我国北方地区防治荒漠化的法律思考

荒漠化问题是当今危害全球人类最严重的问题之一。我国北方地区荒漠化土地面积为 3 2 .8万平方公里 ,约占全国国土面积的 3 .4% ,而且还在进一步发展 ,长此下去 ,令人担忧。笔者提出治理北方荒漠化的主要方面 :6项法律对策 3项政策建议。     

吉林省农村居民消费与收入的关系分析和政策建议

消费是国民经济的重要组成部分.为此,通过对吉林省1985～2005年农村居民消费支出与农村收入的关系进行协整检验并建立误差修正模型,验证了两者之间存在的长期协整关系和短期修正关系.同时,根据分析的结果给出了提高吉林省居民消费水平的相关政策建议.     

闭式Leontief模型为可行的一个实用的判定程序

设Ｔ是某闭式Ｌｅｏｎｔｉｅｆ投入产出模型的投入矩阵，如果有正向量Ｘ使得Ｘ≥ＴＸ，则称该模型为可行的．本文给出闭式Ｌｅｏｎｔｉｅｆ模型是否可行的一个实用的判定程序．     

龙薯1号在丘陵山地高产高效栽培技术研究

为探讨龙薯1号在丘陵山地高产高效栽培技术,2005-2006年对龙薯1号进行了栽培试验,试验采用单因子随机区组排列,重复三次进行。产量对比分析结果显示:种植密度应控制在45500~55500株/hm2;施夹心肥的效益比施夹边肥高;每公顷应施纯氮120 kg、五氧化二磷90 kg、氧化钾210 kg、硼砂15 kg;封垄时喷300kg/hm2多效唑溶液1次。     

近年来我国图书馆读者培训研究综述

本文分析了近年来我国读者培训的发文情况,描述了读者培训研究的主要内容,归纳了读者培训研究的主要特点。     

双壳贝类呼吸代谢的研究进展

呼吸代谢是生物能量学研究的重要内容之一。依据近年来国内外的研究成果,综述了关于贝类呼吸代谢的研究方法,讨论了影响贝类耗氧率的生物因素和非生物因素,展望了贝类呼吸代谢的研究和应用前景。     

Rootstock influence on ‘delicious’ and ‘golden delicious’ apple fruit quality at harvest and after storage

The influence of 9 rootstocks (M2, M7, M25, M26, MM104, MM106, MM109, MM111 and seedling) on fruit quality at harvest and after storage of ‘Wellspur Delicious’ (WS) and ‘Goldspur’ (GS), and of 3 rootstocks (M7, M26 and MM106) on fruit quality of ‘Red King Delicious’ (RK) and ‘Golden Delicious’ (GD) apple (Malus domestica Borkh.) was evaluated during a 4-year period. Fruits from trees on M26 were larger, developed earlier color and soluble solids (SS), and maintained higher levels of acidity (at harvest and during storage) in comparison with other rootstocks. Fruit from trees on M2 tended to have high SS. Fruit color from trees on MM104, MM106 and MM109 tended to be comparatively poor. There were significant rootstock effects on SS, starch, acidity, color, circumference, weight and box size.     

中国兴安,长白落叶松遗传育种研究进展

经过“六五”至“八五”科技攻关，落叶松的林木改良工作取得了很大进展；（１）利用苹果酸脱氢酶，谷氨酸草酰乙酸转氨酶和酯酶对长白落叶松的１４个小群体进行了分析，表明长白落叶松天然群体不仅遗传变异水平较高，而且仍处于哈代－温伯格平衡状态；（２）在落叶松生长性状地理变异规律，最佳种源选择，种源区划等方面取得很多成果；（３）对开花生物学特性及提高种子园种子产量和遗传品质方法做子大量研究；（４）提出了营建１．     

Nitrate leaching in a silage maize field under different irrigation and nitrogen fertilizer rates

Quantification of the interactive effects of nitrogen (N) and water on nitrate (NO₃) loss provides an important insight for more effective N and water management. The goal of this study was to evaluate the effect of different irrigation and nitrogen fertilizer levels on nitrate-nitrogen (NO₃-N) leaching in a silage maize field. The experiment included four irrigation levels (0.7, 0.85, 1.0, and 1.13 of soil moisture depletion, SMD) and three N fertilization levels (0, 142, and 189 kg N ha⁻¹), with three replications. Ceramic suction cups were used to extract soil solution at 30 and 60 cm soil depths for all 36 experimental plots. Soil NO₃-N content of 0-30 and 30-60-cm layers were evaluated at planting and harvest maturity. Total N uptake (NU) by the crop was also determined. Maximum NO₃-N leaching out of the 60-cm soil layer was 8.43 kg N ha⁻¹, for the 142 kg N ha⁻¹ and over irrigation (1.13 SMD) treatment. The minimum and maximum seasonal average NO₃ concentration at the 60 cm depth was 46 and 138 mg l⁻¹, respectively. Based on our findings, it is possible to control NO₃ leaching out of the root zone during the growing season with a proper combination of irrigation and fertilizer management.     

气候变化对中国东北地区生态与环境的影响

【研究目的】综述了气候变化对东北地区的影响,以期在区域发展中能利用气候变化的有利方面,降低其不利的影响;【方法】根据近年来发表的相关论文,文章综述了东北地区已经发生的气候变化影响及未来可能受到的影响;【结果】结果表明,过去100年东北地区的温度升高明显且降水普遍减少,干旱化趋势严峻。温度的升高改善了东北的热量资源,部分农业生产从中受益。但由于气候变化,目前特殊的生态系统如湿地,冻土退化或消失。未来的气候变化,会改变农业生产布局,降低主要作物的产量,生态系统结构发生改变,农牧带沙漠化的风险增加;【结论】东北地区必须客观认识气候变化的利弊影响,采取相应的适应和应对措施,促进区域发展。