复合肥选用技巧

1．复合肥宜做底肥。经过加工造粒的复合肥比粉末肥分解慢，营养元素不易流失和挥发，肥效持续时间长，宜做底肥使用（一般亩用量为30—40公斤），而不宜用于苗期肥和中后期肥，避免贪青徒长。     

蜜本南瓜小拱棚覆盖栽培

1．播种育苗。育苗土用田园土6份、腐熟厩肥4份，分别过筛后混匀配制。另外，每立方米营养土中需加优质腐熟鸡粪粉10-15公斤、过磷酸钙2公斤、三元复合肥3公斤、50％多菌灵可湿性粉剂100克，充分混匀。然后将育苗土装入育苗床，厚10-12厘米；或装入营养钵、纸钵、泥钵中，以供播种。育苗床宽度一般为1．2～1．3米，长度不限（以10米为佳）。     

白垩纪同褶皱重磁化组分揭示中扬子褶皱带构造旋转过程

为研究中扬子褶皱带的变形过程, 对重庆万州地区中三叠世灰岩和中晚侏罗世砂岩进行了古地磁研究. 系统热退磁表明, 侏罗纪样品受现代地磁场重磁化严重, 三叠纪样品分离出3个重磁化组分: 低温(0~200℃)、中温(200~360℃)和高温(400~460℃)组分. 低温组分分布于现代地磁场方向附近, 可能为黏滞剩磁. 逐步展平褶皱检验显示: 中温组分在褶皱展平至 33%±8%时获得, 相应古地磁方向为 D_ec = 11.2°, I_nc = 45.2° (α₉₅ = 4.5°, N = 34), 对应古地磁极位置79.3°N, 219.5°E (d_p = 3.6°, d_m = 5.7°); 高温组分在褶皱展平至50%±27%时获得, 在95%置信范围内取褶皱展平至 70%, 相应古地磁方向为D_ec = 24.2°, I_nc = 49.0° (α₉₅ = 3.6°, N = 23), 对应古地磁极位置为69.2°N, 195.5°E (d_p = 3.1°, d_m =4.8°). 与白垩纪参考古地磁方向或极位置比较, 上述重磁化组分揭示该地区在褶皱变形的中期经历了12.8°±3.5°的顺时针旋转, 而变形后期以来没有发生旋转. 结合前人数据, 认为中扬子褶皱带万州-香溪段部分弯曲是由弯山构造引起的; 湖北蒲圻地区在褶皱变形末期以来经历了27.5°±5.8°的顺时针旋转, 因此至少50%的构造旋转是由于弯山构造导致的. 中扬子褶皱带发生于侏罗纪末期和早白垩纪的褶皱造山事件也揭示了华南-华北地块碰撞可能一直持续到早白垩纪早期.     

自制土化肥

1．土氮磷肥。用动物骨加工成骨粉，其氮磷含量高，是较好的一种底肥，相当于高效氮磷复合肥。方法：将生骨头经蒸煮，除去部分脂肪后粉碎细末，其中含氮2％～6％，含五氧化二磷15％-28％。     

用示波器测量铁磁物质的磁滞回线

论述了铁磁物质磁滞回线测量的基本原理.介绍了如何利用示波器观察和测量铁磁物质的磁滞回线、剩余磁感应强度和矫顽力.同时也详述了怎样描绘介质的基本磁化曲线和μ-H曲线.     

几种复合肥在棉花上应用的对比试验

通过对几种复合肥不同的配比处理,选择出适合本地区棉花生长发育的复合肥品种。     

Do multiple cycles of aeolian deposit-pedogenesis exist in the reticulate red clay sections in southern China？

The Xiangyang reticulate red clay section was newly sampled in high-resolution. The viewpoints different from the previous studies^[1-7] are put forward after studying Munsell color values, weathering degrees, magnetic parameters and stable carbon isotopic compositions of the section.They are as follows: (1) The curves of hue, DCB extracted iron (Fed), DCB extracted iron/total iron ratio (Fed/Fet),weathering index (BA) of the section show that the redness is not significantly correlated with the weathering degree of the layers though the uppermost yellow-brown-colored layer is relatively weakly weathered. The variation in hues of the section is possibly attributed to the change of hematite and goethite contents. It is insufficient to determine the existence of the multiple deposit-pedogenesis cycles in the section, like the Ioess-paleosol sequence in Chinese Loess Plateau, only by the color variation. (2) Magnetic susceptibility (X) values in the non-reticulate and weakly reticulate layers are high; but are quite low in the reticulate red clay layer. The former are more than ten times higher than the latter because of the leaching and collapse of superparamagnetic (SP) and stable single domain (SSD) magnetic particles during the plinthitic processes. Hence, X values in the section are not controlled by weathering and pedogenic processes, and no longer have clear paleoclimatic implication. It is not correct to prove the existence of the multiple deposit-pedogenesis cycles in the section using X curves. (3) The organic δ^13C curve of the section illustrates the reduction of forests and increasing of C4 plants in the study area since the late stage of the Quaternary period. It could not prove the existence of the multiple deposit-pedogenesis cycles in the section either. (4) As a matter of fact, it is difficult to prove the existence of the multiple deposit-pedogenesis cycles in the Xiangyang section like the Ioess-paleosol sequence in Chinese Loess Plateau using the evidence available currently.     

整流器濾波用擺式抗流線圈計算法

(一)当电子管整流器供电給变动的負荷(如振幅操縱的發报机,乙类低頻放大器等)时,共濾波線路的輸入电感常釆用所謂的「擺式」抗流線圈,当通过此种線圈的负荷电流在一定范圍內变化时,其电感值作適应的变化,对於这种抗流線圈电感值变化的要求有以下三項:     

核磁共振技术的发展及其在化学中的应用

核磁共振是一项尖端技术,介绍了核磁共振波谱仪的结构及其主要部件的技术进展情况,同时讨论了共振谱在化学领域的各种应用。     

油管缺陷漏磁场有限元分析

采用有限元技术,建立了油管缺陷漏磁场的静态和瞬态仿真模型。通过对励磁磁场的均匀性、检测速度和缺陷尺寸三种影响因素的仿真分析,比较了静磁场模型和瞬态模型的仿真结果和效率。静磁场模型求解效率高、占用的计算资源少,但是随着检测速度的增大,求解结果明显偏高。瞬态模型能降低速度引起的误差问题,但需要大量的计算资源。给出了用静磁场模型分析缺陷漏磁场应满足的条件。