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A New Credit Spread to Predict Economic Activities in China
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作者 WANG Lei NIE Changhong WANG Shouyang 《系统科学与复杂性学报:英文版》 SCIE EI CSCD 2019年第4期1140-1166,共27页
In recent years,the relationship between bond spreads and macro economy has been studied extensively by economists in western countries.However,few attentions were paid on this topic in China.This essay regards Chines... In recent years,the relationship between bond spreads and macro economy has been studied extensively by economists in western countries.However,few attentions were paid on this topic in China.This essay regards Chinese bond market as a complex system and constructs bond indices for China with the bottom-up approach.The authors use the data of 3,205 non-financial corporate bonds from February 2010 to October 2017 and construct a new spread noted as the PE SOE spread.The authors find that the PESOE spread has a negative impact on economic activities and has the best predictive ability at short-run forecasting horizons,owing to the institutional superiority of the stateowned enterprises in China.The Treasury bond yields are found to have the best predictive ability at long-run horizons.Both spread shock and Treasury yield shock could lead to deflation and declines in economic activities,and the Treasury yield shock has a more severe and persistent impact on the economy due to the financial accelerator mechanism.PESOE spread is proved to be a better indicator for Chinese corporate bond market and can be widely used not only in future Chinese economic studies,but also for Chinese government’s macroeconomic monitoring and warning. 展开更多
关键词 Chinese BOND market corporate BOND SPREADS CREDIT SPREADS financial ACCELERATOR private ENTERPRISES STATE-OWNED ENTERPRISES
Halogen bonding-driven formation of supramolecular macrocycles and double helix
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作者 Chuan-Zhi Liu Satish Koppireddi +2 位作者 Hui Wang Dan-Wei Zhang Zhan-Ting Li 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第5期953-956,共4页
The crystal structures of three intramolecularly hydrogen bonded rigid aromatic amide derivatives,which all bear one iodine atom at one end as the donor and one pyridine unit at the other end as the acceptor,have been... The crystal structures of three intramolecularly hydrogen bonded rigid aromatic amide derivatives,which all bear one iodine atom at one end as the donor and one pyridine unit at the other end as the acceptor,have been described to reveal the utility of halogen bonding in inducing the formation of supramolecular macrocycles.All the three compounds formed intermolecular I···N halogen bonding.For short compound 1,halogen bonding induced the formation of an extended supramolecular array.For longer folded compounds 2 and 3,halogen bonding could hold two molecules to form supramolecular macrocycles even by adopting a highly distorted,energetically less favorable conformation(for 3).Depending on the solvent for the growth of crystals,compound 3 could also gave rise to a halogen bonded supramolecular double helix. 展开更多
关键词 HALOGEN BOND Hydrogen BOND MACROCYCLE FOLDAMER Double HELIX
“债券通”项下我国债券市场对外开放最新进展
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作者 黄思婧 《金融市场研究》 2019年第2期25-33,共9页
2018年以来,人民银行等相关政府部门持续完善与“债券通”相关的配套政策体系,为我国债券市场的对外开放奠定了更为坚实的基础,“债券通”业务规模持续扩大、交易结算更趋活跃。“债券通”作为债券市场对外开放的重要举措,有利于吸引更... 2018年以来,人民银行等相关政府部门持续完善与“债券通”相关的配套政策体系,为我国债券市场的对外开放奠定了更为坚实的基础,“债券通”业务规模持续扩大、交易结算更趋活跃。“债券通”作为债券市场对外开放的重要举措,有利于吸引更多的投资者参与我国债券投资,为境内市场债券发行人广泛利用全球资金创造便捷条件。 展开更多
关键词 债券通 对外开放 债券指数
含双重动态键的可重加工及室温自修复聚氨酯弹性体
