长期施肥处理对双季晚稻叶绿素荧光特征及籽粒产量的影响

研究施肥模式对水稻叶绿素含量及荧光参数的调节作用,对提高水稻光能利用效率及籽粒产量具有重要意义。本研究以水稻品种赣929为试验材料,比较长期定位施磷钾肥(PK)、施氮磷钾肥(NPK)、等养分条件下70%氮磷钾肥配合施用30%有机肥(70F+30M)、50%氮磷钾肥配合施用50%有机肥(50F+50M)、30%氮磷钾肥配合施用70%有机肥(30F+70M)条件下水稻叶绿素荧光参数和产量变化特征。结果表明,水稻旗叶叶绿素含量从齐穗期到成熟期呈下降趋势,且表现为30F+70M50F+50M70F+30MNPKPK。水稻叶绿素荧光参数Fv/Fm随水稻生育期的推进呈降低趋势,其中PK处理Fv/Fm值最低,而施氮处理比不施氮处理Fv/Fm值增加了2.85%～4.18%。叶绿素荧光参数qL、ΦPSII在NPK处理中表现为齐穗期较高, 20 d之后显著降低;在50F+50M、30F+70M处理中表现为齐穗期较低, 20 d以后显著增加;在PK处理、70F+30M处理中一直处于较高水平。NPQ变化趋势与qL基本相反。ETR-PAR光响应曲线拟合结果表明, 70F+30M处理ETRmax、?和Ek值在齐穗期和20 d后值均最高。综合看来,等养分条件下配施30%有机肥具有最优的叶绿素荧光指标组合及籽粒产量;而配施超过50%有机肥由于前期热耗散增大使得用于光合作用的光能份额减少,而施用氮磷钾肥处理则由于后期的衰老使得光能利用效率下降。     

基于Web电子商务平台的食用菌产品共词聚类算法

针对食用菌产品电子商务平台的数据挖掘问题,采用了共词聚类算法进行主题聚类,在密度聚类算法的基础上,使用了移动非密集单元的处理方法实现了共词聚类。该算法克服了传统聚类算法裁剪造成的精度误差,提高了聚类结果的精确度,应用在电子商务平台的效果良好。     

落叶松人工林地位指数级导向曲线模型的研究

本文用约1000块样地资抖,系统地研究了黑龙江省落叶松人工林的地位指数级导向曲线模型。通过林业统计分析软件Statistica6.0对各落叶松人工林数据进行拟合、分析比较,结果为：从拟合精度、曲线走向与散点分布趋势、残差分布等综合考虑,舒马切尔曲线函数比较适合落叶松人工林地位指数级导向曲线模型的拟合。     

泥鳅的生物学特性和人工繁殖及苗种培育

泥鳅是分布广、数量多的杂食性淡水食用鱼,其适应性强、疾病少、成活率高,且繁殖力强,有较高的食疗作用和药用价值。本文从形态特征、生态特性、食性、生长等方面系统介绍了泥鳅的生物学特性,全面介绍了泥鳅亲鱼的选育、人工催产以及苗种培育技术,为泥鳅的人工养殖提供参考资料。     

三峡库区柑桔林水土保持效益分析

对三峡库区2种不同建园方式的柑桔林,从建园开始连续9年定位观测柑桔林水土流失情况,结果表明,梯田柑桔林径流系数在0.047~0.153之间,径流含沙量在425~2170g/m3之间,侵蚀模数在9.37~116.67g/m2之间。25°坡地柑桔林径流系数在0.079~0.378之间,径流含沙量在500~5 050 g/m3之间,侵蚀模数在48.29~1 962.04g/m2之间。在建园初期4年内,25°坡地柑桔林径流系数、径流含沙量和侵蚀模数急剧下降,径流系数由0.378下降到0.103,径流含沙量由5050 g/m3下降到350g/m3,侵蚀模数由1 962.04g/m2下降到131.42 g/m2。4年后,覆盖度的增加有效的抵消了坡度对水土流失的影响,柑桔林覆盖度达到0.82,径流系数,径流含沙量和侵蚀模数分别为0.103~0.253,350~3404 g/m3、14.71~148.4g/m2,表现出较好的水土保持效益。     

