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Chemical Research in Chinese Universities 2013年第1期29卷 95-98页

作者： wang zhi-yuan LIU jun-zhong XU Li-sheng ZHANG Hong-juan LIU Qian JIAO Qing-cai State Key Laboratory of Pharmaceutical Biotechnology School of Life Science Nanjing University Nanjing 210093 P. R. China

Alkoxy-L-serines are useful for peptide syntheses. The demand for alkoxy-L-serines in the pharmaceutical industries continues to increase because of their multiple physiological effects. In this research, an improved method for alkoxy-L-serines synthesis is reported. A series of substrates, DL-fl-alkoxy-a-amino propionamides, was used for the synthesis of alkoxy-serines catalyzed by Escherichia coli cells with peptidase B（PepB） activity. The results show that PepB has a high resolution activity with DL-fl-alkoxy-a-amino propionamides as substrate. Reaction conditions were optimized, i.e., DL-β-methoxy-a-amino propionamide as substrate at pH=9.0, 40 ℃ and 14 h, and the optimal reaction concentration is 400 mmol/L. The results also show that divalent metal cations exhibit different effects on the PepB activity, for example, Zn2＋ and Cu2＋ can obviously inhibit the activity of PepB, whereas Co2＋, Ca2＋, Mn〉 and Mg2＋ at low concentrations can activate PepB. This research provides access to enantiomerically enriched and valuable alkoxy-L-serines from a simple amino-amide racemate.

关键词： Alkoxy-serine DL-β-Alkoxy-a-amino propionamide Enzymatic resolution Peptidase B

Reinforcement of High Impact Polystyrene by Aramid Nanoparticle Fillers Prepared via an In situ Bottom-up Approach

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Chinese Journal of Polymer Science 2024年第8期42卷 1167-1176页

作者： Xiang-jun Gong zhi-Ping Zhao Chang-Mei Sun Ying Zhang Rong-jun Qu Ying wang School of Chemistry and Materials Science Ludong UniversityYantai 264025China

In this work,aramid nanoparticles(ANPs)were prepared in dimethyl formamide(DMF)solution containing high impact polystyrene(HIPS)via a bottom-up *** electron microscopy(TEM)images showed that the obtained ANPs were evenly distributed in the HIPS matrix without any *** composition of the ANPs,i.e.,poly(p-phenyl-p-phenylenediamine)(PPTA),was confirmed by Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and X-ray diffractometer(XRD).The ANP/HIPS composites,obtained after ethanol precipitation,were added to neat HIPS as fillers to fabricate ANP/HIPS composite *** surface roughness and the glass transition temperature(T_g)of the sheets were characterized by atomic force microscope(AFM)and differential scanning calorimetry(DSC),*** with neat HIPS,the mechanical properties of the composite sheet were significantly improved,and the Young's modulus increased from 246.55 MPa to 2025.12 MPa,the tensile strength increased from 3.07 MPa to 29.76 MPa,and the toughness increased from 0.32 N/mm^2 to 3.92 N/mm^2,with an increase rate of 721%,869%and 1125%,***,the thermal stability of the composites improved with the increase in ANP content.

关键词： High impact polystyrene PPTA nanoparticle Reinforce Mechanical property

Interpretation and characterization of rate of penetration intelligent prediction model

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Petroleum Science 2024年第1期21卷 582-596页

作者： zhi-jun Pei Xian-zhi Song Hai-Tao wang Yi-Qi Shi Shou-Ceng Tian Gen-Sheng Li College of Petroleum Engineering China University of Petroleum(Beijing)Beijing102249China State Key Laboratory of Petroleum Resources and Prospecting Beijing102249China Kunlun Digital Technology Co. Ltd.Beijing102206China

Accurate prediction of the rate of penetration(ROP)is significant for drilling *** the intelligent ROP prediction model based on fully connected neural networks(FNN)outperforms traditional ROP equations and machine learning algorithms,its lack of interpretability undermines its *** study proposes a novel interpretation and characterization method for the FNN ROP prediction model using the Rectified Linear Unit(ReLU)activation *** leveraging the derivative of the ReLU function,the FNN function calculation process is transformed into vector *** FNN model is linearly characterized through further simplification,enabling its interpretation and *** proposed method is applied in ROP prediction scenarios using drilling data from three vertical wells in the Tarim *** results demonstrate that the FNN ROP prediction model with ReLU as the activation function performs exceptionally *** relative activation frequency curve of hidden layer neurons aids in analyzing the overfitting of the FNN ROP model and determining drilling data *** the well sections with similar drilling data,averaging the weight parameters enables linear characterization of the FNN ROP prediction model,leading to the establishment of a corresponding linear representation ***,the quantitative analysis of each feature's influence on ROP facilitates the proposal of drilling parameter optimization schemes for the current well *** established linear characterization equation exhibits high precision,strong stability,and adaptability through the application and validation across multiple well sections.

