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硫酸化钛铈氧化物催化剂的抗重金属中毒

环境工程学报 2024年第3期18卷 830-838页

作者：郭帅蒋偲 ISAH Abdulrasheed gambo 刘宏菊李想北京航空航天大学能源与动力工程学院北京100191 北京航空航天大学材料科学与工程学院北京100191 北京航空航天大学空间与环境学院北京100191

工业烟气中氮氧化物高稳定净化催化剂的开发是实现烟气超低排放的重要需求。目前工业上应用最广的SCR商业V_(2)O_(5)-WO_(3)/TiO_(2)催化剂往往面临重金属中毒失活的难题。采用浸渍法改性CeO_(2)载体,开发了具有优异抗重金属(Pb、Zn、Cd... 详细信息

工业烟气中氮氧化物高稳定净化催化剂的开发是实现烟气超低排放的重要需求。目前工业上应用最广的SCR商业V_(2)O_(5)-WO_(3)/TiO_(2)催化剂往往面临重金属中毒失活的难题。采用浸渍法改性CeO_(2)载体,开发了具有优异抗重金属(Pb、Zn、Cd)中毒性能的硫酸化钛铈氧化物催化剂。在气体小时空速(GHSV)360000 h^(-1)、温度300℃条件下,硫酸化钛铈氧化物催化剂Pb、Zn、Cd中毒后NO转化率分别为75%、73%、63%,比商用V_(2)O_(5)-WO_(3)/TiO_(2)催化剂Pb、Zn、Cd中毒后NO转化率分别增加了28%、36%、43%。Raman表征结果显示,硫酸化钛铈氧化物催化剂Pb中毒后仍然保持了较高的氧空位浓度。XPS和H_(2)-TPR表征结果显示,Pb与SO_(4)^(2-)发生相互作用,保护了催化剂表面的Ce活性位点,从而抑制Pb对脱硝活性的影响。NH3-TPD表征结果显示,SO_(4)^(2-)的掺杂能使催化剂表面酸量显著增加,且催化剂在Pb中毒后表面酸量基本不变,从而表现出高稳定的脱硝活性。本研究可为抗重金属中毒SCR催化剂的设计提供支撑。

关键词：氮氧化物 NH3-SCR 铈基催化剂重金属抗中毒

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Characteristics of Gold and Its Mineralization Style in the Boulon Djounga Eastern Perimeter of Liptako Mining Company (Central Southwestern Niger)

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Natural Resources 2024年第1期15卷 28-50页

作者： gambo Ranaou Noura Kamayé Tourba Karimou Dia Hantchi Bouba hassane Moussa Konaté Department of Geology Faculty of Science and Techniques Abdou Moumouni University Niamey Niger Department of Geology Faculty of Science and Techniques Dan Dicko Dankoulodo University Maradi Niger

The Boulon Djounga eastern perimeter is part of the Tiawa operating permit of the Société des Mines du Liptako (SML), located in the central southwestern part of Liptako (Niger). In this study, we used field data, Reverse Circulation (RC) surveys and chemical analyzes of gold to determine the characteristics of gold and its mineralization style. The eastern perimeter of Boulon Djounga is represented by a succession of metabasalts and metasediments both intersected by intrusions of quartz and dolerite dykes, and covered by sandstone and clayey rocks. Gold is present in low contents (0.00 - 0.30 ppm) in the sedimentary cover and in medium (0.30 - 1.00 ppm) or high contents (1.00 - 4.534 ppm) in the metasediments, and in the gray quartz veins and locally in the volcanics. It exists in a disseminated state or in a concentrated state in the surrounding areas in the form of discrete grains associated with sulphurous minerals (pyrite: FeS2, chalcopyrite: CuFeS2 or arsenopyrite: FeAsS). The presence of gold in the quartz veins, and the NE-SW and NW-SE orientations of the ore bodies suggest that the eastern Boulon Djounga gold mineralization would be established during a late magmatic extensive phase.

关键词： Liptako Gold Mineralization Metasediments-Volcanics Quartz Veins Sulphurous Minerals Niger

Modulation of the in vitro Oxidative Stress and Erythrocyte Cell Membrane Integrity Using Aqueous, Hydroethanolic and Ethanolic Stem-Barks Extracts of Greenwayodendron suaveolens (Engl. & Diels) Verdc

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Pharmacology & Pharmacy 2024年第3期15卷 39-61页

