模糊层次评价在油田产能建设投资中的应用

由于投资在油田产能建设当中占的比重很大,所以对油田产能建设当中投资的评价就显得相当重要。凭借已知的模糊层次评价模型,利用油田的实际开采状况得到的产量、井深、投资额的数据,形成了3个因素之间相互组合的不同的各种方案,并且运用敏感性分析方法来确定产量、井深、投资额的权重,对油田产能建设的投资进行相关的经济评价,最终结果以数值的行式表示出来,从而更加直观的确定最佳方案。对油田产能建设中投资规模的确定有着一定的现实意义和借鉴意义。     

Food safety-related refrigeration and freezer practices and attitudes of consumers in Peoria and surrounding counties

Government agencies have recently emphasized the importance of food safety. Reducing the risk of foodborne illnesses within the home requires American consumers to put government refrigeration and freezer recommendations into practice; however, little research has been conducted regarding the use of proper refrigeration and freezer storage practices by consumers. A random sample survey was conducted to examine attitudes and practices of proper refrigeration and storage techniques of consumers in Peoria County, Illinois, and to determine whether gender, age, education, and income level have an effect on these variables. Eighty-one of 500 random sample surveys mailed were returned between 10 January and 15 February 2005. The majority of the participants were female (56, 69.1%), were 50 to 59 years old (18, 22.2%), had a bachelor's degree (33, 40.7%), and had a reported total household income of 60,000 dollars or greater (39, 91.4%). Average attitudinal scores indicated that participants thought it was important to take proper steps to prevent foodborne illnesses in the home; however, 68.8% of participants scored poorly on the practice portion of the survey. Only 12.3% of participants stated that they had a thermometer in their freezer, and 24.7% had one in their refrigerator. Eighty-four percent of respondents did not store eggs correctly in the refrigerator. No significant relationships (P < 0.05) were found within this sample population. These results suggest that further evaluation of consumer practices and attitudes is needed to better understand consumers so that they can be effectively educated about the prevention of foodborne illnesses at home.     

高效液相色谱-光电二极管阵列检测器法测定野山楂中两组分的含量

【摘要】 建立高效液相色谱法测定了野山楂中乌索酸和齐墩果酸的含量,同时采用光电二极管阵列检测器检测两组分的紫外光谱。色谱柱为NucleosilC18柱(4.6mm×250mm,5μm),流动相为甲醇-水(87:13,V/V),流速0.8ml/min,检测波长210nm,柱温26℃。乌索酸在0.1244～2.488μg范围内线性关系良好(r=0.9996),平均回收率为98.1%。齐墩果酸在0.1192～2.384μg范围内线性关系良好(r=0.9999),平均回收率为101.2%。方法简便、准确、重现性好、线性范围宽,适用于测定野山楂中乌索酸和齐墩果酸的含量。     

Resource-conserving agriculture increases yields in developing countries

Despite great recent progress, hunger and poverty remain widespread and agriculturally driven environmental damage is widely prevalent. The idea of agricultural sustainability centers on the need to develop technologies and practices that do not have adverse effects on environmental goods and services, and that lead to improvements in food productivity. Here we show the extent to which 286 recent interventions in 57 poor countries covering 37 M ha (3% of the cultivated area in developing countries) have increased productivity on 12.6 M farms while improving the supply of critical environmental services. The average crop yield increase was 79% (geometric mean 64%). All crops showed water use efficiency gains, with the highest improvement in rainfed crops. Potential carbon sequestered amounted to an average of 0.35 t C ha(-1) y(-1). If a quarter of the total area under these farming systems adopted sustainability enhancing practices, we estimate global sequestration could be 0.1 Gt C y(-1). Of projects with pesticide data, 77% resulted in a decline in pesticide use by 71% while yields grew by 42%. Although it is uncertain whether these approaches can meet future food needs, there are grounds for cautious optimism, particularly as poor farm households benefit more from their adoption.     

