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991.
关于整数的平方和   总被引:2,自引:0,他引:2       下载免费PDF全文
借N2 =[12 ,2 2 ,3 2 ,… ]中之数的一种特殊形式的表达式以及N2 中的部分和表推导出N中之数用N2中之数的和来表达的可能性 ,并提出合理的猜想 .对N3 =[13 ,2 3 ,3 3 ,… ]与N4=[14 ,2 4,3 4 ,… ]也得到一部分类似的结果  相似文献   
992.
溶胶 凝胶技术合成了SiO2 PMMA无机 有机复合材料的均匀体系。用小角X 射线衍射、X 射线能谱仪对所合成的SiO2 PMMA无机 有机复合材料体系进行了粒度的测量。给出了在该种复合材料中 ,无机与有机成分的含量相对变化时 ,体系的粒度并不发生显著变化 ,该体系是有机相被包覆在无机相中所形成的网络等结论  相似文献   
993.
2-氨基 - 5 -氨甲基 - 1-萘磺酸 (氨甲基吐丝酸 )是一种新型活性偶氮染料中间体 ,文献报道大多采用首先把 2 -氨基 - 1-萘磺酸的氨基乙酰化保护 ,然后氨甲基化及水解反应的合成方法 ,其不仅合成步骤长 ,而且需要在高压反应釜中进行。这样的制备条件在实验室操作以及进一步中试及工业化的生产中存在很大局限性。针对这种情况 ,本研究工作对反应条件进行系统的研究后 ,改用直接将 2 -氨基 - 1-萘磺酸氨甲基化合成 2 -氨基 - 5 -氨甲基 - 1-萘磺酸 (氨甲基吐丝酸 )的方法 ,去掉了氨基乙酰化反应 ,使反应步骤简化 ;去掉了高压操作 ,使整个反应过程容易操作。改进的合成方法反应条件温和 ,整体收率稳定 ,维持在 87.2 % ,获得了较好结果。  相似文献   
994.
We recorded slow vacuolar (SV-type) channel currents of Radish vacuoles successfully for the first time by using the whole-vacuolar patch-clamp recording mode. SVtrye currents would increase and threshold potentials of activation would shift towards more negative values with the increase of concentrations of cytosolic Ca2+. When 2.5 mmol/L LaCl3 and 4 mmol/L EGTA were added to bath solutions,SV-type currents were suppressed remarkably. Then adding LaCl3 with different concentrations to pipette solutions, we found that LaCl3 with higher concentrations (> 4 × 10-7 mol/L)had a strong inhibitory effect on SV-type currents, while LaCl3 with lower concentrations (≤4 × 10-7 mol/L) promoted channel currents. This promoting effect provides an important basis at channel level for researching further the effects of rare earth on physiological activities of plants and the production-increase effects of rare earth fertilizers on crops.``  相似文献   
995.
Thermoelectric power (S) measurements have been systematically investigated in high-quality La2-x-Srx-CuO4 single crystals with different Sr concentrations (x =0.03, 0.05, 0.07, 0.1, 0.12). In this doping range studied, S remains positive, and with the increase of Sr concentration,room-temperature thermoelectric power S (290 K) decreases.An empirical formula which presents a relationship between hole concentration P and room-temperature thermoelectric power S (290 K) is reported in this note. Based on the theory of metallic diffusion model, the experimental results are discussed.  相似文献   
996.
Azo dyes have been used in many industries (textile mill, printing and dyeing mill, paper and pulp mill) and have caused great environmental pollution due to complicated constitution and high chemical stability. The construction of azo dyes can be destroyed by ozonization, but not thoroughly when the ozone dosage is controlled to a certain extent and the operating cost is higher. Ozonization decomposed ability with ultrasonic enhancement on azo dyes has been demonstrated in the study. The conclusion derived from this investigation may be summarized as follows: (1) The decoloration rate of arsenazoⅠsolutions during sonozone treatment is more rapid than the rate obtained with ozone alone because the complicated constitution has been destroyed by the O free radical from ozone decomposition. (2) The destructing pathway of arsenazoⅠby ozone with ultrasound is identical with that of by ozone alone: the breakdown of —N== N— bonds, the conversion of benzene ring to carboxylic acid, and —HSO3 bonds to H2SO4. So, pH value of the arsenazo Ⅰ solution continuously drops down to 3.2.  相似文献   
997.
We have studied transmembrane La3+ movement in rat ventricular myocytes for the first time by using the whole-cell patch-clamp recording mode. La3+ (0.01-5.0 mmol/L) could not bring out inward currents through the L-type calcium channel in rat ventricular myocytes, while it could enter the cells by the same way carried by 1μmol/L ionomycin. When the outward Na+ concentration gradient is formed, La3+ can enter the cells via Na-Ca exchange, and the exchange currentsincrease with the increase of external La3+ concentrations. But compared with Na-Ca exchange currents in the same concentration, the former is only 14%-38% of the latter. The patch-clamp experiment indicates that La3+ normally can not enter ventricular myocytes through L-type calcium channel, but it can enter the cells via Na-Ca exchange.  相似文献   
998.
Indicators of δ13C and δ18O of gas hydrate-associated sediments   总被引:1,自引:0,他引:1  
The analyses of δ13C and δ18O of gas hydrate-associated sediments from two cores on Hydrate Ridge in Cascadia convergent margin offshore Oregon, eastern North Pacific show the values of d 13C from -29.81‰ to -48.28‰ (PDB) and d 18O from 2.56‰ to 4.28‰ (PDB), which could be plotted into a group called typical carbonate minerals influenced by the methane in cold venting. Moreover, the values of d 13C and d 18O show a consistent trend in both cores from top to bottom with increasing of d 13C and decreasing of d 18O. This trend could be explained as an effect caused by the anaerobic oxidation of methane (AOM) in depth and the oxygen fraction during the formation of gas hydrate in depth together. These characteristics of d 13C and d 18O indicate that the gas hydrate-associated sediments are significantly different from the normal marine carbonates, and they are deeply influenced by the formation and evolution of gas hydrate. So, the distinct characteristics of d 13C and d 18O of gas hydrate-associated sediments could be undoubtedly believed as one of parameters to determine the presence of gas hydrates in other unknown marine sediment cores.  相似文献   
999.
研究了合山煤在O2 /CO2 方式下SO2 的生成特性 .结果表明在O2 /CO2 方式下 ,由于燃煤的燃烧特性和钙基吸收剂的煅烧分解特性不同于传统燃烧方式 ,SO2 的生成速度加快 ,生成量较空气气氛下大为减少 ,钙基吸收剂的脱硫率随温度升高而增加 ,表明O2 /CO2 方式有利于钙基吸收剂高温脱硫  相似文献   
1000.
对水溶液中酪氨酸缩水杨醛席夫碱和Zn2 现场配位进行了研究,合成了Zn2 席夫碱配合物3种,通过元素分析确定其组成分别为配合物1:Zn·L·Bipy·KAc;配合物2:Zn·L·Phen·0.5H2O;配合物3:Zn·L5·Ap·kAc·1.5H2O.通过可见紫外吸收光谱分析、红外光谱分析、热重分析对这些配合物进行了表征.  相似文献   
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