反相高效液相色谱法测定克林霉素含量

本实验建立了一种快速检测克林霉素HPLC，用反相C18柱分离克林霉，用乙酰胺做内标，在UV205mm条件下，用乙腈－磷酸盐缓冲液－四氢呋喃（V：V：V＝29：70：1）作流动相测定克林霉素含量。结果表明：标准曲线范围在0.05-40mg/mL回归方程为Y＝0.6547X-0.0034(R^3=0.9992）。     

水稻籼粳杂种一代稻米加工和外观品质性状研究

采用不同稻米品质3个粳稻和4个籼稻按完全双列模型设计进行杂交，配组了24个籼粳杂种一代F1，对其主要稻米加工和外观品质性状进行研究。加工品质中糙米率和精米率均接近粳稻品种，与籼稻无关，无胞质效应；整精米率差异很大，但大多介于籼粳双亲之间，并且随粳稻亲本不同，其胞质效应表现不一致。外现品质中垩白度和透明度，大多数介于双亲之间．而垩白率多倾向于亲本的高值。     

7种芸香科种子的发芽试验

试验表明芸香科种子不耐贮藏；除枳壳种子在30℃下萌发最佳外，金桔、红桔、芦柑、甜橙、九里香及花椒均以20～30℃变温为最适萌发温度；花椒种子存在休眠现象，冷湿处理及外源GA可解除休眠促进萌发；在金桔及红桔种子中发现有白化苗。     

不同PEG-6000浓度处理下几种冷季型草坪草抗旱性比较研究

研究了3种冷季型草坪草的6个品种在PEG-6000模拟干旱胁迫条件下的生长表现和生理指标。结果表明：高羊茅的“家园”品种在干旱胁迫条件下具有较好的生长表现、在土壤中的根系分布最深、且能维持较高过氧化氢酶活性，表明其与其他供试品种相比具有较强的抗旱能力。     

Analyses of Interlayer Stresses and Strain Transfer in Smart Laminated Structures

A new model is proposed to analyze the strain/stress transfer relation between host materials and piezoceramic sensors/actuators under bending and axial stress loading. The finite thickness of the adhesive is taken into account. The physical layers of the piezoceramic, adhesive and structure material are further subdivided into thinner layers as fine as necessary in order to improve the accuracy of stress analysis. In each thin layer the in-plane stresses are assumed to vary linearly across the thickness. By satisfying equilibrium equations, constitutive equations and displacement-strain relations, all components of stress, strain and displacement can be expressed as functions of the in-plane forces and the moments of the thin layers. The differential equations governing the in-plane forces and the moments are obtained. Then, this analytical model is used to predict strain transfer from the structure material to the sensor. It is found, both experimentally and theoretically, that the axial strain of the host material is considerably larger than the strain of the sensor, which is directly related to the output voltage. By introducing the so-called strain transfer factor, a relationship between the output voltage of the sensor and the strain of the measured material is derived. The model is used to predict interlayer stress distributions and strain transfer, which are induced by actuator strain. The result was compared with existing experiments and FEM. There is stress concentration between the actuator and adhesive around the edge of the smart structures, which may cause debonding under high stress loading.     

国有公司面临的问题及改造模式的思考

中华人民共和国种子法的实施和中国加入WTO,将使我国的种子经营格局发生重大变化.国有种子公司不再负有供应和调剂本辖区内种子主渠道的职责,也没有区域内的垄断经营的特权,新的种子市场将是打破国界和行政辖区的开放型种子市场,国有种子公司将面临国内外先进种业和其它行业介入种业的强烈冲击.     

NONLINEAR ELASTIC-DAMAGE CONSTITUTIVE EQUATION OF BRITTLE ROCK AND EXPERIMENAAL VERIFICATION

on the basis of the experimental studies of mechanical properties in brittle rock,the generalized elastic modulus,generalized elastic Poisson ratio,irreversible deformation Poisson ratio and damage deformation characteristic arediscussed.And then,a new damage variable is defined.A new nonlinear elastic-damage constitutive equation is built and the damage evolution equation is proposed.The nonlinear elastic-damage constitutive equation is verified in the uniaxialcompression test of quartz sandstone in Chongqing.The results show that reasonableagreement exists between the theoretical analysis and the experimental data.     

红壤坡耕地人工模拟降雨条件下植物篱笆水土保持效应及机理研究

结果表明 ,与大豆单作相比 ,黄花菜和百喜草植物篱笆径流量、侵蚀量分别减少了 4 .6 7% ,37.82 % ,植物篱笆处理和大豆单作处理的径流量、侵蚀量与开始形成径流所经历的时间之间呈显著负相关 ,而径流量与侵蚀量之间为显著正相关关系 ,建立了相应的降雨产流、降雨产沙、径流侵蚀回归模型。植物篱笆的水土保持机理表现在 :植物篱笆地上部的缓流和分流作用 ,有效地减弱径流的携沙能力 ,减少了细沟侵蚀 ;地上部分可阻挡土壤大颗粒和过滤土壤小颗粒 ;植物篱笆地下部根系显著改善了耕层土壤的物理性状 ,显著提高了土壤的抗冲性 ;土壤性状显著增强了土壤的入渗能力 ,植物篱笆带在较长的时间内维持较高的土壤入渗量和较大的稳定入渗速率     

乌桕籽剥壳机械设计

乌桕是1种难得油料作物,可同时提取两种油脂—皮油和梓油。乌桕籽通过脱蜡后剩下黑色籽粒,通过剥壳,将仁、壳分离,桕仁是制取梓油的重要原料。乌桕剥壳机主要由机架、料斗、进料量调节器、辊调节机构、电动机、传动机构、风机及双辊等组成。通过对乌桕籽进入双辊工作区的条件,脱壳过程的分析,根据乌桕籽的粒度实现双辊间距的可调节,乌桕籽...     

不同雨强条件下红壤坡地养分流失特征研究

采用人工模拟降雨装置 ,对红壤坡地养分流失特征进行了试验研究 ,结果表明 :在雨强较大情况下 ,土壤养分以泥沙形式随径流迁移 ;当雨强较小时 ,随径流迁移的可溶态养分流失量占流失泥沙养分量的比例较高 ,土壤养分流失氮、磷、钾分别达到 5 3.12 % ,2 3.1% ,2 1.5 % ;不同形态的养分在流失泥沙中均有养分富集现象 ,但富集率各不相同 ;土壤养分流失量与雨强及泥沙流失量呈正相关关系。