氮磷钾施用量与辣椒品质的相关性研究

采用三因素五水平正交旋转组合设计,用基质盆栽法,研究了氮、磷、钾施用量与辣椒品质的相关性,建立了相应回归方程.结果表明:氮对辣椒干物质的形成起主要作用,钾与辣椒果实维生素C含量呈典型曲线相关,氮与辣椒素含量呈显著直线相关,氮、磷、钾之间存在有显著的交互作用效应.无土栽培辣椒氮、磷、钾最优组合方案为氮:352～388 mg/L;磷:54～62 mg/L,钾:337～409 mg/L.     

氮磷钾施用量与辣椒品质的相关性研究

采用三因素五水平正交旋转组合设计,用基质盆栽法,研究了氮,磷,钾施用量与辣椒品质的相关性。建立了相应回归方程,结果表明：氮对辣椒干物质的形成起主要作用,钾与辣椒果实维生素C含量呈典型曲线相关,氮与辣椒素含量呈显著直线相关,氮、磷、钾之间存在有显著的交互作用效应,无土栽培辣椒氮,磷、钾最优组合方案为氮;352-388mg/L;磷：54-62mg/L,钾：337-409mg/L。     

氮磷钾施用量与辣椒产量的相关性研究

采用三因素五水平正交旋转组合设计 ,用基质盆栽法 ,研究了氮、磷、钾施用量与辣椒产量的相关性 ,建立了相应回归方程。结果表明 :氮肥的施用与辣椒产量的形成呈显著正相关 ,磷、钾也有一定的影响 ,氮磷、氮钾之间的互作达到显著水平。氮磷钾均有利于辣椒果实的发育 ,促进单果重的形成 ,氮的作用最大 ,磷次之 ,钾最小 ,氮磷、氮钾之间的互作达到显著水平。经多元回归和频率分析方法得出无土栽培辣椒氮、磷、钾最优组合方案为氮 :35 2～ 388mg/L ;磷 :5 0～ 70mg/L ;钾 :337～ 4 5 7mg/L。     

土石山地耕地土壤养分空间分布特征研究——以陕西陇县为例

运用地统计和GIS技术,研究陕西省陇县耕地土壤有机质、碱解氮、有效磷和速效钾的空间分布特征,探讨地形因子对养分空间分布的影响。结果表明:耕地土壤有机质、有效磷和碱解氮含量均处于中等偏下水平,速效钾含量位于较高水平。有机质平均含量为11.98g/kg,碱解氮平均含量为67.68mg/kg,有效磷含量变幅较大,平均含量10.26mg/kg,速效钾含量较高,平均为157.95mg/kg。土壤养分含量和地形变量之间存在着显著的相关关系。其中,海拔与速效钾、有机质之间存在显著正相关,与有效磷、碱解氮呈负相关,但相关关系不明显;坡度与有机质、速效钾呈正相关,与有效磷、碱解氮显著负相关;有机质、有效磷、碱解氮阴坡含量高于阳坡含量,速效钾阳坡含量高于阴坡。     

新疆艾比湖湿地土壤有机质与速效养分时空变异及其相关性

于不同时间采集了艾比湖湿地自然保护区博尔塔拉河、精河流域内3个典型样地的4个不同土层土壤,定量测定了其有机质、碱解氮、速效磷和速效钾含量,分析土壤各养分指标的时空变异特征及有机质含量与速效养分的相关性。结果表明,艾比湖湿地有机质含量总体较低,为0.23%~4.27%;碱解氮平均含量为32.08 mg/kg,处于较低水平,与土层深度呈显著负相关;速效磷平均含量为24.21 mg/kg,处于中等水平,与采样时间呈极显著正相关;速效钾整体水平较高,平均含量达246.07 mg/kg,与土层深度呈极显著负相关。有机质含量与碱解氮含量和速效钾含量呈极显著正相关;与速效磷含量相关不显著。土壤有机质含量影响艾比湖湿地土壤速效养分的含量。     

