Optimization of production of nucleopolyhedrovirus ofHelicoverpa armigera throughout larval stages

Studies were carried out to optimize production of nucleopolyhedrovirus of American bollworm,Helicoverpa armigera (Hübner), by treating larvae individually with an inoculum dose that allowed maximal larval growth and also gave the highest occlusion bodies (OB) yield/larva. The maximum virus yield of 12.2x 10⁹ OB/larva was obtained when 6-day-old larvae were fed individually with a dose of 1 x 10³ OB. Topical spiracular treatment of larvae as old as 8 days with 10 μ of 2x 10⁷ OB ml^-1 gave the highest yield, of 15.2x 10⁹ OB from 13-day-old larvae, of 12.8x 10⁸ OB from prepupae and of 1.49x 10⁸ OB from pupae at the time of their death. These studies showed that dietary inoculum is the best route for 6-day-old larvae and topical spiracular treatment is the best for 8-day-old larvae.     

美国优良牧草引种及其利用初探

本文论述从美国俄勒岗淋巴恩布莱格公司引进３６个优良牧草品种，并在福建省上杭县试种筛选的过程。探索在本地区栽培管理这批优良牧草技术及预测在我国南方利用发展前景。     

The community idea in American country life

The American Country LifeAssociation was heir to Theodore Roosevelt'sCountry Life Commission, which examined thegeneral conditions of farming life in the opencountry, and...its larger problems. In1919, Kenyon Butterfield, a member ofRoosevelt's Commission, met withrepresentatives from 30 states and 25 nationalorganizations to form the American Country LifeAssociation. In that year, Butterfield, ACLA'sfirst president, published a book, TheFarmer and the New Day, whose defining chapterwas The Making of Communities: The CommunityIdea. The ACLA was educator created and led.Solutions to rural problems were seen aseducational matters. But educational philosophywas undergoing scrutiny and new educationalconcepts were arising from the bustling,industrializing, urbanizing times of late19th century. The experimental,unconstrained spirit of the nation at the turnof the century was formalized as pragmatism. Aleading pragmatist and educator of the time wasJohn Dewey, a contemporary of Butterfield.The communitarianism of Butterfield and Deweycarried throughout the life of ACLA in avariety of forms. Even after ACLA ended as anorganization in 1976, the concerns and idealscontinued in successor organizations, and canbe found in environmental, sustainableagriculture, and rural life organizationstoday. This paper traces one of continuingthemes of the ACLA, the community idea as a wayof adding a social dimension to agriculture'seconomic policies and development. The ACLAstory is a metaphor for country life throughmuch of 20th century America. ACLA is alsoa lesson in how organizations come into being,flourish, falter, die, and leave their legaciesto future generations.     

美系獭兔的胴体性状和肉品质特性研究

通过对20只美系獭兔屠宰性能和肉品质的测定，研究獭兔的生产性能和肉质特性及它们之间的关系，结果表明：美系獭兔5月龄的平均体重为2.533 kg,商用皮重0.410 kg,屠宰率为60.70%，右后腿重0.182 kg，体长和腰周长分别为30.69和18.04 cm；美系獭兔背最长肌和后腿肉的pH1(宰后1 h的pH)分别为6.42和6.43，pH24(宰后24 h的pH)分别为6.22和6.35,肉色L*值分别为54.66和52.67，a*值分别为12.37和9.89，b*值分别为9.06和4.08；兔肉的滴水损失、熟肉率、蒸煮损失、剪切力值、水分含量和肌内脂肪含量分别为2.06%、62.12%、30.44%、2.453 kg.f、73.60%和1.67%。商用皮重与热胴体重、体长存在极显著的正相关（P<0.01），与商用胴体重存在显著的正相关（P<0.05）。兔的体重（热胴体、商用胴〖JP2〗体、右后腿）、体型（体长和腰周长）与滴水损失、蒸煮损失呈负相关，与熟肉率、剪切力值呈正相关，但相关性都不显著（P>0.05）。     

美国杏李不同栽培模式适应性评价

本文通过对不同品种不同栽培模式美国杏李生长和林地土壤含水量动态变化分析表明:栽培模式3抗旱性好,在研究地可广泛应用;栽培模式2在研究地比较适合在有一定灌溉条件的地区应用;栽培模式1抗旱性适中,可在研究地土壤水分条件尚好的地区应用;栽培模式5可在研究地土壤水分条件尚好的地区控制应用;栽培模式4在研究地不宜采用。     

Multi-scale use of lands providing anthropogenic resources by American Crows in an urbanizing landscape

The conversion of forests and farmlands to human settlements has negative impacts on many native species, but also provides resources that some species are able to exploit. American Crows (Corvus brachyrhynchos), one such exploiter, create concern due to their impact as nest predators, disease hosts, and cultural harbingers of evil. We used various measures of crow abundance and resource use to determine crows’ response to features of anthropogenic landscapes in the Puget Sound region of the United States. We examined land cover and land use composition at three spatial scales: study sites (up to 208 ha), crow home ranges within sites (18.1 ha), and local land cover (400 m²). At the study site and within-site scales crow abundance was strongly correlated with land cover providing anthropogenic resources. In particular, crows were associated with the amount of ‘maintained forest’ cover, and were more likely to use grass and shrub cover than forest or bare soil cover. Although crows did not show a generalized response to an edge variable, they exhibited greater use of patchy habitat created by human settlements than of native forests. Radio-tagged territorial adults used resources within their home ranges relatively evenly, suggesting resource selection had occurred at a larger spatial scale. The land conversion pattern of new suburban and exurban settlements creates the mix of impervious surfaces and maintained vegetation that crows use, and in our study area crow populations are expected to continue to increase. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

后现代主义“反侦探小说”——以《芒博琼博》为例

后现代“反侦探小说”是当代越来越受到评论家关注的一个亚文类。本文在简要梳理“反侦探小说”基本特征的基础上，结合非裔美国作家伊什梅尔·里德的代表作《芒博琼博》，从罪案之谜、侦探形象和叙事结构等方面进一步探讨后现代文本对传统侦探小说的解构。本文认为，对后现代“反侦探小说”政治性的认识，是一个值得商榷的问题。     

美国黑人英语语言特征在电影对白中的表现及分析

屡次被贴上“蹩足英语”标签的美国黑人英语（AAVE）在美国文化发展中所起的作用不容质疑，黑人英语作为黑人文化的源泉一直受到语言学家及社会学家的关注。文中围绕美国黑人英语中BE不变体、否定、嘲讽及黑人俚语运用等典型语言特征，以系列好莱坞经典黑人电影对白为素材，分析了美国黑人英语的“黑人味”。指出作为一种成熟的英语变体，美国黑人英语独特的语言体系及其蕴含的丰富黑人文化元素对研究美国多元文化的变迁具有重要意义。     

美国大学商业化现象及其启示

商业化已经成为美国大学校园里一个普遍的现象.文章首先引入SWOT分析机制,从内部和外部两方面深入探讨美国大学商业化现象产生的原因.接着对商业化现象的四种主要表现形式,即体育竞赛、产学研合作、推广教育课程以及大学内部课程结构的商业化等进行分析.这些商业化既给大学带来利益,也使大学付出代价.大学应该划出一条适当的界限,既保护大学核心价值,又推动大学更好地为社会发展服务.     

美式家具仿古涂饰工艺技术

研究美式家具仿古涂装中的木材着色剂和涂装工艺技术.通过对着色材料成分、着色方法和机理的分析,说明不同的着色剂的作用和适用环境,并介绍仿古做旧的具体工艺程序和操作要点.