标准加入分光光度法同时测定锗和钼

在０．３～０．９ｍｏｌ／Ｌ硫酸介质中，在溴化十六烷基三甲铵（ＣＴＭＡＢ）存在下，５′－硝基水杨基荧光酮（５′－ＮＳＦ）与锗（Ⅳ）和钼（Ⅵ）形成最大吸收波长分别为５１３和５３３ｎｍ的红色配合物，其吸收光谱严重重叠。基于此，本文采用双波长标准加入法对该混合物的显色体系进行研究，建立了同时分光光度测定锗和钼的新方法，并与等吸收双波长法作了比较。     

浓硝酸处理碳纳米管对4-硝基苯酚的吸附性能研究

本文采用浓硝酸氧化法来改性多壁碳纳米管,用Raman光谱、SEM和分光光度计对改性前后的多壁碳纳米管对4-硝基苯酚溶液的吸附能力进行了比较研究。Raman光谱和SEM分析表明浓硝酸处理使碳纳米管端口打开,管变短,并且在表面引入了羟基、羧基等酸性官能团。采用分光光度计测定溶液浓度,计算出浓硝酸处理前后多壁碳纳米管对不同浓度4-硝基苯酚的吸附效率,实验结果表明经浓硝酸处理后的多壁碳纳米管的吸附效率有较大的提高。     

邻硝基苯基荧光酮-钛-吐温-40体系分光光度研究及硅铁合金中钛的测定

系统研究邻硝基苯基荧光酮与钛的显色反应，试验多种表面活性剂对体系的作用及相应的光度性质，从而确定Ti(Ⅳ）－ONPF－Tween－40为较佳体系，在0.084-0.15mol/L HCl介质中形成紫红色配合物，其波长在530nm处的表观摩尔吸光系数ε为1.79×10^5L·mol^-1·cm^-1，配合物组成中Ti:ONPF＝1：4，钛浓度在0－1.2μg/10mL范围内服从比耳定律。应用于直接测定硅铁合金中钛，结果满意。     

Spectroscopic Investigation of the Adsorption of Nitrophenol Isomers on Ammonium Zeolite of Type “Y”

In this study, nitrophenol isomers were adsorbed on synthetic ammonium Y zeolite and the samples acquired were examined with infrared spectroscopy and scanning electron microscopy. The aim of the work is to investigate whether isomeric effects can be monitored after adsorption process. Theoretical calculations of isomers had been performed and the data acquired show that adsorption occurred via bonding from the sites of zeolite.     

对硝基酚分光光度法测定氯氮卓的含量

本文主要研究在硼砂水溶液中 ,氯氮卓与对硝基酚发生荷移反应 ,生成稳定的 1∶ 1络合物。络合物的最大吸收波长为 4 35 nm,表观摩尔吸光系数 ε=3.83× 10 3L·mol-1·cm-1。基于以上反应 ,本方法测定氯氮卓药物制剂含量与文献值基本一致 ,回收率为 99.61%— 10 0 .10 % ,相对标准偏差为 0 .64%     

Selective Etching of N‐Doped Graphene Meshes as Metal‐Free Catalyst with Tunable Kinetics,High Activity and the Origin of New Catalytic Behaviors

New N‐doped reduced graphene oxide (N‐RGO) meshes are facile fabricated by selective etching of 3–5 nm nanopores, with controllable doping of N dopants at an ultrahigh N/C ratio up to 15.6 at%, from pristine graphene oxide sheets in one‐pot hydrothermal reaction. The N‐RGO meshes are illustrated to be an efficient metal‐free catalyst toward hydrogenation of 4‐nitrophenol, with new catalytic behaviors emerging in following three aspects: (i) tunable kinetics following pseudofirst order from commonly observed pseudozero order; (ii) strikingly improved activity with 26‐fold increased rate constant (1.0 s⁻¹ g⁻¹ L); (iii) no induction time required prior to reaction due to depressed back conversion, and dramatically decreased apparent activation energy (E_a) (17 kJ mol⁻¹). The origin of these new catalytic properties can be assigned to the synergetic effects between graphitic N doping and structural defects arising from nanopores. Deeper understanding unveils that the concentration of graphitic N is inverse proportion to E_a, while the pyrrolic N has no impact on this reaction, and oxygenate groups hampers it. The porous nature allows the N‐RGO meshes to conduct catalyze reactions in continuous flow fashion.     

