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991.
Science China Chemistry - 相似文献
992.
Acta Mathematicae Applicatae Sinica, English Series - This paper evaluates the performance of the FW-test for testing part of p-regression coefficients in linear panel data model when p is... 相似文献
993.
为探讨IDose 4迭代重建技术在低剂量CT肾动脉血管造影中的应用价值,选取205例拟行肾动脉CT血管造影患者,随机将其分为4组,A组(51例)采用管电压100 kV、管电流100 mA,碘海醇370 mg I/mL及IDose 4迭代重建技术,B组(51例)采用管电压100 kV、管电流150 mA,碘海醇270 mg I/mL及IDose 4迭代重建技术,C组(51例)采用管电压80 kV、管电流180 mA,碘海醇270 mg I/mL及IDose 4迭代重建技术,D组(52例)管电压120 kV、管电流120 mA,碘海醇370 mg I/mL及滤波反投影(FBP)重建技术。分析各组图像肾主动脉干CT值、噪声(SD)、信噪比(SNR)和噪声比(CNR),受检者接受CT有效剂量(ED)、容积CT剂量指数(CTDI vol)、剂量长度乘积(DLP)、碘摄入量以及重建图像评分差异和诊断效能。结果显示,A、B、C组重建图像评分优于D组,肾动脉主干CT值、SD、SNR、CNR均高于D组,B、C组肾动脉主干CT值、SD略低于A组。A、B、C组CTDI vol、DLP、ED均低于D组,B组CTDI vol、DLP、ED高于A组。A、B、C、D组诊断肾主动脉狭窄准确率分别为92.68%、86.49%、84.62%、82.86%。证实IDose 4迭代重建技术能降低受试者受辐射和造影剂剂量,提高成像质量,在低剂量CT肾动脉血管造影中具有较高可行性和实用性。 相似文献
994.
Jason L. Nyrop Arash Soheili Rong Xiang Fanyu Meng Jacob H. Waldman Xiujuan Jia Rubina Giarre Parmar Benjamin W. Thuronyi J. Michael Williams Lisa DiMichele Michel Journet Bonnie J. Howell Bing Mao Ian W. Davies Steven L. Colletti Laura Sepp‐Lorenzino Erin N. Guidry 《Journal of polymer science. Part A, Polymer chemistry》2014,52(8):1119-1129
Synthetic polymers represent a modifiable class of materials that can serve as adjuvants to address challenges in numerous biomedical and medicinal chemistry applications including the delivery of siRNA. Polymer‐based therapeutics offer unique challenges in both synthesis and characterization as compared to small molecule therapeutics. The ability to control the structure of the polymer is critical in creating a therapeutic. Reported herein, are batch and flow polymerization processes to produce amphiphilic terpolymers through a Lewis acid BF3OEt2‐catalyzed polymerization. These processes focus on controlling reaction variables, which affect polymer structure in this rapid, exothermic, nonliving cationic polymerization. In addition to analytical characterization of the polymers, the in vivo activity of the polymer‐siRNA conjugates is also highlighted—demonstrating that the method of synthesis does affect the in vivo activity of the resulting polymer conjugate. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1119–1129 相似文献
995.
In this work, P2-Na0.6[Mg(II)0.3Mn(IV)0.7] O2 with inoxidizable elements (Na+, Mg2+ and Mn4+) except O2- was synthesized and investigated, which exhibited high reversible capacity (~210 mAh/g) with highly reversible ARR characteristic. 相似文献
996.
