Assessing economic and demographic factors that influence United States dairy demand

Low-fat dairy products are key components of a healthy diet for all Americans. As the USDA increases its focus on nutrition and healthy eating, it is important to understand the underlying demands for dairy products, both the healthy and the less healthy ones. The consumption of fluid milk products has decreased over the last decade, whereas milk used for manufactured dairy products such as cheese, ice cream, yogurt, and butter, and for use as an ingredient in other food products, has risen. The objective of this study is to determine the effects of changes in demographic variables, retail prices, and total dairy expenditure on at-home consumption of dairy products, using purchase data from Nielsen 2007 Homescan (ACNielsen, New York, NY) data. To derive the demand elasticities for 16 products, a censored Almost Ideal Demand System model is used. Results reveal that demographic variables do have effects on the purchase of the 16 products, and own-price elasticities are 1 or greater for all 16 products for both uncompensated and compensated elasticities except 4: ice cream, refrigerated yogurt, processed cheese, and margarine. A substitution relationship exists among all fluid milk categories, natural and processed cheese, low-fat ice cream, and refrigerated yogurt, butter, and margarine.     

提高某多金属矿伴生金回收技术研究

某多金属矿矿石为低品位含金难处理铜矿石,在生产的过程中,伴生金的回收效果不佳。发挥药剂的协同作用,采用丁基铵黑药和Z-200的组合用药,强化含金硫化铜矿的浮选。采用尼尔森重选—浮选联合选别工艺,能获得金品位高达1 243.5 g/t的重选金精矿,金的综合回收率73.79%,较单一浮选工艺,在选铜指标相近的情况下,金的回收率提高了7.11%。尼尔森重选预先回收了大部分颗粒金,减少了金在浮选作业中的损失,达到了早收多收的目的。     

An analysis of at-home demand for ice cream in the United States

Ice cream has been manufactured commercially in the United States since the middle of the 19th century. Ice cream and frozen dessert products comprise an important and relatively stable component of the United States dairy industry. As with many other dairy products, ice cream is differentiated in several dimensions. A censored translog demand system model was employed to analyze purchases of 3 ice cream product categories. The objective of this study was to determine the effect that changes in retail prices and consumer income have on at-home ice cream consumption. The analysis was based on Nielsen 2005 home scan retail data and used marital status, age, race, education, female employment status, and location in the estimations of aggregate demand elasticities. Results revealed that price and consumer income were the main determinants of demand for ice cream products. Calculated own-price elasticities indicated relatively elastic responses by consumers for all categories except for compensated bulk ice cream. All expenditure elasticities were inelastic except for bulk ice cream, and most of the ice cream categories were substitutes. Ongoing efforts to examine consumer demand for these products will assist milk producers, dairy processors and manufacturers, and dairy marketers as they face changing consumer responses to food and diet issues.     

蒙古苏木那林桃勒盖氧化金矿石选冶试验研究

蒙古苏木那林桃勒盖金矿矿石为典型的含金氧化矿,矿石矿物以石英为主,金属矿物含量少,金主要以自然金及银金矿形式存在,赋存状态以裂隙金和粒间金为主,含少量包裹金。根据该矿的矿石性质,采用重选-氰化联合选冶工艺可取得较好的选矿效果。原矿经尼尔森选矿机,可获得含金618.44×10-6的金精矿,金回收率为71.12%,重选尾矿全泥氰化,金浸出率为94.66%,尾矿含金可降至0.17×10-6,金总回收率达98.46%。     

A generalized Clapper–Yule model of halftone reflectance

The Clapper–Yule model of halftone reflectance includes the effects of light diffusion and multiple internal reflection between the ink‐layer and the paper substrate. It models complete scatter—the case in which the distance a photon diffuses is much greater than the screen period. The current work generalizes this to any degree of scatter. The model is presented in terms of probability functions, and the probabilities are calculated from the paper's point spread function (PSF). Photon diffusion within paper is due to two processes: scatter and multiple internal reflection. The usually defined PSF includes both processes. Ink on the paper surface, however, alters the internal reflectance, and so the usually defined PSF depends on the percent ink coverage. The current model separates the effects of scatter from the effects of internal reflection. The PSF introduced here accounts for scatter only—it is independent of the percent ink coverage. It is shown that the generalized Clapper–Yule model corresponds to Yule–Nielsen n‐values significantly greater than 2, unlike the case of no internal reflection for which the maximum n‐value is equal to 2. © 2000 John Wiley & Sons, Inc. Col Res Appl, 25, 402–407, 2000     

