Combining empirical models and the process-based model 3-PG to predict Eucalyptus nitens plantations growth in Spain

Empirical, statistically based models were used to describe the growth and development of Eucalyptus nitens plantations for a range of site productivities and the standard biomass and pulp silvicultural regime currently applied in Northern Spain. The results obtained, along with data gathered from a network of 68 plots, 48 trees felled for biomass estimations and 73 trees sampled for foliar area estimation were used to parameterize the 3-PG model for this species in Northern Spain. Most parameters associated with allometric relationships and partitioning (i.e. bark and branch fraction, basic density, age modifier and mortality) were derived from local data, and the remaining parameters were obtained from published studies on E. nitens or default values previously used for E. globulus. The parameterized model was validated with data from three trials measured from age 3 years until age 8-14 years, and performed better than the empirical model in terms of total stand under bark volume, mean diameter at breast height, basal area and foliar biomass. The process-based model was then used to forecast changes in plantations subjected to a clearwood regime, initializing the model at age 3 years, considering 3 prunings, 2 thinnings and lengthening the rotation to 18 years. This integrated regime was able to provide biomass for bioenergy, pulp or fibreboard wood and also solid wood, with thinning operations assisting the financial viability, and was a potentially good alternative for productive sites.     

Variation and Segregation for Rachis Fragility in Spelt Wheat, Triticum Spelta L.

Spelt wheat, Triticum spelta L., has been proved to be rich-sources of useful genes for tolerance to biotic and abiotic stress, and grain quality. But this crop plant has some undesirable traits including glume tenacity and brittle rachis. Free-threshing and reduced fragility of rachis are very important traits for cultivation. The objectives in the present study were to investigate genetic variation of rachis fragility in a wide range of spelt accessions, to examine its genetic segregation pattern, and to clarify if rachis fragility is associated with dosage of chromosome 5A in aneuploid lines of bread wheat. The results demonstrated that spelt germplasm contains a wide range of rachis toughness, and thus selection of spelt wheat with desirable characteristics combined with an appropriate level of tough rachis would be possible. Spike morphology in the F₂ plants was segregated into the three types, square-headed, speltoid, and compactoid. The F₂ plants with compactoid spikes had the most brittle rachis, followed by the speltoid and square-headed spike F₂ plants. Rachis fragility in bread wheat also had genetic variation and was associated with dosage of chromosome 5A.     

双低菜籽脱皮冷榨膨化新工艺的研究

 将菜籽脱皮分离系统、双螺旋榨油机、高含油料挤压膨化机组装集成，形成了双低菜籽脱皮冷榨膨化新工艺，分析了新工艺的技术经济可行性。新工艺具有降低生产成本，提高产品质量，增加经济效益等突出特点。其生产成本为每吨142.85元，比预榨浸出工艺节约生产成本近20%；冷榨油达到国家二级菜籽油标准；浸出粕粗蛋白质含量达46%以上，达到一级饲料用低硫甙菜粕标准。脱皮冷榨膨化新工艺实现了双低菜籽的高效加工，产业化应用前景广阔。     

马尔可夫过程在基金投资中的应用

马尔可夫过程是一个有着广泛应用的随机过程模型．作者应用此理论解决基金投资问题，得到了一种预测市价走势、确定买卖最佳时机的方法，以期投资收益最佳，并以基金普丰为例，验证了此数学模型的可行性和实用性．     

余甘子果汁加工工艺及设备研究

 针对余甘子果原汁加工工艺中存在的出汁率低,果汁中果核成分高,生产率低等问题,研制了余甘子脱核机,改进了压榨机,重组了工艺设备,使出汁率由原来的25% 提高到40%左右,新工艺获取的果汁中的Vc,类SOD,糖等含量均高于原工艺下的果汁,且口感好,二次沉淀减少,果汁质量好,经济效益显着提高。     

