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A discovery of two slow pulsars with FAST:“Ronin”from the globular cluster M15

Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 166-180页

作者： Dengke Zhou Pei Wang Di Li jianhua fang Chenchen Miao Paulo CCFreire Lei Zhang Dandan Zhang Huaxi Chen Yi Feng Yifan Xiao Jintao Xie Xu Zhang Chenwu Jin Han Wang Yinan Ke Xuerong Guo Rushuang Zhao Chenhui Niu Weiwei Zhu Mengyao Xue Yabiao Wang Jiafu Wu Zhenye Gan Zhongyi Sun Chengjie Wang Jie Zhang Junshuo Zhang Jinhuang Cao Wanjin Lu Research Center for Astronomical Computing Zhejiang LaboratoryHangzhou 311121China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China University of Chinese Academy of Sciences Beijing 100049China New Cornerstone Science Laboratory Shenzhen 518054China Max Planck Institut f¨ur Radioastronomie Bonn 53121Germany Centre for Astrophysics and Supercomputing Swinburne University of TechnologyHawthorn 3122Australia School of Mathematical Sciences School of Physics and Electronic SciencesGuizhou Normal UniversityGuiyang 550001China Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing Guiyang 550001China School of Physics and Electronic Engineering Qilu Normal UniversityJinan 250200China School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550001China College of Physical Science and Technology Central China Normal UniversityWuhan 430079China Tencent Youtu Lab Shanghai 201103China

Globular clusters harbor numerous millisecond pulsars,but long-period pulsars(P 100 ms)are rarely *** this study,we employed a fast folding algorithm to analyze observational data from multiple globular clusters obtained by the Five-hundredmeter Aperture Spherical radio Telescope(FAST),aiming to detect the existence of long-period *** estimated the impact of the median filtering algorithm in eliminating red noise on the minimum detectable flux density(S_(min))of ***,we successfully discovered two isolated long-period pulsars in M15 with periods approximately equal to 1.928451 and3.960716 s,*** the P-˙P diagram,both pulsars are positioned below the spin-up line,suggesting a possible history of partial recycling in X-ray binary systems disrupted by dynamical encounters later *** to timing results,these two pulsars exhibit remarkably strong magnetic *** the magnetic fields were weakened during the accretion process,then a short duration of accretion might explain the strong magnetic fields of these pulsars.

关键词： pulsar globular cluster FAST

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Compatibility evaluation between waterborne epoxy resin and SBR latex modified asphalt emulsion

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第1期11卷 160-171页

作者： jianhua Yang Zhengqi Zhang Ying fang Key Laboratory for Special Area Highway Engineering of Ministry of Education Chang'an UniversityXi'an 710064China

Good compatibility between waterborne epoxy resin(WER)modifier and styrene-butadiene rubber(SBR)latex modified asphalt emulsion(SBRE)is an essential premise for good pavement performance of WER and SBR latex compositely modified asphalt emulsion(WSAE).This study aims to explore the compatibility between WER modifier and *** achieve the goal,several WER modifiers produced by two methods were first selected to modify SBRE,thus the WSAEs were ***,storage stability and workability of the WSAEs themselves,and high-temperature performance,rheological behavior and temperature sensitivity of their evaporated residues were compared and evaluated via performing a series of experiments,respectively,thus the WER modifier possessing an optimal modification effect was *** show that the storage stability of WSAEs is sensitive to the amount of *** incorporation of 1%WERs by the mass of SBRE improves the storage stability of SBRE,while WERs that exceed 1%weaken its storage *** the WERs reach 3%and 4%,the 5 d storage stability of prepared WSAEs will be beyond the limitation of *** WERs into SBRE negatively affects the workability of SBRE,and the workability of WSAEs is adversely influenced by the WERs content and the storage *** ensure the construction,the WSAEs with 3%and 4%WERs should not be stored for more than 36 h and 48 h,*** WERs effectively improve the high-temperature performance of SBRE residue,especially the 3%***,the WERs notably enhance the rheological property and thermal stability of SBRE *** contrast,the WER modifier produced by chemically modified method has a smaller adverse impact on the storage stability and workability of WSAE,and a larger enhancement on the high-temperature performance,rheological property and thermal stability of SBRE residue,which is thus recommended to modify SBRE.

