含苯并噻唑基香豆素类铜离子探针的合成及其性能

以香豆素为母体设计合成了一个新型荧光淬灭香豆素类衍生物探针,并研究了其识别能力和结合方式等。研究发现,该探针对Cu2+具有很高选择性、灵敏性,以及较高的荧光淬灭率(达95.2%)。并且当Cu2+浓度在3×10-6~1.5×10-5mol/L范围内,该探针的荧光强度和离子浓度具有较好的线性关系。     

基于萘酰亚胺为发光团的Cu~(2+)荧光探针的合成与表征

自主合成一种以Schiff-base结构单元为识别位点的萘酰亚胺类荧光探针,该化合物结构经IR、NMR、MS以及元素分析确定。详细考查其对不同金属离子的光谱分辨能力,探针对Cu2+实现"on-off"的光开关效应,表现出较好的选择性,而其他金属离子的加入没有引起明显的光谱变化。在乙醇相中,探针对Cu2+的检出限为5.3×10-7mol/L。实验结果表明:该探针可以用于Cu2+的分析检测。     

一种新型的Cu~(2+)荧光分子探针的合成及性能研究

设计合成了一种新型的铜离子(Cu~(2+))罗丹明酰肼对二苯甲醛荧光分子探针(R)。检测了分子荧光探针对几种金属离子响应的紫外吸收光谱和荧光光谱。研究了它的光谱性能和对Cu~(2+)的识别作用,探针R加入Cu~(2+)时荧光加强,R加入Cu~(2+)之后,溶液由无色变为紫红色,探针R对Cu~(2+)具有专一的选择性。通过实验,考察和确定了荧光分子探针与Cu~(2+)响应的最佳pH和时间,在此基础上进行了定量检测,为了探究探针R和Cu~(2+)的实际配比,通过Job's plot的绘制实验方法,确定了Cu~(2+)与探针的物质的量比是1∶1,推测出了荧光探针R与Cu~(2+)络合物模型。     

反应型香豆素N_2H_4荧光探针的生物成像研究

为合成适用于生物监测的水合肼荧光探针,该文基于水合肼诱导乙酰基脱保护生成7-羟基-4-甲基香豆素的原理,设计合成一种具有高灵敏度、高选择性的水合肼荧光增强型有机分子探针。采用光谱学测试及细胞荧光成像的方法,对探针的性能进行表征。实验结果表明:在缓冲溶液中,加入N_2H_4后,探针溶液的荧光光谱在451 nm处产生一个显著的荧光增强峰(33倍),定量分析检测限为9×10-8mol/L(y=20.316 7+25.177 8x,r=0.999 6),与其他测试物相比,探针表现出对N_2H_4较高的选择性和专一性(F水合肼=787,F其他=22~24);此外,细胞内的荧光成像实验,证明该荧光探针具有潜在检测细胞内N_2H_4的能力。     

基于氨基苯酚类方酸菁的比色荧光探针制备及其在不同溶剂下检测Cu2+和Mg2+性能研究

设计并合成了一种N,N-二丁基-3-氨基苯酚方酸菁染料(ZXSQ),并通过核磁氢谱和高分辨质谱对其结构进行表征。该探针可以在乙腈为溶剂的条件下识别Cu²⁺,颜色由蓝色变为无色；探针在乙醇为溶剂的条件下识别Mg²⁺,颜色泛出强烈的红色荧光。该探针解决了在Cu²⁺和Mg²⁺同时存在下无法区别的问题，实现了双识别且抗干扰的效果。该探针检测限均在10^-6mol/L,具有合成简单、低检测限和高灵敏度等优点，操作简便，能够快速、精准地检测环境以及生物体中的Cu²⁺和Mg²⁺。     

