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Properties and structure of a new non-reactive mold flux for high-Al steel

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Journal of Iron and Steel Research International 2022年第1期29卷 61-70页

作者： Yang Chen Sheng-ping he Zhi-rong Li Xu-bin Zhang qiang-qiang Wang Qian Wang College of Materials Science and Engineering Chongqing Key Laboratory of Vanadium–Titanium Metallurgy and Advanced MaterialsChongqing UniversityChongqing 400044China

During the conventional continuous casting process of high-aluminum steels(w([Al])>0.5 wt.%),some components of slag,such as SiO_(2),B_(2)O_(3),and TiO_(2),could be reduced by aluminum in molten ***,the CaO-BaO-Al_(2)O_(3)-Caf2-Li2O non-reactive mold fluxes were designed using the simplex grid method and molecular dynamics to mitigate the slag-metal interface reaction and stabilize the performance of mold *** results show that the components of nonreactive quinary system are 20-40 wt.% CaO,14-34 wt.% BaO,14-34 wt.% Al_(2)O_(3),4-12 wt.% f,and 4-8 wt.% Li_(2)*** dynamics simulation results show that[AlO_(4)]-tetrahedron acts as network formers and melt network structure is mainly chain and lamellar in the low-viscosity *** cross sections of w(f)=8 wt.%,w(Li_(2)O)=8 wt.%and w(f)=12 wt.%,w(Li2O)=8 wt.% are important reference sections for the design of mold flux,with the compositions of 22-40 wt.%CaO,14-34 wt.% BaO,20-34 wt.%Al_(2)O_(3) and 23-40 wt.%CaO,14-34 wt.%BaO,20-28 wt.% Al_(2)O_(3),respectively.

关键词： Lightweight steel Non-reactive mold flux Molecular dynamics Viscosity Simplex grid method

WAVELET ANALYSIS Of MULTIfRACTAL AND ITS APPLICATION TO PROCESSING TEMPERATURE DATA IN RAYLEIGh-BENARD CONVECTION

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Journal of hydrodynamics 2001年第4期13卷 34-41页

作者： fu, qiang Xia, Ke-Qing Div. of Appl. Mech. Inst. of Sci. Univ. of Sci. and Technol. of PLA Nanjing 211101 China

Wavelet transform was firstly used to analyze te singularity of a given signal, and then with the method of wavelet transform modulus maximum(WTMM), the characters of fractal set of triadic Cantor was studied. The results show that one can, not only determine the position of singular of signal, but also estimate the holder exponent h which describes the strength of singularity and other parameters, such as D(h) and τ(q) correctly. finally, after applying this method to process temperature data in the Rayleigh-Benard convection further, we found that the multifractal hierarchical and multi-scale structure underlying this flow could be entirely revealed from the parameters h, D(h) and τ(q), and the obtained results agree well with the ones determined from the viewpoint of fractal measures.

关键词： heat convection Wavelet transforms

L-shell x-ray fluorescence relative intensities for elements with 62≤Z≤83 at 18 keV and 23 keV by synchrotron radiation

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Chinese Physics B 2023年第8期32卷 270-273页

作者： M Alqadi S AL-humaidi h Alkhateeb f Alzoubi Department of Physics Jordan University of Science and TechnologyIrbidJordan

The relative intensities of L-subshell x-ray fluorescence(XRf)for elements with atomic numbers 62≤Z≤83 were measured at two excitation energies,18 keV and 23 keV,using a synchrotron radiation source at a beamline of the Synchrotron Light Center for Experimental Science and Applications in the Middle East(SESAME),*** experimentally measured results of the relative intensities were compared with the calculated results using the subshell fluorescence yield and the Coster-Kronig transition probabilities recommended by Campbell and the values based on the Dirac-hartree-Slater model by *** experimental and theoretical results are in *** this work,L XRf relative intensities for the elements Sm,Gd,Tb,Er,Ta,W,Re,hg,Pb and Bi at energies of 18 keV and 23 keV were measured.

关键词： L shell x-ray fluorescence(XRf) relative intensities synchrotron radiation

Steroids hydroxylation catalyzed by the monooxygenase mutant 139-3 from Bacillus megaterium BM3

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Acta Pharmaceutica Sinica B 2017年第4期7卷 510-516页

作者： Xing Liu Jian-qiang Kong State Key Laboratory of Bioactive Substance and function of Natural Medicines&Ministry of health Key Laboratory of Biosynthesis of Natural Products Institute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050China