环县甘草人工栽植技术

甘草为豆科多年生草本植物,以根和根茎入药,含甘草酸、甘草素、甘草次酸等,其味甘、性平、无毒,有补脾益气、止咳祛痰、清热解毒、调和诸药的功效,还可做为食品添加剂和化妆品的配料,用途广泛,市场需求量大.以前甘草主要依靠野生资源,但因乱采滥挖而使野生资源面临枯竭.近年来国家实施生态保护,限制采挖和应用野生甘草,各地人工种植甘草已蓬勃兴起.环县2003年种植甘草4 000 hm2,直播种植两年后,条草产量可达4 500～5 000 kg/hm2,按2005年6元/kg计,产值可达27 000～30 000 元/hm2,再加上毛草4 500元/hm2,总产值可达31 500～34 500 元/hm2.实践证明,人工种植甘草可满足市场需求,增加农民收入,其发展前景十分广阔.环县目前人工种植甘草主要采用种子繁殖,现根据笔者种植甘草的实践,将甘草人工种植的技术总结如下.     

苦皮藤素微粉剂对玉米中玉米象种群的控制

苦皮藤素微粉剂1和微粉剂2以不同的浓度混入玉米中,当使用剂量为1000mg/kg时,对玉米象成虫的种群繁殖抑制率分别为96.66%和96.02%,能有效控制玉米象成虫的危害,但对幼虫和卵的控制效果不明显。     

DNA ploidy analysis and the expression of TIMP-2 and E-cadherin in gastric carcinoma

AIM:To investigate DNA ploidy and the expression of TIMP-2 and E-cadherin in gastric carcinoma in order to understand its molecular basis and probable mechanism of invasion and metastasis. METHODS:Immunohistochemical methods were used to detect the expression for TIMP-2 and E-cadherin in 99 cases of gastric carcinoma, 16 cases of adjacent noncancerous mucosa, 16 cases of distant metastases and 25 cases of metastatic lymph nodes. Flow cytometry DNA ploidy and S-phase fraction (SPF) analysis was performed on 47 cases of gastric cancer, 6 cases of adjacent noncancerous mucosa and 4 cases of distant metastasis cancer with the use of formalin-fixed paraffin embedded specimens. RESULTS:The expression of TIMP-2 was significantly correlated with Borrmann’s classification, LN metastasis and the depth of invasion. The expression of E-cadherin was significantly correlated with tumor cell differentiation, Lauren’s classification, Borrmann’s classification, LN metastasis and the depth of invasion. There was a positive relationship between DNA aneuploid rate and differentiation and LN metastasis. There was a positive relationship between SPF that is higher than 15% and tumor size, differentiation and LN metastasis. And there was a significantly difference between carcinoma and noncarcinoma when the expression of E-cadherin, DNA aneuploid rate and SPF were analyzed. There was no correlation between TIMP-2 and E-cadherin. There was a positive relationship between DNA ploidy or SPF and the expression of E-cadherin. CONCLUSION:As the development of tumor progression and heterogeneity, the abnormal expression of TIMP-2 or E-cadherin or the rate of DNA aneupoid or higher SPF gradually correspondingly increases, suggesting that they play a crucial role in gastric carcinoma progression. Furthermore, each factor influences one another and further accelerates the process of tumor progression.     

新的β-二氢沉香呋喃倍半萜多元酯和生物碱的HR-FABMS研究

利用高分辨快原子轰击质谱(HR-FABMS),以(甘油 氯化钠)为基质测定了9个新的β-二氢沉香呋喃倍半萜多酯和生物碱的HR-FABMS。结果表明,所有该类化合物均可以精确地获得[M Na] ,[M H] ,[M H-H2O] 等特征离子的质量和元素组成,从而方便地获得原有该类化合物的分子量和分子式。