蜂王浆复方降血糖作用的初步研究

采用一种特制的蜂王浆中药复方制剂（FSL），通过实验性糖尿病模型，以高（800mg／kg），中（500mg／kg），低（300mg／kg）3个剂量组对试验动物进行灌胃试验。结果显示：蜂王浆复方降糖制剂可显著拮抗四氧嘧啶，肾上腺素引起的血糖升高，且对正常小鼠的血糖值无明显影响，且不会影响正常的糖代谢过程。毒理研究结果表明其最大耐受量为60．00g／kg。     

减租、负担、生产：农业政策与乡村社会结构的变动——以抗战时期晋西北根据地为个案

抗战时期中国共产党领导的抗日根据地的阶级关系发生了巨大变化,从而使整个社会结构重组,中农贫农成为主要的阶级。在这一结构性变动中,减租减息政策、公粮政策和发展生产政策起着决定性作用。减租减息使地主经济受损,出卖土地;公粮政策增加了他们的负担,经济进一步收缩;发展生产政策中地主富农不敢发展,而农民在此过程中得到了利益,买入土地,增收致富。随着地主富农经济和社会地位的下降,其政治地位普遍下降,他们能留在统一战线内部,是抗战时局的发展、根据地形势及他们身边生活环境变化的结果,并不单纯是减租减息政策本身作用的结果。     

小型农机减速箱可重构模块化设计可行性研究

阐述了模块化及可重构模块化的具体含义,给出一小型农机减速箱设计实例,通过对该减速箱运动参数、转速的计算分析,拟定出减速箱的结构图,证明该减速箱进行可重构模块化设计是可行的。     

影响农户减施化肥行为因素实证研究——以云南省洱源县为例

以洱源县6个乡镇农户问卷调查数据为基础,运用因子分析与回归分析方法,对6个乡镇农户参与减施化肥的影响因素进行了研究。结果表明,政府补贴与政府组织教育培训是农户决定是否参与减施化肥的关键因素;农户对化肥利用率与品牌的认知对农户是否参与减施化肥产生较大影响;具有风险偏好、性别为男性、文化程度较高、有特殊经历的农户,农作物种植面积较大、产生的废弃物较多、农业收入较高、属于科技创新示范户的家庭更倾向于在农业生产中减施化肥;农户的环境污染与绿色产品的认知水平对农户是否参与减施化肥基本不产生影响。     

Dune whitening and inter-dune freshwater ponds in NE Brazil

The changes in color of sand dunes from white to yellow or red is often interpreted to signify their age or their source materials. In this study we demonstrate the effect seasonal inter-dune freshwater ponds have on the bleaching of the color of sand dunes by iron reduction in the anaerobic conditions they create. By combining spectral measurements of field samples of dune sand together with the analysis of satellite images covering three dune fields in NE Brazil (Lençóis Maranhenses, Jericoacoara and Canoa Quebrada) we demonstrate its existence in the field. In areas where ponds cover 41% of the dune field (as in Lençóis Maranhenses) an almost total bleaching in the color of the sand occurs after which the dunes remain white with no relation to distance from the coastline. In areas with less ponds (e.g. Jericoacoara or Canoa Quebrada) dune whitening is less active, and there are areas where dune rubification occurs. As this process may have occurred in other dune fields during past climate conditions that may have been different from current ones, interpretations of dunes age based on their color should be handled with care.     

农业废弃物与化肥减量配施对连作晚稻产量、品质及土壤肥力的影响

为探究农业废弃物的氮肥替代能力及后效肥力,于早稻季进行4种等氮处理,即单施化肥（CK）、稻草+化肥（SF）、水葫芦+化肥（HF）和西兰花茎叶+化肥（BF）,以不施氮肥作对照（CK0）;晚稻季仅在SF、HF和BF处理小区内进行稻草还田。早稻以台早733、晚稻以中浙优8号和甬优1540为材料,考察不同处理对水稻产量、品质及土壤肥力的影响。结果表明,农业废弃物与化肥减量配施可提高氮肥利用率和水稻产量,SF、HF和BF处理的晚稻产量分别较CK处理提高5.3%、7.2%和7.6%,其周年产量分别提高-1.7%、3.5%和8.1%;并可改善晚稻的稻米加工品质、外观品质和食味品质,主要提高其糙米率、精米率和整精米率,降低垩白粒率、垩白度（中浙优8号）和蛋白质含量;提高土壤有机质、全氮、有效磷和速效钾含量,降低土壤容重,并缓解土壤酸化。综上,农业废弃物与化肥减量配施利于水稻高产稳产、改善稻米品质和提升土壤肥力,其中以BF处理效果最佳。     