关键词： Waterborne epoxy resin SBR modified asphalt emulsion Workability Rheological property Temperature sensitivity Compatibility evaluation

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细菌外排泵功能及抑制机制的研究进展

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当代医学 2024年第12期30卷 182-186页

作者：方建华李亚威刘静王国瑜向天新江西省传染病防治重点实验室/南昌大学第一附属医院江西南昌330052 南昌大学第一附属医院感染科江西南昌330052 南昌大学第一附属医院呼吸与危重医学科江西南昌330052 南昌大学第一附属医院感控处江西南昌330052

近年来,由于抗生素在临床上的不规范使用,细菌耐药率呈快速增长趋势,显著增加临床的抗感染治疗难度。对于耐药菌而言,外排蛋白基因占所有转运蛋白基因的6%~18%。因此,由外排基因编码的外排泵是细菌产生多重耐药的重要机制之一。最新研... 详细信息

近年来,由于抗生素在临床上的不规范使用,细菌耐药率呈快速增长趋势,显著增加临床的抗感染治疗难度。对于耐药菌而言,外排蛋白基因占所有转运蛋白基因的6%~18%。因此,由外排基因编码的外排泵是细菌产生多重耐药的重要机制之一。最新研究结果表明,外排泵抑制剂是通过抑制外排泵研发针对性抗生素的新治疗靶点,因此,为解决细菌多重耐药性问题,研发外排泵抑制剂势在必行。鉴于此,本研究对细菌外排泵的功能和抑制机制进行综述,以期为临床合理用药及医院感染防控提供帮助与指导。

关键词：外排泵革兰氏阴性菌革兰氏阳性菌外排泵抑制剂

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Comparison of Lubricities of Two Novel Benzotriazole Derivatives Used as Additives in Water-Glycol Hydraulic Fluid

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China Petroleum Processing & Petrochemical Technology 2018年第3期20卷 114-124页

作者： Zheng Zhe Wang jianhua fang jianhua Jiang Zeqi Gu Kecheng Department of Oil Army Logistics University of PLA Chongqing 401311 No. 92228 Unit of PLA Beijing 100072 College of Pharmacy Army Medical University Chongqing 400038

Two kinds of benzotriazole derivatives with and without sulfur(abbreviated as BSC and BC, respectively,) were synthesized and their lubricating, anticorrosion and antirust properties were investigated, when they were used as additives in the water-glycol fluid. The morphology and chemical species of typical elements on the worn surface were examined by the scanning electron microscopy(SEM), the energy dispersive spectrometry(EDS), and the X-ray photoelectron spectroscopy(XPS) in order to reveal the tribological mechanisms. The results indicated that two synthesized additives could effectively improve the anti-wear, friction-reducing, load-carrying, anticorrosion, and antirust properties of the base fluid. The surface analysis illustrated that stable nitrogen-containing absorption films generated by BC should be responsible for its facilitated anti-wear and friction-reducing performance, and the excellent lubricities of BSC should be attributed to the combined action of adsorption film and tribo-chemical film which were composed of iron oxides, iron sulfides and iron sulfates. The superior lubricating properties of BSC as compared to that of BC demonstrated the effectiveness of elemental sulfur in reducing friction and wear, especially under high loads. But corrosion wear is more obvious at a relative high concentration of elemental sulfur.

关键词：水乙二醇添加剂衍生物润滑液体扫描电子显微镜水力同步通信

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Boosted Biodegradability and Tribological Properties of Mineral Base Oil by Methyl Diethanolamine Fatty Acid Esters

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China Petroleum Processing & Petrochemical Technology 2018年第4期20卷 117-124页

作者： Ding jianhua fang jianhua Chen Boshui Zhang Nan Fan Xingyu Zheng Zhe Department of Oil Army Logistics University

