液质联用仪测定蔬菜中氟虫腈及其代谢物的方法

以蔬菜中氟虫腈及其代谢物的测定为例,通过对标准曲线、回收率、精密度、检出限、定量限等技术指标进行检测方法确认,结果表明标准曲线线性关系良好,相关系数均大于0.999,检出限达到0.3μg/kg、定量限为0.001 mg/kg,加标回收率为89.0%~104.0%,精密度RSD在1.03%~6.52%之间。该方法结果均符合标准要求,具有较强实用性和指导性。     

高效液相色谱法测定盐酸咪唑苯脲的含量

建立了高效液相色谱法测定盐酸咪唑苯脲的含量。采用Amethyst C18色谱柱(4.6mm×150mm,5μm);以乙腈-缓冲液(缓冲液为5mmol/L辛烷磺酸钠溶液,含0.1%(体积分数)三乙胺,用冰乙酸调节pH值为3.2)为流动相,乙腈与缓冲液体积比为30︰70;流速为1.0mL/min;检测波长为239nm;柱温为30℃。在39.32～137.62μg/mL范围内,盐酸咪唑苯脲峰面积与质量浓度呈良好的线性关系(r=0.999 3),平均回收率约为99.50%(n=9),RSD值约为0.52%。     

气相色谱法测定盐酸氨溴索口服液中丙二醇和甘油的含量

建立了气相色谱法测定盐酸氨溴索口服液中丙二醇和甘油的分析方法,采用HP-INNOWAX色谱柱进行分离,外标法定量。实验结果表明,丙二醇在50.4～806.0μg/mL范围内线性关系良好,相关系数为0.9995,平均回收率为99.1%,RSD=1.01%;甘油在190.5～3048μg/mL范围内线性关系良好,相关系数为0.9995,平均回收率为99.8%,RSD=0.97%;二者的方法检出限:丙二醇为0.10g/100g,甘油为0.10g/100g,方法检出限低,重复性好,结果准确可靠,适用于盐酸氨溴索口服液中丙二醇和甘油含量的测定。     

HPLC法测定6-甲基尿嘧啶的含量及有关物质

建立了6-甲基尿嘧啶含量和有关物质的高效液相色谱测定方法。采用C18柱,检测波长为263 nm,流动相为甲醇-0.1 mol/L的醋酸铵(二者体积比为40∶60),流速为1.0 mL/min,进样量为20μL。样品检测质量浓度的线性范围为5～200μg/mL(r=0.999 9),平均回收率为99.42%(RSD值为0.51%)。该方法操作简便、快捷,结果准确、可靠,能有效用于产品的质量控制。     

反相高效液相色谱法测定土壤中的糠醛

提出了反相高效液相色谱法(HPLC)同时测定土壤中糠醛的新方法。流动相为甲醇:水=50:50(V/V),流速为1.0mL/min;检测波长为275nm;柱温为30℃。结果表明:该方法的线性回归方程为y=169.9x-2.79,其相关系数为0.999,线性范围为1.0～10μg/mL,方法检出限为0.13mg/kg;分别采用高/中/低浓度加标时平均回收率在80%-95%之间,准确度结果良好;对高/中/低浓度(10/5/1μg/mL)分别测定6次,计算其相对标准偏差在0.09%-1.11%之间(n=6),精密度结果良好。     

顶空气相色谱法测定丹参酮ⅡA磺酸钠原料药中的溶剂残留量

为了建立丹参酮ⅡA磺酸钠中有机溶剂残留量的测定方法,采用顶空气相色谱法,程序升温,色谱柱为HP-INNOWAX毛细管柱,氮气为载气,采用氢火焰离子检测器(FID),外标法计算残留溶剂的含量。在试验的浓度范围内所测结果呈现良好的线性关系(工作曲线的相关系数均在0.999以上),回收率为99.5%~106.3%,RSD为0.2%~1.2%。本方法简便,结果准确,重现性好,可用于多种残留溶剂的同时测定。     

液相色谱-串联质谱法小麦粉中的黄曲霉毒素B1的测定

文章建立了小麦粉中黄曲霉毒素B1(Aflatoxin B1,AFB1)的液相色谱-串联质谱法测定方法。小麦粉中的黄曲霉毒素B1用甲醇-水(70:30)溶液提取,提取液通过免疫亲和柱净化和富集,净化液经过浓缩,定容和过滤后经液相色谱分离,串联质谱检测,同位素内标法定量。研究结果表明:小麦粉中的黄曲霉毒素B1经提取后,检测线性良好,相关系数大于0.999,定量限为0.1μg/kg。加标回收率为90.3%,RSD为3.9%。此方法操作简单,检测快速且灵敏度高,能快速检测出小麦粉中的黄曲霉毒素B1。     

