United States demand for hardwood plywood imports: A distributed lag model     

Jieh-Jen Chou  Joseph Buongiorno 《Agricultural Systems》1982,8(3):225-239

A theoretical model of the United States demand for hardwood plywood imports was developed. Demand derives from activity in the construction industry where costs are minimised subject to a generalised Cobb-Douglas technology. This static model was then modified to reflect dynamic adjustments of imports to prices and housing starts. The resulting model was estimated with monthly data for the period January, 1974 to December, 1979. The choice of either c.i.f., f.a.s. or customs data did not significantly affect the statistical results. No significant substitution was apparent between imported hardwood plywood and domestic hardwood or softwood plywood. Import data appeared to be explained by expectations on housing starts and relative prices. Importers' expectations were represented by Cagan's adaptive expectations model and by Almon's polynomial lag equation. The latter model, relating imports to (i) housing starts and (ii) import prices, gave significantly better results. The maximum lag was of 9 months, with a mean lag of 4·5 months. The long-term elasticity of imports with respect to housing starts was estimated at 1·10 (±0·12). The long-term elasticity with respect to real price was ?1·98 (±0·24), using the price of all commodities as the deflator.  相似文献   

Morbilliviral infection in a pygmy sperm whale (Kogia breviceps) from Taiwanese waters     

Yang WC  Pang VF  Jeng CR  Chou LS  Chueh LL 《Veterinary microbiology》2006,116(1-3):69-76

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Medial canthoplasty for epiphora in dogs: a retrospective study of 23 cases     

Yi NY  Park SA  Jeong MB  Kim MS  Lim JH  Nam TC  Seo K 《Journal of the American Animal Hospital Association》2006,42(6):435-439

The medical records of 23 dogs that underwent medial canthoplasty for treatment of epiphora were reviewed. The most prevalent breed encountered was the shih tzu. Other affected breeds included the Pekingese, Maltese, toy poodle, and pug. All dogs had epiphora associated with medial canthal trichiasis and/or entropion. Other ocular abnormalities included conjunctivitis, keratitis, pigmentary keratitis, corneal ulceration, globe prolapse, and nasal fold trichiasis. After medial canthoplasty, the epiphora resolved in all dogs.  相似文献   

Smoke Water and Heat Shock Influence Germination of Shortgrass Prairie Species     

Yi-Fang Chou  Robert D. Cox  David B. Wester 《Strength and Conditioning Journal》2012,65(3):260-267

Smoke or heat from fire can act as a cue that affects seed germination. We examined germination responses of 10 plant species (six forbs, two shrubs, two grasses) native to the southern High Plains in the United States, to smoke, heat, and their interaction in a laboratory experiment. Smoke treatments were applied by soaking seeds in 1∶5, 1∶10, or 1∶100 (v/v) Regen 2000® smoke solution for 20 h. Heat treatments were applied by placing seeds in an oven at 50°C or 80°C for 5 min. Nine species responded to smoke, heat, or both. Results showed that smoke can enhance, inhibit, or not affect seed germination. Germination capacities of Gutierrezia sarothrae (Pursh) Britton & Rusby and Astragalus crassicarpus Nutt. were promoted by 1∶5 and 1∶100 dilutions of smoke water, respectively; Coreopsis tinctoria Nutt., G. sarothrae, Salvia reflexa Hornem., Digitaria ciliaris (Retz.) Koeler, and Panicum virgatum L. were inhibited by high and/or moderate concentrations of smoke water either in germination percentage or in mean germination time. Germination percentage of Solanum elaeagnifolium Cav. increased following an 80°C heat treatment. Interaction effects between smoke and heat on germination also were detected. Smoke and heat treatments might be useful as management tools for promoting or suppressing specific target species of shortgrass prairie communities in future habitat management.  相似文献   

A Therapeutic Potential for Marine Skeletal Proteins in Bone Regeneration     

David W. Green  Matthew P. Padula  Jerran Santos  Joshua Chou  Bruce Milthorpe  Besim Ben-Nissan 《Marine drugs》2013,11(4):1203-1220

A vital ingredient for engineering bone tissue, in the culture dish, is the use of recombinant matrix and growth proteins to help accelerate the growth of cultivated tissues into clinically acceptable quantities. The skeletal organic matrices of calcifying marine invertebrates are an untouched potential source of such growth inducing proteins. They have the advantage of being ready-made and retain the native state of the original protein. Striking evidence shows that skeleton building bone morphogenic protein-2/4 (BMP) and transforming growth factor beta (TGF-β) exist within various marine invertebrates such as, corals. Best practice mariculture and the latest innovations in long-term marine invertebrate cell cultivation can be implemented to ensure that these proteins are produced sustainably and supplied continuously. This also guarantees that coral reef habitats are not damaged during the collection of specimens. Potential proteins for bone repair, either extracted from the skeleton or derived from cultivated tissues, can be identified, evaluated and retrieved using chromatography, cell assays and proteomic methods. Due to the current evidence for bone matrix protein analogues in marine invertebrates, together with the methods established for their production and retrieval there is a genuine prospect that they can be used to regenerate living bone for potential clinical use.  相似文献   