Methyl diethanolamine fatty acid esters, viz. methyl diethanolamine octanoate and methyl diethanolamine oleate,were prepared. Their impacts on the biodegradability and tribological properties of mineral base oil 400 SN were evaluated by a tester for fast evaluating the biodegradability of lubricants and by a four-ball tester, respectively. The results showed that methyl diethanolamine octanoate and methyl diethanolamine oleate both could markedly promote the biodegradation of the oil and improved its tribological properties. The improvement of biodegradability was attributed to the enhanced growth and quantity of microbes by methyl diethanolamine fatty acid esters. The worn surfaces were analyzed by a scanning electron microscope(SEM) equipped with an energy dispersive spectrometer(EDS) and an X-ray photoelectron spectroscope(XPS). The results indicated that the enhancement of friction-reducing and anti-wear properties of the mineral oil was attributed to the formation of complicated boundary lubrication films composed of species such as Fe_2O_3, Fe_3O_4 and organic nitrogen-containing compounds with a structure of –C-N-or R-NH_2.

关键词： biodegradation wear friction methyl diethanolamine fatty acid esters

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Effect of Oleic Acid Tris-(2-hydroxyethyl) isocyanurate Phosphate Ester on Biodegradability and Tribological Performance of Mineral Lubricating Oil

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China Petroleum Processing & Petrochemical Technology 2018年第2期20卷 97-103页

作者： Ding jianhua fang jianhua Chen Boshui Zhang Nan Fan Xingyu Zheng Zhe Department of Oil Army Logistics University

The oil solubility of synthetic oleic acid tris-(2-hydroxyethyl) isocyanurate phosphate ester(abbreviated as OHTP hereinafter) and its influence on the biodegradability and tribological performance of 400 SN mineral oil were investigated on a tester and a four-ball tribotester,respectively,for fast evaluating the biodegradability of ***,the morphologies and tribochemical species of the worn surfaces lubricated by OHTP-doped oil were studied by scanning electron microscope(SEM) and X-ray photoelectron spectroscope(XPS).The results indicated that OHTP possessed good oil solubility and could improve obviously the biodegradability,the extreme pressure properties,the anti-wear properties and friction-reducing properties of the 400 SN mineral *** analytical results of XPS spectra showed that the composite boundary lubrication films were mainly composed of absorbed films and tribochemical species such as FePO-4,Fe_3(PO_4)_2,Fe_2O_3 and Fe_3O_4,which contributed to improving the tribological performances.

关键词：矿物质磷酸盐性能润滑油扫描电子显微镜 X光检查溶解度形态学

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Biodegradability and Tribological Properties of Mineral Base Oil Enhanced by Caprylic Methyl Diethanolamine Phosphate Ester

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China Petroleum Processing & Petrochemical Technology 2019年第2期21卷 103-109页

作者： Ding jianhua fang jianhua Chen Boshui Liu Ping Fan Xingyu Chen Ran Department of Oil Army Logistics University Chongqing 401311 Military Representative Office in PetroChina Dalian Petrochemical Company Dalian 116033

The influence of synthetic caprylic methyl diethanolamine phosphate ester (abbreviated as MDEACP) on biodegradability and tribological properties of 400SN mineral base oil was studied. The biodegradability of the neat base oil and the oil doped with MDEACP was determined on a biodegradation tester. The tribological properties of the neat base oil and the oil doped with MDEACP were evaluated on a four-ball tester. Moreover, the worn surfaces were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results revealed that MDEACP significantly promoted the biodegradation of the mineral base oil. The improvement in biodegradability was attributed to the enhanced growth and quantity of microbes by MDEACP. Furthermore, MDEACP enhanced the anti-wear properties, the friction-reducing properties, and the extreme pressure properties of the base oil. It was mainly attributed to the formation of the complex boundary lubrication film resulted from the adsorption and tribochemical reactions of MDEACP on the friction surface.

