水产品中孔雀石绿及其代谢物快速检测方法研究

建立一种简便、快速的检测水产品中孔雀石绿及其代谢物残留量的方法。采用乙腈提取、固相萃取柱净化浓缩,氧化剂将隐性孔雀石绿氧化为孔雀石绿,用化学比色法观察结果,从而建立一种简便、快速的初筛方法。加标回收率为70%～95%,相对标准偏差为5.46%～9.90%,孔雀石绿及代谢物的检出限分别为2μg/kg和4μg/kg。本方法相对于国标法操作更简便快速,适用于大批量样品检测。     

免疫学

081627巨细胞病毒特异性抗体IgG检测方法的建立/牛向兰…∥中国计划生育学杂志.—2008,16(8).—484～486为建立一种以0.4U/ml为临界值的巨细胞病毒(CMV)特异性抗体IgG的检测方法。用美国食品与药品监督局(FDA)认证的标准品标定临界值标准,以常规间接酶联免疫测定法(ELISA)进行检测,对检测方法的各个环节进行比较研究,确定检测方法的最佳工艺流程;对179份育龄妇女血清进行检测,并经过FDA认证的ELISA方法为金标准与之进行比较。结果:灵敏度、特异性和准确性分别为100%(160/160)、94.7%(18/19)、99.4%(178/179);批内、批间变异系数分别为6.3%～10.5%,9.3%～14.8%,基本符合ELISA法的标准(10%～15%)。结论:建立的CMV-IgG检测方法灵敏度高、特异性好、重复性好,可用于育龄妇女CMV-IgG水平的检测。表2参4(周继铭)免疫学     

meso-四(4-甲氧基-3-磺酸钠基苯基)卟啉测定Pb(Ⅱ)的实际应用研究

研究了meso-四(4-甲氧基-3-磺酸钠基苯基)卟啉与铅的显色反应:不需加热即可完成络合,表观摩尔吸光系数为2.11×10⁵L·mol-1·cm-1,线性范围为0～1.1μg/mL,抗干扰能力强。应用该方法首次测定实际样品(松花蛋、头发、茶叶、白酒、树叶、河水、工业废水、大米、食品包装袋、罐头盒、韭菜)中痕量铅的质量浓度,结果令人满意。     

杀菌剂室内空白菌量检测方法研究

在依据标准Q/SH 0355—2010《油田采出水处理用杀菌剂技术要求》对杀菌剂产品质量进行检测时,采出水空白菌量室内培养及计数是检测的重要环节。分析了培养基加入量、培养时间及培养温度对培养空白细菌菌量的影响,优化选择培养基体积分数为0.20%、培养温度为(40±5)℃、培养时间为36h,作为培养空白菌量最佳实验条件。针对不同标准对菌量计数方法的不同要求而导致的结果偏差问题,从理论和实验角度进行分析验证,通过对空白菌量室内检测及计数的方法优化,确定绝迹稀释法为最合理计数方法,从而提高了室内杀菌效果检测结果的准确性和时效性,对油田用杀菌剂的质量检测工作有一定的指导意义。     

食品包装中霉菌和酵母菌计数两种检验方法的结果比较

对食品包装中霉菌和酵母计数国标法GB/T4789.15-2010加以改进,把稀释液由无菌蒸馏水改为0.85%无菌生理盐水,培养时由倒置于28℃±1℃温箱中改为正放28℃～30℃温箱中,培养时间由5d改为4d,选择生长菌落在10～100(甚至菌落数为10～50)之间的平皿计数,该法与国际法比较,两法检出的结果无明显差异。     

嘧菌酯的新合成方法

报道了一种广谱高效杀菌剂嘧菌酯的新合成方法,首先以2-氯苯甲腈与4,6-二羟基嘧啶为原料催化合成4-羟基-6-(2-氰基苯氧基)嘧啶,氯化得到4-氯-6-(2-氰基苯氧基)嘧啶。将4-氯-6-(2-氰基苯氧基)嘧啶与(E)-2-(2-羟基苯基)-3-甲氧基丙烯酸甲酯耦合,生成(E)-2-(2-(6-(2-氰基苯氧基)嘧啶-4-基氧)苯基)-3-甲氧基丙烯酸甲酯(嘧菌酯)。3步总收率为79.8%(以2-氯苯甲腈计),原药质量分数为97%。     

