电感耦合等离子体原子发射光谱法测定塑料及其制品中铅、汞、铬、镉、钡、砷

建立了一种对各种塑料及其制品中铅、汞、铬、镉、钡和砷有害元素总量的快速检测方法.样品采用微波消解进行消化,消解后的溶液用电感耦合等离子体原子发射光谱仪(ICP-AES)进行元素检测.方法的检出限为:铅5.5mg/kg、汞3.0mg/kg、铬3.4mg/kg、镉0.5mg/kg、钡3.2mg/kg、砷7.9mg/kg.各种有代表性塑料样品的元素回收率在86.5%～113.6%之间.根据8个实验室3次平行测定数据计算本方法在相应浓度水平的精密度数据Sr、SR、r、R均满足痕量分析要求.此方法可避免塑料的不完全消解及汞、砷等元素的损失,又能快速定量测定样品中的有害元素,快速有效,易于推广.     

便携式X射线荧光光谱法快速检测皮革制品中重金属含量

本文研究并建立了便携式能量色散X射线荧光光谱法(P-EDXRF)直接快速测定皮革制品中铅、镉、铬、汞、砷含量的分析方法,考察了该方法的检测精密度和准确度.实验结果表明,各元素相对标准偏差(RSD,n=11)在2.88％～6.78％之间,铅、汞、砷的检测限均小于2mg/kg,镉、铬的检测限小于5 mg/kg.并同实验室常...     

微型多功能进样技术在搪瓷制食具容器中微量锑测定中的应用研究

[目的]建立双毛细管进样,火焰原子吸收法测定搪瓷制食具容器中微量锑的方法.[方法]本文利用微型多功能进样技术(主要装置为双毛细管)详细研究了氢化物发生对锑火焰原子吸收法测定的各种影响因素,通过在线加入KBH4溶液,测定搪瓷制食具容器在4%醋酸浸泡液中的锑含量.[结果]应用本法测定,大大提高了锑的吸收灵敏度,1μg/mL Sb的吸光度可达0.45～0.48abs.并可抑制绝大部分离子的化学干扰.[结论]用双毛细管在线氢化物发生法能快速测定搪瓷制食具容器中微量锑,结果令人满意.     

氢化物发生原子荧光光谱法同时测定进出口玻璃食具、器皿中有害元素砷、锑迁移量

建立了氢化物发生原子荧光光谱法（HG-AFS）同时测定进出口玻璃食具、器皿中砷、锑迁移量的方法．并对HG-AFS工作参数及条件进行了优化和选择。As检出限为0．02μg/L．Sb检出限为0．03μg／L;回收率范围为96％～101％。本法操作简便、快速、灵敏度高,应用于进出口玻璃食具、器皿中砷、锑迁移量的检测取得了满意的结果。     

ICP-AES内标法测定铜精矿中的铅、砷、镉含量

以锗为内标,用电感耦合等离子体原子发射光谱法同时测定铜精矿中铅、砷、镉元素的含量,有效地消除了仪器及环境波动等非光谱干扰的影响。被测元素在0.5-10.0mg/L的范围内具有良好的线性;铅、砷、镉元素检出限分别为为10.6μg/L、10.8μg/L、6.0μg/L,测试值相对标准偏差分别为1.31%、0.93%、1.05%。同样条件下,测试结果优于直接法测试结果。     

ICP-AES法同时测定搪瓷餐具铅、镉、锑、镍的溶出量

采用ICP-AES法同时测定搪瓷餐具铅、镉、锑、镍的溶出量,并对ICP-AES法测定乙酸(4%)浸泡液时分析线的选择和入射功率、护套气流量、载气压力的影响,以及基体和共存离子的干扰情况等进行了研究.方法简便快速,回收率为100.8%～104.0%,相对标准偏差为0.66%～1.75%.     