关键词： additive biodegradability friction wear extreme pressure properties

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COMPUTATIONAL FLUID DYNAMICS RESEARCH ON PRESSURE LOSS OF CROSS-FLOW PERFORATED MUFFLER

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Chinese Journal of Mechanical Engineering 2007年第2期20卷 88-93页

作者： HU Xiaodong ZHOU Yiqi fang jianhua MAN Xiliang ZHAO Zhengxu School of Mechanical Engineering Shandong University Jinan 250061 China Shandong Construction Machinery Group Co.Ltd Jinan 250100 China School of Computing Derby UniversityDerby DE22 1GB UK

The pressure loss of cross-flow perforated of physical modeling, simulation and data processing. muffler has been computed with the procedure Three-dimensional computational fluid dynamics （CFD） has been used to investigate the relations of porosities, flow velocity and diameter of the holes with the pressure loss. Accordingly, some preliminary results have been obtained that pressure loss increases with porosity descent as nearly a hyperbolic trend, rising flow velocity of the input makes the pressure loss increasing with parabola trend, diameter of holes affects little about pressure loss of the muffler. Otherwise, the holes on the perforated pipes make the air flow gently and meanly, which decreases the air impact to the wall and pipes in the muffler. A practical perforated muffler is used to illustrate the available of this method for pressure loss computation, and the comparison shows that the computation results with the method of CFD has reference value for muffler design.

关键词： Perforated muffler Pressure loss Computational fluid dynamics (CFD) Porosity Flow velocity

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Spectroscopic Analysis of Structural Transformation in Biodiesel Oxidation

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China Petroleum Processing & Petrochemical Technology 2013年第3期15卷 28-32页

作者： Wu Jiang Chen Boshui fang jianhua Wang Jiu Department of Petrochemistry Logistical Engineering University

The oxidation behavior of three biodiesels of different origins,*** oil derived biodiesel,soybean oil derived biodiesel and waste oil based biodiesel,were tested on an oxidation *** chemical compositions of the biodiesels were characterized by gas ***,the structural transformation of fatty acid methyl ester(FAME)of the biodiesels was analyzed by an infrared spectrometer and an ultraviolet absorption *** results demonstrated that the oxidation behavior of biodiesels of different origins was closely related to the composition and distribution of *** concentration of unsaturated FAME with multi-double bonds exhibited poorer oxidation ***,cis-trans isomerization transformation occurred in the unsaturated FAME molecules and conjugated double-bond produced during the oxidation process of *** cis-trans variations corresponded to deeper oxidation *** higher the content of unsaturated FAME with multi-double bonds in a biodiesel,the more the conjugated double bonds was formed.

关键词：生物柴油氧化行为结构转变光谱分析脂肪酸甲酯共轭双键化学组合物气相色谱法

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Pyrolysis Characteristics and Kinetics of Methyl Oleate Based on TG-FTIR Method

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China Petroleum Processing & Petrochemical Technology 2015年第2期17卷 17-25页

作者： Wang Xuechun fang jianhua Chen Boshui Wang Jiu Wu Jiang Department of Military Oil Application & Administration Engineering Logistical Engineering University

The thermal decomposition characteristics of methyl oleate were preliminarily investigated under nitrogen atmosphere by a thermogravimetric analyzer when the ester was heated at a heating rate of 10 ℃/min from room temperature to 600 ℃. Furthermore, the pyrolytic and kinetic characteristics of methyl oleate were intensively studied at different heating rates. The gaseous species obtained during thermal decomposition were also identified by the TG-FTIR coupling analysis. The results showed that the pyrolysis of methyl oleate proceeded in three stages, viz. the drying stage, the main pyrolysis stage and the residual pyrolysis stage. The initial decomposition temperature, the maximum weight loss temperature, the peak decomposition temperature and the rate of maximum weight loss of methyl oleate increased with the increasing heating rates. Gaseous CO, CO2 and H2 O were the typical decomposition products from pyrolysis of methyl oleate. In addition, a kinetic model for thermal decomposition of methyl oleate was built up based on the experimental results using the CoatsRedfern integral method and the multiple-linear regression method. The activation energy, the pre-exponential factor, the reaction order and the kinetic equation for thermal decomposition of methyl oleate were obtained. Comparison of the experimental data with the calculated ones and analysis of statistical errors of pyrolysis ratios demonstrated that the kinetic model was reliable for studying the pyrolysis of methyl oleate. Finally, the kinetic compensation effect between the preexponential factors and the activation energy in the pyrolysis of methyl oleate was also confirmed.

关键词：热解动力学模型油酸甲酯热解特性 IR方法酯基热分解特性多元线性回归方法 TG-FTIR

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