羧甲基壳聚糖-Cu2+配合物催化分解H2O2的研究

研究羧甲基壳聚糖-Cu²⁺配合物对H₂O₂分解的催化活性及影响因素。以壳聚糖为原料,制备水溶性羧甲基壳聚糖(CMC),再以其为配体制备CMC-Cu²⁺配合物,并将CMC-Cu²⁺配合物应用于催化H₂O₂分解的反应,考察了w(CMC)/w(CuCl₂)、体系pH值对H₂O₂分解的影响。结果表明:温度为25℃,w(CMC)/w(CuCl₂)为5∶1时形成的CMC-Cu²⁺配合物,在pH值为7附近,对质量分数为5%的H₂O₂的分解率12h为92.5%,24h为99.5%,说明CMC-Cu²⁺配合物对H₂O₂分解有良好的催化作用。     

不同引发剂引发苯乙烯/丙烯酸丁酯微乳液共聚合竞聚率的研究

以十二烷基硫酸钠/十二烷基苯磺酸钠(SDS/SDBS)为复合乳化剂,分别以水溶性引发剂过硫酸钾(KPS)、油溶性引发剂过氧化苯甲酰(BPO)和氧化-还原引发体系K₂S₂O₈/Na₂SO₃(OR)引发苯乙烯/丙烯酸丁酯(St/BA)微乳液聚合反应,研究了St/BA微乳液共聚合行为,用红外光谱法定量测定了3种引发剂下的共聚物化学组成,绘制了共聚物组成曲线,计算出了竞聚率。     

芬顿污泥颗粒特性及煅烧回收利用研究

为了解决芬顿污泥产量大、难处理的难题,探索其资源化途径,提出以煅烧法处理焦化废水芬顿污泥,并对芬顿污泥颗粒特性及煅烧过程中的铁相变化进行了分析,最后探讨了煅烧产物的资源化途径。结果表明：1）芬顿污泥主要成分为羟基氧化铁(FeOOH)和α型氧化铁(α-Fe₂O₃),铁元素质量分数为48.3%,含有丰富的羟基和羧基等含氧基团,有氧煅烧铁相转化过程为FeOOH→α-Fe₂O₃→Fe₃O₄→α-Fe₂O₃;2）500 ℃有氧煅烧产物为Fe₃O₄,可直接出售实现经济收益;3）酸改性后的350 ℃缺氧煅烧产物(AFS350)可有效吸附去除水中95%以上的锑和砷,480 ℃缺氧煅烧产物（FS480）对水中的铅和铊有较高的吸附容量;4）AFS350对Sb(Ⅴ)和FS480对Tl(I)的吸附符合准二级动力学及Freundlich等温吸附模型,AFS350和FS480表面均有异质性分布的饱和吸附位点,2个吸附过程均是以表面非均相吸附为主的多层化学吸附。煅烧法处理芬顿污泥,方法简单,产物回收率高且用途广,为芬顿污泥资源化提供了可行途径。     

溶胶-凝胶法制备纳米TiO2及其光催化活性的研究

采用溶胶-凝胶法制备纳米二氧化钛,以甲基橙为模型污染物,考察了影响纳米二氧化钛光催化活性的主要因素,并采用TEM,XRD等方法对样品进行了表征。结果表明:具有较高光催化活性的纳米二氧化钛的制备条件是钛酸丁酯、无水乙醇、冰乙酸、水的比例(体积比)为10∶19∶8∶4,500℃下煅烧2h；纳米二氧化钛质量浓度为1g/L时光催化效果最佳；纳米TiO₂具有锐钛矿型晶体结构,平均粒径为10～20nm。     

聚噻吩修饰纳米结构TiO2膜电极光电性能研究

用光电流作用谱、光电流-电势图等光电化学方法研究了聚噻吩(PTh)膜和纳米结构TiO₂/聚噻吩(ITO/TiO₂/PTh)复合膜的光电转换性质。结果表明,PTh膜的禁带宽度为2.02eV,价带位置为-5.86eV,导带位置为-3.84eV。在ITO/TiO₂/ PTh复合膜电极中存在p-n异质结,在一定条件下异质结的存在有利于光生电子-空穴对的分离,PTh修饰ITO/TiO₂电极可使光电流产生波长发生明显红移,从而提高了宽禁带半导体的光电转换效率。在实验条件下,单色光的光电转换效率最高可达到13%。     

