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Low-viscosity oligoether esters(OEEs)as high-efficiency lubricating oils:Insight on their structure‒lubricity relationship

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Friction 2024年第6期12卷 1133-1153页

作者： Hanwen WANG Ying WANG Ping WEN Lin ma Mingjin FAN Rui DONG chunhua ZHANG Shaanxi Key Laboratory of Phytochemistry College of Chemistry&Chemical EngineeringBaoji University of Arts and SciencesBaoji 721013China Key Laboratory of Shaanxi Province for Development and Application of New Transportation Energy Chang’an UniversityXi’an 710064China

Development of energy-efficient lubricants is a way to reduce energy consumption for transportation,with the tendency to design molecules that are beneficial in reducing the viscosity of synthetic oils.Oligoether esters(OEEs),as a low-viscosity ester base oil,have characteristics such as simple synthesis and excellent lubrication effect;however,the application of OEEs in tribology field has rarely been investigated.The objective of the present study is to investigate the effect of structure on the lubricating performance of OEEs and to develop a predictive model for OEEs based on quantitative structure‒property relationship(QSPR)through a combination of experiment and statistical modeling.Results showed that glycol chains contribute positively to lubrication with the ether functional groups increasing the sites of adsorption.Compared to branched-chain OEEs,straight-chain OEEs exhibited reduced wear,which was mainly due to the thicker adsorption film formed by the straight-chain structure.Furthermore,carbon films were detected on lightly worn surfaces,indicating that OEEs underwent oxidation during the friction process.Based on the results of principal component analysis(PCA)and partial least squares(PLS),it could be found that the predictive models of viscosity‒temperature performance,thermal stability performance,coefficient of friction(COF),and wear volume(WV)performed well and robustly.Among them,COF and WV can be best predicted with an R2 of about 0.90.

关键词： oligoether esters(OEEs) low-viscosity ester friction wear quantitative structure-property relationship(QSPR)

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Achieving exceptionally high strength and rapid degradation rate of Mg-Er-Ni alloy by strengthening with lamellar γ' and bulk LPSO phases

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Journal of materials Science & Technology 2024年第1期168卷 88-102页

作者： Chaoneng Dai Jingfeng Wang Yuanlang Pan Kai ma Yinhong Peng Ye Wang Danqian Wang chunhua Ran Jinxing Wang Yanlong ma College of Chemistry and Chemical Engineering Chongqing UniversityChongqing 401331China College of materials Science and Engineering Chongqing UniversityChongqing 400044China National Engineering Research Center for magnesium Alloys Chongqing 400044China College of materials Science and Engineering Chongqing University of TechnologyChongqing 400054China

As-extruded Mg-Er-Ni alloys with different volume fractions of long-period stacking ordered(LPSO)phase and density of lamellar γ' phase were prepared,and the microstructure,mechanical,and degradation properties were investigated.Coupling the bulk LPSO phase and the lamellar γ' phase,and controlling the dynamic recrystallization processes during deformation by adjusting the volume fraction of LPSO and the density of the γ' phase,a synergistic increase in strength and degradation rate can be achieved.On the one hand,the increase in corrosion rate was related to the increased volume fraction of the bulk LPSO phase and the densities of the lamellar γ' phase,which provide more galvanic corrosion.Moreover,high densities of the lamellar γ' phase can provide more corrosion interface by inhibiting the recrystallization process to refine dynamic recrystallized(DRXed)grains during the hot extrusion.On the other hand,the ultimate tensile strength(UTS)and tensile yield strength(TYS)of the Mg-Er-Ni alloy increased from 345 and 265 MPa to 514 MPa and 358 MPa,respectively,which was mainly attributed to grain boundary and texture strengthening,bulk LPSO phase and lamellar γ' phase strengthening.Overall,Mg^(-1)4Er-4Ni alloy,which contains the highest volume fraction bulk LPSO phase and the densities of lamellar γ' phase,re-alized a synergistic enhancement of strength and degradation rate.The UTS,TYS,and degradation rate of Mg^(-1)4Er-4Ni were 514 MPa,358 MPa,and 142.5 mg cm^(-2)h^(-1)(3 wt%KCl solution at 93◦C),respectively.This research provides new insight into developing Mg alloys with high strength and degradation rates for fracturing tool materials in the application of oil and gas exploitation in harsh environments.