35％吡虫啉·福美双悬浮种衣剂的高效液相色谱分析

采用反相高效液相色谱法,对35％吡虫啉·福美双悬浮种衣剂进行定量分析.使用XDB-C18柱和紫外检测器,以甲醇-水为流动相,检测波长260nm,外标法测定悬浮种衣剂中2种成分的含量.结果表明,该方法的标准偏差为0.039％～0.043％,变异系数为0.170％～0.387％,平均回收率分别为99.19％～100.38％、99.25～100.25％.该法操作简单快速,定量准确可靠,适用于产品的常规分析和质控研究.     

薄层色谱法检测苏丹红

探讨用薄层色谱法检测食品中苏丹红色素的可行性,并对高效硅胶G板及聚酰胺薄层板分离苏丹红色素的结果进行比较,发现高效硅胶G板较聚酰胺薄层板分离苏丹红色素更具有优势,其检测灵敏度高:0.3 mg/kg;分析速度快:用聚酰胺薄层板分析一般需要40 min,而高效硅胶G板只需5~10 min;分离清晰:4种苏丹红色素与辣椒色素等干扰色素能够完全分离。该方法适用于基层机构在现场快速检测食品中非法添加的苏丹红色素。     

在用润滑油金属磨粒快速检测研究

采用铁量仪、磁力法和滤膜法,分析检测在用润滑油,研究了一种能够快速检测出油样中的非铁磁性磨粒的方法。铁量仪和磁力法能检测出油液中铁磁性磨粒的总量,但无法有效检测出油样中的非铁磁性磨粒。通过对实际油液的取样稀释过滤,运用手持显微镜或放大镜观察滤膜,能够较快检测出油液中的金属磨粒。     

产黄青霉苯乙酰CoA连接酶基因phl的克隆表达及其纯化酶的性质分析

笨乙酸与CoA反应,生成苯乙酰CoA,利用RT-PCR方法成功地从产黄青霉中扩增得到1737 bp不舍内含子的phl基因,并将其克隆到pET30a原核表达载体,在大肠杆菌BL21(DE3)中低温诱导表达.经SDS-PAGE检测分析,获得与预期大小(62.1kDa) -致的蛋白表达特异条带.通过Ni-NTA亲和层析柱纯化...     

增强Linux系统安全性的措施

L inux系统的安全取决于系统管理员如何来管理它。本文探讨了一系列可以增强安全性的技巧与策略 ,包括 :系统安装原则、BIOS安全、口令安全策略、设计帐户自动注销功能、文件系统和日志安全策略、使用 SSH及 TCP-WRAPPERS,隐藏系统信息、删除所有特殊帐户、关闭控制台程序、限制系统中的 SUID/ SGID程序等。本文最后向 L inux系统管理员提出了一些安全管理方面的建议     

Comparing FTTH access networks based on P2P and PMP fibre topologies

There is an ongoing discussion in the market which Next Generation Access (NGA) architecture best suits future needs and which investment and cost differences exist. The discussion can be subsumed as P2P vs. GPON, which is somewhat misleading as this article reveals. The discussion is driven by the fact that the high capital cost and the long asset life time of fibre mean that the technology choices made today will dominate the opportunities for telecommunication business of all market players, incumbents, competitors, content providers and business and residential users for many years in the future.The paper analyzes the cost and other differences between Fibre-to-the-Home (FTTH) access network architectures and their related different wholesale approaches by using the well-known and understood steady state approach applied in other NGA analyses in the past. In addition to the steady state analysis a dynamic cost evaluation is included taking into account the different investment behaviour of the FTTH architectures over time. The results describe investment and cost differences between architectures, incumbents and wholesale based competitive operators. The analysis has been performed for different geotypes (clusters) of decreasing population density in a representative European settlement structure.     