The search of new substrates with pharmaceutical and industrial potential for biocatalysts including cytochrome P450 enzymes is always challenging. Cytochrome P450 BM3 mutant 139-3, a versatile biocatalyst, exhibited hydroxylation activities towards fatty acids and alkanes. however, there were limited reports about its hydroxylation activity towards steroids. herein, an Escherichia coli-based whole-cell extract containing the recombinant 139-3 protein was used as the biocatalyst to screen 13 steroids. Results revealed that 139-3 was able to specifically hydroxylate androstenedione (1) at 1α-position, generating a hydroxylated steroid 1α-Oh-androstenedione (1a). To investigate whether C-1α hydroxylation catalyzed by BM3 mutant 139-3 could be industrially used, an optimization of catalyzing conditions was performed. Accordingly, the BM3 mutant 139-3 enzyme was observed to display maximum activity at 37 °C, under ph 7.0 for 4 h, with 37% transformation rate. Moreover, four 139-3 variants were generated by random mutagenesis with the aim of improving its activity and expanding substrate scope. Surprisingly, these mutants, sharing a common mutated site R379S, lost their activities towards androstenedione (1). These data clearly indicated that arginine residue located at site 379 played key role in the hydroxylation activities of 139-3. Overall, these new findings broadened the substrate scope of 139-3 enzyme, thereby expanding its potential applications as a biocatalyst on steroids hydroxylation in pharmaceutical industry.

关键词： Cytochrome P450 BM3 139-3 Steroids hydroxylation 1α-Oh-androstenedione Biocatalyst

刺芒柄花素对白细胞介素1β诱导软骨细胞损伤影响的机制

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中国组织工程研究 2025年第12期29卷 2484-2491页

作者：单继新叶锐彬巨少华王强成都体育学院附属体育医院正骨科四川省成都市610041

背景:刺芒柄花素是一种异黄酮类化合物,广泛存在于红车轴草、黄芪、鸡血藤中,具有抑制氧化应激、炎症因子释放及细胞凋亡的作用。目的:探讨刺芒柄花素对白细胞介素1β诱导软骨细胞损伤的影响及机制。方法:①收集骨关节炎患者及单纯半月... 详细信息

背景:刺芒柄花素是一种异黄酮类化合物,广泛存在于红车轴草、黄芪、鸡血藤中,具有抑制氧化应激、炎症因子释放及细胞凋亡的作用。目的:探讨刺芒柄花素对白细胞介素1β诱导软骨细胞损伤的影响及机制。方法:①收集骨关节炎患者及单纯半月板损伤患者的软骨组织,采用实时定量PCR检测miR-135b-5p表达。②体外培养人软骨细胞,分9组培养:正常对照组不进行任何处理,培养48 h;白细胞介素1β组加入白细胞介素1β处理48 h;白细胞介素1β+刺芒柄花素低浓度组加入25μmol/L刺芒柄花素处理24 h后加入白细胞介素1β处理48 h;白细胞介素1β+刺芒柄花素中浓度组加入50μmol/L刺芒柄花素处理24 h后加入白细胞介素1β处理48 h;白细胞介素1β+刺芒柄花素高浓度组加入100μmol/L刺芒柄花素处理24 h后加入白细胞介素1β处理48 h;白细胞介素1β+miR NC组转染miR NC 6 h后加入白细胞介素1β处理48 h;白细胞介素1β+miR-135b-5p组转染miR-135b-5p模拟物6 h后加入白细胞介素1β处理48 h;白细胞介素1β+刺芒柄花素高浓度+anti-miR-NC组转染anti-miR-NC 6 h后加入100μmol/L刺芒柄花素处理24 h,再加入白细胞介素1β处理48 h;白细胞介素1β+刺芒柄花素高浓度+anti-miR-135b-5p组转染anti-miR-135b-5p 6 h后加入100μmol/L刺芒柄花素处理24 h,再加入白细胞介素1β处理48 h。处理结束后进行相关检测。结果与结论:①骨关节炎患者软骨组织中miR-135b-5p表达低于单纯半月板损伤患者(P<0.05)。②与正常对照组比较,白细胞介素1β组软骨细胞miR-135b-5p表达、增殖活力、超氧化物歧化酶活性、Ⅱ型胶原蛋白、Bcl-2蛋白表达均降低(P<0.05),细胞凋亡率、乳酸脱氢酶活性、丙二醛水平、促炎因子水平、基质金属蛋白酶13蛋白、Bax蛋白表达均升高(P<0.05);刺芒柄花素可抑制白细胞介素1β对软骨细胞造成的损伤,并且呈现浓度依赖性。转染miR-135b-5p模拟物可提升白细胞介素1β组miR-135b-5p表达,抑制白细胞介素1β对软骨细胞造成的损伤;转染anti-miR-135b-5p可降低白细胞介素1β+刺芒柄花素高浓度组miR-135b-5p表达,抑制刺芒柄花素发挥软骨细胞作用。③结果表明,刺芒柄花素对白细胞介素1β诱导软骨细胞损伤的保护作用可能与调控miR-135b-5p表达有关。

关键词：刺芒柄花素 miR-135b-5p 软骨细胞氧化应激炎症细胞增殖细胞凋亡

Poisson rectangular pulse(PRP)model establishment based on uncertainty analysis of urban residential water consumption patterns