关键词： Mg-Er-Ni alloy Lamellarγ'and bulk LPSO phases Rapid degradation rate High strength Mechanical and corrosion mechanism

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Photocatalytic Transition-Metal-Free Direct 3-Acetalation of Quinoxaline-2(1H)-ones

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Chinese Journal of Chemistry 2022年第22期40卷 2655-2662页

作者： chunhua ma Hui Meng Jing Li Xianguang Yang Yuqin Jiang Bing Yu Collaborative Innovation Centre of Henan Provincefor Green manufacturing of Fine Chemicals Key Laboratory of Green Chemical Media and ReactionsMinistry of EducationHenan Engineering Research Centre of Chiral Hydroxyl PharmaceuticalHenan Engineering Laboratoryof Chemical Pharmaceutical and Biomedical MaterialsSchool of Chemistry and Chemical EngineeringHenanNormal UniversityXinxiangHenan453007China Green Catalysis Centre College of ChemistryZhengzhou UniversityZhengzhouHenan 45001China

A general transition-metal-free visible-light-promoted 3-acetalation reaction of quinoxaline-2(1H)-ones was developed under mild conditions.By employing 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene(4CzIPN)as an inexpensive photocatalyst,and glyoxylic acid acetal as a radical source,various acetalated quinoxaline-2(1H)-ones were constructed in moderate to good yields.Moreover,the versatility of this protocol is highlighted by the successful application in the late-stage modification of drug molecules and the various functionality transformations.The excellent antitumor activity of the acetalated product demonstrated that this streamlined and sustainable approach could have emerged as a powerful strategy for structural modification in medicinal chemistry.

关键词： Photocatalysis Transition-metal-free Synthetic methods Radical reactions Antitumor activity

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Application Value of NLR,PLR,LMR,HEART score,and POCT in Early Warning and Accurate Graded Diagnosis of High-Risk Chest Pain in Emergency Medicine

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Journal of Clinical and Nursing Research 2024年第4期8卷 93-98页

作者： Shaochang ma chunhua Lin Yanmei Li Yan Chen Guohui Zhang Guandu District People’s Hospital Kunming 650200Yunnan ProvinceChina Guanshang Street Health Service Center Guandu DistrictKunming 650200Yunnan ProvinceChina

Objective: To evaluate the application value of neutrophils/lymphocytes (NLR), platelets/lymphocytes (PLR), lymphocytes/monocytes (LMR), HEART (history, electrocardiogram, age, risk factors, and troponin) score, and point-of- care testing (POCT) in the early warning and precise diagnosis of high-risk chest pain in emergency medicine. Methods: A total of 157 patients with acute chest pain who were admitted to the emergency department and chest pain treatment unit of our hospital between August 2022 and September 2023 were selected. Rapid testing of bedside myocardial markers (ultrasensitive troponin (hs-cTnI), myoglobin (MYO), creatine kinase isoenzyme (CK-MB), D-dimer (D-Dimer), and N-terminal B-type natriuretic peptide precursor (NT-proBNP)) was performed on the patients using a POCT device (ThermoKing BioMQ60proB). A HEART score was used to classify the patients into low (n = 53), intermediate (n = 59), and high-risk (n = 45) groups, and the NLR, PLR, and LMR were calculated. The NLR, PLR, and LMR values were compared among the three groups of patients, and the optimal cutoff values as well as sensitivity and specificity were determined based on receiver operating characteristic (ROC) analysis. Results: The HEART scores of patients in the low-risk, intermediate-risk, and high-risk groups were (2.72 ± 0.24), (4.75 ± 0.56), and (5.32 ± 0.73) respectively, and the differences were statistically significant (P < 0.05). Compared with the low-risk group, the intermediate-risk group and high-risk group had a significantly higher NLR and PLR, and a significantly lower LMR;the high-risk group had higher NLR and PLR and lower values of LMR as compared to the other two groups, and the difference was statistically significant (P < 0.05). The ROC curves suggested that the area under the curve, sensitivity, and specificity of the combined diagnosis of NLR, PLR, LMR, HEART score, and POCT were greater than those of LR, PLR, and LMR with HEART score and POCT alone. Conclusion: The combined application of NLR, PLR, LMR, HEART s