氮磷钾肥配施与马铃薯微型薯产量的相关性

采用三因素五水平正交旋转组合设计,用基质盆栽法,研究氮、磷、钾施用量与微型薯产量的相关性。结果表明,钾肥与产量几乎呈直线相关,增施钾肥可提高微型薯的产量;适宜的磷肥质量浓度能稳定提高微型薯产量;氮肥施用量超过250mg/L不利于微型薯产量的形成。氮、钾肥对微型薯产量存在正向互作,氮肥一定时增施钾肥可获得高产,且钾肥用量越多增产效果越显著;磷、钾肥对产量也存在正向互作,钾肥用量超过400mg/L时,微型薯产量迅速提高。多元回归和频率分析表明,无土栽培微型薯氮、磷、钾最优组合方案为N274.23mg/L,P 59.94mg/L,K 603.46mg/L。     

氮、磷、钾对萝卜产量及硝酸盐含量的影响

采用通用旋转组合设计,利用基质培方法研究了氮、磷、钾施用量对萝卜产量及硝酸盐含量的影响,获得了相应的数学模型.结果表明氮磷钾对产量影响的大小顺序为氮＞磷＞钾,对硝酸盐含量影响的大小顺序为氮＞钾＞磷;无土栽培萝卜时最佳营养液组合方案为N 132～241mg/kg、P2O5 89～129mg/kg、K2O 367～533mg/kg;在保证硝酸盐含量较低(＜785mg/kg)的情况下,获得最高产量(920g/株)时氮、磷、钾三者的水平分别为N 294mg/kg、R2O5 85 mg/kg、K2O 329mg/kg,三者之间的比例为NP2O5K2O=11.8311.6.     

园地主要经济作物氮磷钾与PH相关性研究

为了解古田县果园作物土壤氮、磷、钾养分状况,探讨了果园土壤氮、磷、钾含量与土壤pH值之间的关系。结果表明,古田县园地土壤pH的平均值为5.07,处于酸性水平;全氮的含量均值为1.20g/kg,总体处于中等水平;供试园地土壤碱解氮均值为143.4mg/kg,处于中等水平;供试土壤有效磷均值为29.90mg/kg,处于丰富水平;速效钾含量均值为59.2mg/kg,处于严重缺乏水平。土壤中的氮、磷、钾养分状况与土壤中的pH值呈显著或极显著正相关。因此,改良土壤酸度是供试果园土壤改善氮、磷、钾养分供应的主要措施。     

豫中烟区土壤速效钾与土壤因素及烟叶品质性状的关系分析

采用田间试验与室内分析相结合的方法,分析了豫中烟区土壤速效钾含量对土壤因素及烟叶品质性状的影响。结果表明:豫中烟区土壤速效钾含量平均值为111.63 mg/kg,含量较低,变幅为46.46²48 mg/kg,变异系数较大(37.43%);对于不同植烟地区而言,平顶山土壤速效钾(120.05 mg/kg)含量较高,漯河次之,许昌较低;随着地势的升高,土壤速效钾含量逐渐升高,土壤速效钾含量以低山地区含量(133.57 mg/kg)最高;土壤速效钾含量与有机质(0.370**)、有效氮(0.242**)、速效磷(0.297**)、阳离子交换量(0.351**)呈极显著相关;与土壤粒径0.1248 mg/kg,变异系数较大(37.43%);对于不同植烟地区而言,平顶山土壤速效钾(120.05 mg/kg)含量较高,漯河次之,许昌较低;随着地势的升高,土壤速效钾含量逐渐升高,土壤速效钾含量以低山地区含量(133.57 mg/kg)最高;土壤速效钾含量与有机质(0.370**)、有效氮(0.242**)、速效磷(0.297**)、阳离子交换量(0.351**)呈极显著相关;与土壤粒径0.1⁰.05 mm(-0.188*)和<0.001 mm(0.193*)呈显著相关;土壤速效钾含量与烟叶钾含量、致香物质含量分别建立的回归方程均达到极显著水平。     