Factors related to iron uptake by dicotyledonous and monocotyledonous plants III. Competition between root and external factors for Fe

In comparison studies (11, 12), monocotyledonous corn (Zea mays L.) and oats (Avena byzantina C. Koch) did not respond to Fe stress as effectively nor to the same degree as the dicotyledonous soybeans (Glycine max (L.) Merr.) or tomatoes (Lycopersicon esculentum Mill.). Both the Fe‐inefficient and Fe‐efficient corn and oats developed Fe chlorosis; the Fe‐efficient dicotyledonous plants were green. In the present study, the method of inducing Fe stress was changed to make it less severe. Instead of using only NO₃‐N and no Fe to induce Fe stress (11, 12), both NH₄‐N and NO₃‐N were used along with varied concentrations of Fe. Iron stress was induced with BPDS (4,7‐diphenyl‐l, 10‐phenan‐throline disulfonic acid) and phosphate; both competed with the plant for Fe. Phosphate also inhibits reduction of Fe³⁺ to Fe²⁺ (12). This method of inducing Fe stress in the plants was less severe than using only NO₃‐N and no Fe in the nutrient solutions and we were able to measure a difference in Fe‐stress response for all four plant species (Fe‐inefficient and Fe‐efficient). At the lower Fe treatments, the roots of Fe‐efficient plants usually reduced more Fe³⁺ to Fe²⁺ than did the roots of Fe‐inefficient plants. The ‘inefficient’ ys₁ corn and TAM 0–312 oat roots did not compete with BPDS or phosphate for Fe as effectively as did the ‘efficient’ WF9 corn and Coker 227 oat roots. The same type mechanism for solubilization, absorption, and transport of Fe seems to function in both monocotyledenous and dicotyledenous plants but it is more effective and more readily detected in the dicot than in the monocot plants. The reactions involved in reduction of Fe³⁺ to Fe²⁺ seemed to be confined inside or at the root surface for the inefficient genotypes; the efficient genotypes alter the ambient medium to a greater degree.     

Research on Bridge Structure Noise of Railroads and Underground

This paper analyses the generating mechanism of radiation noise which produced by bridge structures and vibro-acoustic characteristics, and reviews the current situation of the researches on the relevant standards of structure noise at house and abroad. The author summarizes the method of measurement and calculation about structural noise at house and abroad, further notes their limits. This paper explores the impact of such factors as rain speed and other different fluids on structure noise. The noise characteristics of structures like cavity structure and thin-slab structure are also discussed. Strategies for reduce the bridge structure noise are summed up by reducing the vibration of track structure, altering the structure of boundary conditions, increasing the stiffness and changing the bridge cross section. Finally it comes to a conclusion that a combination of these strategies is the root way to settle the question of the bridge structure noise.     

Reduction of Phosphatic and Potash Fertilizer in Sweet Corn Production by Pre-transplanting Application of Potassium Phosphate to Plug Seedlings

Abstract

To develop a new fertilizing system with a reduced amount of phosphatic fertilizer in sweet corn production, we applied potassium phosphate to the plug seedlings before transplanting to the field, and examined its effects on growth, yield, photosynthetic activity and absorption of minerals. The amount of phosphatic and potash fertilizers necessary to grow sweet corn could be reduced by the pre-transplanting KP application (PTKPA) to the plug seedlings. We considered the mechanisms involved in the reduction of P and K application rate by PTKPA as follows; 1) PTKPA increased the P content of plant, which accelerated the root establishment. 2) The advanced root establishment not only reduced the duration of water stress, but also increased absorption of the essential nutrients such as N and Mg. 3) Higher content of N and Mg led to higher chlorophyll content and possibly protein content, which activated photosynthesis during the early growth stage. 4) Improved photosynthetic activities increased NAR during the early growth stage. 5) This increase in NAR accelerated leaf expansion, increasing LAI. 6) Larger LAI during the early growth stage led to larger LAI throughout the growing stage, resulting in a higher CGR and ear yield.     

雨水花园路面径流污染控制研究——以沈阳市为例

以沈阳市为例,从道路绿带与雨水花园技术相结合建设的角度,综合考虑污染物去除效果、材料易获取程度等因素,研究了填料层对TP、TN、COD、SS 4种污染物的去除试验。通过AHP分析法综合评价得出使用高炉渣与活性炭作为街道绿化雨水花园填料层材料时最为经济有效的结论,并综合分析相关研究结果,总结雨水花园的构造条件与运行条件对路面径流污染物去除率的影响,提出了针对污染物控制的沈阳市路旁雨水花园合理建设模式。