Performance Analysis of MIPv4 Regional Registration Combined with Low Latency Handoffs

The mechanism of MIPv4 regional registration and the low latency handoff protocols are introduced. Ways and procedure of pre-registration handoff and post-registration handoff are discussed also. The authors analyze the performance of the low latency handoff protocols combined with low latency handoffs over a wireless access based on IEEE 802. 11 standard in a tree-like network topology. The performance of pre-registration and post-registration scheme is given by simulation.     

紫花苜蓿太阳能干燥系统干燥箱的结构设计

紫花苜蓿是世界范围内种植量最广的牧草之一,低温干燥是常用的贮存方法,可有效保存苜蓿当中的营养成分。太阳能干燥箱可以为苜蓿提供干燥环境,保证干燥温度。为此,设计了一种立式箱式结构干燥箱,并对其工作原理、制作方式、内外部的结构形式及保温材料进行了相应的研究。     

系祖轮配对维持并提高豫州褐壳蛋鸡Ⅲ系生产性能的研究

对豫州褐壳蛋鸡Ⅲ系采用系祖间轮配的选配方法，经过连续3个世代的选育，开产日龄推迟5．72d，开产平均蛋重减少0．87g，72周龄平均蛋重增加2．82g、蛋数增加8．62枚，蛋品质维持在较高水平，蛋壳颜色变深。说明对已育成的纯系采用系祖间轮配的选配方法，可以维持并提高其生产性能。     

Inheritance of tree and fruit characters in progenies from crosses of sweet cherry (Prunus avium L.) cultivars

Summary Approximately 1000 seedlings from 20 combinations crossed in 1979, 1980 and 1981 (Theiler-Hedtrich 1985a) were tested for several characters: fruit set (yield), fruit size, fruit colour, formation of abscission layer and bleeding after fruit removal from fruit stalks, bacterial canker resistance, flowering and harvesting time. From progeny of crosses with Stella as pollinator, 56% (Vittoria × Stella) and 46% (Schüttler × Stella) of the seedlings were self-compatible, of which 14 were high yielding with good fruit size and quality. From the data recorded it can be concluded:fruit set is a recessive character; only 5 to 20% of very good yielding seedlings were obtained in different progeny, even if the parental plants were both very good croppers.Fruit juice and skin colour was in most progenies ‘black’ even if they were from combinations with ‘white’ varieties, e.g., Merton Glory or Schüttler. Only from the combination Schiittler (‘white’) × Stella (‘black’), 50% of the seedlings were ‘white’; Stella therefore is heterozygous for the character of fruit juice and skin colour.Fruit size is evenly distributed in progeny with respect to the fruit size of their parent plants.Abscission layer formation and non-bleeding is a genetically complex character. In combinations where both parent plants formed fruits with complete abscission layers and which were not bleeding after fruit removal from the stalk, this character was inherited only to 50% (Vittoria × Schüttler) or 85% (Vittoria × Frühe von der Weid) in the progeny. For the genetical control of this character further studies are necessary.Bacterial canker susceptibility was evenly distributed in seedlings from all combinations even if the highly resistant cv. Vittoria was used as one parent plant, thereby not confirming the expected results of a higher proportion of resistant seedlings from combinations with Vittoria.Flowering and harvest time of the seedlings from different combinations was within the range of the parent plants. Only in the combination of Vittoria × Stella (mid-to late-ripening season) one seedling out of 99 was found to form ripe fruits two weeks earlier than the parental plants. From the seedlings tested 40 have been chosen for further evaluation or genetical studies.     

几个水稻品种的种子蛋白超薄等电聚焦谱带的差异

利用超薄等电聚焦技术对6个水稻品种种子贮藏蛋白进行了分析，发现供试水稻品种间的谱带有差异，据此差异，能有效区别6个水稻品种。     

中国粮食仓储行业淘汰甲基溴行动

为切实履行我国政府对国际社会<关于消耗臭氧层物质的蒙特利尔议定书>的<哥本哈根修正案>所作出的承诺,中国粮食仓储行业在保障我国粮食安全储备的前提下,在"淘汰甲基溴,保护臭氧层"方面采取了一系列行动(包括调研、确定替代技术、培训、制定规程、建设示范库、研究替代技术等),以达到替代甲基溴的目的.淘汰甲基溴的实际行动,研究新的淘汰甲基溴替代技术,对增强人们保护臭氧层的意识,推广和应用替代技术和确保人类共同家园的可持续发展都具有重要的意义.     

