农村经济改革的成就与深化改革的对策

十年改革,使山东农村经济发生了巨大变化。由统的过死变为搞活,由封闭变为开放,由长期停滞变为蓬勃发展,开始了由自给半自给的自然经济向计划商品经济的转化。按80年不变价格计算的农业总产值十年翻了一番,粮棉油总产量年均增长速度分别为4.5%、26.1%、10.4%,农村人均年纯收入由101.20元提高到517.69元。但改革并非尽如人意,也出现了一些新情况和新问题,特别自85年进入第二步改革以来,改革的难度更大,步履维艰。出路在于坚持改革,在配套改革上下气力。一要在稳定和完善家庭联产承包责任制基础之上,加快价格改革,重建城乡经济利益机制。二要增加农业投入,强化农业这个基础。三要继续调整农村产业结构,积极发展外向型经济。四要加快政治体制改革速度,以促进农村经济体制改革。     

三江平原稻田N_2O通量特征

利用静态暗箱-气相色谱法于2004年11月-2005年10月对三江平原稻田进行了全年连续田间原位观测。结果表明，三江平原稻田全年N2O平均通量为0．052 mg·m^-2·h^-1；冻融期N2O通量范围为0．008N 0．029 mg·m^-2·h^-1，融冻时排放量显著增加；生长期平均通量为0．059 mg·m^-2·h^-1，施肥后及淹水期间水面落干时各出现了两个明显的N2O排放峰，排水后N2O排放通量较淹水期稍增加，但幅度不大。同时分析了冻融期、生长期N2O通量季节变化特征和日变化特征以及和相关环境因子的关系，分析表明。温度决定了稻田全年N2O排放通量的大小，而水分状况则是影响三江平原稻田N2O排放季节变化特征的主要因素。     

贯流式风机风舌结构参数对Ψ-φ曲线影响的研究

本研完用全面试验的方法,将贯流式风机风舌结构参数对Ψ-φ曲线的影响进行了测定,同时,通过对内部流动场的测定和分析,找出了造成影响的原因和规律,为设计和应用贯流式风机提供依据。     

Study of Dynamics of Floodwater Nitrogen and Regulation of Its Runoff Loss in Paddy Field-Based Two-Cropping Rice with Urea and Controlled Release Nitrogen Fertilizer Application

The article deals with the effects of urea and controlled release nitrogen fertilizer （CRNF） on dynamics of pH, electronic conductivity （EC）, total nitrogen （TN）, NH4^＋-N and NO3 -N in floodwater, and the regulation of runoff TN loss from paddy field-based two-cropping rice in Dongting Lake, China, and probes the best fertilization management for controlling N loss. Studies were conducted through modeling alluvial sandy loamy paddy soil （ASP） and purple calcareous clayey paddy soil （PCP） using lysimeter, following the sequence of the soil profiles identified by investigating soil profile. After application of urea in paddy field-based two-cropping rice, TN and NHa＋-N concentrations in floodwater reached peak on the 1st and the 3rd day, respectively, and then decreased rapidly over time; all the floodwater NO3--N concentrations were very low; the pH of floodwater gradually rose in case of early rice within 15 d （late rice within 3 d） after application of urea, and EC remained consistent with the dynamics of NH4^＋-N. The applied CRNF, especially 70% CRNF, led to significantly lower floodwater TN and NH4^＋ concentrations, pH, and EC values compared with urea within 15 d after application. The monitoring result for N loss due to natural rainfall runoff indicated that the amount of TN lost in runoff from paddy field- based two-cropping rice with urea application in Dongting Lake area was 7.47 kg ha^-1, which accounted for 2.49% of urea- N applied, and that with CRNF and 70% CRNF application decreased 24.5 and 27.2% compared with urea application, respectively. The two runoff events, which occurred within 20 d after application, contributed significantly to TN loss from paddy field. TN loss due to the two runoffs in urea, CRNF, and 70% CRNF treatments accounted for 72, 70, and 58% of the total TN loss due to runoff over the whole rice growth season, respectively. And the TN loss in these two CRNF treatments due to the first run-off event at the 10th day after application to early rice decreased 44.9 and 44.2% compared with urea, respectively. In conclusion, the 15-d period after application of urea was the critical time during which N loss occurred due to high floodwater N concentrations. But CRNF decreased N concentrations greatly in floodwater and runoff water during this period. As a result, it obviously reduced TN loss in runoff over the whole rice growth season.     

无公害灭鼠剂克鼠星在陕西退耕还林中的应用效果

[目的]探讨无公害灭鼠剂克鼠星对退耕还林地鼠害的防治效果。[方法]于2000～2004年在陕西省吴旗、甘泉、千阳、麟游、永寿和淳化6县,采用无公害灭鼠剂克鼠星对退耕还林地鼠害进行防治推广试验。[结果]在鼠害严重的造林地,造林前用克鼠星防治1次,造林后再用克鼠星防治1次,平均造林成活率达到97.1%,造林后2年平均保存率达到95.3%,分别比对照提高18.4%和28.5%。果树由于立地条件较好,鼠害防治彻底,2年保存率达到97.3%。应用灭鼠剂克鼠星1号进行鼢鼠防治,春季和秋季的防治效果均在89.4%以上,对达乌尔鼠兔的防治率均在84.7%以上。[结论]灭鼠剂克鼠星的研制与应用,杀灭了害鼠,同时保护了天敌,在农林牧业鼠害的防治方面,具有广阔的应用前景。     

市场经济与高校办学自主权

市场经济要求转变高等教育行政主管部门的职能,赋予高校一定的市场主体资格,以解决高校教育资源供求之间的矛盾。同时,高校已经具备一定的驾驭市场经济的经验和能力,社会、政府以及法律的监管约束机制也已基本形成。当前可以从融资、专业和学科的创设、招生的方式与途径、收费或定价等方面考虑进一步扩大高校办学自主权。     

西部大开发中的耕地问题探讨

西部开发是协调我国地区经济发展的重大战略，西部的开发和建设将带来耕地数量的减少和耕地质量的退化，针对这些问题，提出了应该如何保护耕地的对策。     

作物耐低磷适应机制研究进展

从形态学、生理学、生物化学、分子生物学等方面，综述了作物对低磷胁迫的可能适应机制，重点介绍了碳代谢的改变在作物适应低磷环境上的积极作用，力求为作物耐低磷基因资源筛选及磷高效作物品种改良提供新的思路和理论依据。     

扬州市稻田草相特点及化除技术

水稻田杂草的化学防除,应以草相特征为基础,以不同栽培的杂草发生规律为依据,合理选用化学除草剂.笔者根据扬州地区4大生态类型,水稻4种主要栽培方式杂草发生特征的差异,提出了各自不同的化除技术.     

酵母对有机溶剂耐性的研究

对10株酵母进行了有机溶剂耐受试验.结果发现酒精酵母比其他酵母抗非极性溶剂的能力更强.酵母对有机溶剂的抗性不仅与溶剂的极性、毒性、剂量范围有关,而且与酵母细胞膜的成分、生长培养基、温度等有关.当生长培养基中的Mg2+浓度提高2倍时,多数菌株对有机溶剂的抗性没有影响.温度对所检测酵母的生长及对溶剂的抗性都有一定的影响.