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Chinese Physics B 2018年第3期27卷 487-493页

作者： ji-hua liu School of Mechanical Engineering Tianjin UniversityTianjin 300354China Tianjin Key Laboratory of Modern Engineering Mechanics Tianjin UniversityTianjin 300354China

The deformation process of the microstructure in 2205 duplex stainless steel(DSS)under thermo-mechanical coupling at 250℃was investigated using digital image correlation(DIC).A thermal tension test of duplex stainless steel(2205DSS)with a banded structure was carded out to observe the initial deformation of the *** was found that inhomogeneous strain fields occurred primarily in *** maximum normal strain in austenite was almost pos-itive,while that in ferrite was almost *** addition,a thermal cyclic-loading test was conducted,and the strain field was characterized by *** heterogeneities were induced after 400 cycles,which spread within the austenite and at the phase boundaries with the load *** high tensile-strain regions were always located adjacent to regions of intense compressive *** on the strain matrix sum *** number,we found that hardening occurred in the early cycles followed by softening.

关键词： thermo-mechanical coupling duplex stainless steel digital image correlation(DIC)

Preparation and Characterization of Thermoresponsive Hyperbranched Polyethylenimine with Plenty of Reactive Primary Amine Groups

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Chinese Journal of Polymer Science 2014年第7期32卷 961-968页

作者： hua-ji liu Run-hua Dong 陈宇 Department of Chemistry School of SciencesTianjin UniversityCollaborative Innovation Center of Chemical Science and Engineering

Certain amount of primary amine （NH2） groups of hyperbranched polyethylenimine （HPEI） was first protected by Boc groups. Subsequently, the residual reactive amine groups were reacted with isobutyric anhydride to introduce isobutyramide （IBAm） groups to HPEI. Finally, Boc groups were deprotected to result in HPEI-IBAm-NH2 with 18% of primary amine terminals on the periphery and 80% of IBAm terminal groups （abbreviated as HPEI-IBAm0.80-NH2）. 1H-NMR characterization proved the successful preparation of the product in each step. Compared with its spatial isomer HPEI- IBAm0.8o without primary amine groups, IH-NMR spectra verified that more IBAm groups were located in the interior of HPEI-IBAm0.80-NH2. The further modification of ***-NH2 and HPEI-IBAmo.8o with p-nitrobenzaldehyde demonstrated that ***-NH2 was more reactive than HPEI-IBAm0.80 due to its possession of primary amines. Turbidimetry measurements showed that HPEI-IBAm0.80-NH2 was thermoresponsive in water. In the pH range of 9.5-10 its cloud point temperature （Top） was constant, and it increased obviously upon decreasing the pH below 9.5. The thermoresponsive HPEI-IBAmo.8 exhibited the similar trend, but the pH threshold to achieve the constant Top was around 8.5. Moreover, HPEI-IBAm0.8-NH2 showed higher Top and broader phase transition than HPEI-IBAm0.8. The mechanism leading to the different thermoresponsive properties between HPEI-IBAm0.8-NH2 and its spatial isomer HPEI-IBAm0.8 was discussed.

关键词： Hyperbranched Phase transition Polyethylenimine Spatial isomer Thermoresponsive polymers.

Influence of Aliphatic Amide Terminals on the Thermoresponsive Properties of Hyperbranched Polyethylenimines

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Chinese Journal of Polymer Science 2014年第10期32卷 1338-1347页

作者： Hong-wei Qin hua-ji liu 陈宇 Department of Chemistry School of Sciences Tianjin University and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)

Acetamide （C2）, propionamide （C3）, butyramide （C4）, isobutyramide （i-C4）, isovaleramide （i-C5） and trimethylacetamide （t-C5） groups each were introduced to the terminals of hyperbranched polyethylenimine （HPEI） through the amidation reaction between HPEI and the corresponding anhydride. Moreover, HPEIs terminated with two kinds of amides were also prepared. The first amide was fixed to be i-C4 with 52% degree of amidation （DA）, and the second amide varied from C2, C3, C4, i-C5 to t-C5. All the polymers were characterized by 1H-NMR. Turbidimetry measurements were performed for these polymers in water at different temperatures. With respect to the polymers bearing only one kind of amide group, except C2, all the other amide groups could render thermoresponsive properties to HPEI. The specific ordering of these amide groups to reduce the cloud point temperature （Top） was as follows： i-C5 〉 t-C5 〉 C4 〉 i-C4 〉 C3. Moreover, the more branched i-C4 and t-C5 were better groups than their less branched isomers C4 and i-C5 in the Tcp range of 12-51 ~C to render the sharper phase transition to the thermoresponsive polymers. As for the polymers bearing two kinds of amide groups, the further introduction of C2, C3, C4, i-C5 or t-C5 could effectively endow HPEI bearing 52% of i-C4 with thermoresponsive properties. The specific ordering of these second amide groups to reduce the Top was as follows： i-C5 〉 C4 〉 i-C4 〉 C3 〉 C2. C4, i-C5 and t-C5 were all effective second amide groups to prepare the thermoresponsive polymers with sharper phase transition.

