一道课本习题的引申及其应用

题 :已知一个圆的直径的端点是Ａ (ｘ1,ｙ1) ,Ｂ(ｘ2 ,ｙ2 ) ,求证 :圆的方程是(ｘ -ｘ1) (ｘ -ｘ2 ) + (ｙ -ｙ1) (ｙ -ｙ2 ) =0 .这是人民教育出版社出版的全日制普通高级中学教科书 (试验本 )数学第二册 (上 ) (必修 )Ｐ82 第 3题 .把该题当结论应用 ,已有多文论及 ,本文将给出该题的推论和相应结论的应用 .推论　设直线ｌ∶Ｆ(ｘ ,ｙ) =0与二次曲线Ｇ(ｘ ,ｙ) =0交于不同的两点Ａ(ｘ1,ｙ1) ,Ｂ(ｘ2 ,ｙ2 ) ,由Ｆ(ｘ ,ｙ) =0Ｇ(ｘ ,ｙ) =0 分别消去 ｙ ,ｘ得 ｆ(ｘ) =0 ,ｇ(ｙ) =0 ,并使 ｆ(ｘ) ,ｇ(ｙ)的二次项系数相等 ,则以ＡＢ为直径…     

Analysis of the influence shifts of the acetylene of various effects on frequency saturated absorption lines

Frequency shifts of the acetylene saturated absorption lines at 1.5μm with temperature, gas pressure and laser power have been investigated in detail. The second-order Doppler effect, the recoil effect, the Zeeman effect, the pressure shift and the power shift are taken into consideration. The magnitudes of those shifts caused by various effects are evaluated. In order to reproduce the stability of 5.7 × 10^-14 obtained by Edwards, all necessary conditions are given. The results show that when there is a larger external magnetic field, the Zeeman shift could not be neglected, so that the shield should be employed. And the design of a long cavity is advantageous to reduce the influence of the second-order Doppler effect. The results also show that at least 4-2.5℃ temperature control for cavity can effectively prevent several effects and improve the frequency stability.     

超临界CO2萃取、HPLC法测定川芎中的阿魏酸

采用超临界CO2萃取法提取川芎中的阿魏酸,通过试验确定了最佳超临界萃取条件,萃取罐的温度为60℃、萃取压力为35 MPa、萃取时间为2 h。以甲醇-水-冰乙酸(体积比为30∶70∶0.2)为流动相,用HPLC法测定川芎中的阿魏酸,回收率为92.3%~103.4%,相对标准偏差为2.45%(n=6)。     

[Na(DB18-C-6)(H_2O)_2][Na(DB18-C-6)(SCN)_2]: Two-Dimensional Network Complex Assembled by π-π Stacking Interactions, Hydrogen Bonds and Electrostatic Interactions

ＩｎｔｒｏｄｕｃｔｉｏｎＩｔｈａｓｂｅｅｎｗｉｄｅｌｙａｇｒｅｅｄｔｈａｔｗｅａｋｉｎｔｅｒａｃｔｉｏｎｓｃｏｕｌｄｐｌａｙｖｉｔａｌｒｏｌｅｓｉｎｔｈｅｃｏｎｆｏｒｍａｔｉｏｎａｌｓｔａｂｉｌｉｔｙｏｆａｗｉｄｅｖａｒｉｅｔｙｏｆｃｈｅｍｉｃａｌｓｙｓｔｅｍｓ ,ｗｉｔｈａｐｐｌｉｃａｔｉｏｎｓｒａｎｇ ｉｎｇｆｒｏｍｍａｔｅｒｉａｌｓｓｃｉｅｎｃｅｔｏｍｏｌｅｃｕｌａｒｂｉｏｌｏｇｙ .Ｉｎｐａｒｔｉｃ ｕｌａｒ ,π πｓｔａｃｋｉｎｇａｎｄｈｙｄｒｏｇｅｎｂｏｎｄｉｎｇｉｎｔｅｒａｃｔｉｏｎｓｈ…     

使用高效疏水作用色谱和凝胶色谱纯化重组人干扰素—γ

基因重组人干扰素一y（rhIFN－y）已成功地在大肠杆菌（E．colt）中获得表达．但在纯化工艺中仍有许多问题需要解决，如纯化步骤多、复性不完全及活性回收率低等．为此国内外学者开展了一系列研究，试图使用一些新的分离方法和手段来解决上述问题［‘’‘j．本文利用近年来开发的纯化蛋白质有效工具即高效疏水作用色谱（＊＊me）结合凝胶色谱（％c），从包含体人手，经过合理的工艺按排，成功地将山IFN－y进行了纯化．方法简单、快速，而且避免了rhIFN－y在纯化中采用大量溶剂稀释复性和通过透析来除去变性剂的麻烦．1实验部分1．1仪器…     