作者： Patrick Hervé Diboue Betote Moustapha gambo Abdoulaye Francis Ngolsou Esther Del Florence Ndedi Moni Adeline Sabine Fanta Yadang Fidel Castro Lah Weyepe Gabriel A. Agbor Nga Nnanga Maximilienne Ascension Nyegue Laboratory of Pharmacology and Drugs Discovery Centre for Research on Medicinal Plants and Traditional Medicine Institute of Medical Research and Medicinal Plants Studies Yaoundé Cameroon Laboratory of Microbiology Department of Microbiology Faculty of Science University of Yaoundé I Yaoundé Cameroon Multidisciplinary Laboratory Department of Galenical Pharmacy and Pharmaceutical Law Faculty of Medicine and Biomedical Sciences University of Yaoundé I Yaoundé Cameroon Department of Physicochemical and Pharmaceutical Sciences Faculty of Health Sciences Abdou Moumouni University Niamey Niger Department of Pharmaceutical and Biological Sciences Faculty of Medicine and Pharmaceutical Sciences University of Douala Douala Cameroon Laboratory of Pharmaceutical Technology Centre for Research on Medicinal Plants and Traditional Medicine Institute of Medical Research and Medicinal Plants Studies Yaoundé Cameroon

Pneumonia, a respiratory infection induces acute or chronic inflammation, characterized by increased activity of lymphocytes and neutrophils, thus generating oxygen-free radicals that decrease the endogenous antioxidants defence system. The aim of this experimental study focused on the capacity of nontoxic aqueous, hydroethanolic and ethanolic extracts of Greenwayodendron suaveolens (Engl. & Diels) Verdc. subsp. suaveolens to regulate free reactive species and protein inflammation generated by infectious disease. The phytochemical screenings of G. suaveolens extracts were carried out according to precipitation and colorimetric methods. The total antioxidant and flavonoid contents were determined by the Folin-Ciocalteu and Aluminium Chloride ethanolic methods. The efficiency of G. suaveolens extracts on free radicals was evaluated using DPPH•, ABTS+•, and FRAP methods. The anti-inflammatory properties of extracts were evaluated according to in vitro protein (BSA) denaturation, Proteinase Inhibitory Action, and Red Blood Cell Membrane stabilization assays. The G. suaveolens aqueous, hydroethanolic and ethanolic extracts were used for the acute toxicity assessment according to the OECD protocol. The obtained results showed the presence of flavonoids, phenols, polyphenols, tannins, anthocyanins, alkaloids, terpenoids, and sterols as secondary metabolites families in G. suaveolens extracts. The highest contents of total antioxidants and flavonoids were highlighted in the hydroethanolic extract. However, it’s the G. suaveolens aqueous extract that showed the best free radical DPPH• and ABTS+• scavenging activities (SC50) of 11.06 μg/mL and 15.16 μg/mL respectively. The highest ferric-reducing activity was found in G. suaveolens ethanolic extract with 866.23 μg EGA/mg of dry weight. The hydroethanolic extract has shown a high anti-inflammatory activity through BSA denaturation and erythrocyte membrane haemolysis with i

关键词： Greenwayodendron suaveolens Secondary Metabolites Oxidative Stress Antioxidant Activity Anti-Inflammatory Properties and Oral Acute Toxicity

海上结构管状TY接头平面内弯曲和平面外弯曲引起的载荷应力集中因素分析

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Journal of Marine Science and Application 2022年第4期21卷 78-94页

作者： Mohamadou Aminou Sambo Guy Richard Kol gambo Betchewe Faculty of Sciences University of MarouaMaroua P.O.Box 46Cameroon National Advance School of Mines and Petroleum Industries University of MarouaMaroua P.O.Box 46Cameroon School of Geology and Mining Engineering University of NgaoundéréNgaoundéréP.O.Box 454Cameroon

The aim of this work is to study the stress distributions and the location of hot spots stress in the vicinity of the intersection lines of the tubular elements of the tubular *** the finite element models,we analyze the effects of geometrical parameters on the stress concentration factor in the case of in-plane bending and out-of-plane bending loads,around the weld toe of the tubular *** results reveal the location of the maximum stress concentration factor at the heel or toe in the case of in-plane bending loads and at the saddle point in the case of out-of-plane bending *** parametric equations are established and used to calculate the stress concentration factor at critical locations using the non-linear regression *** results obtained from the finite element analysis are close to the results of the parametric equations and the experimental data from the previous work.

关键词： Offshore platform Tubular TY-joint Stress concentrations Fatigue In-plane bending Out-of-plane bending

轴向载荷作用下管状TY接头几何参数对应力集中系数的影响分析

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Journal of Marine Science and Application 2022年第2期21卷 133-143页

In this paper,the influence of geometric parameters on the stress concentration factors due to three different types of axial loading on 81 TY tubular structures is *** results reveal that,geometric parameters have a considerable impact on the variation of stress concentration factors on tubular TY-joints under axial ***,the highest stress concentration factor values are observed on the vertical brace than on the inclined *** finite element results of the tubular structures were verified by parametric equations and experimental data.A parametric study was carried out by analyses using the nonlinear regression method to obtain parametric *** equations are used to calculate stress concentration factors and to analyse the fatigue resistance of TY-joints due to axial loads.

