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1.
FeCl3和Fe2Cl6与KCl反应的热力学研究   总被引:1,自引:0,他引:1  
用骤冷法研究FeCl3和Fe2Cl6与KCl的反应热力学,结果显示,在温度(638-788)K和压力(0.001 1-0.006 4)MPa范围内,KFeCl4是唯一气态配合物产物.反应(1/2)Fe2Cl6(g)+KCl(s)=KFeCl4(g)的热力学函数是△H(OI)m(298.15,KFeCl4,g)=(19.6±2.0)kJ·mol-1,△S(OI)m(298.15,KFeCl4,g)=(-8.5±3.0)J·mol1·K-1;反应FeCl3(g)+KCl(s)=KFeCl4(g)的热力学函数是△H(OI)m(298.15,KFeCl4,g)=(-56.9±2.0)kJ·mol-1,△S(OI)m(298.15,KFeCl4,g)=(17.4±3.0)J·mol-1·K-1.  相似文献   

2.
化学发光法测定天然水中正磷酸盐   总被引:1,自引:0,他引:1  
本文报道一种测定天然水中正磷酸盐的化学发光方法,原理是基于磷酸根对钼酸铵氧化Ⅰ~-生成Ⅰ_2的催化作用.检测限达4ng/mLPO_4~(3-),线性范围是1×10(-7)—1×10~(-5)M,对2×10~(-7)M PO_4~(3-)测定(n=11)的相对标准偏差小于±2%.  相似文献   

3.
证明了丢番图方程|-x4+6x2y2+3y4|=2z2,(x,y)=1的全部正整数解为(Ⅰ)若z>2y2,则x=|m21n21-6m22n22|,y=m21m22+2n21n22,z=z(±)=(±)[24m21m22n21n22-2(|m21m22-2n21n22|±2m1m2n1n2)2],其中m2,n1满足-n41+6m22n21+3m42=2(D/2)2,2(×)n1m1m2;z=z-时,n2,m1满足(D-4m2m1)n2=m1(m22-n21)和(D+4m2n1)m1=2n2(n21+3m22),z=z+时,n2,m1满足n2(D±4m2n1)=(m22-n21)m1和m1(D(±)4m2n1)=2n2(3m22+n21).(Ⅱ)若z<2y2,则x=|m21n21-6m22n22|,y=m21m22+2n21n22,z=±z0,z0=24m21m22n21n22-2(|m21m22-2n21n22|±2m1m2n1n2)2,其中m2,n1满足-n41+6m22n21+3m42=2(D/2)2,2(×)n1m1m2;z=z0时,n2,m1满足n2(D±4m2m1)=(m22-n21)m1和m1(D(±)4m2n1)=2n2(3m22+n21),z=-z0时,n2,m1满足(D(±)4m2n1)n2=m1(m22-n21)和(D±4m2n1)m1=2n2(n21+3m22).从而更正了梁莉莉,王云葵[1]关于上述方程仅有正整数解(x,y,z)=(1,1,2)的结果.  相似文献   

4.
关于不定方程x~2+4~n=y~3   总被引:1,自引:0,他引:1  
利用代数数论的方法,证明了不定方程x2+4n=y3(其中n∈N,x≡1(mod2),x,y∈Z)仅有整数解(x,y,n)=(±11,5,1)。  相似文献   

5.
目的 了解吉林地区产常见野菜中粗纤维含量及与普通叶菜类含量的区别,为本地区野菜产品开发与居民食用提供依据.方法 根据国家标准对吉林地区山野菜中的粗纤维含量进行测定(酸碱消煮法).采集吉林地区野生野菜7种,人工养殖野菜4种,人工养殖菠菜1种(对照组),进行测定.结果 野生野菜组粗纤维含量最低为柳蒿[(2.74±0.47)×10-2g/g],最高为刺五加[(5.01±0.30)×10-2g/g].人工养殖组粗纤维含量最低为人工养殖刺老芽[(1.58±0.23)×10-2g/g],最高为养殖蒲公英[(2.27±0.20)×10-2g/g],人工养殖菠菜[(2.04±0.16)×10-2g/g].结论 不同种类野菜其粗纤维含量不同,同一区域的同种类野生野菜粗纤维平均含量明显高于人工养殖野菜;人工养殖野菜粗纤维含量与菠菜粗纤维含量并无明显差异.  相似文献   