Using radon risk to motivate smoking reduction: evaluation of written materials and brief telephone counselling

OBJECTIVE: Radon and cigarette smoking have synergistic effects on lung cancer, even when radon concentrations are relatively low. Working through an electric utility company, we sought to reach smoking households with low radon concentrations and motivate smoking cessation or prohibiting smoking in the home. DESIGN: Eligible homes (n = 714) were randomised to receive: (1) the Environmental Protection Agency's (EPA's) "A citizen's guide to radon"; (2) a specially developed pamphlet; or (3) that pamphlet plus brief telephone counselling. PROCEDURE: Utility company "bill stuffers" offered free radon test kits to smoking households. All households received radon test results with an explanatory cover letter. Both the specially developed pamphlet and the telephone counselling emphasised that smoking cessation or prohibiting smoking in the home were the optimal risk reduction strategies. Households were followed up at 3 and 12 months after receiving materials. RESULTS: The specially developed pamphlet and the EPA guide yielded similar outcomes. There was a non-significant trend for telephone counselling to produce greater sustained quitting than the specially developed pamphlet, and phone counselling led to significantly more new household smoking bans. CONCLUSIONS: Working through a public utility company is an efficient way to reach smoking households, and brief telephone counselling is a promising method for promoting household smoking bans and cessation in homes alerted to the risk posed by the combination of radon and smoking.     

Action of lysozyme and nisin mixtures against lactic acid bacteria

Lysozyme was formulated together with nisin for usage against food spoilage lactobacilli. The mixtures demonstrated improved minimal inhibitory concentrations (MIC), compared to the parent compounds, for many of the bacteria and media tested, including high salt media in which lysozyme lost virtually all of its activity. Synergy was also observed through measurement of the kinetics of bacterial killing of L. curvatus 845, in which strain synergy had been observed in MIC assays. The combination of lysozyme and nisin caused more severe cell damage as viewed by scanning electron microscopy, and a consequent change in optical density at 600 nm, compared to the parent compounds, effects that were presumed to reflect the action of lysozyme. In addition, the combination caused more rapid permeabilization (depolarization) of the cytoplasmic membranes of Staphylococcus aureus, an effect that reflected the mechanism of action of nisin. Thus, nisin and lysozyme appear to demonstrate synergy against gram-positive bacteria because they reinforce each others mechanisms of bacterial killing.     

Inhibition of surface spoilage bacteria in processed meats by application of antimicrobial films prepared with chitosan

A study was undertaken to evaluate the feasibility of using antimicrobial films, designed to slowly release bacterial inhibitors, to improve the preservation of vacuum-packaged processed meats during refrigerated storage. The antimicrobial films were prepared by incorporating acetic or propionic acid into a chitosan matrix, with or without addition of lauric acid or cinnamaldehyde, and were applied onto bologna, regular cooked ham, or pastrami. At various times during storage, packages were opened and the amounts of antimicrobial agents remaining in the chitosan matrix were measured. Regardless of film composition or meat product type, propionic acid was nearly completely released from the chitosan matrix within 48 h of application, whereas release of acetic acid was more limited, with 2-22% of the acid remaining in chitosan after 168 h of storage. Addition of lauric acid, but not cinnamaldehyde, to the chitosan matrix generally reduced the release of acetic acid significantly (P < or = 0.05) and the release was more limited onto bologna than onto ham or pastrami. In addition, the efficacies of the various films for inhibiting bacterial growth were tested against indigenous lactic acid bacteria and Enterobacteriaceae, and against Lactobacillus sakei or Serratia liqueficiens, surface-inoculated onto the meat products. Whereas lactic acid bacteria were not affected by the antimicrobial films under study, the growth of Enterobacteriaceae and S. liquefaciens was delayed or completely inhibited as a result of film application. Strongest inhibition was observed on drier surfaces (bologna), onto which acid release was slower, and with films containing cinnamaldehyde, as a result of its greater antimicrobial activity under these conditions.     

不同产量递减方式对气田效益影响研究

首先运用技术经济学的有关原理,结合油藏工程原理的基本知识,建立了气藏储量初始经济产量的评价模型,得到了在不同天然气产量递减方式和不同内部收益率情况下的单井日产量,然后利用这些数据,运用SPSS软件进行了方差分析,得到了调和递减方式下的单井日产量与直线递减和凸型递减方式下的单井日产量有显著性差异的结论。最后通过SPSS软件对内部收益率、单井日产量、产量递减方式的回归,得到调和递减的效益好于指数递减;指数递减好于直线递减;直线递减好于凸型递减;并且单井日产量为气田效益影响的敏感因素的结论,为油气田经济评价方法提供一种思路。