关键词： NLR PLR LMR POCT myocardial markers HEART score Emergency high-risk chest pain

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务农情境下的工作—家庭冲突研究

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中国农业大学学报（社会科学版） 2024年第3期41卷 181-202页

作者：马春华中国社会科学院社会学研究所

本文基于CSS2021年的数据讨论了务农情境下的工作—家庭冲突。研究发现,双向工作—家庭冲突,即“工作对家庭干扰”(WIF)和“家庭对工作干扰”(FIW)不仅存在于非农群体中,也存在于务农群体中。务农群体FIW水平甚至超过了非农群体。在不... 详细信息

本文基于CSS2021年的数据讨论了务农情境下的工作—家庭冲突。研究发现,双向工作—家庭冲突,即“工作对家庭干扰”(WIF)和“家庭对工作干扰”(FIW)不仅存在于非农群体中,也存在于务农群体中。务农群体FIW水平甚至超过了非农群体。在不同的情境中,工作—家庭冲突水平不同,影响因素也不同。因此,在工作—家庭冲突研究、工作—家庭平衡研究和工作—家庭增益研究中,无论是质性研究还是量化研究,都应该将务农群体纳入研究视野;在政策制定层面,国家应关注务农群体在工作—家庭平衡上的需求,他们不仅面临着工作—家庭冲突的困扰,也相对更为脆弱,更需要政策支持。

关键词：工作—家庭冲突务农群体非农群体 WIF FIW

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Extending the solid solution range of sodium ferric pyrophosphate:Off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)as a novel cathode for sodium‐ion batteries

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Carbon Energy 2024年第4期6卷 128-139页

作者： Xiang jun Pu Kunran Yang Zibing Pan chunhua Song Yangyang Lai Renjie Li Zheng‐Long Xu Zhongxue Chen Yuliang Cao Hubei Key Laboratory of Electrochemical Power Sources College of Chemistry and Molecular SciencesWuhan UniversityWuhanChina Key Laboratory of Hydraulic machinery Transients Ministry of EducationSchool of Power and Mechanical EngineeringWuhan UniversityWuhanChina School of Chemistry and Chemical Engineering Jiangsu University of TechnologyChangzhouJiangsuChina Zonergy Corporation ZigongSichuanChina Department of Industrial and Systems Engineering The Hong Kong Polytechnic UniversityHung HomHong Kong SARChina

Iron‐based pyrophosphates are attractive cathodes for sodium‐ion batteries due to their large framework,cost‐effectiveness,and high energy density.However,the understanding of the crystal structure is scarce and only a limited candidates have been reported so far.In this work,we found for the first time that a continuous solid solution,Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2)(0≤α≤1,could be obtained by mutual substitution of cations at center‐symmetric Na3 and Na4 sites while keeping the crystal building blocks of anionic P2O7 unchanged.In particular,a novel off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)is thus proposed,and its structure,energy storage mechanism,and electrochemical performance are extensively investigated to unveil the structure–function relationship.The as‐prepared off‐stoichiometric electrode delivers appealing performance with a reversible discharge capacity of 83 mah g^(−1),a working voltage of 2.9 V(vs.Na^(+)/Na),the retention of 89.2%of the initial capacity after 500 cycles,and enhanced rate capability of 51 mah g^(−1)at a current density of 1600 ma g^(−1).This research shows that sodium ferric pyrophosphate could form extended solid solution composition and promising phase is concealed in the range of Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2),offering more chances for exploration of new cathode materials for the construction of high‐performance SIBs.

