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反式聚环戊烯橡胶合成及结构分析
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作者 贺小进 邱迎昕 +4 位作者 王雪 曹达鹏 陈建军 卜少华 罗俊杰 《北京化工大学学报(自然科学版)》 CAS CSCD 北大核心 2020年第4期45-51,共7页
对反式聚环戊烯橡胶(TPR)的合成进行实验研究,确定了催化剂制备及TPR合成工艺条件,对合成的TPR结构进行表征,结果表明:催化剂陈化后具有较高的活性及稳定性,甲苯及正己烷作为环戊烯聚合溶剂均有较好的效果。当催化剂WCl 6用量(相对于环... 对反式聚环戊烯橡胶(TPR)的合成进行实验研究,确定了催化剂制备及TPR合成工艺条件,对合成的TPR结构进行表征,结果表明:催化剂陈化后具有较高的活性及稳定性,甲苯及正己烷作为环戊烯聚合溶剂均有较好的效果。当催化剂WCl 6用量(相对于环戊烯的质量)为(2.5~3.5)×10^-6 mol/g,分子量调节剂与W物质的量的比为2~3,Al与W的物质的量比为1~3时,单体转化率大于78%,TPR反式结构含量(质量分数)约为85%,玻璃化转变温度小于-92℃,数均相对分子质量在10万~30万之间,相对分子量分布在1.5~2.5之间,满足通用胶的结构及分子量要求。 展开更多
关键词 反式聚环戊烯橡胶 催化剂 陈化 活化剂 分子量调节剂
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反式聚环戊烯橡胶在轮胎胎肩胶中的应用研究
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作者 贺小进 王雪 +2 位作者 邱迎昕 曹达鹏 陈建军 《北京化工大学学报(自然科学版)》 CAS CSCD 北大核心 2020年第3期76-83,共8页
对合成的3种不同相对分子质量的反式聚环戊烯橡胶(TPR)用于轮胎胎肩胶进行了研究,结果表明:与使用天然橡胶(NR)及顺丁橡胶(BR)/NR并用胶相比,TPR硫化胶的回弹性、老化性能、耐磨性和低温性能优异,耐疲劳性能好,动态生热低,滚动阻力小,... 对合成的3种不同相对分子质量的反式聚环戊烯橡胶(TPR)用于轮胎胎肩胶进行了研究,结果表明:与使用天然橡胶(NR)及顺丁橡胶(BR)/NR并用胶相比,TPR硫化胶的回弹性、老化性能、耐磨性和低温性能优异,耐疲劳性能好,动态生热低,滚动阻力小,抗湿滑性稍差,拉伸强度和撕裂性能较差;TPR/NR并用硫化胶与NR相比物理性能有所改善,耐老化性、耐磨性和低温性能优异,回弹性、耐疲劳性及动态生热相当,滚动阻力小,有较好的动态力学性能。相对分子质量较低的TPR2具有较佳的综合性能,TPR不适合单独应用于轮胎胎肩胶,其与NR并用具有较好效果。 展开更多
关键词 反式聚环戊烯橡胶 胎肩胶 物理机械性能 滚动阻力
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Modeling of highly efficient drug delivery system induced by self-assembly of nanocarriers: A density functional study
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作者 JIANG Jian cao dapeng 《Science China Chemistry》 SCIE EI CAS 2013年第2期249-255,共7页
Owing to the importance of drug delivery in cancer or other diseases' therapy, the targeted drug delivery (TDD) system has been attracting enormous interest. Herein, we model the TDD system and design a novel rod-... Owing to the importance of drug delivery in cancer or other diseases' therapy, the targeted drug delivery (TDD) system has been attracting enormous interest. Herein, we model the TDD system and design a novel rod-like nanocarrier by using the coarse grained model-based density functional theory, which combines a modified fundamental measure theory for the excluded-volume effects, Wertheim's first-order thermodynamics perturbation theory for the chain connectivity and the mean field approximation for van der Waals attraction. For comparison, the monomer nanocarrier TDD system and the no nanocarrier one are also investigated. The results indicate that the drug delivery capacity of rod-like nanocarriers is about 62 times that of the no nanocarrier one, and about 6 times that of the monomer nanocarriers. The reason is that the rod-like nanocarriers would self-assemble into the smectic phase perpendicular to the membrane surface. It is the self-assembly of the rod-like nanocarriers that yields the driving force for the targeted delivery of drugs inside the cell membrane. By contrast, the conventional monomer nanocarrier drug delivery system lacks the driving force to deliver the drugs into the cell membrane. In short, the novel rod-like nanocarrier TDD system may improve the drug delivery efficiency. Although the model in this work is simple, it is expected that the system may provide a new perspective for cancer targeted therapy. 展开更多
关键词 INTERFACE POLYMERS MICROSTRUCTURE statistical thermodynamics SELF-ASSEMBLY targeted drug delivery
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First-principles insight into the entanglements between superionic diffusion and Li/Al antisite in Al-doped Li1+xAlxGe2–x(PO4)3(LAGP)