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作者 田丽蓉 杨莉 +1 位作者 王占华 夏和生 《高分子学报》 SCIE CAS CSCD 北大核心 2019年第5期527-534,共8页
通过同时向聚合物的主链和交联点引入2种动态共价键—Diels-Alder (D-A)键和二硫(S―S)键,制备了具有自修复、可重加工性能的聚氨酯(PU-SSDA)弹性体.一方面分布在主链和交联点的动态键使聚合物分子链通过可逆的断裂重组实现自修复,另一... 通过同时向聚合物的主链和交联点引入2种动态共价键—Diels-Alder (D-A)键和二硫(S―S)键,制备了具有自修复、可重加工性能的聚氨酯(PU-SSDA)弹性体.一方面分布在主链和交联点的动态键使聚合物分子链通过可逆的断裂重组实现自修复,另一方面,交联的PU中同时存在线性的分子链,从而提高了断面间分子的运动性能,使被破坏的断面间迅速浸润,提高修复效率. PU-SSDA在室温下修复60 min的修复效率可达93%.此外,这些聚氨酯材料可以利用无溶剂一步法制备,作为环境友好材料具有广泛的应用潜力. 展开更多
关键词 Diels-Alder键 S–S键 室温自修复 重加工 聚氨酯
Synthesis and Properties of Reversible Disulfide Bond-based Self-healing Polyurethane with Triple Shape Memory Properties
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作者 Han Jia Kun Chang Shu-Ying Gu 《高分子科学:英文版》 CSCD 2019年第11期1119-1129,共11页
A reversible disulfide bond-based self-healing polyurethane with triple shape memory properties was prepared by chain extending of random copolymer poly(lactide-co-caprolactone)(PCLA), hexamethylene diisocyanate (HDI)... A reversible disulfide bond-based self-healing polyurethane with triple shape memory properties was prepared by chain extending of random copolymer poly(lactide-co-caprolactone)(PCLA), hexamethylene diisocyanate (HDI), polytetrahydrofuran (PTMEG), and 4,4,-aminophenyl disulfide. The chemical structures were characterized using 1H nuclear magnetic resonance (^1H-NMR) spectroscopy, Fourier transform infrared spectroscopy (FTIR), and gel permeation chromatography (GPC). The thermal properties, selfhealing properties, triple-shape memory effect, and quantitative shape memory response were evaluated by differential scanning calorimetry (DSC), tensile tests, two-step programming process thermal mechanical experiments, and subsequent progressive thermal recovery. The self-healing mechanism and procedures were investigated using polarizing optical microscopy (POM) and an optical profiler. It was concluded that self-healing properties (up to 60%) and triple-shape memory properties around 35 and 50℃(with shape fixation ratios of 94.3% and 98.3%, shape recovery ratios of 76.6% and 85.1%, respectively) were integrated to the shape memory polyurethane. As-prepared polyurethane is expected to have potential applications in multi-shape coatings, films, and step-by-step deploying structures. 展开更多
关键词 SELF-HEALING REVERSIBLE DISULFIDE BOND TRIPLE shape memory POLYURETHANE
Hydrogen Bonding Assembled 3D Supramolecular Structures Formed by 5-Amino-2,4,6-triiodoisophthalic Acid and TV-Heterocyclic Aromatic Ligands
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作者 YU Wenli ZHANG Mingjuan +2 位作者 LIU Kang YANG Yu WANG Lei 《高等学校化学研究:英文版》 SCIE CAS CSCD 2019年第5期806-811,共6页
Three salts constructed by 5-amino-2,4,6-triiodoisophthalic acid(ATIPA) with N-heterocycles aromatic coformers such as pyridine tetrazolium, tetramethylpyraziiie and cyanuric acid were synthesized by slowing evaporati... Three salts constructed by 5-amino-2,4,6-triiodoisophthalic acid(ATIPA) with N-heterocycles aromatic coformers such as pyridine tetrazolium, tetramethylpyraziiie and cyanuric acid were synthesized by slowing evaporation of solvent. X-Ray single crystal analysis shows that hydrogen protons of the carboxyl groups transfer to nitrogen atoms of the N-heterocyclic coformers to form N-H…0 hydrogen bonds in all the three compounds. A huge amount of H-bonds play significant role in tlie construction of these compounds and all of them generate 3D structures through strong O-H…N, O-H…O, N-H…O and weak C-H…O hydrogen bonds. Moreover, solvent water molecules are indispensable in the formation of compounds 1 and 3, which constitutes different supramolecular synthons to bridge individual molecules and chains to form stable structures. In addition, these crystal structures were further characterized by themiogravimetric analysis and infrared spectroscopy. 展开更多
