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1.
今年是吉林大学徐如人教授和庞文琴教授执教六十年暨八十华诞.本期<高等学校化学学报>作为特刊,收集了来自徐如人教授和庞文琴教授的学生以及一些同事和合作者的60篇学术论文以及二位德高望重的教授在不同年代的一些工作和生活的照片.这些论文和照片分别以不同的视野和角度记载和诠释了先生们的学术足迹和风貌,也展示了他们过去60年在无机化学教学与科研的辛勤耕耘和杰出贡献.  相似文献   

2.
潘传智 《大学化学》1988,3(1):14-16
本文提出将状态性质的加和性分为三种:部分加和性、组分加和性和基因加和性。这样分类后,容量性质和强度性质的区别与联系更加清晰。凡容量性质必定具有部分加和性,而强度性质必定没有部分加和性。因此,用有无部分加和性来区分状态性质为容量性质和强度性质是最确切的,不易引起误解。部分加和性就是通常说“容量性质在一定条件下有加和性”的那种加和性。  相似文献   

3.
结晶高聚物的结晶度与密度有密切关系,体积结晶度和重量结晶度与聚合物的非晶密度、结晶密度和实际密度之间都存在对应的关系,在一般的教学中,都是利用密度加和性和比容加和性来推导这2个关系公式的,本文以更加简洁易懂的体积加和性和重量加和性非常简单地推导出了这2个关系公式,便于学生掌握和理解。  相似文献   

4.
探讨了使用微波灰化技术消化原油和成品油样品,并使用氢化物发生-原子荧光光谱法测定其中铅和砷的含量.研究了铅测定的灰化保护剂和砷测定的灰化助剂,并优化了仪器工作条件和实验条件.该方法测定原油和重油中铅的平均回收率分别为96.8%和96.7%,相对标准偏差分别为1.03%和0.93%;测定原油和重油中砷的平均回收率分别为90.0%和90.3%,相对标准偏差分别为2.39%和2.63%.  相似文献   

5.
研究了加入镧或钇和不加镧钇的QBel.9合金性能差别。采用相同的加工工艺加工的含镧和钇和QBel.9和不含镧和钇的QBel.9合金的样品,然后观察和检测三种合金的质量和性能。  相似文献   

6.
红外光谱与核磁共振波谱在甲壳素结构研究中的应用   总被引:13,自引:0,他引:13  
本文综述了红外光谱和核磁共振波谱在甲壳素和壳聚糖的乙酰度、衍生物的取代位置和取代度、晶体结构和结晶度以及构型和构象、与离子和其他分子间的相互作用等研究领域的应用状况,引用文献61篇。  相似文献   

7.
中药指纹图谱学体系在中药创制中的作用   总被引:3,自引:0,他引:3  
孙国祥  毕开顺 《色谱》2008,26(2):172-179
从整体论、系统论和复杂科学的角度论述了中药指纹图谱学体系的构成背景和核心任务。中药指纹图谱学体系具有体系科学性质,是从系统性和整体性角度研究中药(包括植物药)的物质基础和作用机制以及药代动力学规律和相关制剂技术的崭新学科。该体系以中药指纹图谱信息学为核心和桥梁,包括中药指纹图谱测试学、中药指纹图谱质控学、中药指纹图谱谱效学、中药指纹药物动力学、中药指纹药剂学和中药生物指纹图谱学。该体系的研究需采用复杂科学和体系科学的理论和方法,突破线性思维和还原分析,强调宏观和系统的有机综合,应用数学科学原理和方法来开辟中药创制的新模式。中药指纹图谱学的理论体系和方法是解析中药的主导技术和实现中药现代化的核心力量,该体系理论和技术的成熟及完善可为现代中药创制提供强有力的理论和技术支撑。中药指纹图谱学体系的最终目的是为人类和有益生物研制出疗效显著、安全、可控的现代化中药。  相似文献   

