大型屋面板制作主肋钢筋的改进

本文通过分析、计算、现场实践.采用高强钢丝Φ_5~k,取代原Ⅰ、Ⅱ级钢筋制作大型屋面板,结果表明.提高了强度等级.工期、观感、降低了工程造价.     

The Economic Impact of the Trout,Oncorhynchus mykiss,Industry on Transylvania County,North Carolina

Abstract

The commercial culture of rainbow trout, Oncorhynchus mykiss, in Transylvania County, North Carolina, generated approximately $9 million in economic output in 2002. Commercial trout farming began in North Carolina more than 45 years ago. Twenty of the 57 commercial trout farms in production in North Carolina are located in Transylvania County, ranging in size from 1,135 to 204,300 kg annual production in 2002. North Carolina presently ranks second in the United States in commercial trout production, behind Idaho. The study shows that, in 2002, the trout industry generated about $9 million in economic output, created 201 jobs, and generated $3 and $0.9 million, respectively, as labor income and tax revenue in 2002. This is particularly important for Transylvania County where economic prosperity depends on locally available jobs and diversification of economic activities.     

发展中国家实行金融自由化的利弊分析

金融自由化已成为发展中国家金融改革与发展的目标 ,但是 ,大部分发展中国家仍然担心金融自由化可能破坏本来就脆弱的金融体系 ,故而未能在金融自由化方面取得长足的进展。近期有许多经济学家依据经验和实证证明 ,金融自由化对经济发展之“利”要大于损害脆弱金融体系之“弊” ,并在长期中促进发展中国家经济发展。笔者对有关观点进行了分析和介绍。     

花椰菜主要经济性状的配合力分析

采用６×６双列杂交法研究了花椰菜１０个经济性状的配合力，结果表明：现球期、成熟期、株高、株展、单株生物学产量，叶片数等性状在相当程度上受非加性基因控制；单株经济产量和与花球质量有关的花球直径花球纵径、紧实度等性状则受加性基因效应影响大。     

花生新品种比较试验

对7个花生新品种进行了对比试验,结果表明:豫花15号、花育16号产量位居第1、第2位,且其他经济性状优良,生产上值得推广.     

吉安林化产业发展的现状与对策

吉安林业化工资源丰富，但林化产业发展滞后，通过对该产业存在问题的分析，提出加快该产业发展的对策。     

我国主要经济动物魏氏梭菌分离及血清型鉴定

对分离于7种经济动物的98株魏氏梭菌疑似物进行理化性质鉴定表明，分离菌符合魏氏梭菌特征。中和试验证实，分离于兔、狐狸、貉、水貂、麝鼠、犬的菌株均为A型；分离于鹿的菌株85．4％（35／41）为A型，14．6％（6／41）为C型，说明目前我国经济动物魏氏梭菌感染以A型为主。     

《经济林研究》近10年载文分析

应用文献计量法对《经济林研究》1993-2002年10年间发表载文的刊容特征、题材类型、基金论文、作者合著关系、论文全国分布情况进行统计分析。总结本刊具有的特点和优势．揭示载文内在规律．促进全国经济林发展事业．提供了参考依据．     

Economic opportunity survey of small scale dairy farms of the north west province of Cameroon

An Economic Opportunity Survey was conducted on dairy farms in the North West Province of Cameroon. Results showed that median (range) number of cows in milk per farm was zero point six (0–4) and six (3–12) in the zero grazing and transhumance systems, respectively. Medians (range) of three (0–24) and four (3–10) litres of milk were sold per farm per day, corresponding to 30% and 60% of milk produced. 24% and 13% of total cattle per herd were milking cows in the zero grazing and transhumance systems respectively. Median milk production per cow on one day was two (0–25) and two (1–3) litres. Median calf production interval was 14.5 (12–25) and. 21.5 (14–29) months. More milk produced per day represented the best economic opportunity in both systems while reduced age at first calving and longer lactation length were the next in both. Wastage of milk through spoilage from poor hygiene and lack of cooling was a major problem. Holstein cows, which were in the zero grazing system, had unexpectedly short lactations. Constraints identified led to the setting up of interventions of training and advice for farmers and of better nutrition.     

长江中游不同玉稻种植模式产量及资源利用效率的比较研究

发展长江中游玉米生产是解决本区域玉米产需矛盾的根本途径。近年来随着长江中游玉米的快速发展,该地区出现了春玉米–晚稻、双季玉米和早稻–秋玉米等新型的一年两熟制种植模式,为探明其适应性和实用性,2013—2014年在湖北省武穴市设置了传统种植的双季稻(对照)、春玉米–晚稻、双季玉米和早稻–秋玉米共4种两熟制种植模式,分析比较其周年产量及光、温、水资源利用效率和经济效益。结果表明,春玉米–晚稻和双季玉米周年产量显著高于早稻–秋玉米和双季稻。与双季稻相比,春玉米–晚稻周年产量、光能生产效率、光能利用率、积温生产效率、水分利用率及经济效益分别提高18.3%、14.1%、23.4%、16.4%、37.2%和44.3%,双季玉米分别提高了13.5%、8.1%、26.1%、11.4%、88.8%和37.8%。春玉米其产量、积温生产效率、水分利用率及经济效益两年平均比早稻分别高出30.6%、29.5%、57.2%和96.1%,而秋玉米和晚稻之间产量无显著差异。不同玉稻模式周年产量差异主要源于第一季春玉米和早稻产量的差异。可见,春玉米–晚稻和双季玉米是适宜在长江中游推广的两熟制种植模式。