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Environmental Science and Ecotechnology 2024年第2期18卷 53-59页

作者： Jiaxin Zhang Dragan Savic qiang Xu Kuo Liu Zhimin qiang Key Laboratory of Drinking Water Science and Technology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing100085China University of Chinese Academy of Sciences Beijing100049China KWR Water Research Institute Nieuwegein3430BBthe Netherlands Centre for Water Systems University of ExeterExeterEX44QFUnited Kingdom faculty of Civil Engineering University of Belgrade11000BelgradeSerbia Beijing Waterworks Group Co.Ltd Beijing100031China

The commonly used Poisson rectangular pulse(PRP)model,employed for simulating high-resolution residential water consumption patterns(RWCPs),relies on calibration via medium-resolution RWCPs obtained from practical *** introduces inevitable uncertainty stemming from the measured RWCPs,which consequently impacts the precision of model *** we enhance the accuracy of the PRP model by addressing the uncertainty of *** established a critical sampling size of 2000 household water consumption patterns(hWCPs)with a data logging interval(DLI)of 15 min to attain dependable *** Genetic Algorithm calibration,the optimal values of the PRP model's parameters were determined:pulse frequency lλ=91 d^(-1),mean of pulse intensity E(I)=0.346 m^(3) h^(-1),standard deviation of pulse intensity STD(I)=0.292 m^(3) h^(-1),mean of pulse duration E(D)=40 s,and standard deviation of pulse duration STD(D)=55 ***,validation was conducted at both hWCP and RWCP *** recommend a sampling size of2000 hWCPs and a DLI of30 min for PRP model calibration to balance simulation precision and practical *** study significantly advances the theoretical foundation and real-world application of the PRP model,enhancing its role in urban water supply system management.

关键词： Residential water consumption pattern Uncertainty analysis Poisson rectangular pulse model Model establishment

Palladium-catalyzed intermolecular C–h amidation of indoles with sulfonyl azides

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Science China Chemistry 2015年第8期58卷 1349-1353页

作者： Ziwei hu Shuang Luo qiang Zhu State Key Laboratory of Respiratory Disease Guangzhou Institutes of Biomedicine and health Chinese Academy of Sciences

A new kind of intermolecular indole C–h amidation reaction catalyzed by the most frequently used palladium catalyst has been *** azide was employed as an innovative nitrogen source and environmentally benign nitrogen... 详细信息

关键词： C-h amidation indole palladium sulfonyl azide

Carbon-hydrogen activation in China

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Science China Chemistry 2015年第8期58卷 1245-1248页

作者： Zhang-Jie Shi Guo-qiang Lin College of Chemistry and Molecular Engineering Peking University Shanghai Institute of Organic Chemistry Chinese Academy of Sciences

Transition metal catalyzed C-h functionalization is one of the most important and challenging research fields in or- ganic chemistry and has rapidly evolved in recent decades. Some recent achievements in the field include i） minimizing the pre-activation procedures of substrates, ii） reducing waste production, and iii） shortening synthetic steps by de- veloping direct activations and straightforward transfor- mations of C-h bonds. With the rapid developments in chemistry and the continuous support of the Chinese gov- ernment, Chinese chemists have played important roles in this emerging field in the past two decades. To stimulate the continued success of Chinese chemists, this work provides an intensive account of the current status of this important field in China's Mainland.

关键词： Activation analysis Transition metals

Experimental study on geochemical characteristic of methane hydrate formed in porous media

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Journal of Natural Gas Chemistry 2009年第2期18卷 217-221页

作者： qiang Chen Changling Liu Yuguang Ye Qingdao Institute of Marine Geology the Ministry of Land and Resources Qingdao 266071 Shandong China The key Laboratory of Marine hydrocarbon Resources and Environment Resources the Ministry of Land and Resources Qingdao 266071 Shangdong China

The natural occurrence of methane hydrates in marine sediments has been intensively studied over the past decades, and geochemical charac-teristic of hydrate is one of the most attractive research fields. In this paper, we discussed the geochemical anomaly during hydrate formation in porous media. By doing so, we also investigated the temperature influence on hydrate formation under isobaric condition. It turns out that sub-cooling is an important factor to dominate hydrate formation. Larger subcooling provides more powerful driving force for hydrate formation. During the geochemical anomaly research, six kinds of ions and the total dissolved salt （TDS） were measured before and after the experiment in different porous media. The result is that all kinds of ionic concentration increased after hydrate formation which can be defined as salting out effect mainly affected by gas consumption. But the variation ratio of different ions is not equal. Ca^2＋ seems to be the most significantly influenced one, and its variation ratio is up to 80%. finally, we theoretically made a model to calculate the TDS variation, the result is in good accordance with measured one, especially when gas consumption is large.

关键词： hydrate formation porous media subcooling salting out effect geochemical anomaly