关键词： Aliphatic amide Hyperbranched Phase transition Polyethylenimine Thermoresponsive polymers

Influence of Sodium Dodecyl Sulfate on the Phase Transition of Thermoresponsive Hyperbranched Polymer in Water

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Chinese Journal of Polymer Science 2016年第5期34卷 585-593页

作者： hua-ji liu yue-yue xu 陈宇 Department of Chemistry School of SciencesTianjin Universityand Collaborative Innovation Center of Chemical Science and Engineering(Tianjin)Tianjin 300354China

The influence of sodium dodecyl sulfate（SDS） on the cloud point temperature（Tcp） of the aqueous solution of thermoresponsive hyperbranched polyethylenimine derivative HPEI-IBAm was studied systematically. When pH was below 8.5, HPEI-IBAm was positively-charged. Initially, the Tcp of HPEI-IBAm decreased significantly, followed by an obvious increase with the increase of SDS concentration. The lower the pH was, the higher the SDS concentration was required to achieve the minimum Tcp. When pH was above 8.5, HPEI-IBAm was neutral and raising the SDS concentration led to the gradual increase of Tcp. Compared to linear poly（N-isopropyl acrylamide）（PNIPAm）, the Tcp of the current hyperbranched HPEI-IBAm was more sensitive to SDS. The thermoresponsive HPEI-IBAm/SDS complex was used as host to accommodate the non-polar pyrene in water. The lowest SDS concentration for effectively enhancing the solubility of pyrene in water was around 6.4 mmol·L^-1. When HPEI-IBAm was present, the SDS concentration threshhold was decreased to about 0.31 mmol·L^-1. Fluorescence technique with pyrene as the hydrophobic probe demonstrated that the SDS concentration of 7.2 mmol·L^-1 was required to form the hydrophobic domain to accommodate pyrene guests without HPEI-IBAm, while only 0.2 mmol·L^-1 of SDS was required in the presence of HPEI-IBAm.

关键词： acrylamide solubility hydrophobic isopropyl systematically polar dodecyl pyrene accommodate derivative

Hyperbranched Polymeric Fluorosurfactants:Synthesis,Surface Activity and Their Application in Firefighting Foams

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Chinese Journal of Polymer Science 2023年第11期41卷 1767-1777,I0009页

作者： Dan-Ling Yang Pei-Yao Chen Yan Wang Shuang Zhuang Yu Chen hua-ji liu Department of Chemistry School of ScienceTianjin UniversityTianjin 300354China Tianjin Fire Research Institute of MEM Tianjin 300381China

Fluorosurfactants are the key ingredients in the formulations of aqueous film-forming foams(AFFFs)for extinguishing flammable liquids,thus developing high-efficient and low-toxic fluorosurfactants is desirable in AFFFs ***,a series of hyperbranched polymeric fluorosu rfactants(HPFs)were successfully synthesized through sequentially modifying hyperbranched polyethylenimine(PEI)with the hydrophilic poly(ethylene glycol)(PEG)chains and the hydrophobic C6/C4-based perfluoroalkyl chains,which were verified by FTIR,^(1)H-and^(19)*** surface tensions of all the HPFs in water were measured,and the corresponding physicochemical parameters were *** was found that the surface activities of HPFs could be tuned through adjusting the ratio of PEG to perfluoroalkyl chains,the length of perfluoroalkyl chains,the molecular weight of PEI core,but not the PEG chain *** the binary mixture of HPFs with the commercial small molecule fluorosurfactant Capstone^(TM)1157(C1157),a strong synergism led to the elevation of surface activity,which was attributed to the efficient encapsulation of C1157 guests by the compact hyperbranched HPFs as the *** utilization of HPF/C1157 as fluorosurfactant ingredients in AFFF formulations could realize much higher fire-extinguishing efficiency towards flammable oils than the control AFFFs prepa red from the polymeric Capstone^(TM)1460 or the neat C1157.