贵州某低品位石英脉型金矿石选矿试验

贵州某石英脉型金矿石金含量为3.04 g/t,金属硫化物中的金和单体金是金存在的主要形式,金的产出形态有浑圆粒状、板片状和角粒状等,嵌布粒度微细。为了高效回收该矿石中的金,进行了选矿试验研究。结果表明：矿石在磨矿细度为-0.074 mm占55.6%情况下,采用尼尔森选矿机重选,获得了金品位为236.01 g/t、金回收率为26.39%的尼尔森重选金精矿;尼尔森重选尾矿再磨至-0.074 mm占80.44%后,采用1粗3精2扫、中矿顺序返回浮选流程处理,获得了金品位为41.37 g/t、金回收率为57.84%的浮选金精矿;总精矿金品位为55.78 g/t,金回收率为84.23%。     

Relationships between Academia,State and Industry in the Field of Food and Nutrition: The Norwegian Chemist Sigval Schmidt‐Nielsen (1877–1956) and His Professional Roles, 1900–1950

The aim of this article is to shed light on the relationships between science, state and industry in the field of food and nutrition in Norway in the first half of the 20th century with reference to the scientist Sigval Schmidt‐Nielsen (1877–1956). Schmidt‐Nielsen was a health authority employed state chemist at the university in the Norwegian capital and later professor of technical organic chemistry at the Norwegian Institute of Technology in Trondheim. We explore his roles, his research and his consultancy for state and industry at the university and at the institute. The early 1900s were important for the shaping of food and nutrition science as well as the growth of the food industry. During this period, food control and food regulations were implemented. Norway, the context in which Schmidt‐Nielsen worked had only become an independent nation in 1905, and the state administration, as well as the university and institute were young institutions. We argue that this specific situation paved the way for the roles Schmidt‐Nielsen played in academia, state and industry. By combining a biographical approach and a multi‐institutional perspective, new relations between different fields within food and nutrition became visible.     

阿联酋某尼尔森体系拱桥设计与分析

阿联酋Boulevard桥拱肋之间没有设置横撑,因此拱肋平面外稳定成为控制设计的采用Midas/civil软件建立有限元计算模型,考虑4种极限荷载状态组合,针对施工阶段和使用阶段,对尼尔森体系拱桥的结构设计、稳定性及动力特性进行分析与讨论.同时介绍横梁与系梁连接节点、系梁连接节点和拱肋连接节点的局部构造和处理方法.结果表明设计分析均满足现行规范要求.     

某金矿快速浮选工艺与重—浮联合工艺对比试验研究

在对某金矿矿石性质研究的基础上,采用快速浮选工艺与重—浮联合工艺进行对比试验研究,探索两种工艺的最优流程与药剂制度。结果表明,原矿金含量为2.43 g/t,其他有价金属含量较少,当磨矿细度为-0.074 mm占70%时,裸露金含量占57.49%,其他主要为黄铁矿和毒砂包裹金。在-0.074 mm占70%的细度条件下,采用快速浮选工艺,可获得金品位54.20 g/t、回收率70.81%的金精矿1和金品位17.52 g/t、回收率19.76%的金精矿2,金综合回收率达到90.57%;采用重—浮联合工艺,可获得金品位177.2 g/t、回收率29.44%的重砂和金品位30.68 g/t、回收率59.52%的金精矿,金综合回收率为88.96%。两种工艺均贯行的是“能收早收”的原则,但选矿指标略有差异,快速浮选工艺有利于提高金的回收率,而重—浮联合工艺则有利于获得部分高品位精矿产品。可根据实际情况选择不同的工艺流程。     

An Architecture of Exception: Transgressing the Everyday – Superflex's Flooded McDonald's

In Flooded McDonald's, a film by Danish artists' collective Superflex, the familiar sight of the fast-food restaurant is replaced by ‘a slowly emerging apocalyptical composition’, as the interior floods, objects are displaced and the retail space fills with water. Jonathan Mosley describes how this destabilised and other disaster-invoked visions of architecture – structures and spaces breaking down – enable us to use our imagination to test the parameters of the everyday.