关于Diophantine方程y2=px(x2+2)的一点注记

设p是奇素数,运用初等数论方法证明了:如果P=16k4+1,这里k为正奇数,则方程y2=px(x2+2)无正整数解(x,y).     

镍电极掺杂[x(Y2O3)+y(Er2O3)]的MH/Ni电池性能研究

研究了在镍电极活性物质中掺杂一定量的[x(Y2O3) +y(Er2O3)](x+y=1,其中x=0,0.5,1.0)对MH/Ni电池的性能影响.利用不同环境温度(25℃～55℃)下恒流充放电、高温(65℃)放电态搁置等方法测试了电池的性能.结果表明,常温下镍电极掺杂[x(Y2O3)+y(Er2O3)]的MH/Ni电池的放电容量和放电平台比未掺杂的电池稍低,但随温度的升高,它的放电容量和高温储存性能等均明显优于未掺杂的电池,镍电极掺杂[x(Y2O3) +y(Er2O3)]提高了MH/Ni电池的高温性能.常温下,电池以1C,100%DOD循环200周后,镍电极掺杂[x(Y2O3) +y(Er2O3)]的MH/Ni电池容量损失较少,利用X射线衍射(XRD)、交流内阻分析结果表明,镍电极活性物质循环后的相结构差别不大,但掺杂的电池循环前后内阻变化较小.综合实验结果,当x=0.5时,电池的性能最佳.     

一类平面方程的几何意义

根据点P(x0,y0,z0)与椭球面x2/a2+y2/b2+z2/c2=1的三种位置关系,给出平面方程x0x/a+y0y/b2+z0z/c2=1的三种几何意义.     

预测冬季不同结构大棚内气象要素值的不同数学模型比较研究

[目的]为有效调节大棚内的光照、气温和湿度提供理论依据.[方法]对3种常见结构塑料大棚内外150 cm的冬季光照、气温和湿度等气象要素进行对比观测、分析,建立预测不同结构大棚气象要素值的多种数学模型.[结果]单栋塑料大棚的光照预测模型以多项式y=-0.000 6x3+0.002 9x2+0.740 4x+0.079 9最为确切,气温预测模型以乘幕y =0.759 3x1.1554最为确切,相对湿度预测模型以多项式y =0.000 00 03x5-0.000 1x4+0.013 1 x3-0.873 2x2+29.823-347.99最为确切;3连栋塑料大棚的光照预测模型以多项式y=-0.000 5x2+0.470 61x-0.015最为确切,气温预测模型以指数函数y=4.662 9e0.089x最为确切,相对湿度预测模型以多项式y=-0.0004x3+0.0136x2+0.205 1x +35.056最为确切;6连栋塑料大棚的光照预测模型以直线y =0.399 6x+0.0536,最为确切,气温预测模型以指数函数y=4.622 7e0.897x最为确切,相对湿度预测模型以多项式y =-0.000 08x3+0.089x2+0.645 9x+21.191最为确切.[结论]建立了冬季以棚外气象要紊值预测不同结构大棚内气象要素值的数学模型.     

Photoluminescence properties of M2ZnSi2O7:Eu2+（M=Sr,Ba）

The hardystonite phosphors of Eu2+ activated M2ZnSi2O7(M=Sr,Ba) were synthesized by combustion-assisted method.They were systematically characterized by photoluminescence excitation and emission spectra.The emission spectra of these two phosphors showed that the main emission peaks are at 475 and 503 nm due to 4f65d1→4f7 transition of Eu2+.Both phosphors could be efficiently excited in the wavelength range of 250-425 nm where the near ultraviolet light-emitting diode was well matched.The(x,y) color coordinates were determined with the emission values(x,y)=(0.41,0.21) and(0.16,0.45) for the M2ZnSi2O7:Eu2+(M=Sr,Ba) phosphors.     