丹尼斯凤梨“3414”施肥效应试验

为了解满足丹尼斯凤梨生长发育所需氮磷钾的最佳用量,利用“3414”方案分别建立了氮、磷、钾施肥量与植株干重、株高、冠幅、叶片数的回归方程,结果表明,由一元二次函数导出最大干重、株高、冠幅、叶片数的氮、磷、钾施用量为N 151.82～175.7 mg/L 、P2O522.79～23.38 mg/L、K2O 258.25～298.5 mg/L;由三元二次函数导出最大干重、株高、冠幅、叶片数的氮、磷、钾施用量为N 153.13～216.51 mg/L、P2O5 19.78～28.33 mg/L、K2O 253.28～311.8 mg/L;较为适合丹尼斯凤梨生长发育的氮磷钾(N:P2O5:K2O)的比例为1:0.29～0.32:2.00～2.44.     

Hotspots, basalts, and the evolution of the mantle

The trace element concentration patterns of continental and ocean island basalts and of mid-ocean ridge basalts are complementary. The relative sizes of the source regions for these fundamentally different basalt types can be estimated from the trace element enrichment-depletion patterns. Their combined volume occupies most of the mantle above the 670 kilometer discontinuity. The source regions separated as a result of early mantle differentiation and crystal fractionation from the resulting melt. The mid-ocean ridge basalts source evolved from an eclogite cumulate that lost its late-stage enriched fluids at various times to the shallower mantle and continental crust. The mid-ocean ridge basalts source is rich in garnet and clinopyroxene, whereas the continental and ocean island basalt source is a garnet peridotite that has experienced secondary enrichment. These relationships are consistent with the evolution of a terrestrial magma ocean.     

Climate change, deforestation, and the fate of the Amazon

The forest biome of Amazonia is one of Earth's greatest biological treasures and a major component of the Earth system. This century, it faces the dual threats of deforestation and stress from climate change. Here, we summarize some of the latest findings and thinking on these threats, explore the consequences for the forest ecosystem and its human residents, and outline options for the future of Amazonia. We also discuss the implications of new proposals to finance preservation of Amazonian forests.     

Pre-Columbian urbanism, anthropogenic landscapes, and the future of the Amazon

The archaeology of pre-Columbian polities in the Amazon River basin forces a reconsideration of early urbanism and long-term change in tropical forest landscapes. We describe settlement and land-use patterns of complex societies on the eve of European contact (after 1492) in the Upper Xingu region of the Brazilian Amazon. These societies were organized in articulated clusters, representing small independent polities, within a regional peer polity. These patterns constitute a "galactic" form of prehistoric urbanism, sharing features with small-scale urban polities in other areas. Understanding long-term change in coupled human-environment systems relating to these societies has implications for conservation and sustainable development, notably to control ecological degradation and maintain regional biodiversity.     

Diamonds, Eclogites, and the Oxidation State of the Earth's Mantle

The reaction dolomite + 2 coesite --><-- diopside + 2 diamond + 2O(2) defines the coexistence of diamond and carbonate in mantle eclogites. The oxygen fugacity of this reaction is approximately 1 log unit higher at a given temperature and pressure than the oxygen fugacities of the analogous reactions that govern the stability of diamond in peridotite. This difference allows diamond-bearing eclogite to coexist with peridotite containing carbonate or carbonate + diamond. This potential coexistence of diamond-bearing eclogite and carbonate-bearing peridotite can explain the presence of carbon-free peridotite interlayered with garnet pyroxenites that contain graphitized diamond in the Moroccan Beni Bousera massif at the Earth's surface and the preferential preservation of diamond-bearing eclogitic relative to peridotitic xenoliths in the Roberts Victor kimberlite.     

清真雅正与清代书院八股文教育

清真雅正是清代朝廷推行的衡文准则，包括在理、法、辞、气等方面有所要求。为了引导生徒作文步入正轨以及促进健康文风的形成，清代一些书院将清真雅正纳入八股文教育的范畴，清真雅正在书院学规、课艺甄选、课艺评点等内容中有着重要体现。为了便于生徒理解清真雅正，施教者要求研习明清时期八股文名家善本，用范文来指导习作。清代一些书院在进行清真雅正教育时，重视将为文上的开导与为人上的训迪结合起来，从而为国家培养品学兼优的科举人才，实现文学教育的崇高理想。