肉桂醛催化选择加氢制氢化肉桂醛

采用煤质活性炭作载体,分别用HNO3、H2O2和(NH4)2S2O8进行预处理,然后用浸渍法负载PdCl2,在H2流中还原得到Pd/C催化剂,用于肉桂醛(CAL)选择加氢制氢化肉桂醛(HCAL)的反应。考查了Pd负载量,反应温度和压力对加氢反应的影响,优化了反应条件。进一步考查了助剂Fe、Co、Ni[1]对反应的影响。最终,CAL转化率为98%,HCAL选择性为88%。     

天然林择伐经营技术的应用研究

按照森林可持续经营的原则，从天然林生态保护角度出发，以福建省永安市为例。利用森林分类经营方法对天然林经营进行科学分类，提出天然林因林因地实行合理的择伐方式是实现天然林可持续发展的有效途径，为天然林择伐经营的具体实施提供科学依据。     

天然林直径分布的线性表达及其应用

利用非线性函数的线性化方法,使传统的天然林直径分布的反"J"型曲线转化为直线形式,并探讨了直线参数变化的直观表现。通过对长白山天然林123个固定试验地林分直径分布的线性拟合,平均相关系数为0.98,表明天然林的直径分布线性化表达是可行的。可利用参数设计择伐株数和预估采伐前后的直径分布。参数在天然林择伐作业设计中可操作性强,研究结果可以为天然林经营,特别是为择伐作业提供依据。     

水曲柳性状相关选优方法的探讨

根据30株天然水曲柳解析木资料，运用相关分析原理，对其胸径、树龄、树高之间关系进行了探讨，并利用其回归方程，编制了天然水曲柳胸径、树龄、树高相关表，为石沉大海 曲柳选优找到了简便可靠的方法。     

Effects Of Thinning In a Water-Limited Holm Oak Forest

ABSTRACT

A natural holm oak forest was selectively thinned to test thinning as a tool to reduce tree mortality, increase productivity, and reverse the recent regression of the dominant species (Quercus ilex) induced by climate change. Thinning increased aboveground productivity and reduced stem mortality in this Mediterranean forest during four years just after thinning, contributing to the maintenance of forest functioning under changing climatic conditions. Q. ilex was the only species positively affected by the thinning: stem growth increased for all stem sizes, and mortality was significantly lower in thinned plots. On the contrary, mortality rates of Phillyrea latifolia and Arbutus unedo were not significantly lower. Stem growth increased for P. latifolia only in the smallest stem-size class. Our results highlight the suitability of selective thinning for improving the forest productivity and ensuring the conservation of Mediterranean coppices. Other benefits of selective thinning, such as a decrease in the risk of fire dispersion and an increase in the water supply for human populations, are also discussed.     

长白落叶松生长性状早晚相关及早期选择的研究

本文对３０年生９０株人工长白落叶松树干解析生长变异及早期预测进行了研究，结果表明，树高、胸径、材积的变异随着年龄增大而减小，１４～１８龄是生长变异由剧烈分化到趋向稳定的转折年龄，此时树高、胸径、材积等的幼龄至成熟龄相关达极显著水平，选择效率也处在较高水平，确定长白落叶松早期选择年龄为１４年。     

灵芝适生树种

本文列举了７７种灵芝适生树种，分属２０科４２属，其中常用树种主要属于壳斗科、杜英科、金缕梅科；段木栽培效果比较理想的树种是福建山樱花（野樱），并介绍了芝树的选伐及段木的熟化处理。     

"三北"地区国外灌木树种引进

1998—2002年共引进国外灌木种批76个、58种，其中41个种在青海天然分布区之外，为首次引进新属、新种或新品种。将引进种批经催芽处理后，分别按引进年度进行春播或秋播。共有54个种批出苗，占总引进种批的78．9％。分别在理水渡域的西宁和黄河流域的循化两地建立定植圃。西宁定植苗木41种，正常开花结实的有8种；生长正常无干梢的有8种；干梢较严重，但第二年萌发出新枝的有7种；不能越冬巳被淘汰的有3种。循化定植苗木37种，正常开花结实的有9种；生长正常无干梢的有11种；干梢较严重，但第二年萌发出新枝的有4种。在初步选择的适应音海东部的树种中，可用于退耕还林、荒山治理的生态型树种有6种，可用于庭院及四旁绿化的园林型树种有12种。     

Challenges facing arthropod biological control: identifying traits for genetic improvement of predators in protected crops

Biological control is an efficient pest control method but there are still limitations that are hindering its wider adoption. Genetic improvement of biological control agents (BCAs) can help to overcome these constraints, but the choice of key attributes for better performance that need to be selected is still an open question. Several characteristics have been suggested but the harsh reality is that selective breeding of BCAs has received a lot of attention but resulted in very little progress. Identifying the appropriate traits to be prioritized may be the first step to reverse this situation. In our opinion, the best way is to look at the factors limiting the performance of key BCAs, especially generalist predators (pesticide compatibility, prey‐density dependence, non‐suitable crops, and extreme environmental conditions), and according to these challenges, to choose the attributes that would allow BCAs to overcome those limitations. The benefits of selection for higher resistance to toxins, whether artificially applied (pesticides) or plant produced (plant defenses); increased fitness when feeding on non‐prey food (supplemented or plant‐derived); and better adaptation to extreme temperature and humidity are discussed. In conclusion, genetic improvement of BCAs can bring about new opportunities to biocontrol industry and users to enhance biocontrol resilience. © 2020 Society of Chemical Industry     

Differential Cl−/Salt Tolerance and NaCl‐Induced Alternations of Tissue and Cellular Ion Fluxes in Glycine max,Glycine soja and their Hybrid Seedlings

The salt‐sensitive Glycine max N23674 cultivar, the salt‐born Glycine soja BB52 population, and their hybrid 4076 strain (F₅) selected for salt tolerance generation by generation were used as the experimental materials in this study. First, the effects of NaCl stress on seed germination, tissue damage, and time‐course ionic absorption and transportation were compared. When qualitatively compared with seed germination appearance in culture dishes, and tissue damages on roots or leaves of seedlings, or quantitatively compared with the relative salt injury rate, the inhibition on N23674 was all the most remarkable. After the exposure of 140 mm NaCl for 1 h, 4 h, 8 h, 12 h, 2 days and 4 days, the content of Cl^? gradually increased in the roots and leaves of seedlings of BB52, 4076 and 23674. Interestingly, the extents of the Cl^? rise in roots of the three experimental soybean materials were BB52 > 4076 > N23674, whereas those in leaves were just on the contrary. Secondly, by using the scanning ion‐selective electrode technique (SIET), fluxes of Na⁺ and Cl^? in roots and protoplasts isolated from roots and leaves were also investigated among the three experimental soybean materials. After 140 mm NaCl stress for 2, 4 and 6 days, and when compared with N23674, slighter net Cl^? influxes were observed in root tissue and protoplasts of roots and leaves of BB52 and 4076 seedlings, especially at the cellular protoplast level. The results indicate that with regard to the ionic effect of NaCl stress, Cl^? was the main determinant salt ion for salt tolerance in G. soja, G. max and their hybrid, and the difference in their Cl^?/salt tolerance is mainly attributed to the capacity of Cl^? restriction to the plant above‐ground parts such as leaves.