唐钢二炼铁厂1#号高炉热风主管、围管三叉口组合砖的计算(续)

如图，同⑷式7Z1=(R2WN－y12)1/2°－/Cos9 x1·°tg9 =(7502－ y12)1/2°－ / Cos9x1·°tg9 (8)由⑴、⑺、⑸、⑹、⑻式可求出全部M1点的空间座标M1(x1，y1，z1。)（）3M2座标的计算公式x2、y2在圆，(oxy，Raw上，根据圆的参数方程) x2 = Rzw Cosα·=830Cosα (9) y2 = Rzw Sinα·=830Sinα (10)如图7 Z2=(R2ww－y22)1/2°－/Cos9 x2·°tg9 =(9302－y22)1/2°－/Cos9 x2·°tg9 (11)由、、式可求出全部(9)(10)(11)M2点的空间座标M2(x2，y2，z2。)根据…     

不同精粗比例TMR日粮对中产奶牛能量代谢的影响

本研究以40头中等产奶量的荷斯坦奶牛为研究对象,应用随机分组试验设计将试验动物分为四组,I组为对照组,II,Ⅲ和Ⅳ组为试验组,日粮精粗比例依次为50%:50%,40%:60%,35%:65%,30﹪:70﹪.研究日粮不同精粗比例对奶牛能量代谢的影响.结果表明:随着粗饲料比例的增加,粪能总体呈增加趋势,试脸II组显著(P<0.05)低于试验Ⅳ组;消化能总体呈增加趋势,试验II组和Ⅲ组显著(P<0.05)高于其它组;总能表观消化率总体呈降低趋势,试脸II组显著(P<0.05)高于试验I组和Ⅳ组,统计分析得出总能食入量(x,MJ/d)与总能表砚消化率(y,%)呈二次线性相关:y=-0.0007x2+0.60x-45.53,r2 = 0.61;表观代谢能总体呈增加趋势,试验II组和Ⅲ组显著(P<0.05)高于试验I组;消化能代谢率以试验II组和Ⅲ组较高;试验II组总能代谢率显著(P<0.05)高于试验I组和Ⅳ组;统计得出粗饲料采食量(x,kg/d)与消化能代谢率(yl,%)和总能代谢率(y2、%)均呈二次曲线相关关系:y1=-0.069x2+2.48x +63.71,r2 =0.37,y2=-0.18x2+6.54x+6.49,x=0.38.总能除去代谢能、产奶能和维持能后剩余部分计为沉积能(包括体增热),试验II组和Ⅲ组沉积能较高,统计得出粗饲料采食量(x,kg/d)与沉积能(y,MJ/d)存在显著的对数相关关系:y=40.69Ln(x)+ 79.89,r2=0.51.综合分析得出,当TMR日粮的精粗比例为40%:60﹪时,能量的消化率、代谢率和利用效率最高.     

确定疲劳裂纹扩展速率曲线转折点的数学方法

本文提出了确定疲劳裂纹扩展速率曲线转折点的数学方法——曲率判定法。其原理是:根据y=f(x)的相对曲率τ=y_x~n/(1 y_x~(′2))~(3/2)的正负和大小来判定曲线的转折点,这里x=1g(△K),y=Ig(da/dN)。给出了y′_x和y″_x的计算方法。用六种金属材料的实验数据进行了验证,并与其他数学方法进行了对比,结果表明:曲率判定法优于其他方法,其准确性比其他方法好得多。     

