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51.
本文首先运用考虑非期望产出的SBM-SupSBM模型估计我国各省市绿色技术创新效率并进行分类:稳定上升类、平稳类、大幅度波动类以及下降类。之后从企业内部和外部两方面对绿色技术创新效率提升的影响因素提出假设,着重考虑大幅度波动类别省份的效率提升。运用面板数据模型各影响因素进行验证,结论显示:企业规模对绿色技术创新效率波动较大的省份起到显著的抑制作用,环境规制和技术进步对绿色技术创新效率波动较大的省份作用不明显。针对分析结果,提出结论:在提升绿色技术创新效率的过程中,应注重企业规模和技术进步的协同作用,以及技术的开放程度。  相似文献   
52.
The single machine group scheduling problem is considered. Jobs are classified into several groups on the basis of group technology, i.e. jobs of the same group have to be processed jointly. A machine set-up time independent of the group sequence is needed between each two consecutive groups. A schedule specifies the sequence of groups and the sequence of jobs in each group. The quality of a schedule is measured by the criteriaF 1, ...,F m ordered by their relative importance. The objective is to minimize the least important criterionF m subject to the schedule being optimal with respect to the more important criterionF m–1 which is minimized on the set of schedules minimizing criterionF m–2 and so on. The most important criterion isF 1, which is minimized on the set of all feasible schedules. An approach to solve this multicriterion problem in polynomial time is presented if functionsF 1, ...,F m have special properties. The total weighted completion time and the total weighted exponential time are the examples of functionsF 1, ...,F m–1 and the maximum cost is an example of functionF m for which our approach can be applied.The research of the authors was partially supported by a KBN Grant No. 3 P 406 003 05, the Fundamental Research Fund of Belarus, Project N 60-242, and the Deutsche Forschungsgemeinschaft, Project Schema, respectively. The paper was completed while the first author was visiting the University of Melbourne.  相似文献   
53.
The electroanalytical determination of avidin in solution, in a carbon paste, and in a transgenic maize extract was performed in acidic medium at a carbon paste electrode (CPE). The oxidative voltammetric signal resulting from the presence of tyrosine and tryptophan in avidin was observed using square-wave voltammetry. The process could be used to determine avidin concentrations up to 3 fM (100 amol in 3 l drop) in solution, 700 fM (174 fmol in 250 l solution) in an avidin-modified electrode, and 174 nM in a maize seed extract. In the case of the avidin-modified CPE, several parameters were studied in order to optimize the measurements, such as electrode accumulation time, composition of the avidin-modified CPE, and the elution time of avidin. In addition, the avidin-modified electrode was used to detect biotin in solution (the detection limit was 7.6 pmol in a 6 l drop) and to detect biotin in a pharmaceutical drug after various solvent extraction procedures. Comparable studies for the detection of biotin were developed using HPLC with diode array detection (HPLC-DAD) and flow injection analysis with electrochemical detection, which allowed biotin to be detected at levels as low as 614 pM and 6.6 nM, respectively. The effects of applied potential, acetonitrile content, and flow rate of the mobile phase on the FIA-ED signal were also studied.  相似文献   
54.
低钴AB5型稀土系贮氢电极合金的研究   总被引:5,自引:0,他引:5  
为了进一步降低AB5型混合稀土系贮氢合金的成本,采用Cr,Si,Cu替代Co和调节化学计量比的方法制备低钴AB5型贮氢合金。结果表明:3种取代元素在寿命方面的效果依次为Si>Cr>Cu,在放电容量和活化性能方面依次是Cu>Cr>Si。Cr,Cu,Si只有少量的替代才可能发挥其有利影响;通过非化学计量比的调节,低钴混合稀土系贮氢电极合金的放电容量、活化性能及倍率放电能力都能较好地达到实用要求,但是循环寿命有待提高。  相似文献   
55.
