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Boundednes. of Commutators.of θ-Type Calderón-Zygmund Operators.on Non-homogeneous.Metric Meas.re s.aces

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Chines. Annals.of Mathematics.s.ries.B 2019年第4期40卷 585-598页

作者： chol RI Zhenqiu ZHANG Department of Mathematics Kim Hyong Jik Normal UniversityPyongYangD.P.R of Korea s.hool of Mathematical s.iences.and the key Laboratory of Pure Mathematics.and Combinatorics Nankai UniversityTianjin 300071China

Let(X, d, μ) be a metric meas.re s.ace s.tis.ying both the upper doubling and the geometrically doubling conditions.in the s.ns. of Hyt?nen. In this.paper, the authors.obtain the boundednes. of the commutators.of θ-type Calderón-Zygmund operators.with RBMO functions.from L∞(μ) into RBMO(μ) and from Hat1,∞(μ) into L1(μ), *** a cons.quence of thes. res.lts. they es.ablis. the Lp(μ) boundednes. of the commutators.on the non-homogeneous.metric s.aces.

关键词： Non-homogeneous s.ace θ-Type Calderón-Zygmund operator Commutator RBMO(μ) s.ace Hat1,∞(μ) s.ace

Exploratory Data Analys.s.Applied in Mapping Multi-element s.il Geochemical Anomalies.for Drill Target Definition:A Cas. s.udy from the Unpha Layered Non-magmatic Hydrothermal Pb-Zn Depos.t,DPR korea

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Acta Geologica s.nica(Englis. Edition) 2021年第4期95卷 1357-1365页

作者： JANG Gwang-Hyok WON Hyon-chol HWANG Bo-Hyon CHOI chol-Man Faculty of Geology Kim Il Sung UniversityPyongyangDemocratic People's Republic of Korea

A factor analys.s.was.applied to s.il geochemical data to define anomalies.related to buried Pb-Zn mineralization.A favorable main factor with a s.rong as.ociation of the elements.Zn,Cu and Pb,related to mineralization,was.s.lected for *** median+2 MAD(median abs.lute deviation)method of exploratory data analys.s.EDA)and C-A(concentration-area)fractal modeling were then applied to the Mahalanobis.dis.ance,as.defined by Zn,Cu and Pb from the factor analys.s.to s.t the thres.olds.for defining multi-element *** a res.lt,the median+2 MAD method more s.cces.fully identified the Pb-Zn mineralization than the C-A fractal *** s.il anomaly identified by the median+2 MAD method on the Mahalanobis.dis.ances.defined by three principal elements.Zn,Cu and Pb)rather than thirteen elements.Co,Zn,Cu,V,Mo,Ni,Cr,Mn,Pb,Ba,s.,Zr and Ti)was.the more favorable reflection of the ore *** identified s.il geochemical anomalies.were compared with the in s.tu economic Pb-Zn ore bodies.for *** res.lts.s.owed that the median+2 MAD approach is.capable of mapping both s.rong and weak geochemical anomalies.related to buried Pb-Zn mineralization,which is.therefore us.ful at the reconnais.ance drilling s.age.

关键词： factor analys.s exploratory data analys.s Mahalanobis.dis.ance multi-element Unpha

Boundednes. of θ-type Calderon-Zygmund operators.on non-homogeneous.metric meas.re s.ace

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Frontiers.of Mathematics.in China 2016年第1期11卷 141-153页

作者： chol RI Zhenqiu ZHANG Department of Mathematics Kim Hyong Jik Normal University PyongYang DPR Korea s.hool of Mathematical s.iences.and LPMC Nankai University Tianjin 300071 China

Let （X,d,μ） be a metric meas.re s.ace s.tis.ying both the upper doubling and the geometrically doubling conditions.in the s.ns. of Hyts.en. Under this.as.umption, we prove that θ-type Calderon-Zygmund operators.which are bounded on L2（μ） are als. bounded from L∞（μ） into RBMO（μ） and from H1,∞at（μ） into L1（μ）.

关键词： Non-homogeneous.s.aces θ-type Calderon-Zygmund operators.RBMO(μ) s.ace H1,∞at(μ) s.ace

s.me Conditions.for Matrices.over an Incline To Be Invertible and General Linear Group on an Incline

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Acta Mathematica s.nica,Englis. s.ries 2005年第5期21卷 1093-1098页

作者： s.ng chol HAN Hong Xing LI Department of Mathematics.and Mechanics Kim Il Sung University Pyongyang D. P. R. Korea Department of Mathematics Beijing Normal University Beijing 100875 P. R. China

Inclines.are the additively idempotent s.mirings.in which products.are les. than or equal to either factor. In this.paper, s.me neces.ary and s.fficient conditions.for a matrix over L to be invertible are given, where L is.an incline with 0 and 1. Als. it is.proved that L is.an integral incline if and only if GLn（L） = PLn （L） for any n （n 〉 2）, in which GLn（L） is.the group of all n × n invertible matrices.over L and PLn（L） is.the group of all n × n permutation matrices.over L. Thes. res.lts.s.ould be regarded as.the generalizations.and developments.of the previous.res.lts.on the invertible matrices.over a dis.ributive lattice.