注射用甲硫氨酸维生素B1的细菌内毒素检查

为考察注射用甲硫氨酸维生素B₁的细菌内毒素检查法的可行性,采用《中华人民共和国药典》(2005年版)细菌内毒素检查法。结果得知,注射用甲硫氨酸维生素B₁质量浓度为0.25mg/mL的稀释液可用灵敏度为0.25EU/mL的鲎试剂进行细菌内毒素检查,实验中3个批号的注射用甲硫氨酸维生素B₁经检查均符合规定。     

不动点集为RP1(2m)∪RP2(2m)∪RP(3)的带有对合的光滑流形

设(M^r,T)是一个具有对合T的r(r>2m+4)维光滑闭流形,它的不动点集为F。本文给出了F=RP₁(2m)∪RP₂(2m)∪RP(3)时对合的协边类(其中m为奇数),RP表示实射影空间。     

Cu-11Fe-4Cr原位复合材料在HSO-3和/或Cl-介质中的耐蚀性

采用选择腐蚀技术,提取了Cu-11Fe-4Cr原位复合材料中Fe-Cr纤维,并测定了其电极电位。通过间歇式盐水喷雾实验和极化曲线测定,研究了Cu-11Fe-4Cr原位复合材料在HSO-₃和/或Cl-介质中的腐蚀行为。用扫描电镜对腐蚀产物和腐蚀表面进行分析。结果表明, Cu-11Fe-4Cr原位复合材料中,E(Cu)3+NaCl)和 NaHSO₃介质中的E(Fe-Cr) －E(Cu)显著高于NaCl 介质中的E(Fe-Cr)－E(Cu),Cu-11Fe-4Cr原位复合材料在NaCl介质中的腐蚀失重最小,在NaCl介质中具有良好的耐蚀性。     

高效液相色谱法测定淡水鱼中抗生素残留量

抗生素富集于鱼体内,通过食物链对人类健康构成危害。通过对高效液相色谱仪的检测波长、流动相及流速、提取方法等几方面的优化,使用Spherisorb C₁₈ 柱,以V(乙腈)∶V(磷酸二氢钠)(EDTA的浓度为0.001mol/L)=28∶72作为流动相,在355nm的检测波长下,成功地进行了人工饲养淡水鱼体内的四环素、金霉素、土霉素等残留物的定量检测,平均回收率约为98.0%,平均相对标准偏差约为4.63%。     

石家庄市冬防期细颗粒物污染特征及源解析

为了探究石家庄市冬防期细颗粒物（PM_2.5）的主要污染来源,推动石家庄市环境空气质量持续改善,采用在线单颗粒气溶胶质谱仪（SPAMS）捕集的PM_2.5粒子信息,结合自适应共振神经网络分类方法（ART-2a）和石家庄市污染源谱图信息,对2017年10月1日—2018年3月31日、2019年10月1日—2020年3月31日、2021年10月1日—2022年3月31日的石家庄市PM_2.5污染物来源进行解析。结果表明：1）石家庄市冬防期PM_2.5主要受燃煤源、机动车尾气源、工业工艺源共同作用的影响,3种污染源对PM_2.5浓度的贡献率超过60%;2）第3阶段与前2个阶段相比,在不同月份和污染时段机动车尾气源对PM_2.5贡献率占比均升高9个百分点以上,贡献占比最大,机动车尾气源逐渐取代工业工艺源成为PM_2.5首要污染源;3）受春节影响,2月份机动车尾气源对PM_2.5贡献率明显降低;4）第3阶段燃煤源和工业工艺源对PM_2.5浓度的影响降低,但2个污染源对PM_2.5浓度的贡献率仍然较大,贡献占比超过30%。研究结果为石家庄市进一步加强对机动车尾气源的管控提供了依据,同时对未来石家庄市提前采取针对性污染源管控,减缓大气污染的发生提供了数据支撑。     

Divergent patterns of engagement in Internet standardization: Japan,Korea and China