CIS与现代企业管理美学

概括性介绍了 ＣＩＳ（Ｃｏｒｐｏｒａｔｅ Ｉｄｅｎｔｉｔｙ Ｓｙｓｔｅｍ）的三大基本组成，并阐述了它与现代企业管理密不可分的相互联系及所处的举足轻重的地位，指出导入ＣＩＳ是现代企业谋求发展的重要手段。     

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.     

Indigenous peoples’ nutrition transition in a right to food perspective

In indigenous communities the nutrition transition characterized by a rapid westernization of diet and lifestyle is associated with rising prevalence of chronic disease. Field work and literature reviews from two different policy environments, Argentina (Jujuy) and Canada (Nunavut), identified factors that add to indigenous peoples’ disease risk. The analytical framework was the emerging human right to adequate food approach to policies and programmes. Indigenous peoples’ chronic disease risk tends to increase as a result of government policies that infringe on indigenous peoples’ livelihoods and territories, undermining their economic system, values and solidarity networks. Policies intended to increase food security, including food aid, may also fuel the nutrition transition. There is a need to explore further the connection between well-intended policies towards indigenous peoples and the development of chronic diseases, and to broaden the understanding of the role that different forms of discrimination play in the westernization of their lifestyles, values and food habits. Food policies that take due account of indigenous peoples’ human rights, including their right to enjoy their culture, may counteract the growth of chronic disease in these communities.     

Diffusion and usage of public e-services in Europe: An assessment of country level indicators and drivers

We analyze the state of the art of indicators on e-government, e-health, e-procurement and e-participation. We survey the main methodological properties of these indicators, and highlight their heuristic potential. Further, we address empirically the issue of the explanation of the availability scores, i.e. how the supply of the various e-services in each country is affected by political, institutional and socio-economic differences, and is followed by actual usage. The econometric analysis uncovers the importance of broadband penetration and higher education as drivers for most of the types of e-services and users (citizens and businesses). Moreover, a corruption-free and agile public sector proves to be an important pre-condition for more effective supply and usage. Despite data limitations and the complexity of the underlying diffusion phenomena, our study is the first truly longitudinal contribution aimed at disentangling the common drivers of such an important phenomenon – the e-services availability and usage across European countries. As such, this work appears useful to inform the policy debate and practice, in a phase characterized by a prospective reorientation of the public e-services provision and policy agenda.     

一种高精度的频率标准比对系统

频率标准源可以提供精确的标准频率,在测定频率标准源的各项性能指标时,要求测试系统必须具有很高的比对精度。所设计的频率标准比对系统采取多级倍频 混频方式使频率偏差逐级扩大后再测量,从而避免了直接进行高次倍频的困难,提高了测量精度,可以对高精度的频率标准的准确度、长短期频率稳定度进行快速测量,是一种高精度时畴参数测量系统。     

A strategic skill based model of supplier integration and its effect on supply management performance

Supplier integration is a tool to help organizations gain competitive advantage. Strategic supply management skills and the supply management function's perceived status are hypothesized as antecedents to supplier integration leading to supply management performance. The sample for this study includes 152 executive level supply management professionals. The empirical results suggest that strategic skills and perceived status are essential antecedents to supplier integration and subsequent performance. Further, the relationship between strategic skills and performance is mediated by supplier integration. Results of a dominance analysis also suggest which strategic skills are most likely to explain status integration, and performance. These findings have significant implications for supply management theory and practice.     

Cost allocation of WCDMA and wholesale pricing for mVoIP and data services

This study estimates cost-based prices for wholesale voice and data services provided to 3G (WCDMA) MVNOs according to their distinct types. For estimation, 3G MVNOs are classified into different types, and the overall cost of WCDMA facilities are separated into voice and data components based on their subscriber rates, actual traffic rates, as well as efficiency consideration of traffic rates. The study then calculates cost-based wholesale prices of voice and data services for each of the 3G MVNO types. The result of this study shows that a cost-plus pricing scheme can help achieve the policy goals of the regulator, namely, lowering telecommunications tariffs and facilitating the introduction of new convergent-type services, far more effectively than the current retail-minus pricing scheme. The findings of this study may assist firms in developing business models based on 3G networks and telecom regulators in designing policies related to interconnection, mVoIP, prepaid calls, wholesale services, and network neutrality.