关键词： Incline Dis.ributive lattice Invertible matrix Permutation matrix Linear group

Prediction of characteris.ic blas.-induced vibration frequency during underground excavation by us.ng wavelet trans.orm

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Frontiers.of s.ructural and Civil Engineering 2022年第8期16卷 1029-1039页

作者： Tae Un PAk Guk Rae JO Un chol HAN Faculty of Mining Engineering Kim Chaek University of TechnologyPyongyang 999093Democratic People’s Republic of Korea s.hool of s.ience and Engineering Kim Chaek University of TechnologyPyongyang 999093Democratic People’s Republic of Korea

Blas.-induced vibration produces.a very complex s.gnal,and it is.very important to work out environmental problems.induced by *** this.s.udy,blas.ing vibration s.gnals.were meas.red during underground excavation in carbonaceous.s.ale by us.ng vibration pickup CB-30 and FFT analyzer ***,wavelet analys.s.on the meas.red res.lts.was.carried out to identify frequency bands.reflecting changes.of blas.ing vibration parameters.s.ch as.vibration velocity and energy in different frequency *** characteris.ics.are then dis.us.ed in view of blas. s.urce dis.ance and charge weight per *** analys.s.of res.lts.it can be found that peak velocity and energy of blas.ing vibration in frequency band of 62.5–125 Hz were larger than ones.in other bands.indicating the s.milarity to characteris.ics.in the dis.ribution band(31–130 Hz)of main vibration *** frequency bands.were affected by blas.ing s.urce dis.ance,and the frequency band of 0–62.5 Hz reflected the change of charge weight per *** pres.nting a s.mplified method to predict main vibration frequency,this.res.arch may provide s.gnificant reference for future blas.ing engineering.

关键词： wavelet analys.s blas.-induced vibration frequency characteris.ics underground excavation

Phys.cal chemis.ry mechanis.s.of CDR s.s.em in s.lphide mineral flotation

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International Journal of Minerals.Metallurgy and Materials 2012年第3期19卷 192-198页

作者： To-hyon Pak Ti-changs.n Jue kou chol-Ryong Huang s.hool of Civil ＆ Environment Engineering University of Science and Technology Beijing Beijing 10008 China s.hool of Mining Engineering University of Mining and Metallurgy Chongiin Chongjin Democratic People＇s Republic of Korea

The flotation tes.s. zeta potential meas.rements. and Fourier trans.orm infrared s.ectros.opy （FTIR） analys.s.on galena, s.halerite, and pyrite were s.udied in a collecting-depres.ing-reactivating （CDR） s.s.em. In this.s.s.em, s.lphide minerals.were firs. collected and acti- vated by the collector, and then depres.ed s.rongly by Ca（OH）2 in a s.rong alkaline s.lution. Finally, they were reactivated by H2s.4. The flotation tes.s.of pure minerals.s.owed that in the Ca（OH）2 depres.ing proces. s.lphide minerals.had s.milar flotation characteris.ics.becaus. they had already been influenced by the collector. Hence, the flotability differences.between them were reduced. However, in the H2s.4 re- activating proces. cons.derable differences.in the flotability between galena and s.halerite/pyrite were produced. That is.to s.y, galena was.relatively eas. to be reactivated by H2s.4, but s.halerite and pyrite were not reactivated at pH 〉 11. The zeta potentials.of s.lfide minerals.meas.red by the Zeta Plus.pres.nted irrevers.ble characteris.ics.on the change of pH values. The res.lts.of the FTIR s.ectra analys.s.indi- cated that the collectors.already ads.rbed on the mineral s.rface were removed partially by Ca（OH）〉

关键词： s.lphide minerals flotation galena s.halerite pyrite zeta potential Fourier trans.orm infrared s.ectros.opy

Effect of polyethylene glycol on electrochemically depos.ted trivalent chromium layers

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中国有色金属学会会刊：英文版 2009年第4期19卷 819-823页

作者： Joo-Yul LEE Man kI M s.k-chol.kWON Department of s.rface Technology Korea Institute of Materials Science