关键词： Fully connected neural network Explainable artificial intelligence Rate of penetration ReLU active function Deep learning Machine learning

隐丹参酮通过调节SDF-1/CXCR4信号通路保护人骨髓间充质干细胞免受过氧化氢诱导的细胞凋亡

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现代生物医学进展 2024年第14期24卷 2639-2644,2665页

作者：李华侯春霞王俊芝刘玉强肖克源长治医学院附属医院/长治市人民医院药剂科山西长治046000 长治医学院附属医院/长治市人民医院中心实验室山西长治046000

目的:探讨隐丹参酮调节基质细胞衍生因子-1(SDF-1)/C-X-C型趋化因子受体4(CXCR4)信号通路抑制过氧化氢诱导的人骨髓间充质干细胞(BMSC)凋亡的作用机制。方法:体外培养人骨髓间充质干细胞(HBMSC),利用H2O2建立氧化应激模型。将HBMSC细胞... 详细信息

目的:探讨隐丹参酮调节基质细胞衍生因子-1(SDF-1)/C-X-C型趋化因子受体4(CXCR4)信号通路抑制过氧化氢诱导的人骨髓间充质干细胞(BMSC)凋亡的作用机制。方法:体外培养人骨髓间充质干细胞(HBMSC),利用H2O2建立氧化应激模型。将HBMSC细胞分为对照组(不进行氧化应激诱导)、模型组(500μmol/L H2O2诱导24 h)、隐丹参酮低剂量组(10μmol/L)、隐丹参酮中剂量组(20μmol/L)、隐丹参酮高剂量组(40μmol/L)。细胞计数试剂盒(CCK-8)检测细胞活性;流式细胞术检测细胞凋亡;酶联免疫吸附法(Elisa)检测细胞葡萄糖摄取量和乳酸水平;微量法检测细胞中谷胱甘肽(GSH)、超氧化物歧化酶(SOD)、丙二醛(MDA)含量;蛋白质印迹法(Western blot)检测细胞中半胱氨酸天冬氨酸蛋白酶3(caspase-3)、B淋巴细胞瘤-2相关X蛋白(Bax)、B淋巴细胞瘤-2(Bcl-2)、SDF-1、CXCR4蛋白表达情况。结果:与对照组比较,模型组HBMSC细胞葡萄糖摄取量和乳酸水平、GSH、SOD活性、Bcl-2蛋白表达、SDF-1/CXCR4信号通路蛋白表达下降,细胞凋亡率、凋亡蛋白caspase-3、Bax表达、MDA含量上升(P<0.05);与模型组比较,隐丹参酮低、中、高剂量组HBMSC细胞葡萄糖摄取量和乳酸水平、GSH、SOD活性、Bcl-2蛋白表达、SDF-1/CXCR4信号通路蛋白表达上升,细胞凋亡率、凋亡蛋白caspase-3、Bax表达、MDA含量下降(P<0.05),且隐丹参酮低、中、高剂量组各指标差异具有统计学意义(P<0.05)。结论:隐丹参酮可能通过促进SDF-1/CXCR4信号通路转导,抑制过氧化氢诱导的BMSC氧化应激损伤,抑制其凋亡,其中高剂量隐丹参酮的效果最好。

关键词：隐丹参酮人骨髓间充质干细胞 SDF-1/CXCR4信号通路氧化应激细胞凋亡

品种和生育期对紫花苜蓿的生产性能、营养品质和矿物质元素的影响

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饲料研究 2024年第10期47卷 105-112页

作者：王志军包健丁霞马唯钦赵牧其尔马宏伟贾玉山格根图内蒙古农业大学草原与资源环境学院/农业农村部饲草栽培、加工与高效利用重点实验室内蒙古呼和浩特010020 内蒙古农业大学沙漠治理学院内蒙古呼和浩特010020 内蒙古正时生态农业(集团)有限公司内蒙古呼和浩特010020

试验分析品种和生育期对紫花苜蓿的生产性能、营养品质和矿物质元素的影响,从而确定赤峰地区高产优质的紫花苜蓿品种及最适生育期。研究以7个引进的紫花苜蓿品种作为研究材料,比较7个品种的现蕾期、初花期和盛花期的生产性能和营养品质... 详细信息