关键词 Hydrogen bond SUPRAMOLECULAR structure X-Ray diffraction N-Heterocyclic AROMATIC ligand
Creating a Bond
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作者 Wang Jun 《北京周报:英文版》 2019年第8期34-35,共2页
Chinese bonds’inclusion in flagship global index boosts faith in the economy From April,Chinese bonds will be included in the U.S.Bloomberg Barclays bond index,China’s central bank confirmed.The Bloomberg Barclays G... Chinese bonds’inclusion in flagship global index boosts faith in the economy From April,Chinese bonds will be included in the U.S.Bloomberg Barclays bond index,China’s central bank confirmed.The Bloomberg Barclays Global Aggregate Index,one of the three most. 展开更多
关键词 In PBC Creating a BOND
考虑粘结作用及抗剪栓钉传力的巨型钢管混凝土柱共同工作性能分析
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作者 张元植 罗金辉 李元齐 《建筑结构》 CSCD 北大核心 2019年第5期109-116,124共9页
采用数值模拟手段对考虑粘结作用及抗剪栓钉传力的巨型钢管混凝土柱共同工作性能进行分析。首先介绍了ABAQUS程序中的材料本构模型、钢管、混凝土界面模型和抗剪栓钉简化本构模型。通过与相关文献试验结果进行对比,充分验证了本文理论... 采用数值模拟手段对考虑粘结作用及抗剪栓钉传力的巨型钢管混凝土柱共同工作性能进行分析。首先介绍了ABAQUS程序中的材料本构模型、钢管、混凝土界面模型和抗剪栓钉简化本构模型。通过与相关文献试验结果进行对比,充分验证了本文理论模型的合理性与精确度。在此基础上,分别对只考虑粘结作用的巨型钢管混凝土柱和考虑粘结作用+抗剪栓钉的巨型钢管混凝土柱进行数值参数分析,主要考察巨型柱截面尺寸、管壁宽厚比、粘结强度、栓钉布置间距等对竖向荷载传递的影响。结果表明,粘结作用对混凝土共同工作性能的影响有限,单纯依靠粘结传力,钢管、混凝土两者不能够很好地共同工作;设置抗剪栓钉提高了巨型钢管混凝土柱共同工作性能。最后建议不应完全依赖粘结作用与抗剪栓钉传力,在设计时应通过设置足够的传力构造来保证巨型柱钢管、混凝土共同工作。 展开更多
关键词 巨型钢管混凝土柱 荷载传递路径 粘结作用 抗剪栓钉传力 共同工作性能
Syntheses, Crystal Structures and Hydrogen-bonding Motif of Two Glycoluril Derivatives 预览
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作者 刘雪梅 王东华 +1 位作者 宋新建 王军刚 《结构化学》 SCIE CAS CSCD 2019年第5期754-760,669共8页
The synthesis and aggregation behavior of two glycoluril derivatives were descrybed.The crystal of compound 1 belongs to the triclinic system,space group P1,with a=8.946(1),b=13.445(2),c=20.361(3)?,α=89.517(3),β=84.... The synthesis and aggregation behavior of two glycoluril derivatives were descrybed.The crystal of compound 1 belongs to the triclinic system,space group P1,with a=8.946(1),b=13.445(2),c=20.361(3)?,α=89.517(3),β=84.405(3),γ=86.325(3)°,Z=2,V=2432.1(6)?3,Dc=1.293 g·cm-3,C48H34N6O6·2DMSO,Mr=947.07,F(000)=992,μ=0.170 mm-1,the final R=0.1606 and wR=0.2410 for 4382 observed reflections(Ⅰ>2σ(Ⅰ)).The crystal of compound 2belongs to the monoclinic system,space group P21/c,with a=9.500(3),b=24.522(8),c=17.997(6)A,Z=2,V=4054(2)A^3,Dc=1.296 g·cm^-3,C48H34N6O6,Mr=790.81,F(000)=1648,μ=0.087mm-1,the final R=0.2146 and wR=0.2535 for 2878 observed reflections(Ⅰ>2σ(Ⅰ)).Unlike the highly conserved R22(8)hydrogen-bonding amide···amide homosynthon,the structural analysis indicated that compound 1 selected the C(20)hydrogen-bonding motif and 2 selected the R22(34)hydrogen-bonding motif,which revealed the competition from remote solvent molecule and the interference of the molecular hydrocarbon core in crystal packing.The supramolecular structure revealed molecule 1 is further linked into a one-dimensional chain and 2 into a two-dimensional interwoven plane by N–H···N hydrogen bonds. 展开更多
关键词 hydrogen bond GLYCOLURIL supramolecuclar SYNTHONS crystal engineering
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A New One-dimensional Complex Assembled by 4-Nitrobenzoic Acid and Bis(imidazol) Ligands:Syntheses, Structures and Theoretical Calculations 预览
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作者 李秀梅 潘亚茹 +2 位作者 刘博 周实 常鹰飞 《结构化学》 SCIE CAS CSCD 2019年第5期783-790,670共9页
