不同镁肥对烤烟产量和品质的影响

通过田间试验探讨不同镁肥对烤烟产量和品质的影响。研究结果表明福建省烟区土壤增施镁肥可提高烤烟产量14.28～19.19%,增加上等烟叶数量8.77～12.75%,每667m2增加经济效益181.88～242.47元。以施用氢氧化镁的增产效果最好,氧化镁和硫酸镁次之。     

高铁酸钡的电化学合成研究

以2BaO·Fe2O3为正极材料、GP镍氢和镍铬二次商业电池的阴极材料为负极.以13.5 mol·dm-3KOH溶液为电解液,在隔膜电解池中电化学合成高铁酸钡。在合成温度为20℃,电流密度约0.18mA/cm2、电化学合成时间约为50小时的条件下,充电电压为1.45-1.58V,高铁酸钡产率为52.1%。     

One hundred and fifty years of sprint and distance running – Past trends and future prospects

Sprint and distance running have experienced remarkable performance improvements over the past century. Attempts to forecast running performances share an almost similarly long history but have relied so far on relatively short data series. Here, we compile a comprehensive set of season-best performances for eight Olympically contested running events. With this data set, we conduct (1) an exponential time series analysis and (2) a power-law experience curve analysis to quantify the rate of past performance improvements and to forecast future performances until the year 2100. We find that the sprint and distance running performances of women and men improve exponentially with time and converge at yearly rates of 4% ± 3% and 2% ± 2%, respectively, towards their asymptotic limits. Running performances can also be modelled with the experience curve approach, yielding learning rates of 3% ± 1% and 6% ± 2% for the women's and men's events, respectively. Long-term trends suggest that: (1) women will continue to run 10–20% slower than men, (2) 9.50 s over 100 m dash may only be broken at the end of this century and (3) several middle- and long-distance records may be broken within the next two to three decades. The prospects of witnessing a sub-2 hour marathon before 2100 remain inconclusive. Our results should be interpreted cautiously as forecasting human behaviour is intrinsically uncertain. The future season-best sprint and distance running performances will continue to scatter around the trends identified here and may yield unexpected improvements of standing world records.     

钢结构材料在高温(火灾)条件下的力学性能试验研究

从基本的钢结构材料在高温下的力学性能着手 ,进行高温条件下钢结构材料的性能试验 ,建立高温下钢材的屈服强度、极限强度、弹性模量和极限应变随温度变化的力学模型 ,为高温 (火灾 )条件下钢结构的结构分析提供依据。     

Fibonacci数列与对角形行列式

通过对Fibonacci数列与对角形行列式的研究,得到了它们之间的密切关系。     

农村税费改革再检视

农村税费改革的实质是建立有利于农业和农民的收入分配制度,理顺国家、集体、农民个人的利益关系;改革的目的是切实减轻农民负担,促进农村的全面发展。但在具体的改革进程中,改革的复杂性、艰巨性在阶段性成果之后逐渐彰显,改革之路还很艰难漫长。     

对音程、和弦、旋律听力练习的方法

好的听觉是学习好音乐的关键。为提高学生听辨音乐的水平和能力,对音程、和弦、旋律听力练习的方法概括为:练习音程从理论上熟悉、记住音程的名称,音响上记住音高和效果;和弦听写用听辨、模唱、构唱记原位、转位音响;旋律听写通过大量视唱、背唱、默写来储存、掌握基本要素。     

混联式滑车的构造及技术特点分析

深入分析了“顺穿法”和“花穿法”绕制的单行并联式滑车组在起重工作时的受力性能，通过对滑车组的偏心距和倾斜角计算，证明偏心距及倾斜角较大时对滑车组的工作和使用寿命存在很不利的影响。详细分析了混联式滑车的构造和受力性能，并对其起重时的偏心及倾斜角进行了计算，计算结果表明该新型滑车组在构造和技术上具有明显的优越性。混联式滑车于1996年获得国家发明专利。     

甲烷氧化偶联催化剂的制备及表征

本文报道了一系列甲烷氧化偶联催化剂的制备过程及其催化性能,筛选出一个催化性能优良,又具有赣南特色的甲烷氧化偶联催化剂,其组成是Mn_2O_3—Na_3WO_4/SiO_2,代号W—34,并用XRD,BET,UV—DRS,EPR,LRS等方法对该催化剂进行了表征。结果表明,在最佳反应条件下,在W—34催化剂上甲烷转化率为36.8％,C_2烃收率达到22.9％。在该催化剂中,W是以Na_2WO_4形式存在,Mn则以Mn_2O_3形式存在,而SiO_2已由无定型构型转变成。一方石英构型。     

秦巴高寒山区玉米抗灾高产栽培试验研究

在秦巴高寒山区，玉米地膜覆盖栽培可早播避春寒，早熟防秋涝，增产显著，技术经济效益高，产量8080.4kg/hm^2，较拱膜覆盖营养钵育苗移栽增产19．6％，较露地直播增产49．6％，拱膜覆盖营养钵育苗移栽采用坑道地膜育苗，育苗期增温防寒效果好，产量6756.4kg/hm^2，较露地直播提早成熟4.3d，增产25．08％，早熟品种中夏2号生育期较短，产量较丹玉13号提高3．23％，生产上可扩大示范中夏2号玉米新品种。