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作者 JIANG ChangKun LU Xia cao dapeng 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2020年第9期1787-1794,共8页
As an ion conductor, the Al-doped Li1+xAlxGe2-x(PO4)3(LAGP) demonstrates the superionic Li diffusion behavior, however,without the convinced verifications. In this context, the density functional theory(DFT) calculati... As an ion conductor, the Al-doped Li1+xAlxGe2-x(PO4)3(LAGP) demonstrates the superionic Li diffusion behavior, however,without the convinced verifications. In this context, the density functional theory(DFT) calculations are employed to clarify the structural origin of the fast Li ion migration kinetics in LAGP solid electrolytes. The calculated results show that doping of Al leads to an emerging high-energy 36 f Li site, which plays an important role in promoting the Li diffusion and can largely lower the Li ion diffusion energy barrier. Moreover, the Li/Al antisite defect is investigated firstly, with which the Li ions are excited to occupy a relatively high energy site in LAGP. The obvious local structural distortion by Li/Al antisite results in the coordination change upon Li diffusion(lattice field distortion), which facilitates the Li diffusion significantly and is probably the main reason to account for the superionic diffusion phenomenon. Therefore, the occupation of Li at high-energy sites should be an effective method to establish the fast Li diffusion, which implies a rewarding avenue to build better Li-ion batteries. 展开更多
关键词 Li1+xAlxGe2–x(PO4)3(LAGP) Li/Al antisite superionic conductor first-principles calculations Li ion batteries
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Nitrogen-doped graphene as an excellent candidate for selective gas sensing
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作者 MA CongCong SHAO XiaoHong cao dapeng 《Science China Chemistry》 SCIE EI CAS 2014年第6期911-917,共7页
The toxic gases,such as CO and NO,are highly dangerous to human health and even cause the death of person and animals in a tiny amount.Therefore,it is very necessary to develop the toxic gas sensors that can instantly... The toxic gases,such as CO and NO,are highly dangerous to human health and even cause the death of person and animals in a tiny amount.Therefore,it is very necessary to develop the toxic gas sensors that can instantly monitor these gases.In this work,we have used the first-principles calculations to investigate adsorption of gases on defective graphene nanosheets to seek a suitable material for CO sensing.Result indicates that the vancancy graphene can not selectivly sense CO from air,because O2 in air would disturb the sensing signals of graphene for CO,while the nitrogen-doped graphene is an excellent candidate for selectivly sensing CO from air,because only CO can be chemisorbed on the pyridinic-like N-doped graphene accompanying with a large charge transfer,which can serve as a useful electronic signal for CO sensing.Even in the environment with NO,the N-doped graphene can also detect CO selectively.Therefore,the N-doped graphene is an excellent material for selectively sensing CO,which provides useful information for the design and fabrication of the CO sensors. 展开更多
关键词 first-principles calculation sensor design CHEMISORPTION charge transfer
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