A new Zn(Ⅱ)coordination polymer,[Zn(nba)2(mbix)]2n(1,Hnba=4-nitrobenzoic acid,mbix=1,3-bis(imidazol-1-ylmethyl)-benzene),was synthesized and characterized by elemental analyses,IR spectra,TG,fluorescence spectroscopy... A new Zn(Ⅱ)coordination polymer,[Zn(nba)2(mbix)]2n(1,Hnba=4-nitrobenzoic acid,mbix=1,3-bis(imidazol-1-ylmethyl)-benzene),was synthesized and characterized by elemental analyses,IR spectra,TG,fluorescence spectroscopy,single-crystal and powder X-ray diffractions.It belongs to the triclinic system,P1 space group,with a=9.341(2),b=13.029(3),c=23.660(6)A,α=99.603(6)°,β=90.461(6)°,γ=90.597(5)°,V=2838.9(12)?3 and Z=2.It shows one-dimensional chains which are further linked by C–H···O hydrogen bonds andπ-πstacking interactions to yield a three-dimensional supramolecular structure.In addition,the Natural Bond Orbital(NBO)was analyzed in using the PBE0/LANL2DZ method built in Gaussian 09 Program.The calculation results indicated obvious covalent interaction between the coordinated atoms and Zn(Ⅱ)ion. 展开更多
关键词 synthesis crystal structure 4-nitrobenzoic acid Zn(Ⅱ) complex natural BOND ORBITAL
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How long a C–C bond can be? An example of extraordinary long C–C single bond in 1,2-diarylamino-o-carborane
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作者 Yile Wu Jie Zhang Zuowei Xie 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第8期1530-1532,共3页
How long a C-C bond can be?A question has long fascinated chemists.This work reports an example of extraordinary long C-C bond distance of 1.990(4)?observed in single-crystal X-ray structure of 1,2-(NHMes)2-o-carboran... How long a C-C bond can be?A question has long fascinated chemists.This work reports an example of extraordinary long C-C bond distance of 1.990(4)?observed in single-crystal X-ray structure of 1,2-(NHMes)2-o-carborane(2;Mes=2,4,6-trimethylphenyl).DFT calculations show that hyperconjugation of lone pairs of the nitrogen atoms into the emptyσ^*orbital of the cage C-C bond is the origin of the bond elongation.Such hyperconjugation can be suppressed if the two nitrogen atoms in 2 are linked to a Lewis acidic germanium(Ⅱ)center. 展开更多
关键词 O-CARBORANE C–C single BOND HYPERCONJUGATION AMINE X-RAY structure
Main Regulations of CAPM Model and Its Modern Modification 预览
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作者 Lamara Qoqiauri Nino Qoqiauri 《管理研究:英文版》 2019年第1期15-32,共18页
The article gives readers the main regulations of elaboration of capital actives evaluating model(CAPM)theory,topics of its practical usage,common ways of definition of investments(securities)optimal portfolio and on ... The article gives readers the main regulations of elaboration of capital actives evaluating model(CAPM)theory,topics of its practical usage,common ways of definition of investments(securities)optimal portfolio and on the basis of CAPM theory it is discussed evaluating methods of investing business,and it is highlighted two criteria of portfolio chosen by an investor—profit and risk.Besides,it is discussed modern modification of the mentioned model on the point of time horizon,a problem of time factor measurement while evaluating risk and profit,also evaluation of investing effectivity by using sharp coefficient.The work presents and evaluates possible income of securities and possibilities of risks in a modern way,which is characteristic only for CAPM model and it is considered to be its positive side. 展开更多
关键词 SECURITIES risk INCOME CAPM model stock MARKET bond MARKET optimal PORTFOLIO investments market sharp coefficient
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Selective modification of two-dimensional MoS2 nanosheets by polymer grafting