6.
采用 SCF、TPO、IL- 3、IL- 6、IL- 1细胞因子 ,从脐血单个核细胞定向诱导巨核细胞的形成。比较了 SCF+ TPO+ IL- 1、SCF+ TPO+ IL- 3、SCF+ TPO+ IL- 63种细胞因子组合对刺激巨核细胞生成的作用 ,经体外培养 8d后 ,CD41 + 细胞占培养物的比例分别达到 ( 5 .64± 0 .77) %、( 5 .73± 1 .2 4 ) %和 ( 2 0 .1± 2 .5 3) % ;每 1 0 4个细胞可形成巨核祖细胞集落形成单位 ( CFU- MK)为( 1 3.7± 5 .7)个、( 1 5 .0± 3.6)个和 ( 93.7± 1 6.0 )个。在 SCF+ TPO+ IL- 6体系中增加 IL- 6的浓度 ,可提高培养液中 CD41 + 细胞的纯度。当 IL- 6的浓度从 1 0μg/L增加到 5 0μg/L时 ,CD41 + 细胞的比例可从 ( 2 0 .1± 2 .5 3) %提高到 ( 2 6.81± 3.2 0 ) % ,但每 1 0 4个细胞形成 CFU- MK数目却从( 93.7± 1 6.0 )个减少到 ( 4 5± 8.6)个 ;这说明 IL- 6对巨核细胞的刺激主要作用在其发育的后期。采用 SCF+ TPO+ IL- 3+ IL - 6细胞因子组合 ,由 1× 1 0 6个单个核细胞培养一周后可诱导出 ( 1 .61±0 .5 8)× 1 0 5个 CD41 + 细胞 ,占培养物的比例可达到 ( 1 8.8± 1 .64) % ,每 1 0 4个细胞形成 CFU- MK数目可达到 ( 1 2 1 .8± 1 0 .3)个。这一结果为进一步体外大量扩增巨核细胞提供了基础  相似文献   

7.
关于丢番图方程x4+mx2y2+ny4=z2(Ⅲ)   总被引:1,自引:0,他引:1  
利用Fermat无穷递降法 ,证明了方程x4 +mx2 y2 +ny4 =z2 在 (m ,n) =(± 18,5 4 ) ,(36 ,- 10 8) ,(± 36 ,10 8) ,(± 18,- 10 8) ,(- 18,10 8) ,(± 36 ,75 6 )时均无正整数解 ,并且获得了方程在 (m ,n) =(± 6 ,-2 4 ) ,(± 12 ,132 ) ,(- 36 ,- 10 8) ,(18,10 8)时无穷多组正整数解的通解公式 .  相似文献   

8.
用Helena全自动电泳分析系统 (REP)对 10 0份健康人血清标本进行电泳分析 ,经电泳可将血清蛋白分为白蛋白 (Alb)、α1球蛋白、α2 球蛋白、β球蛋白、γ球蛋白 5个组分 ,将各组数据用医学评价系统进行统计学处理 ,计量资料以 x±s表示 ,结果表明 :电泳法所得各组分百分比值及A/G值的参考范围分别为 :Alb(5 9.0 8± 7.4 4 ) % ,α1球蛋白 (3.14± 1.0 8) % ,α2 球蛋白 (8.4 9± 4 .0 6 ) % ,β球蛋白 (9.79± 3.9) % ,γ球蛋白 (19.5 1± 6 .98) % ,A/G值 1.4 7± 0 .4 2 ;化学法所得A/G值的参考范围为 2 .0 2± 0 .6 8.对各组测定值进行统计学处理 ,α1球蛋白、α2 球蛋白、β球蛋白和A/G值的参考范围均属正态分布 ,而Alb、γ球蛋白的参考范围不属正态分布 ;各样本电泳法A/G值与化学法A/G值经t检验呈非相关显著正相关 ,r=0 .76 83(P <0 .0 0 0 1)  相似文献   

9.
利用两相滴定法在(25±0 5)℃下测定了仲壬基苯氧基乙酸(CA-100)在水中的溶解度S,离解常数Ka,以及庚烷中的二聚常数K2和水-庚烷两相间的分配常数Kd.实验测得S=1 30×10-4mol/L,Ka=2 94×10-4,K2=3 29×102,Kd=4 15×102.  相似文献   

10.
1989年Tijdeman猜想设a,b,c是互素的正整数,m,n,r是大于1的正整数,则方程ax m+by n=cz r在1/m+1/n+1/r<1时仅有有限多组整数解;本文利用数论方法及Fermat无穷递降法,证明了丢番图方程x 8+my 4=z 2在m=±p,±2p,±4p,±8p及素数p满足一定条件下无正整数解,完善了Mordell等人的结果;并且获得了方程x 4-2py 4=z 2和x 4+8py 4=z 2的无穷多组正整数解的通解公式,从而获得了Tijdeman猜想与广义Fermat猜想的研究进展.  相似文献   

