A STUDY ON HEAT AND MOISTURE STATE OF HULL LAYER FOR THERMAL INSTULATION OF A COLD STORAGE

This paper analyses the thermal moist characteristics of the hull layer beside an air layer at lower temperature in an envelope for a cold storage and presents a new method of waterproof by air layer. With test data from engineering practice, the theory on the barrier of self moisture proof at the surface sublayer of the hull layer in an attic on a cold storage is proven. The dried zone about three phase point is confirmed. It is a new knowledge for thermophysics on thermal design of a cold storage with an optimum thermal performance.     

以粮温实测数据为例探讨低温储粮的可行性

通过对高大平房仓粮温进行跟踪检测，分析比较了粮温变化情况，并探讨了低温储粮的可行性。     

温室地下贮热系统设计研究

为了降低温室环境调控能耗。根据育苗不同阶段对气温与土壤温度的要求，设计了温室地下贮热系统，并阐述了系统的组成和贮热原理；同时，分析了各设计参数对系统贮热性能的影响。这样不仅为系统设计与理论分析奠定了基础，对其它类似地下贮热系统的设计、研究也具有参考意义。     

干旱地区家庭雨水集储装置的设计

宁夏甘肃两省是我国严重缺水地区。缺水严重影响了该地区人民正常生活和工农业的发展。为此，针对家庭用水设计了屋顶雨水集储装置；在尽量减少建筑费用的情况下，选用了地下建池、拦污栅等污水处理装置，可为干旱地区建造家庭雨水集储装置提供一些参考依据。     

我国粮食仓储技术的概况与发展

粮食安全储存是个世界性难题,如何发展、提升和完善粮食仓储技术是我国政府面临的一项亟待解决的课题.为此,在提出粮食仓储技术内涵的基础上,首先概述总结了我国粮食仓储设施及方式的发展历程;其次在分析国内储粮技术研究发展现状的基础上,重点介绍了低温储粮、气调储粮两种绿色环保型储粮技术及计算机技术在仓储上的应用;论述了我国仓储设备的整体发展现状;最后指出了我国仓储技术的存在的问题与发展趋势.     

重力式计量包装机的设计与研究

介绍了定量包装机的结构、气缸选型以及料仓容积等参数的计算。该机配以PLC气动控制装置、嵌入式电脑核心的包装机控制仪,具有高精度、高速度及长期工作可靠性好等特点。它可以和自动取袋、封口机配合使用,根据不同物料的料性及工艺要求,进行自动称重包装,从而满足了国内粮食及其初深加工产品计量包装的性能指标要求,并广泛应用于粮食、化工等行业。     

广东三岭山森林公园主要人工林碳汇功能及其经济价值评价

本文以广东三岭山森林公园的马尾松、尾叶桉、大叶相思人工林为研究对象，研究对比它们的碳储量和碳汇经济价值，为评价广东的3个优势造林树种的碳汇能力及为广东的造林选择提供依据。结果表明：3种人工林树种单位碳储量由大到小排列次序为：尾叶桉(166.89 t·hm-2)＞大叶相思(128.72 t·hm-2)＞马尾松(70.12 t·hm-2)。3种人工林平均碳汇经济价值按大小排列次序为：尾叶桉(45611.04元·hm-2)＞大叶相思(35179.18元·hm-2)＞马尾松(19163.80元·hm-2)。尾叶桉是这3种人工林中碳储量的主要部分，对广东三岭森林公园发挥着巨大的碳汇功能并具有强大的碳汇经济价值。因此，可以考虑在广东省碳汇造林时选择尾叶桉种植。     

张河湾抽水蓄能电站1号机组转子安装出现的问题及解决方法

文章介绍了张河湾抽水蓄能电站转子结构特点及安装工艺,分析了转子安装过程中出现的磁轭冲片受损、拉紧度不够等原因及解决办法,介绍了如何解决安装过程中分块式压板的水平度调整。     

Calcium nutrition of the sugarbeet

Abstract

When sugarbeet seedlings are transferred from a complete nutrient solution to one from which Ca has been withheld, the rootlets and tops fail to develop. The same transfer at the eight‐leaf stage causes the rootlets to become stubby and swollen at the tips and blade expansion becomes modified; particularly the upper portions of the blades attaining nearly full development, which pucker and often develop a cupping or hooding effect; a unique symptom characteristic of Ca deficiency. As each new leaf develops, the blade area becomes smaller until only a black tip remains at the apex of the petiole, which is the symptom referred to as tip‐burn for this petiole and the successively . shorter petioles formed as Ca deficiency increases in severity. Strangely, these symptoms also appear during periods of rapid growth when the nutrient solution contains as much as 10 to 28 milliequivalents per liter of Ca or when soils are high in Ca. This implies that Ca absorption and possibly translocation limits the Ca supply at the growing point. Increasing Mg in the nutrient solution decreases Ca uptake and increases Ca deficiency. Potassium deficiency, unexpectedly, induces Ca deficiency apparently by decreasing the translocation of Ca to the growing point.

These phenomena suggest the hypothesis that when ion absorption takes place from the root exchange site that has the affinity for H > Ca > Mg > K > Na, then the H generated internally replaces, and the roots absorb, Na, K and Mg preferentially. Externally, Ca would be adsorbed preferentially from the nutrient solution by the exchange complex, and with the addition of Mg, it would compete for the common adsorption site of Ca and limit Ca absorption internally. Under these conditions potassium‐deficient nutrient solutions would not induce Ca deficiency by decreasing Ca absorption but rather by decreasing Ca translocation. Theoretically, Ba would replace H more readily than Ca on the exchange complex, and therefore, Ba would be adsorbed preferentially and Ca uptake would increase. This effect of Ba was verified experimentally.

Since the translocation of ⁴⁵Ca to the growing point was found to be unrestricted under Ca‐sufficient and Ca‐deficient conditions and since the formation of insoluble Ca compounds such as phosphate or oxalate did not account for the Ca deficiency at the growing point, the cause of the Ca deficiency at the growing point is most likely the higher priority of the storage root for Ca over tops when leaf blades and storage root are both expanding rapidly. However, Ca retransport from older to younger parts of the sugarbeet plant may be restricted by the formation of Ca phosphate under Ca‐deficient conditions and Ca oxalate under Ca‐sufficient conditions.

Calcium deficiency increases net photosynthesis per unit blade area initially, probably because of blade puckering, but not on a per unit chlorophyll basis.     

温度对黑鲷无水保活工艺的影响

比较了-2,0,2,4,6℃等5种不同无水保活温度下,黑鲷(Sparus macarocephlus)的成活率、O2消耗量、CO2排放量、血清皮质醇及肌糖原的变化趋势。结果表明:在0℃条件下,无水保活36 h后,黑鲷成活率为100%,0℃组在整个无水保活过程中耗氧量最少,CO2释放量上升最缓慢,其皮质醇含量始终接近正常值,因此,0℃为黑鲷最佳无水保活温度。