8.
通过荧光光谱法和紫外吸收光谱法研究了超氧化物歧化酶和茉莉酸甲酯之间的相互作用。经过荧光光谱法的研究表明,超氧化物歧化酶和茉莉酸甲酯的相互作用是一个静态猝灭的过程,它们之间是以氢键和范德华力结合的,同时得到超氧化物歧化酶和茉莉酸甲酯的结合位点数n,表观结合常数K和热力学参数ΔH,ΔG,ΔS。而根据非放射性能量转移的F rster理论和同步荧光光谱证明茉莉酸甲酯和超氧化物歧化酶的相互作用位点同时接近超氧化物歧化酶色氨酸(Trp)和酪氨酸(Tyr)残基。  相似文献   

9.
吕继涛  张淑贞 《化学进展》2012,(12):2374-2383
随着纳米科技的发展和纳米材料的广泛应用,进入环境中的纳米材料必将随之增加。由于纳米材料可能对生态环境和人体健康带来潜在的危害,了解环境中纳米材料的浓度水平和行为有助于正确认识和评价纳米材料的环境风险,并做出相应的防治对策。然而,纳米材料所具有的诸多特殊性质直接影响它们的环境行为和生态毒性,因此,环境中纳米材料的分析不仅包括浓度的定量测定,还包括对其组成、粒径和表面电荷等性质的表征,是一项具有挑战性的工作。本文综述了近年来关于环境纳米材料分离、表征及检测的相关手段和方法,重点包括场流分离、色谱分离和电泳分离在纳米材料分离以及显微和谱学技术在纳米材料分析中的应用;提出了一些思考和展望,希望能够增进对环境中纳米材料分离和分析方法的了解,有助于纳米材料环境分析方法的建立和推动纳米材料环境行为和生态毒理研究的进一步规范。  相似文献   

10.
异鼠李素(IS)和芦丁(RU)是沙棘中存在的两种黄酮类化合物,具有很强的抗氧化活性,能有效清除体内的自由基。由于其在沙棘原料中含量低,还原性强,其标准品的制备和提纯难度较大。该研究采用乙醇溶解和高压液相制备相结合的方法制备了高纯度的IS和RU,并通过红外光谱、紫外光谱、质谱和核磁共振C/H谱进一步鉴定其化学结构。采用典型高效液相色谱法对获得的IS和RU产品的均一性(瓶内和瓶内)和稳定性(长期:6个月,-20 ℃;短期:1周,4 ℃和-20 ℃)进行验证。统计分析数据表明,IS和RU产品具有良好的均匀性和稳定性。采用多家实验室(n = 8)联合定值方式确定所制备的IS和RU标准物质的纯度分别为99.16%和99.22%,扩展不确定度分别为0.14%和0.13%。该研究获得的IS和RU标准物质可作参考物质用于药物分析或沙棘类产品的质量评价,具有良好的应用前景。该研究为沙棘中IS和RU标准物质的制备和质量验证提供了有效的方法,可推广应用于其他标准物质的制备过程。  相似文献   

11.
We propose a unique soft actuator—a paper actuator—based on carbon-nanotube-composite paper (CNT-composite paper), which is a composite of carbon nanotubes (CNTs) and paper. CNT-composite paper has highly efficient properties because of the contained CNTs, such as high electrical conductivity and semiconducting properties. We are considering using CNT-composite paper for various devices. In this study, we successfully developed a paper actuator. We determined the structure of the paper actuator by referencing that of bucky-gel actuators. The actuator operates using the force generated by the movement of ions. In addition to making the paper actuator, we also attempted to improve its performance, using pressure as an index and an electronic scale to measure the pressure. We investigated the optimal dispersant for use in paper actuators, expecting the residual dispersant on the CNT-composite paper to affect the performance differently depending on the type of dispersant. Referring to research on bucky-gel actuators, we also found that the addition of carbon powder to the electrode layers is effective in improving the pressure for paper actuators. We believe that the paper actuator could be used in various situations due to its ease of processing.  相似文献   

12.
The improvement in the tensile strength and water repellency of paper after treatment with a 2-propanol solution of a methyltrimethoxysilane (MTMS) oligomer was studied using filter paper. Titanium butoxide introduced in the solution as a catalyst effectively reacted with the MTMS oligomer, and a Si–O–Ti bond was generated inside the paper. The tensile strength of the paper was remarkably improved by this treatment of impregnation and polymerization of the MTMS oligomer. It was speculated that the reaction proceeded by consuming water that existed among the cellulose fibers by hydrogen bonding, because there was little difference in the tensile strength between the paper treated in air and the paper treated in a dry box. The methoxy groups in the MTMS oligomer demonstrated their good ability of making a three-dimensional network, and at the same time, the methyl groups in the oligomer showed their excellent water repellency. As a result, the treated paper had a good tensile strength even under wet conditions.  相似文献   

