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疏水缔合水溶性聚合物AP4清水溶液的流变特征 被引量:16
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作者 曹宝格 李华斌 +3 位作者 罗平亚 胡延民 陈中华 张勇 《油田化学》 CAS CSCD 北大核心 2005年第2期168-172,共5页
提高采收率用商品疏水缔合聚合物AP4为丙烯酰胺、丙烯酸、烷基二甲基烯丙基氯化铵共聚物,分子量1.7×106,水解度18.2%,疏水基含量<1%,由粘浓曲线求得临界缔合浓度CAC为1000 mg/L.用矿化度487 mg/L的清水配制AP4溶液,溶液粘度在4... 提高采收率用商品疏水缔合聚合物AP4为丙烯酰胺、丙烯酸、烷基二甲基烯丙基氯化铵共聚物,分子量1.7×106,水解度18.2%,疏水基含量<1%,由粘浓曲线求得临界缔合浓度CAC为1000 mg/L.用矿化度487 mg/L的清水配制AP4溶液,溶液粘度在45℃、7.34 s-1测定.AP4溶液45℃粘度-剪切速率(0.1~1000 s-1)曲线,溶液浓度≤CAC时在低剪切速率下出现振荡,振荡强度和振荡区宽度随溶液浓度降低而增大,之后出现假塑性和胀流性:溶液浓度≥CAC时依次出现牛顿性、假塑性和胀流性.假塑性区流变曲线符合幂律,给出了不同浓度(400~2000 mg/L)的7个AP4溶液的假塑性区宽度,K和n值.浓度800和1000 mg/L的AP4溶液在45℃、不同剪切速率(200~1550 s-1)下剪切2 min后,粘度保留率(30%~20%)和静置时粘度恢复率(80%~130%)相当分散,剪切速率低时粘度恢复率<100%;对于浓度1500mg/L的AP4溶液,剪切速率对粘度保留率(~10%)和粘度恢复率(>100%)的影响大大减小.从分子内和分子间缔合结构在剪切作用下的破坏和再生解释了疏水缔合聚合物溶液的流变性和剪切后粘度恢复性.图6表2参11. 展开更多
关键词 疏水缔合聚合物 水溶液 流变性 粘度.剪切速率关系曲线 抗剪切性 幂律参数 浓度的影响
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论加速可靠性增长试验(Ⅴ)单独故障时间数据的统计方法 被引量:11
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作者 周源泉 朱新伟 《推进技术》 EI CAS CSCD 北大核心 2001年第4期265-268,共4页
基于Arrhenius或逆幂律 幂律模型 ,对恒定应力加速可靠性增长试验 (CSARGT)的单独故障时间数据的情况 ,给出了统计分析方法 ,并用数值例说明了这些方法。
关键词 可靠性增长试验 单独故障时间 数据统计分析 ARRHENIUS 恒定应力加速可靠性增长试验 CSARGT 统计检验方法 幂律-幂律模型 幂律模型增长参数 MonteCarlo方法
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From Allan Variance to Phase Noise:A New Conversion Approach
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作者 张升康 王学运 +1 位作者 王宏博 杨军 《Journal of Measurement Science and Instrumentation》 CAS 2011年第4期358-363,共6页
A new mathematical method is proposed to convert the oscillator instability parameters from Allan variance to Spectrum Density(SD)of random phase fluctuations,which is the inversion of the classic transformation formu... A new mathematical method is proposed to convert the oscillator instability parameters from Allan variance to Spectrum Density(SD)of random phase fluctuations,which is the inversion of the classic transformation formula from SD to Allan variance.Due to the fact that Allan variance does not always determine a unique SD function,power-law model of the SD of oscillator phase fluctuations is introduced to the translating algorithm and a constrained maximum likelihood solution is presented.Considering that the inversion is an ill-posed problem,a regularization method is brought forward in the process.Simulation results show that the converted SD of phase fluctuations from Allan variance parameters agrees well with the real SD function.Furthermore,the effects of the selected regularization factors and the input Allan variances are analyzed in detail. 展开更多
关键词 oscillator instability Allan variance phasenoise Spectrum Density of Phase Fluctuation( SDPF REGULARIZATION
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Mapping Nuclear Decay to a Complex Network 被引量:1
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作者 李永 方锦清 刘强 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第3期490-492,共3页
Nuclear decay is investigated by the view of network science and the relationship of nuclear decay among different radionuclide can be mapped to a network topology directly.The network includes 1410 nodes and 1275 edg... Nuclear decay is investigated by the view of network science and the relationship of nuclear decay among different radionuclide can be mapped to a network topology directly.The network includes 1410 nodes and 1275 edges.The average degree of the network of nuclear decay is about 1.8,the cumulative degree distribution still meets the typical power-law distribution,and the corresponding exponent is about 4.1.Not considering their dynamic behavior,the fitting parameters of the nuclear decay network are obtained according to the LUHNM theory proposed by our group before.Their cumulated degree distributions of the nuclear decay network match well.The idea and method may provide a new way to study some other problems of nuclear physics. 展开更多
关键词 nuclear decay complex network LUHNM
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