外源复合酶对移地保护圈养马来熊日粮营养消化率的影响

利用外源复合酶对移地保护圈养的 9只马来熊日粮营养物质及能量消化率进行了测定 ,经单因子方差分析结果表明 ,在圈养马来熊日粮中添加一定量的外源复合酶 ,能提高马来熊对日粮营养物质的消化率 ,其中 ,添加 0 3%饲料量的酶能显著提高日粮粗蛋白的消化率(P <0 0 5) ;添加 0 5%的酶 ,能显著提高日粮粗纤维、粗蛋白质消化率 (P <0 0 5)。此研究结果可应用于马来熊的饲养中 ,提高其饲料报酬     

一种适合稻区紫云英生产实际的紫云英加工调制方式

将紫云英鲜草分离为草汁、细渣、纤维状渣；以粉状能量精料为载体吸收汁液；3种制品都以晾晒的方式进行干燥。晾晒时，3种制品综合占场面积较原草减少近90％；3种制品均可在一个晴日内风干，比原草干燥速度提高一倍余；细渣品质与国标一级苜蓿草粉相当；“二次拌汁料”、“三次拌汁料”之粗蛋白、粗纤维含量符合生长肥育猪饲养标准；加工方式切合稻区紫云英生产实际及产区综合条件，有推广价值，且易推广。     

The effects of stubble burning and tillage on soil carbon sequestration and crop productivity in southeastern Australia

Abstract. In Australia, stubble burning and tillage are two of the major processes responsible for the decline of soil organic carbon concentration in cropped soils, and the resulting soil degradation. However, the relative importance of these two practices in influencing the soil organic carbon concentration and the long-term impact on soil quality and productivity are not clear. The effects of stubble burning as practised by farmers in southeastern Australia were evaluated in two field trials, one of 19 years duration, the other of 5 years. Conventional tillage (three tillage passes) led to greater loss of soil organic carbon than stubble burning. Loss of total soil organic carbon attributed to stubble burning in the 0–10 cm layer was estimated to be 1.75 t C ha⁻¹ over the period of the 19-year trial, equivalent to 29% of that lost due to tillage. In the 5-year trial, no change in soil organic carbon due to stubble burning was detectable. Changes in soil quality associated with stubble burning detected in the longer trial included a reduction in macro-aggregate stability, and increases in pH and exchangeable K⁺. Only the latter two were detected in the shorter trial. A higher mean wheat yield (average 0.15 t ha⁻¹) following stubble burning was observed in the 19-year trial but not in the 5-year trial. Research to monitor the longer term effects of stubble burning is needed, and to identify conditions where loss of soil organic carbon is minimized.     

稀薄燃烧空燃比控制技术

为解决能源和环境两大难题,使发动机工作在稀薄燃烧区,而稀薄燃烧技术的关键是发动机空燃比的控制;采用先进的计算机控制技术使发动机在最佳稀薄空燃比下工作,有效改善发动机动力性、燃油经济性、降低尾气污染。     

玉米幼芽提取物凝胶对家兔皮肤烧伤的抗氧化损伤作用

制备1,1.5和2 mg/g的玉米幼芽提取物(Extract of maize plumule,EMP)凝胶,用2 mol/L的NaOH复制家兔皮肤烧伤模型,并分别用上述EMP凝胶进行治疗,同时设立EMP盐酸溶液阴性对照组、烧伤止痛膏阳性对照组和生理盐水空白对照组,各组均连续处理14 d。于烧伤后第1,7,14和21天取各组家兔烧伤部位皮肤,制成100 mg/g组织匀浆液,检测超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性及丙二醛(MDA)含量,并进行组织病理学和透射电镜观察,探讨EMP凝胶对家兔皮肤烧伤脂质过氧化损伤和炎症反应的影响。结果表明,与空白对照组相比,EMP凝胶治疗组SOD和CAT活性极显著提高(P<0.01),MDA含量显著(P<0.05)或极显著(P<0.01)降低(除7 d时1 mg/g EMP凝胶治疗组外);与阴性对照组相比,EMP凝胶治疗组SOD和CAT活性显著(P<0.05)或极显著(P<0.01)提高、MDA含量显著(P<0.05)或极显著(P<0.01)降低(除7 d时1 mg/g EMP凝胶治疗组外);EMP凝胶可促进组织细胞生长,减轻皮肤局部组织炎症反应,与阳性对照组结果一致。表明EMP凝胶在皮肤烧伤治疗中具有较强的抗脂质过氧化损伤、抑制炎症及促进愈合的作用。     

刺五加"全光喷雾"硬枝扦插育苗试验

刺五加为扦插难生根树种，以1．5a生刺五加苗为母株采穗扦插，其平均生根率达60％以上，最高达90％。     

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.     

沙棘全光照喷雾嫩枝扦插育苗试验研究

生长季节,利用全光照喷雾育苗装置,在塑料容器中装入河沙∶锯末∶田土=5∶2∶3的混合基质,将插穗用质量分数为1.0×10-4的ABT3号生根粉溶液浸根1h或质量分数为5.0×10-5的溶液浸根2h后扦插,扦插深度6～8cm,能有效地提高沙棘嫩枝扦插苗生根率及成活率。     

天然气发动机国Ⅴ排放技术研究

研究天然气发动机技术的发展,选取稀薄燃烧的技术路线。通过对电控量的标定和后处理的匹配,使单燃料天然气发动机排放达到国Ⅴ排放标准。