Tb3+修饰的MOF荧光探针的制备及L-色氨酸识别性能

以金属-有机骨架材料UiO-66-(COOH)2为基底,采用后修饰法负载Tb3+制备了荧光材料Tb3+@UiO-66-(COOH)2,用于选择性检测色氨酸.利用透射电子显微镜(TEM)、X射线粉末衍射仪(XRD)、比表面积分析仪、红外光谱仪(FT-IR)、X射线光谱仪(XPS)等表征方法分析多孔材料的形貌、成分、孔道特性,利用紫外/可见分光光度计(UV-Vis)和荧光光谱仪研究材料的发光特性及氨基酸识别性能.结果表明:MOF材料中配体向Tb3+的能量转移,诱导材料发出明亮的绿色荧光.在13种氨基酸中,只有色氨酸(Trp)对Tb3+@UiO-66-(COOH)2具有明显的荧光淬灭效应,这是由于色氨酸的紫外吸收峰和Tb3+@UiO-66-(COOH)2的荧光激发光谱有较大重合,表明二者对紫外光的吸收具有竞争性,削弱了Tb3+@UiO-66-(COOH)2的紫外光吸收,从而降低了材料的发光强度.进一步发现该材料可灵敏地检测色氨酸(检测限5.53μmol/L),同时具有良好的抵抗来自其他氨基酸干扰的能力.因此,本工作证明了Tb3+@UiO-66-(COOH)2可作为选择性检测色氨酸的荧光探针,同时也为未来色氨酸荧光探针的设计提供了一定的借鉴.     

运用荧光定量PCR技术检测中肋骨条藻的研究

以rDNA序列为寻找种特异性引物的靶区域,通过分析中肋骨条藻rDNA序列,设计出7套适合用于实时荧光定量PCR方法(RFQ-PCR)的引物与探针,经引物验证,选择Primer6(F/R)进一步分析,对比扩增序列及核酸杂交验证,表明该探针可作为中肋骨条藻特异性探针.最后以Primer6(F/R)和TaqMan6建立了定量检测中肋骨条藻的RFQ-PCR方法,并绘制出了定量检测中肋骨条藻的标准曲线,测定数据用镜检计数进行了验证,证明该方法是准确可靠的.     

N掺杂石墨烯量子点的制备及在Fe~(3+)检测中的应用研究

研究了用热解柠檬酸制备发蓝光的石墨烯量子点(GQDs),并在此基础上,用(NH4)2CO3作N源,在水热条件下制备N掺杂石墨烯量子点(N-GQDs)。通过透射电子显微镜(TEM)、X射线光电子能谱仪(XPS)、傅里叶红外光谱仪(FT-IR)、紫外-可见吸收光谱仪(UV-Vis)、荧光光谱仪等对样品的结构和光学性能进行表征。此外,基于荧光淬灭原理,利用N-GQDs构建了一种检测Fe3+的荧光探针。研究表明,N-GQDs的荧光强度随Fe3+浓度的增大而降低,在0~60μmol/L范围内,N-GQDs荧光强度与Fe3+浓度有较好的线性关系,且该探针的检测限低达0.925μmol/L。     

基于萘酰亚胺为发光团的Cu2＋荧光探针的合成与表征

自主合成一种以Schiff-base结构单元为识别位点的萘酰亚胺类荧光探针,该化合物结构经IR、NMR、MS以及元素分析确定。详细考查其对不同金属离子的光谱分辨能力,探针对Cu2＋实现＂on-off＂的光开关效应,表现出较好的选择性,而其他金属离子的加入没有引起明显的光谱变化。在乙醇相中,探针对Cu2＋的检出限为5.3×10-7mol/L。实验结果表明：该探针可以用于Cu2＋的分析检测。     

识别Cu2+的中氮茚衍生物荧光探针分子的设计与合成

合成了荧光性能良好的中氮茚化合物5,用IR、1 H NMR等手段表征其结构;研究各种金属离子对其荧光性能的影响,结果表明Cu2+能显著地猝灭其荧光,而余者则几无影响;其紫外吸收峰值随着Cu2+浓度的增加而增加,表明二者存在着化学反应。此化合物有望作为重金属离子Cu2+的荧光探针。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.