Minimizing electron‐hole recombination in modified TiO2 photocatalysis: electron transfer to solution as rate‐limiting step in organic compounds degradation

4‐Stilbenecarboxaldehyde (4SCA) at pH 3 was added to TiO₂ anatase to form a new catalyst where the aldehyde carbonyl group reacts with the TiO₂‐OH to form the corresponding acetal (4SCA‐TiO₂). 4SCA‐TiO₂ significantly retards the electron recombination when it is illuminated with ultraviolet B light because of the formation of a stable radical anion·^?4SCA‐TiO₂ that we have detected spectroelectrochemically. The light excited electron on the catalysis is transferred relatively slow to solution. Therefore, the electron transfer to solution is the rate‐limiting step for water‐dissolved organic compound degradation when 4SCA‐TiO₂ is used as photocatalyst. For instance, degradation rate constants using naphthalene (Naph) and p‐nitrophenol (PNP) in an ample pH range support the proposal. Accordingly, rate constants are faster when the standard redox potential of the involved electron acceptor in the solution increases. In fact, this condition can be tuned to promote reactivity. The affinity between the organics being degraded and 4SCA‐TiO₂ also influences on the degradation rate constants.     

Theoretical analysis and simulation of conjugate heights for dual-conjugate AO system in lidar

A multi-conjugate adaptive optics （MCAO） can offer a possibility of widening field of view （FOV） characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle＇s expressions of two deformable mirrors （DMs） MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.     

Quick single-photon detector with many avalanche photo diodes working on the time division

Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.     

Characterization of PolyA and PolyC mismatches by Raman spectroscopy

A.C mismatches are studied by Raman spectral characterization of PolyA, PolyC, and their equimolar complex in solution of 0.14 mol/L Na ,pH7.0.Experimental results show that A·C mismatches occur to be A/B (mainly A) conformers, and unlike Watson-Crick base pairing, this kind of mismatches is stabilized by only one hydrogen bond involving cytosine N4H2 and adenine N7.The formation of A·C complex makes the base stacking interactions much stronger, and conformation of the backbone more ordered, which leads to obvious Raman hypochromic effect with some shifts in corresponding bands.     

Improvement of four-wave mixing-based wavelength conversion efficiency in dispersion shifted fiber by 40-GHz clock pumping

40-GHz clock modulated signal as a pump to improve the efficiency of four-wave mixing (FWM)-based wavelength conversion in a 26.5-km dispersion shifted fiber (DSF) is investigated. The experimental results demonstrate that the conjugated FWM component has higher intensity with the clock pumping than that with the continuous-wave (CW) light pumping. The improvement of FWM-based wavelength conversion efficiency is negligible when the pump power is less than Brillouin threshold. But when the pump power is greater than Brillouin threshold, the improvement becomes significant and increases with the increment of pump power. The improvement can increase up to 9 dB if pump power reaches 17 dBm.     

Multi-pulse operation of a Kerr-lens mode-locked femtosecond laser

Our experimental results show that the presence of a proper amount of negative group velocity dispersion is essential to multi-pulse operation of a Kerr-lens mode-locked femtosecond laser. We demonstrate that the pulse separations and the number of pulses contained within a cavity round trip are strongly dependent on the initial perturbations. The results allow us to get a better understanding on the influences of the convoluted self-phase modulation and intra-cavity dispersions on the stable multi-pulse oscillation in a Kerr-lens mode-locked femtosecond laser.