关键词： Offshore structure Tubular TY-joint Stress Concentration Factor Fatigue Axial load

Theoretical investigation on the impact of an oscillating time-dependent pressure gradient on Dean flow in a porous annulus

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Propulsion and Power Research 2021年第3期10卷 294-302页

作者： Basant K.Jha Dauda gambo Department of Mathematics Ahmadu Bello UniversityZariaKaduna810Nigeria

In this article,a theoretical analysis on flow in a curvilinear horizontal coaxial cylinder with permeable walls has been ***,the transient impact of an oscillating pressure gradient has been taken into *** non-linear time-dependent partial differential equation accountable for the flow has been transformed using the classical Laplace transform *** solution of the momentum equation has been obtained in Laplace *** to the intricacy of the Laplace domain solutions,a numerical inversing technique which is established upon the Riemann-sum approximation(RSA)has been utilized to transform the Laplace domain solutions to time *** reveal that the outcome of suction on the porous walls and boosting the frequency of oscillation renders skin frictions on both walls of the cylinder less *** instability of the Dean vortices in the annular gap can be suppressed by amplifying the frequency of oscillating pressure gradient while time is maintained.

关键词： Annulus Dean flow Oscillating timedependent pressure gradient Riemann-sum approximation(RSA)

Dynamical System Approach to a Coupled Dispersionless System： Localized and Periodic Traveling Waves

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Chinese Physics Letters 2009年第6期26卷 55-57页

作者： gambo Betchewe Ecole Nationale Superieure Polytechnique University of Yaounde I PO Box 8390 Cameroon Department of Physics Faculty of Science University of Yaounde I PO Box. 812 Cameroon The Abdus Salam International Centre for Theoretical Physics PO Box 586 Strada Costiera II-34014 Trieste Italy

We investigate the dynamical behavior of a coupled dispersionless system describing a current-conducting string with infinite length within a magnetic field. Thus, following a dynamical system approach, we unwrap typical miscellaneous traveling waves including localized and periodic ones. Studying the relative stabilities of such structures through their energy densities, we find that under some boundary conditions, localized waves moving in positive directions are more stable than periodic waves which in contrast stand for the most stable traveling waves in another boundary condition situation.

关键词： gamma-ray bursts gamma-rays relativity

Travelling Wave Solutions to Stretched Beam's Equation: Phase Portraits Survey

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Communications in Theoretical Physics 2011年第4期55卷 605-608页

作者： gambo Betchewe Kuetche Kamgang Victor Bouetou Bouetou Thomas Timoleon Crepin Kofane Higher Teacher's Training College of Maroua University of Maroua Ecole Nationale Superieure Polytechnique University of Yaounde I Department of Physics Faculty of ScienceUniversity of Yaounde I

在这份报纸，跟随阶段肖像分析，我们调查身体上在结束戳下面描述一根有弹性的横梁的横向的摆动的一个系统的 integrability。作为结果，我们发现这个系统实际上包括旅行波浪的二个家庭：积极明确、否定明确的速度的亚声、超声的周期的... 详细信息

在这份报纸，跟随阶段肖像分析，我们调查身体上在结束戳下面描述一根有弹性的横梁的横向的摆动的一个系统的 integrability。作为结果，我们发现这个系统实际上包括旅行波浪的二个家庭：积极明确、否定明确的速度的亚声、超声的周期的波浪，分别地并且积极明确的速度的局部性的亚声的塑造环的波浪。表示这个系统像精力当描绘它的阶段肖像动力学时，我们证明局部性的旅行挥动的这些 multivalued 作为周期的旅行波浪 asymptotically 趋于的边界答案出现。

关键词：相图分析行波解梁方程拉伸物理描述周期波系统横振动

ON OTHER WAVE GUIDE IN STATIONARY PLANETARY WAVE PROPAGATIONS IN WINTER NORTHERN HEMISPHERE

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Science in China,Ser.B 1984年第6期27卷 610-624页

作者：黄荣辉 K.gambo Institute of Atmospheric Physics Academia Sinica. Beijing Geophysical Institute Tokyo University Japan

In this paper, the refractive index squared of stationary planetary waves in the isothermalatmosphere is computed theoretically. It has been discovered that there should be the otherwave guide pointing from the lower troposphere in middle and high latitudes toward the uppertroposphere in low latitudes in addition to the polar wave guide in the vertical and lateral pro-pagations of stationary planetary waves in winter. The vertical and lateral propagations of stationary planetary waves responding to an idealiz-ed forcing mechanism, for example, an idealized topography or stationary heat sources overthe Northern Hemisphere have been investigated by means of a quasigeostrophic, steady-state,34-level model with Rayleigh friction, Newtonian cooling effect and the horizontal kinematicthermal diffusivity included in a spherical coordinate system. The computed results have veri-fied that there actually is the other wave guide in the stationary planetary wave propagationsin winter. The vertical distributions of

关键词： ON OTHER WAVE GUIDE IN STATIONARY PLANETARY WAVE PROPAGATIONS IN WINTER NORTHERN HEMISPHERE