宣痹通络颗粒中丹皮酚含量测定

文章通过建立高效液相色谱法测定宣痹通络颗粒中丹皮酚含量。采用十八烷基硅烷键合硅胶为填充剂(Agilent Eclipse XDB-C_(18)4.6×250mm,5μm);流动相为乙腈-水(35∶65);流速为1.0mL/min;检测波长274nm;柱温25℃;进样量为10μL。实验结果显示系统适用性试验,进样5次,RSD为0.11%,分离度R=2.349;线性范围,4.208~105.200μg/mL,r=1;重复性试验,6份样品RSD=0.59%;回收率试验,平均回收率为99.39%,RSD为0.61%。结果表明,本方法操作简便,重复性好,精密度、准确度高。     

气相色谱-FID技术测定化妆品中的乌洛托品

采用气相色谱-FID技术建立了一种测定化妆品中乌洛托品含量的方法。样品经过甲醇超声提取后,气相色谱分离,外标法定量测定。实验结果表明:乌洛托品质量浓度在2~200 mg/L范围内,线性方程为Y=0.715 8X-0.433 2,相关系数r=0.999 5,方法定量限为20μg/g,回收率为85.0%~106.8%,相对标准偏差小于5%(n=6)。该方法操作简单,重复性好,回收率高,是一种快速测定化妆品中乌洛托品含量的方法。     

GC法测定索非布韦的残留溶剂

通过建立GC法,测定索非布韦中甲醇、乙醇、二氯甲烷、正己烷、乙酸乙酯、四氢呋喃和甲苯7种残留溶剂的方法。采用直接进样法,色谱柱为DB-624毛细管柱(75m×0.53mm,3.0μm),程序升温,检测器为FID,进样口温度为160℃,检测器温度为250℃,载气为氮气(9mL/min),分流比为5:1,进样量为1.0μL。空白溶剂与上述溶剂之间分离度良好(>3)、理论塔板数(>10000)符合要求,并不干扰样品残留溶剂的测定,各溶剂的系统精密度(RSD<5.0%)、线性关系(R>0.999)、准确度(100%～106%,RSD<5.0%)、检测限、定量限均符合要求。本方法准确、可靠,可用于索非布韦的残留溶剂测定。     

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.     

面向对象的程序设计

用Ｃ＋ ＋ 语言阐述面向对象程序设计中封装和继承的概念以及在实际中怎样运用这些概念提高程序设计水平。     

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.     

应用CGI技术创建CAI网页计数器

:CGI( Common Gateway Interface)是应用程序与 Web服务器交互的一个标准接口 ,利用该技术可以实现 HTML不具备的交互式主页功能。本文将通过“教育窗”主页的访问 (点击 )计算器的开发应用实例 ,提出了两种使用 CGI技术实现点击计数的方案     

钻井现场H2S气体的探测及防护

在钻井生产过程中，实施HSE管理体系，预防和控制H2S，保护每一位员工不受H2S气体危害，是钻井生产过程中HSE工作的重要一环。阐述了有害气体H2S的物理特性、毒性标准，介绍了几种常用的H2S气体探测器，以及具体操作方法。     

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.     

Migration to 3G wireless broadband internet and real options: The case of an operator in India

The paper focuses on third generation wireless technologies and on alternative technologies for wireless local area networks. The authors present the evolutionary migration path from second to third generation systems. Technological, economic and behavioral factors related to decision-making towards the migration are proposed. As an example, the paper studies the case of the national incumbent operator of India. It analyzes qualitatively the migration problem from the perspective of the operator, the equipment manufacturer and the users. For the quantitative analysis, real options are used to value the investment decisions. The analysis suggests that the initial (sunk) investment cost, the average revenue per user, the growth of the subscriber base and the volatility of the markets are the key factors in the investment process.     

Collectivism,individualism, and outgroup cooperation in a segmented China

A consistent theme in cross-cultural management research is that collectivists are more cooperative than individualists. We use Hofstede's measure for individualism–collectivism and combine it with an experimental measure of cooperation to test this relationship in China. In contrast to the established paradigm, we find that groups with higher individualistic scores are more cooperative than those groups with higher collectivistic scores. We attribute these results to groups being composed of outgroup members. In addition, we find that subjects from the more developed coastal area are more individualistic and cooperative than are subjects from inland China.

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.     

压入式局部通风技术及管理

局部通风技术及管理在大中小型煤矿广泛应用,如何管理和应用局部通风是掘进安全生产不可忽视的环节,无论从风量的设计、各种安全设施的使用等都是非常重要的。有一套系列化的设计和管理模式是掘进安全生产的重要保证,本文从掘进设计到掘进结束做了详细的使用和管理。