三维网状冠醚配合物（Bu4N){[K(18-C-6)][Cd4(dmit)2(dmt)3]}的合成与结构

研究了18-冠-6（18-C-6）与KSCN，CdCl2.2.5H2O,(Bu4N2)[Zn(dmit)2] (dmit=4,5-dimercapto-1,3-dithiole-2-thione,C3S5^2-)的反应，生成的标题配 合物（1）通过元素分析，红外光谱，单晶X射线衍射进行了表征，配合物属单斜晶 系，空间群C2/c，晶体学数据：a=3.4780(7)nm,b=1.5170(3)nm,c=2.8440(6)nm,β =105.93(3)°,V=14.427(3)nm^3,Z=8,F(000)=7872,R1=0.0425,wR2=0.0739,配合物 由一个Bu4N^+阳离子和一个{[K(18-C-6)][Cd4(dmit)2(dmt)3]}-(dmt=4,5- dimercapto-1,2-dithiole-3-thione,C3S5^2-)配阴离子组成，{[K(18-C-6)[Cd4 (dmit)2(dmt)3]}-通过K…S，S…S弱相互作用形成三维网状结构。     

全固态锂离子选择性电极研究

研究了新型载体HPMBP-TOPO体系几种全固态锂离子选择性电极（涂丝电极、单层全固态电极、聚吡咯修饰层内接触电极）的性能。与传统型电极相比，固态电极响应斜率有所降低，而选择性稍有提高。其中聚吡咯修饰层内接触电极性能为最佳，该电极响应斜率为56.7mV/decade，并具有良好再现性和长期稳定性。     

苯并15-冠-5与Na_2[M(SCN)_4](M=Pd,Pt)配合物的合成与结构

合成了苯并15-冠-5与Na_2[M(SCN)_4] (M = Pd, Pt)生成的配合物：[Na(B15- C-5)]_2[Pd(SCN)_4] (1), {[Na(B15-C-5)][Na(B15-C-5)(H_2O)]}[Pt(SCN)_4] (2)。1为单斜晶系，空间群P2_1/n，a = 1.0164(6) nm，b = 1.3743(3) nm，c = 1.4987(7) nm，β = 95.248(6)°，V = 2.0847 nm~3，Z = 2，D_(calcd) = 1. 47 g/cm~3，F(000) = 944，R = 0.053，wR = 0.072。2为三斜晶系，空间群P(1- bar)，a = 1.1484(2) nm，b = 1.4210(3) nm，c = 1.5026(3) nm，α = 62.500 (3)°，β = 72.393(3)°，γ = 73.106(4)°，V = 2.0398(7) nm~3，Z = 2， D_(calcd) = 1.674 g/cm~3，F(000) = 1028，R_1 = 0.0327，wR_2 = 0.0885。1 由两个[Na(B15-C-5)]~+配阳离子和一个[Pd(SCN)_4]~(2-)配阴离子组成，两者通 过Na-N键形成中性配合物，[Na(B15-C-5)]~+A相对钯原子呈反式排列。2由[Na (B15-C-5)]~+和[Na(B15-C-5)(H_2O)]~+配阳离子和一个[Pt(SCN)_4]~(2-)配阴离 子组成，它们也通过Na-N键形成中性配合物，配阳离子相对铂原子呈顺式排列。2 的两个分子通过氢键形成二聚结构。     

二维网状冠醚配合物——苯并15-冠-5、二苯并18-冠-6与Na_2[Pt(SCN)_6]配合物的合成与结构

合成了苯并 15 冠 5、二苯并 18 冠 6与Na2 [Pt(SCN) 6]的配合物 :[Na(B15 C 5 ) ]2 [Pt(SCN) 6](1) ,[Na(DB18 C 6 ) ]2 [Pt(SCN) 6](2 ) ,并通过元素分析、红外光谱、单晶X射线衍射进行了表征 .1为单斜晶系 ,空间群P2 1/c,a =1.0 974(5 )nm ,b =1.5 187(7)nm ,c=1.36 32 (6 )nm ,β =96 .40 7(7)°,V =2 .2 5 6 8(18)nm3 ,Z =2 ,Dcalcd=1.746g/cm3 ,F(0 0 0 ) =1184,R1=0 .0 35 7,wR2 =0 .0 86 8.2为三斜晶系 ,空间群P1- ,a =1.2 5 0 0 (3)nm ,b =1.2 82 5 (3)nm ,c=1.934 2 (4 )nm ,α=10 6 .82 (3)° ,β =10 2 .5 1(3)° ,γ =10 3.0 4(3)°,V =2 .75 6 2nm3 ,Z =2 ,Dcalcd=1.5 79g/cm3 ,F(0 0 0 ) =1316 ,R1=0 .0 36 4,wR2 =0 .0 771.配合物分别由两个 [Na(B15 C 5 ) ]+ ,[Na(DB18 C 6 ) ]+ 配阳离子和一个[Pt(SCN) 6]2 -配阴离子组成 .配阳离子和配阴离子通过Na—N键形成二维网状结构     

Pressure- and temperature-dependent luminescence from Tm3+ ions doped in GdYTaO4

Luminescent properties of Tm³⁺-doped GdYTaO₄ are studied for exploring their potential applications in temperature and pressure sensing.Two main emission peaks from ³H₄→³H₆ transition of Tm³⁺are investigated.Intensity ratio between the two peaks evolves exponentially with temperature and has a highest sensitivity of 0.014 K^?1 at 32 K.The energy difference between the two peaks increases linearly with pressure increasing at a rate of 0.38 meV/GPa.Intensity ratio between the two peaks and their emission lifetimes are also analyzed for discussing the pressure-induced variation of the sample structure.Moreover,Raman spectra recorded under high pressures indicate an isostructural phase transition of GdYTaO₄ occurring at 4.46 GPa.