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作者 Hang Bian Xuejian Zhang +1 位作者 Dexin Huang Ning Zhang 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第2期311-313,共3页
As an emerging two-dimensional (2D) nanomaterial, single layer ora few layers of molybdenum disulfide (MoS2) has drawn significant attention in the past decade. In the present work, we report a strategy in direct crea... As an emerging two-dimensional (2D) nanomaterial, single layer ora few layers of molybdenum disulfide (MoS2) has drawn significant attention in the past decade. In the present work, we report a strategy in direct creating polymer brushes on MoS2 surfaces via S—C bond in the presence of UV light. The modification of MoS2 nanosheets can be achieved bilaterally or homolaterally by performing the UVgrafting polymerization on exfoliated MoS2 nanosheets or a single layer of MoS2 deposited on a silicon substrate. A series of vinyl monomers including methyl methacrylate (MMA), styrene (St) and 2-isopropenyl-2-oxazoline (IPOx) could be applied to this approach, leading to the formation of poly (methyl methacrylate) (PMMA), polystyrene (PS) and poly (2-isopropenyl-2-oxazoline) (PIPOx) brushes.AFM, IR, and XPS characterizations indicate the successful formation of homogeneous brush layers on MoS2 surfaces. The polymer brushes modified MoS2 may found potential applications in photo dynamic therapy and sensing technologies. 展开更多
关键词 MOLYBDENUM DISULFIDE Polymer BRUSHES SIPGP Surface MODIFICATION S-C BOND
Removal of polycyclic aromatic hydrocarbons from different soil fractions by persulfate oxidation
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作者 Xiaoyong Liao Qiongzhi Liu +2 位作者 You Li Xuegang Gong Hongying Cao 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第4期239-246,共8页
Removal of polycyclic aromatic hydrocarbons(PAHs) from different soil fractions of contaminated soil was investigated by using activated persulfate oxidation remediation in our research. The results showed that the li... Removal of polycyclic aromatic hydrocarbons(PAHs) from different soil fractions of contaminated soil was investigated by using activated persulfate oxidation remediation in our research. The results showed that the light fraction, which accounted for only 10% of the soil, contained 30% of the PAHs at a concentration of 4352 mg/kg. The heavy fraction contained more high-molecular-weight PAHs, and the total PAH concentration was 625 mg/kg. After being oxidized, the removal rate of PAHs was 39% in the light fraction and nearly 90% in the heavy fraction. Among the different fractions of the heavy fraction,humic acid contained the highest concentration of PAHs, and consequently, the highest removal efficiency of PAHs was also in humic acid. Compared with the light fraction, the heavy fraction has more aromatic compounds and those compounds were broken down during the oxidation process, which may be the removal mechanism involved in the oxidation of high-ring PAHs. Similarly, the enhancement of C= C bonds after oxidation can also explain the poor removal of high-ring PAHs in the light fraction. These results imply that different fractions of soil vary in composition and structure, leading to differences in the distribution and oxidation efficiencies of PAHs. 展开更多
关键词 Soil FRACTION PERSULFATE OXIDATION PAHs Organic MATTER BOND
锈蚀钢筋混凝土柱的修正压-剪-弯分析模型研究 预览
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作者 邢国华 杨成雨 +2 位作者 常召群 秦拥军 张广泰 《工程力学》 EI CSCD 北大核心 2019年第8期87-95,共9页