关键词： extending solid‐solution range off‐stoichiometric Na_(3)Fe_(2.5)(P_(2)O_(7))_(2) sodium‐ion batteries structure-function relationship

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Development of peptidomimetic hydroxamates as PfA-M1 and PfA-M17 dual inhibitors: Biological evaluation and structural characterization by cocrystallization

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Chinese Chemical Letters 2022年第5期33卷 2550-2554页

作者： Anil Kumar marapaka Priyanka Sankoju Guozhen Zhang Yongzheng Ding chunhua ma Vijaykumar Pillalamarri Renu Sudhakar Bharati Reddi Puran Singh Sijwali Yingjie Zhang Anthony Addlagatta Department of Medicinal Chemistry Key Laboratory of Chemical Biology(Ministry of Education)School of Pharmaceutical SciencesCheeloo College of MedicineShandong UniversityJi’nan 250012China Department Applied Biology CSIR-Indian Institute of Chemical TechnologyTarnakaHyderabadTelangana-500007India Academy of Scientific and Innovative Research(AcSIR) Ghaziabad-201002India CSIR-Centre for Cellular and Molecular Biology TarnakaHyderabadTelangana-500007India

Plasmodium parasites causing malaria have developed resistance to most of the antimalarials in use,in-cluding the artemisinin-based combinations,which are the last line of defense against malaria.This ne-cessitates the discovery of new targets and the development of novel antimalarials.Plasmodium falciparum alanyl aminopeptidase(PfA-M1)and leucyl aminopeptidase(PfA-M17)belong to the M1 and M17 family of metalloproteases respectively and play critical roles in the asexual erythrocytic stage of development.These enzymes have been suggested as potential antimalarial drug targets.Herein we describe the devel-opment of peptidomimetic hydroxamates as PfA-M1 and PfA-M17 dual inhibitors.Most of the compounds described in this study display inhibition at sub-micromolar range against the recombinant PfA-M1 and PfA-M17.More importantly,compound 26 not only exhibits potent malarial aminopeptidases inhibitory activities(PfA-M1 K i=0.11±0.0002μmol/L,PfA-M17 K_(i)=0.05±0.005μmol/L),but also possesses remarkable selectivity over the mammalian counterpart(pAPN K_(i)=17.24±0.08μmol/L),which endows 26 with strong inhibition of the malarial parasite growth and negligible cytotoxicity on human cell lines.Crystal structures of PfA-M1 at atomic resolution in complex with four different compounds including compound 26 establish the structural basis for their inhibitory activities.Notably,the terminal ureidoben-zyl group of 26 explores the S2' region where differences between the malarial and mammalian enzymes are apparent,which rationalizes the selectivity of 26.Together,our data provide important insights for the rational and structure-based design of selective and dual inhibitors of malarial aminopeptidases that will likely lead to novel chemotherapeutics for the treatment of malaria.

关键词： Aminopeptidase Dual inhibitor Antimalaria Peptidomimetic Plasmodium falciparum

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Crystalline-amorphization-recrystallization structural transition and emergent superconductivity in van der Waals semiconductor SiP under compression

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 115-122页

作者： chunhua Chen Zhenyu Ding Yonghui Zhou Yifang Yuan Nixian Qian Jing Wang Shuyang Wang Ying Zhou Chao An Min Zhang Xuliang Chen Xiaoping Yang Mingliang Tian Zhaorong Yang Anhui Key Laboratory of Low-Energy Quantum materials and Devices High Magnetic Field LaboratoryHFIPSChinese Academy of SciencesHefei 230031China Science Island Branch of Graduate School University of Science and Technology of ChinaHefei 230026China Key Laboratory of material Physics Ministry of EducationSchool of Physics and MicroelectronicsZhengzhou UniversityHefei 230601China Institutes of Physical Science and Information Technology Anhui UniversityZhengzhou 450001China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China