Yang Liu Linlin Zhong Aijun Yang Xiaohua Wang Mingzhe Rong Junhui Wu 《Plasma Chemistry and Plasma Processing》2018,38(5):1133-1149
Our work aims at the computation of combined diffusion coefficients in CO2–metal (Cu, Fe, Al) mixtures at a temperature interval of 2000–30,000 K at 0.1 MPa and aims at the investigation of the impact of the concentration and nature of metal vapor (Cu, Fe, Al) on diffusion phenomena. The combined diffusion coefficients have four components, more specifically, combined ordinary diffusion coefficient, combined electric field diffusion coefficient, combined temperature diffusion coefficient and combined pressure diffusion coefficient due to the gradients of the species densities, applied electrical field temperature and pressure. The results indicate that, for Cu and Fe, the combined diffusion coefficients are quite identical under the condition of same metal concentrations (1 and 10% mass concentration). Compared with Cu and Fe under the same metal concentrations (1 and 10%), Al results in a larger enhancement of combined electric field and ordinary diffusion coefficients while smaller enhancement of combined temperature diffusion coefficients. All the combined diffusion coefficients exhibit an upward trend with metal concentrations except for combined electric field, temperature and pressure diffusion coefficients. These three mentioned coefficients are attenuated by the metal vapor above the certain concentration such as, in the case of combined temperature diffusion coefficients, 70% Cu, 70% Fe and 50% Al for CO2–Cu, CO2–Fe and CO2–Al mixtures respectively. Namely, compared with Cu and Fe, less quantity of Al is required to achieve the maximum of combined diffusion coefficients. Maximum peaks for the combined coefficients are shifted to the higher temperature with increasing metal concentrations. 相似文献
997.
998.
Zhang Guoping Zhang Jiawei Niu Fangfang Zhang Fan Zhao Songfang Wang Mingliang Gao Yongju Sun Rong Wong Chingping 《Journal of Sol-Gel Science and Technology》2018,85(3):703-711
Journal of Sol-Gel Science and Technology - In this work, a novel bridged organosilane precursor, adamantane-bridged organosilane (ADBO), was synthesized successfully which was employed to prepare... 相似文献
999.
Thermomechanical properties of polyurethanes (PUs) strongly depend on the molecular interactions and microphase structure.In this work,two chain extenders with different ratios,flexile 1,4-butanediol (BDO) and branched trimethylolpropane mono allyl ether (TMPAE),are used to tune the molecular interactions and microphase structures of a series of biodegradable thermoplastic polyurethanes (TPUs).In TPUs,the biodegradable polycaprolactone (PCL,Mn of 2000) is used as soft segment while 1,6-diisocyanatohexane (HDI) and chain extenders are used as hard segment.Fourier transform infrared spectroscopy (FTIR),proton nuclear magnetic resonance spectroscppy (1H-NMR),gel permeation chromatography (GPC),differential scanning calorimetry (DSC),dynamic mechanical analysis (DMA) and mechanical tests were performed to characterize the bulk structure and properties of TPUs.Compared with BDO,the steric bulk of TMPAE is larger.The increment of TMPAE can help to increase the hydrogen bond content,microphase separation,and the elastic modulus ratio (R),which would strongly affect the thermomechanical property of the TPUs.The results of this work verify the importance of the structure of chain extender on the properties of TPUs.It provides valuable information for further understanding the structure-property relationships of these polyurethanes. 相似文献
1000.
Liyuan Han Caiyin You Qin Wang Shaohua Guo Ke Xu Weihua Zhang Rong Yang 《Russian Journal of Electrochemistry》2018,54(1):49-55
α-NaFeO2 layered LiNi1/3Co1/3Mn1/3O2 cathode materials were synthesized by mechanical milling accompanied by the solid phase sintering. The sample exhibited a good crystallinity and layered structure while sintered at 900°C, which can be further improved by adding a pre-sintering process at 500°C before high temperature sintering. The sample with a pre-sintering process presents an average particle size about 0.6 μm, and a hexagonal crystalline structure. The optimally fabricated sample showed a first charge capacity of 210.2 mA h/g, discharge capacity of 171.2 mA h/g with a current rate of 0.2 C within the voltage range of 2.7~4.5 V. With increasing the current rate to 1 C, the charge–discharge capacity faded quickly during the cycling process, which can be partially recovered while operated at a low current rate. However, the capacity fading at a current rate of 2 C was largely irreversible. The evolution of the surface chemical states was evaluated using X-ray photoelectron spectroscopy on the charged and discharged samples to understand the high rate capacity fading. 相似文献