Difference in cutting age for highest profit by methods for calculating CO<Subscript>2</Subscript> emission trading and the price of CO<Subscript>2</Subscript>

 The amounts of CO₂ that are absorbed and emitted by forest in a model stand area were determined using two calculation methods, namely the flow approach and the stock approach for emission trading, to understand the relationships between the cutting age for the highest profit rate (CAHPR; optimum tree ages to be cut so as to maximize the profit) and (1) the prices of CO₂ and (2) the balance between CO₂ emission and absorption. The resultant CAHPR differed between these two CO₂ accounting methods, which give different tree ages for maximum log volume yield. A rise in CO₂ price caused the CAHPR to approach the tree age of maximum log volume in the flow approach method, and to deviate from the tree age of maximum log volume in the stock approach method. Even at the same CO₂ price, the CAHPR differed between the CO₂ accounting methods. At low CO₂ prices, the CAHPR did not affect situations where the difference of average profit is large by cutting age. On the other hand, the CAHPR was greatly affected at low CO₂ prices when the mean log volume growth changed with tree age. These trends were found to be universal. Received: September 18, 2001 / Accepted: October 25, 2002 Acknowledgments This study is one of the fifth science study subsidy projects of the Japan Forest Technology Association. Correspondence to:K. Sakata     

间作植物根系对Pb斑块胁迫适应机制

为研究间作体系植物根系受Pb胁迫的形态学适应机制,利用根箱试验设计Pb斑块胁迫下玉米、小花南芥单作和玉米与小花南芥间作处理。结果表明:在Pb斑块(0、1000 mg·kg~(-1))处理根箱条件下,间作小花南芥根生物量的相对关系指数显著增加,小花南芥根趋向有Pb斑块生长,根系表面积显著增加,间作模式极显著影响小花南芥根系形态;间作玉米根生物量的相对关系指数显著降低,玉米根趋向无Pb斑块生长,Pb处理极显著影响玉米根系形态。径级在1.5 mmd3≤2.5 mm根表面积显著影响间作小花南芥与玉米对Pb的响应。研究表明,根间相互作用激发小花南芥根系趋向Pb斑块,玉米根系趋向无Pb斑块,揭示了超富集植物与作物间作体系促进两种植物根系趋向性适应的重要原因。     

Approaches to Promote China＇s Low Carbon Agricultural Development

Low carbon agriculture is a new production mode of green agriculture development to face the challenge of the global climate change, and a kind of innovation on developing circular agriculture. Up to n...     

超高产粳型水稻生长发育特性的研究

【目的】水稻是中国最重要的粮食作物，实现水稻超高产对保证国家粮食安全有重要作用。本研究旨在探讨超高产水稻（产量>11 t·ha-1）的生长发育特性。【方法】4个中熟粳稻品种（含品系）连嘉粳2号、华粳5号、0026和9823种植于大田，对其物质生产和产量形成进行了观察分析。【结果】与高产水稻（CK，产量为8.98～9.16 t·ha-1）相比，超高产水稻每穗颖花数多，结实率高，千粒重与CK无显著差异；超高产水稻移栽至拔节期的茎蘖数较CK少，但分蘖成穗率较高；超高产水稻的叶面积指数、光合势和干物质积累，生育前期较CK低，抽穗期与CK无显著差异，抽穗后则显著高于CK。超高产水稻各生育时期的根冠比、抽穗至成熟的根系伤流量以及粒叶比、茎鞘物质运转率和收获指数均显著高于CK。【结论】提出了中熟粳稻超高产群体的生育诊断指标：总颖花量>4.5万/m2，结实率>90%，千粒重>26 g；茎蘖成穗率>80%，抽穗期叶面积指数7.5～8.0，全生育期光合势>5×106 m2·d·ha-1，成熟期总干重>22 t·ha-1，收获指数>0.51；抽穗期粒叶比[颖花/叶(cm2)]>0.58，根冠比>0.25，根系伤流量>5 g·m-2·h-1。对培育超高产水稻群体的调控途径与关键栽培技术进行了讨论。     

提高高校青年教师教学能力的途径

为了提高青年教师教学能力,对黑龙江八一农垦大学青年教师教学能力现状进行了分析,通过培养教师自主学习能力、完善教师培养培训体系、建立科学的教学考评制度、加强师风师德建设和教师交流多元化等途径,使青年教师的教学能力和水平明显提高。     

油茶幼林土壤养分限制因子的研究

利用土壤养分状况系统研究法，对江西宜春油茶幼林土壤进行了养分限制因子的研究。结果表明：宜春油茶幼林土壤养分限制因子为N、P、Ca，盆栽不施N、P、Ca作物分别减产63．97％、61．32％和19．08％。     

模糊物元模型在新疆农业水资源可持续利用评价中的应用

在模糊物元分析的基础上,结合欧氏贴近度的概念,提出了基于欧氏贴近度的模糊物元分析方法。在对区域水资源可持续利用进行综合评价时,把各地区各开发利用阶段作为物元的事物,以它们的各项评价指标及其相应的模糊量值构造复合模糊物元,通过计算与标准模糊物元之间的欧氏贴近度,并采用层次分析法计算各评价指标的权重,实现对各地区水资源可持续利用的综合评价与排序。该模型被应用到新疆农业水资源可持续综合评价中,取得了较好的效果,对新疆水资源的开发具有重要的指导意义。     

论建设工程价格的合理确定

建设工程价格的合理确定关系着整个工程项目的建设质量,因此说工程造价管理问题是建设工程的核心问题。科学有效的制定建筑工程造价,可以保证建筑工程的顺利完工和建设质量。因此,建筑企业必须要重视建设工程造价问题。文章从建设工程造价合理确定的意义入手,探究我国建设工程合理确定价格的方法与途径。     

Rabies Antibodies in Vaccinated Dogs

Forty-seven healthy, owned dogs were vaccinated with Madivak and 85 with Rabisin. Geometric mean titres of 17.40 and 1.03 IU/ml were measured by the rapid immunofluorescent focus inhibition test 30–40 and 350–370 days, respectively, after a single injection. Four out of 130 (3.1%) and 18 out of 106 (17% ) dogs had a titre of less than 0.5 IU/ml in serum 30–40 and 350–370 days after vaccination. Twenty-one dogs (19.8%) had a titre of 0.5 IU/ml 350–370 days after vaccinaton. There was no significant difference in antibody levels between animals vaccinated with Rabisin or Madivak. Our results indicate that a booster is always necessary after a single injection to ensure that all dogs have a lasting antibody titre.     

抑制素免疫及其基因工程疫苗的构建

本文叙述了抑制素的特性、免疫原性及来源途径,并论述了其对提高家畜繁殖力的作用,同时提出了抑制素基因疫苗构建的方法及基因疫苗的优势。