电感耦合等离子体质谱法测定石膏及其制品中铅、镉等10种元素

通过对进出口石膏及其制品特性的研究,摸索出适合石膏及其制品消解的方法,并对传统的仪器方法进行分析比较,最终确定了完整的检测路线。实验中试样经酸消解后过滤得到澄清溶液,用电感耦合等离子体质谱仪对试液中的铅、镉、铬、砷、汞、铜、锌、锰、镍、钴进行测定,10种元素的检出限和定量限分别为0.07mg/kg和0.2 mg/kg,加标回收率为87.0%-104.1%,相对标准偏差均小于10%。     

单色聚焦X射线荧光光谱法测定粮食中镉、铅、砷

为建立以单色聚焦X射线荧光光谱法快速测定粮食中的镉、铅、砷检测方法为基础,设定粮食中镉、铅、砷限值的判定区间,以期为监管提供筛查依据,本文采用单色聚焦X射线荧光光谱法快速测定粮食中镉、铅、砷含量,并将这种方法与电感耦合等离子体质谱法(ICP-MS)进行比较.前处理样品粒径粉碎粒径<380μm;X射线荧光光谱法镉、铅、砷...     

ICP-MS测定50种市售大米中铅、砷、镉、铬、汞的方法研究以及风险评估

应用微波消解-电感耦合等离子体质谱法(ICP-MS)同时测定大米中铅、砷、镉、铬、汞5种重金属含量。实验结果表明:5种元素标准曲线相关系数均大于0.999 8,精密度实验的RSD小于5%,加标回收率在76%～102%,检出限均低于0.02 mg·kg~(-1)。基于该方法得到的检测结果结合FAO/WHO规定的每日允许摄入量(ADI)、暂定每日可耐受摄入量(PMTDI)以及健康风险指数(RI)对50种市售大米样品进行重金属暴露健康风险评估均低于相关限量标准,处于安全水平。     

LA-ICP-MS同时测定奶粉中铅、镉、铜、铁元素含量

本文建立了采用激光剥蚀与电感耦合等离子体质谱联用法(LA-ICP-MS)同时测定奶粉中铅、镉、铜、铁元素含量的初筛方法。奶粉样品经压片机压制,通过激光剥蚀系统激发形成气溶胶,利用电感耦合等离子质谱仪进行定量。结果表明,铅、镉在0～50.00μg/L浓度范围内,铜在0～500.0μg/L浓度范围内,铁在0～5.00 mg/L浓度范围内的线性关系良好。决定系数(R²)分别为0.9981、0.9998、0.9991、0.9994,均符合大于0.995的要求;铅元素回收率为82.4%～103.0%,镉元素回收率为70.5%～98.3%,铜元素回收率为85.5%～101.8%,铁元素回收率为89.7%～101.3%,相对标准偏差(RSD)均小于10%。该方法简便、快捷、高效、污染小、准确性好,适用于奶粉中铅、镉、铜、铁元素含量的快速初筛检测。     

China and Africa, Fiendship, Pace,Cooperation and Dvelopment

The Forum of China-Africa Cooperation（FOCAC）.was held in Nowember, as well as the The 2nd Sino-African Entrepreneurs Conference ,marking the milestone of the China-Africa relations which have experienced the test of several thousand years,     

HOPE,FEAR, AND ASPIRATIONS

We propose a rank‐dependent portfolio choice model in continuous time that captures the role in decision making of three emotions: hope, fear, and aspirations. Hope and fear are modeled through an inverse‐S shaped probability weighting function and aspirations through a probabilistic constraint. By employing the recently developed approach of quantile formulation, we solve the portfolio choice problem both thoroughly and analytically. These solutions motivate us to introduce a fear index, a hope index, and a lottery‐likeness index to quantify the impacts of three emotions, respectively, on investment behavior. We find that a sufficiently high level of fear endogenously necessitates portfolio insurance. On the other hand, hope is reflected in the agent's perspective on good states of the world: a higher level of hope causes the agent to include more scenarios under the notion of good states and leads to greater payoffs in sufficiently good states. Finally, an exceedingly high level of aspirations results in the construction of a lottery‐type payoff, indicating that the agent needs to enter into a pure gamble in order to achieve his goal. We also conduct numerical experiments to demonstrate our findings.     