P53突变蛋白表达对弥漫大B细胞淋巴瘤预后的预测作用

目的 探讨p53突变蛋白表达对弥漫大B细胞淋巴瘤(DLBCL)预后的预测作用,指导个体化治疗.方法 随机选择初治DLBCL患者62例,应用免疫组织化学方法检测p53突变蛋白和CD10、bcl_6、MUM1的表达,分析p53突变蛋白表达与患者临床特征、分子分型以及预后的关系.结果 48.4%(30/62)的患者表达p53突变蛋白.p53突变蛋白表达与初始治疗反应有关(x2=20.365,P=0.040),阳性组的完全缓解率为33.3%(10/30),阴性组为59.4%(19/21);与分子分型有关(x2=31.023,P=0.021),阳性组非生发中心型比例显著高于阴性组,分别为83.3%和56.2%;与其他临床特征无关.多因素生存分析显示p53突变蛋白表达是独立的预后预测因子,阳性组的无进展生存期和中位生存期均短于阴性组(x2=36.784,P=0.005和x2=35.276,P=0.006).结论 p53突变蛋白表达是DLBCL独立的不良预后因子,能够用来指导个体化治疗.     

Synthesis of LiEu1-xBix（MoO4）2 red phosphors by sol-gel method and their luminescent properties

The Bi3+ doped molybdate-based red-emitting phosphors, LiEu1-xBix(MoO4)2, were successfully synthesized with a sol-gel method. The prepared LiEu1-xBix(MoO4)2 phosphors exhibited pure and intense red emission at 613 nm under the excitation of near-UV 394 nm. It was discussed in detail that the influence of the synthesis conditions such as the doping concentration of Bi3+, the dose of citric acid, pH of the precursor solution and the sintering temperature on the emission intensity of the phosphors. According to the results, the optimal condition was obtained: the doping concentration of Bi3+ was 15 mol.%, molar ratio of citric acid to metal ions was 1.5:1, pH of the precursor solution was 1.0 and the sintering temperature was 800 ?C. The X-ray diffraction (XRD) patterns of the LiEu0.85Bi0.15(MoO4)2 phosphor prepared under the optimal condition indicated that the phosphor was single phase with tetragonal scheelite structure. The Commission Internationale de l’E-clairage (CIE) chromaticity coordinates of LiEu0.85Bi0.15(MoO4)2 were (x=0.655, y=0.345), which were closer to the national television stan-dard committee (NTSC) standard values (x=0.670, y=0.330) than that of a commercial red phosphor of Y2O2S:Eu3+(x=0.630, y=0.350). This LiEu0.85Bi0.15(MoO4)2 red phosphor is a promising candidate for the fabrication of white light-emitting diode (W-LED) with near-UV chips.     

CaO-SiO_2-Na_2O-CaF_2-Al_2O_3-MgO保护渣系的Al_2O_3吸收速率和粘度

采用CaO -SiO2 -Na2 O -CaF2 -Al2 O3-MgO渣系 ,通过测定熔渣的粘度和Al2 O3吸收速率 ,研究连铸保护渣的Al2 O3吸收速率与粘度及化学成分之间的关系。在一定条件下 ,当CaO SiO2 为1 .2左右时 ,粘度达到最小值 ,Al2 O3吸收速率达到最大值 ,分别为 0 .1 0Pa·s、8.4 0 3× 1 0 - 4 kg·m- 2 ·s- 1 。随着渣中Na2 CO3含量、CaF2 含量和MgO含量的增加 ,粘度减小 ,Al2 O3吸收速率增大。随着渣中Al2 O3含量的增加 ,粘度增大 ,Al2 O3吸收速率减小。粘度为Al2 O3吸收速率的主要控制因素。随着熔渣粘度的增加 ,连铸保护渣的Al2 O3吸收速率逐渐减小。     

Biological activity and phosphorylation of 2'-azido-2'-deoxyuridine and 2'-azido-2'-deoxycytidine

2'-Azido-2'-deoxyuridine and 2'-azido-2'-deoxycytidine were evaluated for their inhibitory activity against ribonucleotide reductase and for subsequent cell growth inhibition. Their mono- and di-phosphates were synthesized and their inhibitory activities against the reductase were also determined in a permeabilized cell system, along with the two nucleosides. The results of the present study identify the first phosphorylation step involved in the conversion of the two azidonucleosides to the corresponding diphosphates to be rate-limiting in the overall activation.