土著微生物对尾矿中重金属的淋滤研究

生物淋滤对尾矿的重金属污染处理的效果已经得到了广泛的认可.在对酸性尾矿中的土著氧化硫硫杆菌以及氧化亚铁硫杆菌进行分离以及加富培养的基础上，分别运用单一菌种以及混合菌种对尾矿样本进行淋滤处理.通过12 d的淋滤实验，实验室结果表明，分离出的氧化亚铁硫杆菌以及氧化硫硫杆菌等土著微生物具有较高的利用价值.同时实验表明，在采用适当菌种的前提下，尾矿中重金属的溶解率都得到了不同程度的提高：土著氧化亚铁硫杆菌对Zn的淋滤效果最好，达到了98.12%；对于Cu的淋滤，土著氧化亚铁硫杆菌与土著氧化硫硫杆菌的混合菌种的效果最好，达到88.75%.     

巴西蕉叶面积指数的动态模型研究

巴西蕉叶面积指数的动态模型研究     

安经理

<正>近几年,由于各种事物缠身,很少有机会像前些年一样,能够常常走访基层的经销商、零售商和农户。今年,趁着"十一"的长假,开着车走访了一下华北地区的客户,放松一下紧张的工作气氛和心情,也未尝不是一     

猪夜间磨牙的原因与防治

总结了造成猪磨牙的环境、营养及疾病方面的因素,并提出了针对性的防治措施,以供养殖者参考.     

基于“3414”试验的巴西蕉施肥效应与最佳施肥量

分别采用三元二次、一元二次和直线加平台等肥料效应模型,对海南省福山镇蕉园2年的"3414"试验数据进行分析。结果表明,三元二次模型模拟的最佳施肥量为:N 0.374 kg/株、P2O50.289 kg/株、K2O 0.891 kg/株;根据产量趋势特点,一元二次模型模拟的最佳施肥量为:N 0.400 kg/株、P2O50.214 kg/株、K2O 0.901 kg/株。可见三元二次模型模拟的最佳施肥量只有部分指标高于一元二次模型。综合考虑试验结果,初步确定巴西香蕉最佳施肥量为:N0.374~0.400 kg/株、P2O50.214~0.289 kg/株、K2O 0.891~0.901 kg/株。     

不同施氮量对莴苣品质及产量的影响

以"美国大速生"莴苣为试材,采用小区试验和化学测定相结合的方法,研究了氮肥施用量对莴苣产量和品质的影响。结果表明:随着氮肥施用量的增加,莴苣中可溶性糖含量、维生素C含量及产量都呈先上升后下降的趋势,硝酸盐含量呈上升趋势;综合分析,莴苣高产优质的尿素施用量为20g/m2。     

巴西蕉产量与果实形态特征的相关分析

2011～2013年采用“3414”完全试验设计方案,对巴西蕉(Musa AAA Cavendish cv.‘Baxi’)成熟期果实主要农艺性状与产量之间的关系进行相关和通径分析。结果表明,第三梳果指外弧长、果指内弧长、果指周长、第三梳果指重4个经济性状与巴西蕉单株产量呈极显著正相关关系,果指数与巴西蕉单株产量呈极显著负相关关系,香蕉第三梳平均果指周长对产量的直接作用最大、果指内弧长次之,果指外弧长通过内弧长、果指粗、果指重及果指数对产量的间接作用最大。对巴西蕉果主要农艺性状与产量之间的相关性进行回归分析,得产量预测回归模型：FDW=-264.680LFOA+752.534FIA+1 274.990FF+375.053NF+2.098DWC-15 694.983,通径分析表明,自变量果指外弧长、内弧长、果指粗及果指重对单株产量的增加具有重要作用,因此,在强调高产育种的性状选择上,在果形选择方面,可将重点集中于这4个性状上,从而缩小育种过程中良性性状的选择范围,提高育种效率。     

Safety Assessment of Circular Arches Tunnel Evacuation on Surrounding Geotechnical Environment

Based on the stochastic medium theory, influence on the surrounding rock and soil by tunnel excavation was studied. formula for predicting movement and deformation of rock and soil mass caused by tunnelling were deduced. And especially for the tunnel with circular arch section, half analytic solution for this problem was put forward. Furthermore, a program was developed to compute the movement and deformation of the rock and soil mass resulted from excavation. The deformation failure criterion of stochastic medium for estimating the surroundings safety was provided and was applied in an engineering example, which proved that the results of the research were reasonable and significant for the tunnel safety construction.     

Numerical analysis on the performance of spiral antennas

The surfaces of the Planar Spiral Antennas and Conical Spiral Antennas are analyzed with planar triangle. The surface currents of the antennas are solved by using the Method of Moment (MoM) based on the RWG basis function. The input impedance, directivity, gain, radiated power and radiation field of the antenna can be found. The results indicate that, in very wide frequency band, the value of the input impedance equals to the theoretical value of Self-Compensated antennas (in agreement with Babinet-booker' principle), which is,188.5 ohm , the half of the wave impedance of free space, while the directivity, gain and radiated power are stable within the frequency band. When the antenna is driven by the signal of derivative Gaussian pulse, the radiating electric field waveform is obtained by the Fourier transform. When the spiral antenna is used as the pulse radiation antenna, the waveform of the radiation electric field shows the characteristics of the Gaussian quadratic differential.