试验分析品种和生育期对紫花苜蓿的生产性能、营养品质和矿物质元素的影响,从而确定赤峰地区高产优质的紫花苜蓿品种及最适生育期。研究以7个引进的紫花苜蓿品种作为研究材料,比较7个品种的现蕾期、初花期和盛花期的生产性能和营养品质的差异。结果表明:随着生育期的推进,株高呈现增加趋势,盛花期的株高显著高于现蕾期和初花期(P0.05)。现蕾期,54V09品种的Ca、Mg、S元素的含量最高,55V12品种的P、K元素的含量最高。通过分析3个生育期的7个品种各指标的均值,并利用隶属函数法进行综合评价,得出现蕾期品质最佳。不同紫花苜蓿品种的营养品质排名依次为:54V09>55V12>WL168>三得利=猎人河>金皇后=阿尔岗金。研究表明,在赤峰阿鲁科尔沁地区,现蕾期收获可以获得高产优质的饲料,54V09和55V12品种适合在赤峰地区推广种植。

关键词：紫花苜蓿品种生育期生产性能营养品质矿物质元素

Luminescence and Site Occupancy of Eu2＋ in Ba2 Ca（BO3）2

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Chinese Physics Letters 2011年第1期28卷 190-192页

作者： LI Pan-Lai wang zhi-jun YANG zhi-Ping GUO Qing-Lin Colleg-e of Physics Science and Technology Hebei University Baoding 071002

A green phosphor Ba2Ca（BOa）2：Eu2＋ was syntheMzed by a high temperature solid-state reaction method under a reductive amosphere,, The luminescence and site occupancy of Eu2＋ in Ba2Ca（BOa）2 are investigated. Ba2Ca（BO3）2：Eu2＋ shows one green band （537nzn） under 400nln near ultraviolet excitation which is suitable for UV LED. Ca2＋ and Ba2＋ ions in Ba2Ca（BO3）2 are replaced by Eu2＋ ions, the Ba2Ca（BO3）2：Eu2＋ shows a dissymmetrical emission band. The influence of Eu2＋ doping concentrations on the emission intensity of Ba2Ca（BOa）2：Eu2＋ is studied. It is found that the emission intensity is influenced by the Eu2＋ concentration and reaches the maxinmm value at 2% Eu2＋, According to the Dexter theory, the concentration quenching mechanisms of Eu2＋ in Ba2 Ca（B03）2 are the d - d interaction,

关键词：

2D–3D dual carbon layer confined ultrasmall VN nanoparticles for improving lithium-ion storage in hybrid capacitors

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Rare Metals 2024年第1期43卷 65-75页

作者： Zhao-Wei Hu Hui-Fang Li Peng wang Wan-Li wang Lei Yang Xiao-jun wang zhi-Ming Liu College of Electromechanical Engineering Shandong Engineering Laboratory for Preparation and Application of High-Performance Carbon-MaterialsQingdao University of Science&TechnologyQingdao 266061China Research Center for Intelligent and Wearable Technology College of Textiles and ClothingQingdao UniversityQingdao 266071China

Lithium-ion capacitors(LICs) of achieving high power and energy density have garnered significant attention. However, the kinetics unbalance between anode and cathode can impede the application of LICs. Vanadium nitride(VN) with a high theoretical specific capacity(~ 1200 m Ah·g^(-1)) is a better pseudocapacitive anode to match the response of cathode in LICs. However, the insertion/extraction of Li-ions in VN's operation results in significant volume expansion. Herein, the VN/N-r GO-5composite that three-dimentional(3D) dicyandiamidederived-carbon(DDC) tightly wrapped VN quantum dots(VN QDTs) on two-dimentional(2D) reduced graphene oxid(r GO) was prepared by a facile strategy. The VN QDTs can reduce ion diffusion length and improve charge transfer kinetics. The 2D r GO as a template provides support for nanoparticle dispersion and improves electrical conductivity. The 3D DDC tightly encapsulated with VN QDTs mitigates agglomeration of VN particles as well as volume expansion. Correspondingly, the LICs with VN/Nr GO-5 composite as anode and activated carbon(AC) as cathode were fabricated, which exhibits a high energy density and power density. Such strategy provides a perspective for improving the electrochemical properties of LIC anode materials by suppressing volume expansion and enhancing conductivity.

