人造板表面装饰环保工艺技术探讨

营造绿色健康的生活环境已成为我国社会乃至全人类十分关心的问题。着重介绍人造板装饰环保工艺的技术。     

树形结构对果树生产能力的影响分析

果树树形与结构是影响果树产量的重要因素,笔者结合国内外的研究状况,综述了不同树形结构对光能利用率、营养与生殖、抗逆性、产量品质、实际生产的影响,指出适宜的栽植密度、合理的树形结构是保证果园光照良好,产量和品质提高的重要措施。     

不同切割酸度对奶豆腐品质影响研究

研究不同切割酸度对奶豆腐品质的影响,以确定其最佳切割酸度。采用单因素试验设计,切割酸度分别为45°T～50°T、55°T～60°T、65°T～70°T、75°T～80°T、85°T～90°T。在其他工艺条件相同的情况下,分别加工一批奶豆腐,然后测定奶豆腐的性能指标。结果表明,随着切割酸度的增加,奶豆腐的感官评定值先增加,然后逐渐降低;奶豆腐的pH4.6可溶性氮含量、质量分数12%TCA可溶性氮和游离氨基酸总量都逐渐增加;而pH值和水分含量逐渐降低。以感官评定值为主指标,结合其他性能指标,确定切割酸度为65°T～70°T。     

生物技术专业应用型本科人才培养体系的完善

结合应用型人才的培养目标与生物技术专业的特点,从培养大学生实践能力和创新能力的方法及如何增强适应社会的能力等方面进行了探讨,完善生物技术专业人才培养体系,使生物技术专业的人才培养向应用型转变,从而更好的适应市场和社会的需求。     

寿竹埋鞭育苗繁殖试验

寿竹因其竹秆、笋、箨壳的经济价值极高,具有广阔的产业化开发前景。但是,由于寿竹开花不结实,竹秆节部无休眠芽(隐芽)和根点,大面积造林一直受制于种苗短缺的难题。从育苗时间、竹鞭鞭龄、覆盖措施、激素处理等方面试验研究了寿竹埋鞭育苗繁殖技术,结果表明:3月上旬埋鞭育苗效果最好,成苗株数和成苗率与其它育苗时段有显著差异;2年生、3年生竹鞭的育苗效果明显好于1年生的竹鞭,尤以2年生竹鞭最好;小拱棚覆盖较不覆盖提前发笋出苗12d,与其它3种覆盖措施的效果有显著差异,成苗率达77.9%,而其它3种覆盖处理的效果无明显差异;100×10-6ABT2号生根粉处理效果最好,成苗数较清水处理提高100%以上。     

Food provisioning strategies,food insecurity,and stress in an economically vulnerable community: the Northern Cheyenne case

Living in poverty is associated with high levels of protracted stress associated with health problems. Economic and food insecurity are particularly poignant aspects of poverty and condition the work of securing basic daily needs of families. Recent studies suggest that levels of stress increase as family food needs rise. This paper presents new findings which clarify the relationship of food provisioning to stress levels, by examining actual food provisioning strategies and food insecurity among the Northern Cheyenne Indians of southeastern Montana. Results clearly show that stress varies by types of food acquisition strategies. Contrary to our expectations, more complex strategies, including relatively unpredictable and cumbersome food provisioning activities, are not linked to higher stress levels in our analysis. Controlling for food security levels, households using a combination of local programs and informal subsistence sources are the least stressed, despite the demands of managing a large number of food sources. Households primarily using Food Stamps are the most likely to experience high levels of stress. Interviews with Food Stamp recipients show that potential sources of stress include inadequate allocations of Food Stamps, difficulty achieving and maintaining eligibility, challenges to complying with paperwork and appointment requirements, as well as personal obstacles and community barriers to making food stamps last. Analyses indicate that contradictions between local cultural norms for food provisioning and the realities of food insecurity in this context promote strategies emphasizing greater independence from federal food programs.     

Molecular divergence and application of the ITS-5.8S rDNA and RUBISCO spacer in <Emphasis Type="Italic">Porphyra haitanensis</Emphasis> Chang et Zheng (Bangiales,Rhodophyta)

To select a reliable and sensitive method for discriminating strains of Porphyra haitanensis, the nucleotide sequence of the internal transcribed spacer 1 to internal transcribed spacer 2 regions (ITS-5.8S) of nuclear ribosomal DNA and the intergenic spacer region of RUBISCO were compared in five wild and five cultivated Porphyra haitanensis strains. Based on molecular analyses, sequences of ITS-5.8S (about 1,210 bp) could be divided into three regions: ITS1, 5.8S, and ITS2. The ITS1 and ITS2 sequences of each strain differed, even between individuals collected from the same site. In contrast, 5.8S rDNA and RUBISCO spacer sequences were identical among the ten P. haitanensis strains, although differences were found among different Porphyra species. Phylogenetic analysis also supported these conclusions. These sequence features of highly conserved regions and diversified regions that occurred repeatedly in ITS-5.8S could be useful in discriminating germplasm of P. haitanensis strains or Porphyra species. In contrast, the RUBISCO spacer is only suitable for identifying Porphyra species. New coupled primers were designed to amplify only the 5.8S rDNA and ITS2 region of Porphyra. The sequences of these amplified fragments can be readily used to identify germplasm or to perform phylogenetic analysis of Porphyra spp.     

机械运输对伊朗北部山林陡峭集材道土壤的干扰

A study was conducted to investigate the effects of skid trail slope and traffic levels on soil disturbances at two soil depths (0–10 and 10–20 cm). The treatments were set at four traffic levels (2, 7, 12 and 20), two slope classes (<20% and >20%) and two soil depths (0–10 and 10–20 cm). Results show that skidder traffic, longitudinal slope and soil depth have significant effect on soil bulk density in skid trail. Comparison of average soil bulk density in different traffic levels shows that there are significant differences in average bulk density between different traffic levels and control (p<0.05). The average bulk densities in different slopes and soil depths are significantly increased with increase in traffic levels, maximized at 12 passes (p<0.05), but there are no significant differences between 12 and 20 passes. The interaction effects between traffic and soil depth are significant (F _0.05,3=0.109, p<0.001). For all traffic treatments, there are significant differences in soil moisture content between the two slope classes and the two depths (p<0.001). However, the interaction effects between traffic levels and slope classes are not significant (p >0.05), although skidder traffic and slope affected soil moisture content.     

Influence of Humic Products on Soil Health and Potato Production

Since 1900, soil organic matter (SOM) in farmlands worldwide has declined drastically as a result of carbon turnover and cropping systems. Over the past 17 years, research trials were established to evaluate the efficacy of different commercial humates products on potato production. Data from humic acid (HA) trials showed that different cropping systems responded differently to different products in relation to yield and quality. Important qualifying factors included: source; concentration; processing; chelating or complexing capacity of the humic acid products; functional groups (Carboxyl; Phenol; Hydroxyl; Ketone; Ester; Ether; Amine), rotation and soil quality factors; consistency of the product in enhancing yield and quality of potato crops; mineralization effect; and influence on fertilizer use efficiency. Properties of humic substances, major constituents of soil organic matter, include chelation, mineralization, buffer effect, clay mineral-organic interaction, and cation exchange. Humates increase phosphorus availability by complexing ions into stable compounds, allowing the phosphorus ion to remain exchangeable for plants’ uptake. Collectively, the consistent use of good quality products in our replicated research plots in different years resulted in a yield increase from 11.4% to the maximum of 22.3%. Over the past decade, there has been a major increase in the quality of research and development of organic and humic acid products by some well-established manufacturers. Our experimentations with these commercial products showed an increase in the yield and quality of crops.