随着服役时间的增加,混凝土结构中钢筋易发生锈蚀,引起混凝土结构承载性能下降,严重影响工程结构的继续使用。该文在分析纵筋锈蚀后的屈曲效应、箍筋锈蚀后的约束效应、混凝土和钢筋材料性能劣化的基础上,建议了考虑锈蚀影响的钢筋、混... 随着服役时间的增加,混凝土结构中钢筋易发生锈蚀,引起混凝土结构承载性能下降,严重影响工程结构的继续使用。该文在分析纵筋锈蚀后的屈曲效应、箍筋锈蚀后的约束效应、混凝土和钢筋材料性能劣化的基础上,建议了考虑锈蚀影响的钢筋、混凝土及锈蚀钢筋与混凝土界面粘结性能的本构模型,以锈蚀钢筋混凝土柱为研究对象,对反复荷载作用下钢筋混凝土柱的分析模型进行修正,建立了锈蚀钢筋混凝土柱压-剪-弯交互作用下极限承载力计算模型,并通过21根锈蚀混凝土柱的试验结果对建议分析模型进行了验证。研究结果表明:锈蚀钢筋混凝土柱极限承载力试验值与计算值之比的平均值为1.021,方差为0.014,建议模型极限承载力预测值与试验结果吻合较好,可用于低周反复荷载作用下锈蚀钢筋混凝土柱的承载力分析。 展开更多
关键词 粘结 锈蚀 极限强度 压-剪-弯交互作用 钢筋混凝土柱
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Redox-sensitive prodrug nanoassemblies based on linoleic acid-modified docetaxel to resist breast cancers
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作者 Meng Li Liwen Zhao +5 位作者 Tao Zhang Yue Shu Zhonggui He Yan Ma Dan Liu Yongjun Wang 《药学学报:英文版》 CSCD 2019年第2期421-432,共12页
Prodrug nanoassemblies, which can refrain from large excipients, achieve higher drug loading and control drug release, have been placed as the priority in drug delivery system. Reasoning that glutathione(GSH) and reac... Prodrug nanoassemblies, which can refrain from large excipients, achieve higher drug loading and control drug release, have been placed as the priority in drug delivery system. Reasoning that glutathione(GSH) and reactive oxygen species(ROS) are highly upgraded in tumor tissues which makes them attractive targets for drug delivery system, we designed and synthetized a novel prodrug which utilized mono thioether bond as a linker to bridge linoleic acid(LA) and docetaxel(DTX). This mono thioether-linked conjugates(DTX-S-LA) could self-assemble into nanoparticles without the aid of much excipients. The mono thioether endowed the nanoparticles redox sensitivity resulting in specific release at the tumor tissue. Our studies demonstrated that the nanoassemblies had uniform particle size, high stability and fast release behavior. DTX-S-LA nanoassemblies outperformed DTX solution in pharmacokinetic profiles for it had longer circulation time and higher area under curve(AUC). Compared with DTX solution, the redox dual-responsive nanoassemblies had comparable cytotoxic activity. Besides, the antitumor efficacy was evaluated in mice bearing 4 T1 xenograft. It turned out this nanoassemblies couldenhance anticancer efficacy by increasing the dose because of higher tolerance. Overall, these results indicated that the redox sensitivity nanoassemblies may have a great potential to cancer therapy. 展开更多
关键词 DOCETAXEL NANOASSEMBLIES Mono THIOETHER bond Linoleic acid Pharmacokinetics ANTITUMOR efficacy
Influence of Bitumen Emulsion Spray on Pavement Performance 预览
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作者 John Richardson Connor Campbell 《交通与运输工程:英文版》 2019年第3期138-143,共6页
Bitumen emulsion sprays have an important part to play in the achievement of durable,efficient road pavement construction.Clearly,spraying of bond coats or tack coats at the interface of the bound layers should improv... Bitumen emulsion sprays have an important part to play in the achievement of durable,efficient road pavement construction.Clearly,spraying of bond coats or tack coats at the interface of the bound layers should improve the likelihood of full bond and of resistance to the entry of water through the layers,both of which are needed to meet the design objectives and for the pavement to continue to function properly.BS 594987 recommends bond coats,which are typically polymer modified bitumen emulsion,as best practice and their use is prevalent for the whole range of paved areas in the UK.Recent work examines the effect of different rates of spread of bitumen emulsion sprays on interlayer adhesion and permeability,and attempts to ascertain whether there are optimum quantities to obtain the desired effects. 展开更多