关键词： Vanadium nitride(VN)quantum dots Reduced graphene oxide(rGO)nanosheets Dicyandiamide-derived-carbon 2D–3D dual carbon layer Lithium-ion capacitors

The occurrence characteristics of oil in shales matrix from organic geochemical screening data and pore structure properties:An experimental study Author links open overlay panel

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Petroleum Science 2024年第1期21卷 1-13页

作者： Zi-zhi Lin jun-Qian Li Shuang-Fang Lu Qin-Hong Hu Peng-Fei Zhang jun-Jie wang Qi zhi Hong-Sheng Huang Na Yin Yue wang Tian-Chen Ge National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao 266580ShandongChina School of Geosciences China University of Petroleum(East China)Qingdao 266580ShandongChina Sanya Offshore Oil&Gas Research Institute Northeast Petroleum UniversitySanya 572025HainanChina College of Earth Science and Engineering Shandong University of Science and TechnologyQingdao 266590ShandongChina

The occurrence characteristics of shale oil are of great significance to the movability of shale *** this study,the occurrence characteristics of oil in the shale matrix at Funing Formation shale in Subei Basin were quantitatively evaluated by organic geochemistry and microscopic pore structure characterization *** Multiple Isothermal Stages Pyrolysis(MIS)experiment results show that the content of total oil,adsorbed oil,and free oil in the shales are 3.15-11.25 mg/g,1.41-4.95 mg/g,and 1.74-6.51 mg/g,*** which the silicon-rich shale has the best *** relative content of free oil shows an increasing trend in pores with pore diameters greater than 3 *** the relative content of free oil reaches 100%,the pore size of silicon-rich shale is about 200 nm,while that of calcium-rich shale,clay-rich shale,and siliceous mixed shale is about 10 *** occurrence law of adsorbed oil is opposite to that of free oil,which indicates that shale oil will occur in the pores and fractures in a free state in a more extensive pore size range(>200 nm).This study also enables us to further understand the occurrence characteristics of shale oil under the interaction of occurrence state and occurrence space.

关键词： Shale oil Occurrence characteristics Sequential solvent extraction Low-temperature nitrogen adsorption Funing Formation Dongtai Depression

产科护士围产期姑息照护知信行量表的编制及信效度检验

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护理学报 2024年第2期31卷 6-11页

作者：张国春李海云褚梁梁程雪王君芝山东第一医科大学第一附属医院护理部山东济南250014

目的编制适合我国文化背景的产科护士围产期姑息照护知信行量表,检验量表信效度。方法根据知信行理论,依据文献及德尔菲专家函询编制量表初稿,调查604名产科护士以检验量表的信效度,形成正式版量表。结果产科护士围产期姑息照护知信行... 详细信息

目的编制适合我国文化背景的产科护士围产期姑息照护知信行量表,检验量表信效度。方法根据知信行理论,依据文献及德尔菲专家函询编制量表初稿,调查604名产科护士以检验量表的信效度,形成正式版量表。结果产科护士围产期姑息照护知信行量表包括3个维度,11个因子,共51个条目;量表总体Cronbachα系数是0.959,重测信度Cronbachα系数是0.976,内容效度是0.980;探索性因子分析提取11个公因子,累积方差贡献率为87.745%,验证性因子分析显示,量表模型拟合度良好。结论产科护士围产期姑息照护知信行量表具有良好的信度和效度,并有一定的推广价值,可作为评估量表应用于临床实践。

关键词：围产期姑息照护德尔菲法知信行量表信度效度

Oxidation resistant low-alloyed Ti alloys with good ductility

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Rare Metals 2024年第8期43卷 3921-3936页

作者： Meng Li Zhang-zhi Shi jun-Yi Xu Fu-zhi Dai Xiang-Min Li Zi-Lin Li Lu-Ning wang Beijing Advanced Innovation Center for Materials Genome Engineering State Key Laboratory for Advance Metals and MaterialsSchool of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijingBeijing 100083China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004China

Oxidation resistance enhancement of pure Ti often comes at the cost of reduced ductility,which is frequently the problem through alloying with sole Al,Si,W,Mo and *** overcome the short coming of single element alloying,this paper proposes a multi-element low-alloying strategy to take advantage of synergistic effects and resolve the conflict between oxidation resistance and *** demonstrates that the addition of a small quantity of Ta(0.51wt%)can boost both oxidation resistance and ductility in comparison to pure ***,the combined addition of a small amount(0.54 wt%)of Ta,Nb and Si not only preserves good ductility of pure Ti,but also reduces mass gains to 14%-67%of pure Ti during 100 h oxidation at 650-850℃in *** indicates even better oxidation resistance than that obtained through the use of Ta,Nb,or Nb+Ta *** Ta+Nb+Si alloying creates an oxide layer that is less porous and more resistant to stratification and ***,a 3-μm N-rich layer can form in the Ti substrate beneath the oxide scale,in which phase transformation generates coherent Ti_(2)N with(0001)_(Ti)as the habit plane,with N atoms prefers to diffuse along■than along[0001]_(Ti).The completely transformed Ti_(2)N region or partially transformed Ti+Ti_(2)N region can effectively impede oxygen ***,the multielement low-alloying strategy is promising for enhancing both oxidation resistance and mechanical properties of metallic materials in the future.

关键词： Ti alloys Multi-element Co-alloying Oxidation resistance Mechanical properties