This article analyzes the engagement of Japanese, Korean and Chinese participants in the development of Internet standards at IETF on the basis of four quantitative metrics: attendance, patenting, authorship and leadership. The results are strikingly divergent. Japanese involvement in Internet standardization began early and Japan was, for many years, second only to the U.S. in terms of IETF participation. Though Japanese participation has declined since the early 2000s, Japan remains a major contributor to IETF standardization. Korean involvement in IETF has always been significant, but below the levels of Japan and major European countries. Korean participation in IETF has also declined over the past decade, and has been dominated by one firm, Samsung. Though meaningful Chinese involvement in IETF did not begin until the mid-2000s, it has rapidly expanded in recent years. Today, China is a major player in numerous areas of Internet standardization in terms of three metrics (participation, patenting and leadership), and is rapidly gaining in terms of document authorship as well. Most of China׳s recent IETF involvement can be attributed to Huawei, though other Chinese firms have recently begun to increase their participation in the organization. Thus, contrary to some views that China׳s engagement with standardization is primarily one of indigenous innovation and “catching up”, China׳s experience with IETF demonstrates deliberate and effective engagement with a major Western standards-development organization on its own terms.     

Whose Image is it Anyway?: Some Considerations of the Curricular Importance of Subject Image in Secondary School Design and Technology Education

This paper explores the idea that a sense of school subject image is a necessary feature of curriculum management and a potent force for change. The discussion centres on the view that all school subjects have an image and that if those intimately involved with the subject do not control the image then someone else does! In such circumstances the image is the product of past encounters and old euphemisms and is unlikely to hold the changed realities.The UK developments in Design and Technology education (the term Design and Technology is used to denote the school subject defined under this heading by the UK National Curriculum, 1995) have created something of an image problem which has interesting international parallels. Some of these problems are due to clearly discernible internal tensions and an ambiguous relationship with other subject areas.Through greater attention to subject image internal controversies might be acknowledged and resolved, relationships with other subject areas can be more meaningfully understood and practitioners can be helped to make sense of curriculum change.     

蒸汽热量计量应用的探析

研究了石油化工企业的燕汽计量情况,着重对蒸汽热量计量的合理性进行了分析,阐述了蒸汽热量计量的依据及计算方法,以及蒸气热量计量对节能降耗的重要意义.     

论传统旗袍文化与现代时装

中国的旗袍文化蕴含着非常丰富的文化内涵和设计思想,如今旗袍的普及受到一定的限制,只有经过改良,才可变局限性为可行性,才可使旗袍焕发青春,走向新时代。     

望峰岗矿井贯通测量技术分析

在深部开采矿井两井间贯通测量时,利用加测陀螺定向边和用四架法代替传统的三架法测量,分析了由起始边的方位角误差引起的支导线终点误差及由测角量边引起的导线终点的点位误差.     

工程施工质量控制和管理要点

提高施工中质量管理工作水平，为公司今后发展打下良好基础。     

高油价影响我国经济

从2004年初以来，国际油价急剧攀升，文章分析了原油价格居高不下的原因，对未来油价的走势及其对我国经济的影响和冲击进行了预测，面对这种情况我国必须采取应对措施：树立节能消费理念；促进技术创新，推动产业升级；建立石油战略储备、推出原油期货、推动多元化战略等。     

亲油性纤维材料性能及应用

纤维素纤维是自然界广泛分布的天然纤维,像法桐球果纤维、木棉纤维、杨花纤维、蒲公英绒纤维,都是纤维素纤维,纤维具有吸油快、吸油量大、拒水的性能特点,纤维不易进行纺织生产加工,但可以作为海面吸油材料使用,并且加工方法简单,吸油效果好。     

Optimizing receiver performance using harm claim thresholds

More and more systems need to be squeezed together in frequency, space and time in order to satisfy the growth in demand for radio services. However, greater proximity increases the risk of service breakdowns caused both by poor interference tolerance in receivers and by inappropriate signals radiated by transmitters.     

Broadband expectations and the convergence of ranks

Broadband Internet service to widely held to be a significant contributor to economic development and global competitiveness, and comparison of adoption rates across countries are common. This paper presents evidence that the relative broadband Internet adoption ranks across the Organisation for Economic Co-Operation and Development (“OECD”) countries are converging to the wireline telephone adoption ranks in the mid 1990s. This was a time when wireline telephone service had reached maturity, but before consumers began to abandon traditional telephone services for mobile services and Internet telephone technologies. As such, in the absence of better data on household adoption, wireline telephone rank is a useful proxy for a country's ultimate fixed-line broadband penetration rank. Having such an educated guess available regarding broadband rank should reduce the amount of anxiety over rankings, since similar rankings across the two services implies suitable broadband performance. Large departures, alternately, may be a cause for concern or delight. Like prior analyses, the findings suggest that the adoption of communications services is largely an economic and demographic issue.