11.
长江口崇明东滩冬季沉积物水界面营养盐通量   总被引:4,自引:0,他引:4  
对长江口崇明东滩冬季沉积物中营养盐早期成岩过程和沉积物 水界面营养盐通量及其影响因素进行了研究.其中,高潮滩对各项营养盐均有显著吸收,中潮滩主要表现为对TIN和SiO2-3的释放,低潮滩由于受到局部水动力作用影响,营养盐通量存在较大不确定性.分子扩散作用对沉积物 水界面营养盐通量的贡献不大.由于潮滩对于水体PO3-4浓度的影响能力高于对TIN和SiO2-3的影响能力,潮滩能够在一定程度上促进水体中N/P和Si/P比的增加.  相似文献   

12.
《科学通报(英文版)》1998,43(18):1536-1536
The relaxation of the highly vibrationally excited CO (v=1-8) by CO\-2 is studied by time_resolved Fourier transform infrared emission spectroscopy (TR FTIR). 193 nm laser photolysis of the mixture of CHBr\-3 with O\-2 generates the highly vibrationally excited CO(v) molecules. TR FTIR records the intense infrared emission of CO(v→v-1). The vibrational populations of each level of CO(v) have been determined by the method of spectral simulation. Based on the evolution of the time resolved populations and the differential method, 8 energy transfer rate constants of CO(v=1-8) to CO 2 molecules are obtained: (5.7±0.1), (5.9±0.1), (5.2±0.2), (3.4±0.2), (2.4±0.3), (2.2±0.4), (2.0±0.4) and (1.8±0.6) (10 -14 cm 3·molecule -1·s -1), respectively. A two_channel energy transfer model can explain the feature of the quenching of CO(v) by CO 2. For the lower vibrational states of CO, the vibrational energy transfers preferentially to the υ\-3 mode of CO 2. For the higher levels, the major quenching channel changes to the vibrational energy exchange between CO(v→v-1) and the υ\-1 mode of CO 2.  相似文献   

13.
《科学通报(英文版)》1998,43(19):1621-1621
The vibrational energy transfer from highly vibrationally excited CO to H 2O molecules is studied by time-resolved Fourier transform infrared emission spectroscopy (TR FTIR). Following the 193 nm laser photolysis of CHBr 3 and O 2 the secondary reactions generate CO(v). The infrared emission of CO(v→v-1) is detected by TR FTIR. The excitation of H 2O molecules is not observed. By the method of the spectral simulation and the differential technique, 8 rate constants for CO(v)/H 2O system are obtained: (1.7±0.1), (3.4±0.2), (6.2±0.4), (8.0±1.0), (9.0±2.0), (12±3), (16±4) and (18±7) (10 -13cm 3·molecule -1·s -1). At least two reasons lead to the efficient energy transfer. One is the contributions of the rotational energy to the vibational energy defect and the other is the result of the complex collision. With the SSH and ab initio calculations, the quenching mechanism of CO(v) by H 2O is suggested.  相似文献   

14.
The Hilly Sichuan Basin is one of the most populous agricultural regions in the Upper Yangtze River Basin and has an area of about 105000 km2. Cropland ratios and population densities vary between 0.3 and 0.7 and be-tween 400 and 800 people/km2, respectively, in the Si-chuan basin. The basin is considered as one of the most severely eroded regions in the Upper Yangtze River Basin as well in China. Soil erosion rates were reported mostly to be greater than 5000 t·km-2·a-1 by the first st…  相似文献   

15.
实验研究了安装有平板及45°平板扰流内构件的管式换热器传热与压降特性,结果表明:管内插入平板和45°平板扰流内构件时,换热器传热性能和压降特性随扰流内构件组数NRe的增加而增大;当Re ≥ 2.6×104时,换热器压降增加比较显著;当N>6时,平板内构件换热器传热性能强化稍优于45°平板内构件换热器,但是压降明显较大;两种内构件组数不宜超过9组。在实验研究范围内,平板和45°平板内构件换热器传热性能分别是空管换热器的1.66~3.47倍和1.67~3.38倍,压降分别是空管换热器的6.25~29.57倍和3.61~10.77倍。Re在1.9×104左右时,平板和45°平板综合性能评价因子达到最大,分别约为1.24和1.57,说明45°平板内构件换热器综合性能优于平板内构件换热器。随后进一步采用数值模拟方法对换热器的传热和流动特性进行了模拟,结果表明:有角度平板可以使流场旋转产生二次流动,强化了传热,降低了换热器压降的增幅。因此,将有角度的内构件插入管式换热器中可有效增加换热器的综合传热性能。  相似文献   