关键词 BOND COAT BITUMEN EMULSION road PAVEMENT permeability
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Strong dual-crosslinked hydrogels for ultrasound-triggered drug delivery
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作者 Wenxu Sun Heting Jiang +8 位作者 Xin Wu Zhengyu Xu Chen Yao Juan Wang Meng Qin Qing Jiang Wei Wang Dongquan Shi Yi Cao 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第1期115-119,共5页
Hydrogels that can respond to dynamic forces either from endogenous biological activities or from external mechanical stimuli show great promise as novel drug delivery systems (DDS).However,it remains challenging to e... Hydrogels that can respond to dynamic forces either from endogenous biological activities or from external mechanical stimuli show great promise as novel drug delivery systems (DDS).However,it remains challenging to engineer hydrogels that specifically respond to externally applied mechanical forces with minimal basel drug leakage under normal stressful physiological conditions.Here we present an ultrasound responsive hydrogel-based DDS with special dual-crosslinked nanoscale network architecture.The covalent crosslinks endow the hydrogel high mechanical stability and greatly suppress deformation-triggered drug release.Meanwhile,the dynamic covalent boronate ester linkages between hydrogel backbone and the anti-inflammation compound,tannic acid (TA),allow effective ultrasound-triggered pulsetile release of TA.As such,the hydrogel shows distinct drug release profiles under compression and ultrasound.A proof-of-principle demonstration of the suppression of inflammation activation of macrophage upon ultrasound-triggered release of TA was also illustrated.We anticipate that this novel hydrogel-based drug delivery system can be used for the treatment of inflammatory diseases on load-bearing tissues,such as muscle and cartilage. 展开更多
关键词 HYDROGEL dynamic COVALENT BOND mechanical force drug release
Hand-holding and releasing between the anion and cation to change their macroscopic behavior in water 预览
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作者 Kosuke Kuroda Yumiko Shimada Kenji Takahashi 《绿色能源与环境:英文版》 CSCD 2019年第2期127-130,共4页
Despite the similarity of ionic liquid and zwitterion,their some properties such as conductivity and hydrophobicity are different.Here we developed a novel phosphonium salt having a dynamic covalent bond between anion... Despite the similarity of ionic liquid and zwitterion,their some properties such as conductivity and hydrophobicity are different.Here we developed a novel phosphonium salt having a dynamic covalent bond between anion and cation,enabling reversible structural shift between free ion pair and zwitterion.With the phosphonium salt,control of the macroscopic phase behavior in aqueous solution,i.e.forming mono-or biphasic systems,upon exposure to an acid or base was reversibly achieved,based on the structural shift of the phosphonium salt.CO2/N2 bubbling reversibly changed the phase behavior as well as acid/base,leading to green separation systems. 展开更多
关键词 Ionic liquid ZWITTERION Phase separation Dynamic COVALENT bond
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考虑信用风险的债券投资组合优化模型 预览
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作者 陈志明 陈丹彤 《征信》 北大核心 2019年第6期20-26,共7页
企业债券因高收益特性而成为广受欢迎的投资标的,然而高收益伴随着高风险,企业的经营不善可能导致债券违约。目前债券投资决策的诸多分析忽视了信用风险,少数考虑的只是将其简单视为外生变量。研究发现:在变化幅度相同的条件下,违约率... 企业债券因高收益特性而成为广受欢迎的投资标的,然而高收益伴随着高风险,企业的经营不善可能导致债券违约。目前债券投资决策的诸多分析忽视了信用风险,少数考虑的只是将其简单视为外生变量。研究发现:在变化幅度相同的条件下,违约率对债券投资比例的影响远远大于收益率的影响,因此投资组合决策应该更多地考虑风险因素而非利润因素。 展开更多
关键词 债券 投资组合优化 信用风险 KMV 动态违约点 理想点法
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