13.
During natural ageing, paper undergoes colour changes and becomes brittle. It is mainly due to the degradation of cellulose, the main component of paper fibres. From the viewpoint of conservation/protection of paper-based information carriers, as well as of the utilisation of secondary fibres, knowledge of the impact of a decrease of the degree of polymerisation (DP) of cellulose on mechanical properties of paper becomes of key importance. In this paper, correlations between the decrease of DP of cellulose and the loss of paper folding endurance (FE) using three model samples (pure cellulose, groundwood pulp paper, and degraded groundwood pulp paper) at accelerated ageing were investigated. The existence of such correlations between DP and FE is supported by experimental results; the correlations are linear for pure cellulose and groundwood pulp paper ageing, while exponential correlation was observed in case of degraded groundwood pulp paper. The results indicate that the rate of paper degradation can be evaluated by means of the rate of glycosidic bonds breaking in cellulosic polymer chains both for cellulose and groundwood pulp paper.  相似文献   

14.
The review summarizes the use of ligninolytic enzymes in bleaching processes in paper industries. The awareness of society regarding pollution problems demands an effort to develop novel and less polluting processes for paper production. In this regard, there is an emerging interest in various applications of microbes and enzymes. Previously, appropriate enzymes were unavailable, apart from partial use in modification of starch for application in paper coatings. Continued exploration has led to the improvement in enzymes that offer remarkable profits to paper industries.  相似文献   

15.
Biodeterioration phenomena represent a complex of physical and chemical alteration processes in various materials, such as those constituting the objects that represent our cultural heritage. The biodegradation of paper is conditioned by several variables such as the materials from which cellulose is obtained, the manufacturing processes employed, the occurrence of other affecting substances such as lignin or metallic compounds, and by the environmental conditions in which papers are conserved. In this study, biodeterioration of paper was artificially induced in order to evaluate the role of a range of chemical and physical variables on damage caused by cellulolytic fungi. A variable pressure SEM instrument was used to characterise paper samples with different fibre origins, and alterations obtained in vitro. Two fungal strains, Aspergillus terreus Thom and Chaetomium globosum Kunze, which are cellulolytic species frequently associated with paper spoilage, were used to produce stains with characteristics close to those observable on art objects made from paper. The stains obtained on the different samples of paper were compared at both low and high magnification, in order to visualize the macro- and microscopic characteristics of paper fibres, inorganic constituents, impurities, and the deteriorating agents related to the spoiled areas. During this survey it was observed that single paper characteristics can strongly influence the intensity and the results of the fungal action. For example, the activity of a fungal strain on paper grades containing fibres of the same origin, but with different sizing, led to the formation of profoundly different stains and alterations. Moreover fungal structures, analysed by low vacuum SEM, in areas on paper corresponding to the stains appeared in different physiological states suggesting an important effect of paper constituents on fungal growth and their sporulating ability.  相似文献   

16.
《Electroanalysis》2017,29(11):2628-2637
This paper demonstrates, for the first time, the use of paper‐based electrochemical devices coupled to external solid working electrodes. The paper‐based electrochemical cells were fabricated using inexpensive and largely available office paper, according to a simple protocol that consists on the creation of hydrophobic barriers using paraffinized paper and preheated metal stamp. The counter and reference electrodes were integrated to the paper platform through the deposition of carbon and silver inks, respectively. The electrochemical paper analytical device (ePAD) was coupled to external glassy carbon rod electrode modified with reduced graphene oxide doped with Cu nanoparticles through meniscus configuration. The analytical usefulness of this electrochemical approach was demonstrated through the simultaneous determination of paracetamol and caffeine in biological samples. The analytes were successfully quantified in real urine samples and limits of detection of 24.6 nM (paracetamol) and 36.1 nM (caffeine) were obtained. The paper platform showed good stability (RSD of 1.07 % for the peak currents and 1.43 % for the peak potentials) and satisfactory performance. The use of solid electrodes coupled to paper electrochemical devices, firstly demonstrated here, opens new possibilities for the utilization of ePADs in electrochemistry and electroanalytical chemistry and offers advantages such as the extremely reduced consumption of reagents and the minimal generation of wastes.  相似文献   