16.
The permeation and eytotoxicity of three insulin-mimetic vanadium(Ⅲ, Ⅳ, Ⅴ)-dipicolinate complexes were studied using the MDCK cell monolayer in comparison with the Caeo-2 cells. On MDCK cell monolayer, the apparent permeation coefficients (Papp) were estimated to be (7.5±1.0)×10^-6, (1.0±0.2)×10^-6, (1.7±0.4)× 10^-6cm/s for V(Ⅴ), V(Ⅵ), and V(Ⅲ)-dipie complexes, respectively. The permeability of V(Ⅴ)-dipie complexes is much better than the others, which is in agreement with its better hypoglycemie effect in animal tests. On Caeo-2 cell monolayer, Papp were found to be in the range of 1-3×10^-6 ends and not to be affected by excessive amounts of dipieolinate ligand. By contrast, the permeability in the AP→BL direction across the MDCK monolayer increased greatly in the presence of free ligands, suggesting existence of active transport mechanism of vanadium complex anions on the MDCK cells. The eytotoxieity of the three complexes was found similar and the IC50 were measured in the range of 0.6-0.9 mmol/L for MDCK cells and 1.6--2 mmol/L for Caco-2 cells. The cytotoxicity of three vanadium complexes was conceivably in consistence with their permeability, suggesting that the toxicity, permeation and cellular metabolism of vanadium complexes are closely related.  相似文献   

17.
4-香豆酸:辅酶A连接酶是杨树木质素合成途径的关键酶之一,催化维管植物木质素合成羟基肉桂酸及其衍生物辅酶A酯化合物的形成.对毛白杨的重组Pt4CL1蛋白的不同肉桂酸衍生物底物的酶促动力学进行了分析,Pt4CL1对肉桂酸、4-香豆酸、咖啡酸、阿魏酸具有催化活性,其中的4-香豆酸、咖啡酸、阿魏酸,Km(μM)值分别为55.02±3.5、52.94±6、44.62±4,Vmax(nM.S-1)值分别为4.23±0.27、4.12±0.11、2.16±0.07;4-香豆酸,咖啡酸,阿魏酸的Kcat(S-1)值分别为44.73×10-3、43.57×10-3、7.61×10-3;对4-香豆酸,咖啡酸,阿魏酸的Kenz(M-1.S-1)值分别为823、812.98、170.55.Pt4CL1对肉桂酸的催化能力很弱,而对芥子酸没有催化活性.结果表明,Pt4CL1对4-香豆酸的催化效率最高,对咖啡酸的催化效率略低于4-香豆酸,而对阿魏酸的催化效率最低,对咖啡酸的催化效率略有很高的转化效率.  相似文献   

18.
Hf isotopic compositions of the standard zircons for U-Pb dating   总被引:48,自引:4,他引:48  
Zircon, a common accessory mineral in various kindsof rocks, is an important subject for U-Pb isotopic dating.With requirements for high spatial resolution with highprecision and accuracy, SHRIMP (Sensitive High Resolu-tion Ion Micro Probe) and LA-ICPMS (Laser AblationInductively Coupled Plasma Mass Spectrometry) nowserve as the important tools in zircon U-Pb dating. Sinceboth methods need standard zircon for external age cali-bration, an ideal standard zircon is critical for obtai…  相似文献   

19.
两类具有最优代数免疫阶的奇变元布尔函数   总被引:1,自引:0,他引:1  
奇变元的对称布尔函数中达到最优代数免疫阶的有且仅有两个:f0和f0+1.在此基础上构造了两类奇变元的具有最优代数免疫阶,有较高代数次数,并且非线性度等于2^n-1-(n-1(n-1)/2)的平衡非对称布尔函数.  相似文献   

20.
本文报道了用邻苯二甲醛(OPA)-β-巯基乙醇衍生化、反相梯度洗脱、荧光检测分析法对吉首产白蕾蘑(ClitocybeCandidaBres)子实体的十六种氨基酸含量检测结果,其氨基酸总量为24mg/100mg(干品),必需氨基酸组分齐全,含量为8.67mg/100mg,占氨基酸总量的36.1%。该检测法分离效果好,平均回收率达95%,氨基酸保留时间的变异系数平均为1.0±0.4%,其含量变异系数平均为2.8±0.7%,在10pmol-2nmol范围内,线性关系系数平均为0.987±0.008.  相似文献   

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