两种食用菌硝态氮含量变化研究

采用重氮偶合比色法研究了平菇、木耳硝酸盐、亚硝酸盐含量和不同加工、贮存条件下的含量变化，目的在于提高人们对食用菌硝酸盐、亚硝酸盐毒性的认识。结果表明：鲜平菇、木耳硝酸盐含量分别为86．57mg／kg、118．54mg／kg，比一级标准分别低345mg／kg、226mg／kg；亚硝酸含量分别为3．01mg／kg、2．54mg／kg，都比限量低37mg／kg。从硝酸盐、亚硝酸盐含量角度看，平菇、木耳的安全系数很高，可以放心食用。水煮后硝酸盐含量升高，但仍在安全值内；亚硝酸盐含量降低，降低幅度盐水较小。贮存期间硝酸盐、亚硝酸盐含量均降低。     

The social construction of production externalities in contemporary agriculture: Process <Emphasis Type="Italic">versus</Emphasis> product standards as the basis for defining “organic”

The analysis distinguishes two types of standards for defining organic produce; process standards and product standards. Process standards define organic products by the method and means of production. Product standards define organic by the physical quality of the end product. The National Organic Program (NOP) uses process standards as the basis for defining organic. However, the situation is complicated by agricultural production practices, which sometimes result in the migration of NOP prohibited substances from conventional to organic fields. When this interaction alters the value of the product or the costs of production, a production externality is said to exist. Defining organic using process, rather than product standards, influences the burden and character of production externalities. The NOPs emphasis on process standards reduces the likelihood that production externalities will emerge.B. James Deaton is an Assistant Professor in the Department of Business and Agricultural Economics, University of Guelph, Canada. His research examines environmental and natural resource issues. He is particularly interested in the manner in which laws, rules, and standards influence environmental quality, natural resource use, and economic development. Additional research examines the relationship between different forms of private property and economic development, public support for various criteria used to preserve farmland, and the social construction of production externalities in agriculture. Prior to his PhD training, he worked on economic development projects in Lesotho (Southern Africa) and the Appalachian region of eastern Kentucky.John P. Hoehn is a Professor of Environmental and Natural Resource Economics in the Department of Agricultural Economics, Michigan State University. His teaching and research activities address environmental and natural resource policies, benefit-cost analysis of environmental improvements, methods for valuing non-market goods, improved institutions for protecting, managing, and using environmental resources, and the economics of ecological resources. He teaches core courses in the departmental and university-wide graduate programs in environmental and resource economics.     

层次分析法在县域生态环境质量评价中的应用

以四川井研县为例,结合正在进行的乐山市新一轮土地利用规划修编的部分基础资料,阐述了层次分析(AHP)法在县域生态环境质量评价中的应用.结果表明,AHP法可大大提高全值定量的理性成分,得到更加符合实际的成果.     

小麦品种百农64的慢白粉病QTL分析

白粉病是我国小麦的主要病害，发掘慢白粉抗病基因及其紧密连锁的分子标记是培育慢病性品种的基础。本实验利用100个SSR标记和58个AFLP标记，分析百农64×京双16组合218个F2:3系的基因型，构建了由158个位点组成的遗传连锁图，在小麦连锁群上覆盖3114 cM。2003-04和2004-05年度将该群体种植于北京和安阳两点，鉴定各个家系对白粉病的抗性。采用复合区间作图法进行慢白粉病的QTL分析，发现3个控制慢白粉病的QTL，其中位于2B和2D 染色体的2个QTL在两种环境下均能检测到，贡献率分别为9.6%～11.3%和21.2%~26.1%。QTL遗传效应表现为加性和部分显性，其加性效应均来自抗病亲本百农64。     

果病清加工技术及室内毒力测定研究

介绍了混配制剂50％果病清悬浮剂的加工工艺，并以苹果黑星病和苹果轮纹病为供试菌种，测定了果病清的室内毒力。结果表明，当多菌灵与高脂膜以2：3混合时，其对两种病原菌的共毒系数最高，分别为253.99和626.92，EC50分别为21.5μg/g和2.9μg/g。因此，认为该技术路线可行，配比合理。