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1.
以四氯化碳和三氯乙酸甲酯分别与苯乙烯(St)发生原子转移自由基加成反应,合成了多官能卤化物1-苯基-1,3,3,3-四氯丙烷(TCPP)和2,2,4-三氯-4-苯基丁酸甲酯(MTCPB),然后分别以TCPP和MTCPB为引发剂、氯化亚铜为催化剂、2,2'-联吡啶为配体,进行St的原子转移自由基聚合反应。采用核磁氢谱和凝胶渗透色谱对聚合物结构和分子量进行分析表征,结果表明:聚合物分子量与单体转化率之间存在较好的线性关系;TCPP和MTCPB都是St原子转移自由基聚合的双官能度引发剂。  相似文献   
2.
讨论了强迫振动下的非线性 Duffing 方程的摄动问题。 运用多重尺度法构造出渐近近似解,最后通过Gronwall 不等式对余项进行估计,证明了近似解的一致有效性。  相似文献   
3.
In the updip portion of the Yulin Gas Field in the Ordos Basin, there are no any structural, stratigraphic and sedimentary lithologic seals. Using thin-section petrography, ultraviolet fluorescence microscopy, micro-thermometry and Raman microspectrometry, this paper finds out the diagenetic trap and studies the diagenetic history of this field. It was revealed that three phases of diagenesis and hydrocarbon charging happened in late Triassic, late Jurassic and the end of early Cretaceous respectively. In the first two phases, acid geofluid entered the reservoir and caused dissolution and cementation. Although the porosities had been increased, further compaction accompanying re-subsidence resulted in tight sandstone and conglomerates. Till the end of the early Cretaceous, bulk of gas migrated into the tight reservoir. Cementation, however, kept on in the updip portion of this field due to low gas saturation and formed the diagenetic trap. The mechanism for gas accumulation was changed from deep basin gas to diagenetic trap, which offers a sealing condition that can retain gas for much longer time.  相似文献   
4.
吸波材料研究一直是军事隐身技术领域中的前沿课题,而四氧化三铁磁性材料又是当前国内外研究的热点,其在大尺度空间动态吸波隐身模型的建立在军事领域具有很高的实用价值。为研究四氧化三铁颗粒大尺度空中动态吸波效果,数值模拟计算出散布在大尺度空中粒径长分别为0.25μm和10.57nm的Fe3O4颗粒在入射电磁波频率为2~18GHz范围内的电磁损耗和18GHz频率时随时间变化的动态电磁损耗。结果表明:入射电磁波频率为2~18GHz频率范围内时,10.57nm的Fe3O4颗粒散布空间产生的电磁损耗为0.40W到11.59W,在18GHz频率时,电磁损耗为11.381W到11.559W;入射电磁波频率为2~18GHz频率范围内时,0.25μm的Fe3O4颗粒散布空间产生的电磁损耗为0.22W到4.88W,在18GHz频率时, 电磁损耗为4.812W到4.899W。可见Fe3O4颗粒具有良好的吸波效果且纳米Fe3O4颗粒吸波性能优于微米Fe3O4颗粒。  相似文献   
5.
We studied the multiple-channel filters based on photonic heterostructures consisting of single-negative permittivity and single-negative permeability media. The results showed that the number of resonance modes inside the zero-φeff gap increases as the number of heterogenous interface M increases. The number of resonance modes inside the zero-φeff, gap is equal to that of heterogenous interface M, and it can be used as M channels filter. This result provides a feasible method to adjust the channel number of multiple-channel filters. When losses are involved, the results showed that the electric fields of the resonance modes decay largely with the increase of the number of heterogenous interface and damping factors. Besides, the relationship between the quality factor of multiple-channel filters and the number of heterogenous interface M is linear, and the quality factor of multiple-channel filters decreases with the increase of the damping factor. These results provide feasible methods to adjust the quality factor of multiple-channel filters.  相似文献   
6.
DAMA实验正在意大利国家核子研究所(I.N.F.N.)的格朗萨索国家实验室(LNGS)运行.DAMA实验主要研究银河系银晕内的暗物质粒子.目前的DAMA/LIBRA采用的是250kg高放射性纯度的NaI(Tl)晶体,加上第一代实验DAMA/NaI(约100kgNaI(Tl)晶体),DAMA实验已经积累了13个年周期的数据,总曝光量高达1.17ton·yr,观测到显著性为8.9σ的与模型无关的暗物质年调制信号,这是银河系银晕内存在暗物质粒子的证据.本文描述DAMA实验的设置运行情况以及近期主要物理结果.  相似文献   
7.
固体酸催化剂和载体上芳烃的选择性硝化   总被引:3,自引:0,他引:3  
硝化研究的重要意义之一是探索更具选择性的方法。该文讨论了应用同体酸催化剂和载体,在醋酐存在下,采用硝酸盐和载体硝酸盐硝化甲苯和氯苯的选择性.8种金属硝酸盐中,硝酸铜表现好的硝化特性。层状粘士较沸石分子筛、杂多酸盐等是颇具前景的芳烃选择性硝化催化剂和载体.四氯化碳和甲苯为较好的溶剂介质.阻此条件,甲苯和氯苯的划邻硝化产物比例分为1.2和5.6,较之硝硫混酸的结果(甲苯0.6,氯苯1.8).其对位硝化能力显著提高。  相似文献   
8.
Oil cracking gas plays an important role in the resources of natural gas in the basins with high and over mature marine source rocks in China. The prediction of the oil cracking gas resources becomes nec-essary and urgent in the gas exploration in these basins. A marine crude oil sample was pyrolyzed using sealed gold tubes system. The pyrolysates including gas,liquid and solid were quantitatively analyzed. Based on the pyrolysis data and kinetic calculation,the yield correlativity among gas,liquid and solid products was regressed with high correlative coefficients to establish a prediction model suitable for the resource estimation of oil cracking gas. The verification formula for this model was also established on the principle of mass conservation. The affecting factors and the application precondi-tions of this prediction model were discussed. This model would enlighten and provide some new ideas for the resource assessment of natural gas in the high and over mature marine carbonate source rock areas in China. It is expected to be valuable in gas exploration.  相似文献   
9.
研究一类带小扰动的Raman散射的数学模型的相关问题,使用积分方程和Banach不动点定理证明初值问题的解的存在唯一,并利用多重尺度法求解渐近解,再借助积分方程和Gronwall不等式得到渐近解的余项估计,从而证明了渐近解的一致有效性。  相似文献   
10.
对于带微扰的KdV方程ut+6uux+uxx=εR(u),(ε>0),在初值u0(x)∈C∞(-∞,+∞),当|x|→∞时指数衰减的条件下,分别构造出带两种不同扰动项的KdV方程的扰动孤立波解满足的能量关系式,并运用能量分析方法对扰动的孤立波解进行先验估计,得到如下结论:(1)R(u)=δ(εt)u, δ(s)∈C[0,+∞),δ(0)=0,时,解在-∞<x<+∞,0≤εt≤T内一致有界;(2)R(u)=-Δ(εt)uxxx,Δ(0)=0,Δ(s)∈C1[0,+∞), 解在-∞<x<+∞,0≤εt≤T,0≤ε≤ε1内一致有界。  相似文献   
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