17.
Paper industry generates a considerable amount of wastes. Their composition mainly depends on the type of paper produced and the origin of cellulose fibres. Nowadays, in Spain, 40% of solid wastes generated by the paper and pulp industry are deposited directly in landfill, 25% are used in the agriculture, 13% in the ceramic industry and 7% in the concrete production. In the last years, thermal treatment methods like combustion, pyrolysis and gasification have been widely study as alternative techniques for the valorization of different organic waste materials. The main objective of the present work is to study the pyrolysis behaviour of different paper mill waste materials. For this reason, a wide characterization of eight paper mill waste materials from different origins was performed using SEM, FTIR, DRX and thermogravimetric techniques. Paper mill sludges from recycled paper, mainly wastes obtained from deinking process, showed high CaCO3 and clays contents. Compared with the elevated total organic matter content (TOM) of paper mill waste materials their low organic carbon content determined by Cr2O72− oxidation reveals the elevated chemical stability of organic matter, due to high content on cellulose fibres. Analysis of samples by SEM indicates that successive recycled processes of paper leads to paper mill waste materials with more degraded fibres. XRD analyses show as crystalline cellulose was present in reject and primary sludge from paper mills that produced paper from virgin wood. However, crystalline cellulose content significantly decreased in waste materials from recycled paper. Finally, thermogravimetric analysis indicates that presence or mineral matter and degradation of cellulose significantly influences their pyrolysis behaviour. In general, weight loss of paper mill waste materials started at lower temperatures than pure cellulose. In waste materials from recycled paper weight loss continues at temperatures highest than 500 °C due to kaolinite dehydration and carbonates decomposition.  相似文献   

18.
There is current interest in using agro-based biopolymers in industrial applications. Because cottonseed protein is abundantly available, it would be useful to explore its feasibility as a polymeric additive and possible substitute for petroleum-based materials. In this work, we studied cottonseed protein isolate as a paper additive and observed its effects on the paper’s dry and wet strength. The tensile strength of paper was found to vary with the amount of the protein applied. By application of an 11% protein solution to the paper, the dry and wet strength increased by 33 and 16% compared with the paper by itself, respectively. The combined use of cottonseed protein and an acid (acetic, adipic, aspartic, and citric acids) to promote adhesion resulted in even greater dry paper strength but not in greater wet paper strength. Thermogravimetric analysis, infrared spectroscopy, and scanning electron microscopic studies suggested that the protein interacted with acid and that both components interacted with paper fibers to produce increased strength.  相似文献   

19.
In this paper we report a new idea for synthesizing polyaniline in an ordinary filter paper. The synthesis was carried out by a process in which aqueous acidic aniline solution and the oxidizing agent H(2)O(2) was added to the paper drop by drop and in sequence. Uniform polymerization could be obtained with the addition of reagents in either sequence. The polymer formation led to a green coloration of the paper. Formation of the emeraldine salt of polyaniline was confirmed by UV-vis and FTIR spectroscopy. Scanning electron microscopic measurements were made for surface characterization of the polymer formed in the paper. The same paper was used as a sensor for ammonia in vapor and in solution, for acid and base as well as endpoint indication, and also to filter acids and bases. We found that, using the polymer-containing paper, ammonia concentrations in a solution as low as 14 ppm could be measured.  相似文献   

20.
水性纸品上光涂料是用于印刷品的精加工及包装材料的表面整饬的一种涂料,具有成本低、无污染、无毒无害、性能优良,运输方便等优点,是当前印刷上光涂料的主要发展方向。目前,国内的水性纸品上光涂料生产技术多样化,质量参差不齐,且成本高,耐水、耐磨、光泽度性能都达不到高档印刷品的上光要求,70%的高档水性纸品上光涂料需要依靠进口。本文系统地介绍了目前国内外水性纸品上光涂料的研究进展,总结了水性纸品上光涂料的各自特点与应用,并提出一种水性纸品上光涂料制备的新方法。  相似文献   

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