van der Waals(vdW)semiconductors have gained significant attention due to their unique physical properties and promising applications,which are embedded within distinct crystallographic symmetries.Here,we report a pressure-induced crystallineamorphization-recrystallization transition under compression in binary vdW semiconductor SiP.Upon compression to 52 GPa,bulk SiP undergoes a consecutive phase transition from pristine crystalline to amorphous phase,ultimately to recrystallized phase.By employing synchrotron X-ray diffraction experiments in conjunction with high-pressure crystal structure searching techniques,we reveal that the recrystallized Si P hosts a tetragonal structure(space group I4mm)and further transforms partially into a cubic phase(space group Fm3m).Consistently,electrical transport and alternating-current magnetic susceptibility measurements indicate the presence of three superconducting phases,which are embedded in separate crystallographic symmetries—the amorphous,tetragonal,and cubic structures.Furthermore,a high superconducting transition temperature of 12.3 K is observed in its recovered tetragonal phase during decompression.Our findings uncover a novel phase evolution path and elucidate a pressure-engineered structure-property relationship in vdW semiconductor SiP.These results not only offer a new platform to explore the transformation between different structures and functionalities,but also provide new opportunities for the design and exploration of advanced devices based on vdW materials.

关键词： recrystallization transition amorphous

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Fiscal Pressure,Land Finance and Ratchet Effects of House Prices

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China Finance and Economic Review 2018年第1期7卷 73-94页

作者： Yunfeng Tang chunhua ma School of Public Administration Zhejiang University of Finance&Economics Zhejiang University of Finance&Economics China

In this paper,we focus on the issues of local governments’fiscal pressure,land finance and house prices,and systematically analyze how local governments’fiscal pressure and land finance lead to China’s ratcheting up of house prices.The results show that to release the fiscal pressure,local governments tend to increase land revenue and obtain high real estate related revenue by raising house prices.In this sense,the increase of the land transfer price will result in the increase of the cost of real estates,and eventually leading to the increase of house prices.That is to say,local governments’fiscal pressure will not only result in the increase of house prices directly but also consolidate the ratchet effects of house prices.

关键词： land finance fiscal pressure ratchet effects of house prices

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天然气运移轻烃地球化学示踪--以鄂尔多斯盆地东胜气田为例

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石油勘探与开发 2024年第2期51卷 273-284页

作者：吴小奇倪春华马亮帮王付斌贾会冲王萍中国石化石油勘探开发研究院无锡石油地质研究所江苏无锡214126 中国石化油气成藏重点实验室江苏无锡214126 中国石化华北油气分公司油气勘探管理部郑州450006 中国石化华北油气分公司勘探开发研究院郑州450006

基于天然气中轻烃化合物组成分析和区域性对比,结合组分和甲烷碳同位素组成特征,揭示轻烃地球化学特征对鄂尔多斯盆地东胜气田上古生界天然气运移和水溶及逸散等示踪作用,探讨运移作用对特定轻烃指标的关联效应。研究表明:①东胜气田二... 详细信息

基于天然气中轻烃化合物组成分析和区域性对比,结合组分和甲烷碳同位素组成特征,揭示轻烃地球化学特征对鄂尔多斯盆地东胜气田上古生界天然气运移和水溶及逸散等示踪作用,探讨运移作用对特定轻烃指标的关联效应。研究表明:①东胜气田二叠系下石盒子组天然气C5−7异构烷烃含量高于正构烷烃,C6−7轻烃组成呈链烷烃优势分布且芳香烃含量明显偏低(小于4.0%),C7轻烃主体呈甲基环己烷优势分布,整体表现出煤成气特征且受到了水溶等作用影响;②东胜气田天然气经历了自南向北的游离相运移,并在充注后发生不同程度的水溶作用,其中泊尔江海子断裂以北什股壕地区天然气在聚集后具有明显的散失;③长距离的游离相运移导致天然气C7轻烃中甲基环己烷相对含量和甲苯/正庚烷值降低、正庚烷/甲基环己烷值和庚烷值增大,水溶作用导致轻烃异庚烷值增大,天然气散失导致什股壕地区天然气中C5−7正构烷烃相对异构烷烃含量增加。

关键词：鄂尔多斯盆地东胜气田二叠系下石盒子组轻烃化合物成熟度天然气成因运移相态散失作用

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