关键词： Aqueous film-forming foams Firefighting Fluorosurfactant Hyperbranched polymer Surface activity

Pancharatnam Phase of a Mesoscopic Coupled Circuit

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Communications in Theoretical Physics 2005年第3X期44卷 555-558页

作者： ji Ying-hua liu Qing LUO Hai-Mei HU Ju-Ju Department of Physics Jiangxi Normal University Nanchang 330027 China

We derive a formula of the nonadiabatic noncyclic Pancharatnam phase for a mesoscopic circuit with coupled inductors and capacitors. It shows that, because of coupling effect, the circuit is in squeezed quantum state initially, and the time evolution of Pancharatnam phase exhibits an oscillation in a complex way. Especially we find that when the capacity of the coupled capacitors is larger than that of other ones in the circuit, with the variation of time Pancharatnam phase becomes nearly periodic square-wave, which perhaps can provide a new approach for the realization of quantum logic gate.

关键词： mesoscopic coupled circuits Pancharatnam phase oscillation

A new ginsengenin containing an oxacyclopentane-ring isolated from the acid hydrolysate of total ginsenosides

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Chinese Chemical Letters 2013年第6期24卷 524-526页

作者： Qing-Xiang Guan De-Ya Sun ji-hua liu Wei Li Qin Meng Cong Geng jian-Yuan Yin School of Pharmacy Jilin University Beijing Laviana Pharmactech Co. Ltd.

Bioassay-guided fractionation of the acid hydrolysate of total ginsenosides of Panax ginseng *** （Araliaceae） led to the isolation of a novel ginsengenin（1）.The structure of 1 was determined as （20S,22S）-dammar-22,25-epoxy-3β,12β,20-triol by extensive spectroscopy and single-crystal X-ray diffraction *** cytotoxicity of 1 was further tested against SWl 116,HCTl 16,and A549 cells by the MTT method,with IC50 values in the range of 2.96-30.9μmol/L.

关键词： Ginsengenin Oxacyclopentane Cytotoxicity

Mapping Major Restore Genes for C-type Cytoplasmic Male Sterility in Maize with SSR Marker

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Agricultural Sciences in China 2002年第3期1卷 269-273页

作者： TANG ji-hua, liu Zong-hua, CHEN Wei-cheng, HU Yan-min, ji Hong-qiang, ji Liang-yue, XIE Hui-ling and huaNG Xi-lin(Henan Agricultural University, Zhengzhou 450002 ) Henan Agricultural University Zhengzhou 450002

Through observation about the restoration of male fertility of F2 and BC, progeny, we found that the restoring line Fengkel had two duplicating restorer genes. The restorer gene R/5 in Fengkel background was located on chromosome 5L by SSR method; it linked with bnlg1711, bnlg1346 and phi058, the genetic distances with bnlg1711, bnlg1346, and phi058 were 7.51cM, 1.68cM, and 9.87cM respectively; the restorer gene Rf4 was mapped on chromosome 8S linked with bnlg2307.

关键词： Maize C-cytopIasmic male sterility Restorer genes SSR makers

Stability and Bifurcation Analysis of Man-machine System with Time Delay

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Chinese Quarterly Journal of Mathematics 2012年第2期27卷 196-203页

作者： YANG ji-hua liu Mei Department of Mathematics and Computer Science Ningxia Teacher's University Guyuan 756000China

A mathematical model of man-machine system is *** on the reference [4],the direction and stability of the Hopf bifurcation are determined using the normal form method and the center manifold ***,the existence of Hopf-... 详细信息

关键词： man-machine system stability Hopf bifurcation Hopf-zero bifurcation

Coastal blue carbon ecosystems in China

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China Geology 2022年第1期5卷 193-194页

作者： Fa-ming Wang jing-fan Zhang Si-yuan Ye ji-hua liu Xiaoliang Research Station of Tropical Coastal Ecosystems South China Botanical GardenChinese Academy of SciencesGuangzhou 510650China Guangdong Provincial Laboratory of Southern Ocean Science and Engineering(Guangzhou) Guangzhou 511458China Qingdao Institute of Marine Geology China Geological SurveyQingdao 266237China Marine Research Institute Shandong UniversityQingdao 266237China

*** are blue carbon ecosystems?Coastal blue carbon ecosystems(BCEs)consists of salt marshes,mangroves,and seagrass *** function as carbon(C)sink is an important pathway to reduce atmospheric carbon dioxide(CO_(2))conc... 详细信息

关键词： ecosystems carbon capacity