多相混输泵叶轮不同区域增压性能     

史广泰  王志文 《排灌机械工程学报》2019,37(1):13-17

为了改善多相混输泵叶轮域的增压性能,提高混输泵叶轮的做功能力,选用标准的k-ε湍流模型,分别在纯水条件不同流量下和设计流量不同含气率下进行了数值计算,对多相混输泵叶轮不同区域的增压性能展开了研究.结果表明：从叶轮进口到出口,各级叶轮叶片工作面和吸力面压差大的区域主要集中在叶轮的前半段,且在叶轮前半段,越靠近轮缘,叶轮的增压性能越强,越靠近轮毂,叶轮的增压性能越弱,在叶轮后半段,越靠近轮缘,叶轮的增压性能越差,越靠近轮毂,叶轮的增压性能越强;在不同流量下,随着流量的增大,叶片工作面和吸力面的压差逐渐减小,流量对叶轮前半段叶轮叶片工作面和吸力面压差的影响先增大后减小,流量对叶轮后半段叶轮叶片工作面和吸力面压差的影响逐渐减小;在不同含气率下,含气率越高,对混输泵叶轮的增压性能影响越大,且随着含气率的升高,叶片工作面和吸力面压差下降越快.研究结果对多相混输泵叶轮的进一步优化设计提供重要的理论依据.  相似文献   

A cell-based screening identifies compounds from the stem of Momordica charantia that overcome insulin resistance and activate AMP-activated protein kinase     

Cheng HL  Huang HK  Chang CI  Tsai CP  Chou CH 《Journal of agricultural and food chemistry》2008,56(16):6835-6843

Treatment of insulin resistance is a critical strategy in the prevention and management of type 2 diabetes. The crude extracts from all parts of Momordica charantia L. have been reported by many studies for the effective treatment of diabetes and related complications. However, the exact ingredients responsible for the hypoglycemic effect and the underlying mechanism of their actions have not been well characterized because of the lack of a proper assay and screening system. A new cell-based, nonradioactive, and nonfluorescent screening method was demonstrated in this study to screen for natural products from the stem of M. charantia, aiming to identify hypoglycemic components that can overcome cellular insulin resistance. The results suggest triterpenoids being potential hypoglycemic components of the plant and the mechanism underlying their action involving AMP-activated protein kinase.  相似文献   

衡阳市的气候条件和春大豆栽培     

曾鸿飞 《作物学报》1985,11(1):47-51

依据1975～1981年衡阳市的气象资料和春大豆亩产量资料,首先用正交多项式回归方法估计了趋势产量,然后用费希尔积分回归模式和逐步回归方法计算出了该市气候因子和离趋势产量间的积分回归公式。这样,就选出了影响春大豆产量的主要气候因子,同时求出了它们对春大豆产量的影响系数。研究表明春大豆产量显著地受每旬平均温度,旬  相似文献   

红枣干燥技术与装备研究进展     

刘德成  郑霞  肖红伟  姚雪东  单春会  常安太  丑维新 《农机化研究》2022,44(1):8-18

为了探索开发适宜缩短红枣干燥时间、提高红枣干燥品质的技术与装备,综述了红枣单一与联合干燥发展现状与研究进展,并在此基础上进行了红枣干燥技术与装备的对比分析.同时,阐述了预处理对红枣干燥特性的影响,以期为在研究红枣干燥特性和干燥装备现状的基础上,对不同红枣干制品实施适宜的干燥加工技术与研制新型干燥装备提供理论依据与技术支...  相似文献   

非对称翼型反装对H型垂直轴风力机流场分布的影响     

李寿图  杨从新  史广泰  张旭耀 《排灌机械工程学报》2018,36(2):141-145

H型垂直轴风力机(H-VAWT)是典型的升力型垂直轴风力机,且有集群式发展的潜力和优势.文中采用数值模拟的研究方法,建立二维模型,对比分析了使用非对称翼型的H-VAWT叶片反装时的流场结构,以及反装时叶片数对H-VAWT流场分布的影响.结果表明:对于非对称翼型的H-VAWT,叶片反装所产生的尾流湍流强度较叶片正装时大,且尾流的恢复能力差,进而影响到H-VAWT在风场中的布局,但是叶片的正装和反装对H-VAWT附近外流场中Y方向上流场分布的影响基本一致;随着叶片数的增加,反装叶片的H-VAWT本身产生尾流的湍流强度增加,这增强了下风轮区域叶片和上风轮区域叶片所产生湍流的相互作用,但是叶片数为3时,叶片的正装和反装所产生的湍流差别不大.  相似文献