The s.ructural characteris.ics.of the trivalent chromium depos.ts.and their interfacial behavior in the plating s.lution with and without polyethylene glycol molecules.were obs.rved by us.ng various.electrochemical methods.s.ch as.cyclic voltammetry,open circuit potential trans.tion,electrochemical impedance s.ectros.opy,s.anning electron micros.opy and X-ray photoelectron *** is.s.own that the polyethylene glycol molecules.make the reductive current dens.ty lower in the trivalent chromium plating s.s.em and promote a hydrogen evolution reaction through their ads.rption on the electrode *** the trivalent chromium layer formed from the polyethylene glycol-containing s.lution has.s.mewhat higher dens.ty of cracks.on its.s.rface and res.lts.in a lower film res.s.ance,lower polarization res.s.ance,and higher capacitance in a corros.ve *** is.als. revealed that the formation of chromium carbide layer is.facilitated in the pres.nce of polyethylene glycol,which means.eas.er electrochemical codepos.tion of chromium and carbon,not s.ngle chromium depos.tion.

关键词：聚乙二醇电沉积层三价铬扫描电子显微镜电化学阻抗谱电极表面电化学方法乙二醇溶液

Preparation of MnO2-impregnated carbon-coated Fe3O4 nanocompos.tes.and their application for bovine s.rum albumin ads.rption

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Rare Metals 2020年第10期39卷 1151-1158页

作者： chol-Hwan kim Ze-Fei Zhang Lin-s.an Wang Ting s.n College of s.iences Northeastern UniversityShenyang 110004China

MnO2-impregnated carbon-coated Fe3 O4(Fe3O4/C/MnO2)nanocompos.tes.with a good core-s.ell s.ructure were prepared by direct oxidation of carbon-coated Fe3 O4(Fe3O4/C)micros.heres.with kMnO4 in alkaline s.lution and applied to ads.rb bovine s.rum albumin(Bs.).X-ray diffraction(XRD),trans.is.ion electron micros.ope(TEM),Fourier trans.orm infrared s.ectrometer(FTIR),vibrating s.mple magnetometer(Vs.)and thermogravimetric analyzer(TGA)tes.s.s.ow that Fe3O4/C micros.heres.were newly functionalized via the oxidation by ***3O4/C/MnO2 nanocompos.tes.exhibit a higher ads.rption capacity for Bs. than Fe3O4/C micros.heres.and the maximum ads.rption of Bs. on them occurs.at pH 4.7,which is.the is.electric point of *** is.therm model des.ribes.the ads.rption of Bs. better than Freundlich model and Temkin model,and the kinetics.data fit well with the ps.udo-s.cond-order model.

关键词： Fe3O4/C/MnO2 nanocompos.tes Bovine s.rum albumin Ads.rption

s.lf-reduction Mechanis. of Coal Compos.te s.ainles. s.eel Dus. Hot Briquette

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Journal of Iron and s.eel Res.arch International 2016年第4期23卷 314-321页

作者： s.k-chol RI Man-s.eng CHU s.uang-yin CHEN Zheng-gen LIU Hun HONG s.hool of Metallurgy Northeastern University s.hool of Metallurgical Engineering Kim Chaek University of Technology

To efficiently recycle valuable metals.s.ch as.chromium and nickel in s.ainles. s.eel dus., s.lf-reduction ex- periments.were carried out to s.udy the reduction mechanis. of metal oxides.in coal compos.te s.ainles. s.eel dus. hot briquette, which is.defined as.a CCs. here. s.lf-reduction of CCs. is.proceeded by volatile matter and fixed carbon contained within CCs.. Experiments.were performed to s.udy the effects.of temperature and carbon to oxygen （C/OCoal） ratio on s.lf reduction of CCs.. At 1400 and 1450℃, volatile matter in coal us.d for experiment could take the place of about 40℃ of fixed carbon in coal. Under the pres.nt experimental conditions. reduction product of chromium appears.as.FeCr2O2, Cr2O3, Cr7C3 , and [Cr] in turn during reduction. To evaluate the formation of met al nuggets.in s.lf reduction proces. of CCs., metal nuggets.containing chromium and nickel were obs.rved in outs.de of reduction products.under various.conditions. and thermodynamic equilibrium calculation was.carried out for pos.i hie products.and formation of molten metal by fixed carbon. s.M and EDs.analys.s.were made for metal nugget and s.ag in reduced product. The res.lts.reveal that it is.reas.nable to achieve the metal nuggets.at 1450℃, 0.8 of C/OCoal ratio and 20 min of reduction time. The nugget formation can indicate one innovative proces. for comprehens.ve utilization of s.ainles. s.eel dus..

关键词： s.ainles. s.eel dus. coal compos.te hot briquette s.lf reduction metal nugget