SUPPLY CHAIN MANAGEMENT AND ITS RELATIONSHIP TO LOGISTICS,MARKETING, PRODUCTION,AND OPERATIONS MANAGEMENT

The renaming of the Council of Logistics Management (CLM) to the Council of Supply Chain Management Professionals (CSCMP) ushered in some interesting definitional dialogue and debate within the practitioner and academic communities. Inherent in emerging definitions is the notion that SCM encompasses activities traditionally considered aspects of production, logistics, marketing, and operations management. Defining SCM in such a broad scope (i.e., a “within” and “across” functions perspective), while considered by many scholars as the true representation of the essence of SCM, creates confusion regarding the appropriate organizational level within a business that is best suited for managerial decision making regarding the phenomenon. This paper contributes to the emerging SCM dialogue by highlighting the functional spaces (the “within” function perspective), relationships, and conceptual overlaps (the “across” functions perspective) between marketing, logistics, production, operations, and supply chain management. By comparing and contrasting the literature‐based conceptual boundaries of each discipline, a framework is proposed that more clearly captures the essence of the SCM decision making sphere. Managerial insights and future research implications are presented.     

蒂芙尼,地位与财富的象征

那是一种很特殊的蓝,温柔地透着幸福的光彩,打开盒子上面的白色缎带,眼睛中的光芒映射出钻石的华彩。“嫁给我吧”,这是最悦耳的话语,一种爱的承诺被牢牢地攥在手中。最近,身边经常传来结婚的喜讯,让人也被一种满满的幸福所包围,不由想起了蒂芙尼（Tiffany）,想起了它经典的订婚钻戒。虽然没有卡地亚的豪华,但是蒂芙尼有着美国式的简洁、明朗,每件作品带着美国人与生俱来的直率、乐观和乍现的机智。     

DISUTILITY, OPTIMAL RETIREMENT, AND PORTFOLIO SELECTION

We study the optimal retirement and consumption/investment choice of an infinitely-lived economic agent with a time-separable von Neumann–Morgenstern utility. A particular aspect of our problem is that the agent has a retirement option. Before retirement the agent receives labor income but suffers a utility loss from labor. By retiring, he avoids the utility loss but gives up labor income. We show that the agent retires optimally if his wealth exceeds a certain critical level. We also show that the agent consumes less and invests more in risky assets when he has an option to retire than he would in the absence of such an option.
An explicit solution can be provided by solving a free boundary value problem. In particular, the critical wealth level and the optimal consumption and portfolio policy are provided in explicit forms.     

BESSEL PROCESSES, ASIAN OPTIONS, AND PERPETUITIES

Using Bessel processes, one can solve several open problems involving the integral of an exponential of Brownian motion. This point will be illustrated with three examples. The first one is a formula for the Laplace transform of an Asian option which is "out of the money." The second example concerns volatility misspecification in portfolio insurance strategies, when the stochastic volatility is represented by the Hull and White model. The third one is the valuation of perpetuities or annuities under stochastic interest rates within the Cox-Ingersoll-Ross framework. Moreover, without using time changes or Bessel processes, but only simple probabilistic methods, we obtain further results about Asian options: the computation of the moments of all orders of an arithmetic average of geometric Brownian motion; the property that, in contrast with most of what has been written so far, the Asian option may be more expensive than the standard option (e.g., options on currencies or oil spreads); and a simple, closed-form expression of the Asian option price when the option is "in the money," thereby illuminating the impact on the Asian option price of the revealed underlying asset price as time goes by. This formula has an interesting resemblance with the Black-Scholes formula, even though the comparison cannot be carried too far.     

ADVERTISING,PERCEIVED QUALITY AND STRATEGIC ENTRY DETERRENCE AND ACCOMODATION(*)

Abstract. When faced with the choice between two brands of a homogeneous good, consumers—cetevis paribus—have been observed to prefer the brand with which they have become familiar through advertising to the unadvertised brand. Some consumers are even prepared to pay a price premium for the advertised brand. Taking this behaviour as a datum, we show that an incumbent monopolist can use advertising to erect a barrier to entry or to influence the nature of entry (strategic entry accomodation).