温室作物叶-气系统水流阻力研究初探

温室作物叶-气系统水流阻力的确定对计算作物蒸腾量、制定温室作物灌溉制度以及调控温室小气候具有重要意义,但测量难度较大。该文通过对温室作物周围环境微气象条件的连续观测，计算分析了温室作物叶-气系统水流阻力各分项即叶片周围层流副层边界层阻力(r_b)、冠层上方湍流边界层阻力(r_g)、空气动力学阻力(r_e)和叶片气孔阻力(r_i)的变化规律。结果表明：温室内r_b比较稳定，平均约235 s/m，且与环境因素关系不甚密切；温室内黄瓜、西红柿类植物生殖生长期r_g<b，在计算r_e时，r_g的影响可忽略，取r_e≈r_b；利用基于能量平衡方程和空气动力学方程得出的叶-气温差计算公式计算得到r_i，符合其变化的一般规律；在此基础上计算了温室黄瓜的蒸腾速率，与实测值的一致性较好。     

土壤养分空间变异及合理取样数研究

土壤养分存在明显的空间差异，田间土壤养分合理取样数取决于养分要素自身空间变异程度和人们对数据精度的要求。若空间变异大、精度要求高则需要较多采样数，反之需较少样点数。计算结果表明，极大多数养分要素的合理取样数较实际取样数有较大幅度减少，意味着可大幅降低采样及分析成本。据统计学空间自相关和半方差函数方法研究结果，养分要素存在一定的空间自相关性，但不同方向上的自相关性有明显差异，独立间距也因养分要素而异。研究结果可为精准农业土壤养分样点密度设定、养分要素等值线绘制及精准施肥提供支持。     

气象因子和土壤质地影响下刺槐蒸腾对土壤水分有效性的响应

On the Loess Plateau of China, a dry soil layer may form due to excess transpiration, leading to degradation of black locust(Robinia pseudoacacia) stands. In order to better manage projects involving black locust, this study was intended to investigate the response of black locust transpiration rate to soil water availability as affected by meteorological factors using two representative soils(loamy clay and sandy loam) on the Loess Plateau. Four soil water contents were maintained for black locust seedlings grown in pots initially outdoors and then in a climate-controlled chamber, by either drying or irrigating the pots. In both environments, daily transpiration rates were related by a power function to air temperature and by a logistic function to reference evapotranspiration(ET0). Transpiration rates were more susceptible to changes in the meteorological conditions in the sandy loam than in the loamy clay soil. The transpiration rate in the well-watered treatment was greater for black locust grown in the sandy loam than in the loamy clay soil. Normalized transpiration rates were unaffected by ET0 until a critical value of soil water content(θc) was attained; the θc value decreased significantly for the loamy clay soil but increased significantly for the sandy loam soil when ET0 increased. These suggested that the effect of the meteorological condition on the transpiration characteristics of black locust was dependent on soil texture.     

混凝土防渗渠道冬季输水运行中冻胀与抗冻胀力验算

为了明确渠道冬季输水时防渗衬砌层结构的抵抗渠床基土冻胀破坏作用的能力,该文理论分析了大气负温下,介入刚性防渗面层对渠基土冻胀的约束,得到作用于坡板上冻胀力的作用形式为法向冻胀力和指向坡顶的切向冻胀力,对被视为底端简支、板内无接缝、受冻胀作用的构件受力进行理论分析,得到冬季输水渠道边坡板的冻胀问题属于非垂直非全周的冻拔问题的结果,并进一步根据力学基本原理研究了刚性面层(衬砌层)承受荷载力的求解方法。依据桩的抗冻拔验算和拉弯构件的强度验算可实现冬季输水渠道抗冻胀力的计算,建立了适用于防渗渠道刚性衬砌结构设计的方法,为冬季输水梯形混凝土防渗抗冻胀渠道衬砌层厚度的准确确定提供了计算方法。