Fluorescence has been the preferred choice for data quantification in biomedical microarray formats since their earliest days. As much as the formats have grown and evolved over the years, the methods in optical analysis have become ever more sophisticated and complex in order to produce more and better output. This review will provide an insight into the most common methods and the state-of-the-art of all areas in microarray fluorescence analysis. Starting with an overview on microarray formats with a focus on their demands on the readout, the most common and useful organic fluorescent stains are discussed before proceeding on to other approaches; the use of semiconductor nanocrystals (quantum dots), polymer and silica nanoparticles and fluorescent proteins. Ways to enhance the intrinsically low signal on biochips have become increasingly important as they offer a sound approach towards the detection of low concentration sample content. The three main categories are presented: amplification using DNA, enzymes, and dendrimers. As much diversity as on the microarrays themselves can be found at the detection device. Standard optical microarray detectors, and non-standard methods using fluorescence anisotropy, fluorescence lifetime imaging (FLIM) and fluorescence resonance energy transfer (FRET), and their advantages and disadvantages are discussed.  相似文献   
56.
王文昭  方唯硕 《有机化学》2007,27(12):1453-1462
综述了近8年来液相平行合成和组合合成中应用的不同技术, 包括可溶性载体、氟合成技术、离子液体、固相试剂树脂以及低聚乙烯二醇(OEG)衍生物的应用等几方面内容. 论述了它们的基本原理以及相关的应用实例, 并着重强调了目标化合物的分离纯化方法.  相似文献   
57.
As a new concept for the design of effective photocatalysts, an ion beam technology using accelerated metal ions, a metal ion implantation and an ionized cluster beam (ICB) method, have been applied to design unique photocatalysts. The metal ion implantation of TiO2 and Ti-containing zeolites with highly accelerated metal ions (V+, Cr+, etc.) is useful in designing photocatalysts that can operate efficiently under visible light irradiation. Also, an ICB method with a low acceleration energy is useful in preparing transparent TiO2 thin films on various types of substrates for the efficient photocatalytic degradation of pollutants diluted in water and air. The combination of the ICB method and metal ion implantation can develop the TiO2 thin films that are able to operate not only under UV light but also under visible light irradiation.  相似文献   
58.
金鑫  王晓英 《化学学报》2019,77(4):340-350
口腔癌系头颈部癌,癌组织均位于口腔内,其非侵入性早期诊断是减少该病死亡的有效手段.唾液系口腔癌变相关物质首先释放进入的体液,取材方便,安全无创,是口腔癌普查筛选、早期诊断的首选指标.本文对唾液肿瘤生物标志物的种类、目前国内外常用的检测方法进行概述,重点阐述新型电化学生物传感方法在口腔癌相关唾液肿瘤生物标志物检测方面的相关应用及其最新研究进展.并对口腔癌相关唾液肿瘤生物标志物电化学传感技术的未来发展方向提出展望,拟为其深入研究与应用提供参考.  相似文献   
59.
郑会勤 《化学教育》2019,40(22):82-87
以高校基础化学实验"从海带中提取碘""三草酸合铁(Ⅲ)酸钾的制备"为例,分别探讨了微视频技术在化学基本操作实验和综合设计型实验中的具体应用;此外,举例说明利用Flash软件制作的虚拟微视频可以在仪器分析实验中清晰地再现仪器真实操作中的每一个步骤,弥补了学生在实验前无法实际操作仪器的不足。实践证明,微视频技术的应用,丰富了基础化学实验教学模式,增强了学生自主学习的能力和动手能力,提高了实验成功率和实验教学效果。  相似文献   
60.
烟碱分子烙印聚合物的吸附特性   总被引:10,自引:0,他引:10  
刘莺  刘学良  王俊德 《分析化学》2003,31(10):1202-1206
利用分子烙印技术,以烟碱为烙印分子,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,合成了对烟碱具有特异性作用的分子烙印聚合物P(Nic);通过平衡吸附实验,评价了其对烟碱的亲和力和选择性。与非烙印聚合物相比,P(Nic)对烟碱表现了很高的亲和力;Scatchard分析表明在P(Nic)中存在对烟碱有不同的亲和力的两类作用位点。通过与氨基吡啶类物质在P(Nic)上的吸附行为比较,表明P(Nic)对烟碱具有很好的选择性。本工作证明了用P(Nic)作为固相萃取(SPE)材料选择性地从烟草烟雾中提取烟碱的可能性。  相似文献   
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