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Particle Size Distribution and Characterization of High Siliceous and microporous materials

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Journal of materials Science & Technology 2005年第4期21卷 563-570页

作者： S.KDurrani J.Akhtar m.ahmad m.J.moughal Nuclear materials Division Pakistan Institute of Nuclear Science and Technology P.O. Nilore Islamabad PakistanNuclear Materials Division Pakistan Institute of Nuclear Science and Technology P.O. Nilore Islamabad PakistanNuclear Physics Divisions Pakistan Institute of Nuclear Science and Technology P.O. Nilore Islamaad PakistanNuclear Materials Division Pakistan Institute of Nuclear Science and Technology P.O. Nilore. Islamabad. Pakistan

Particle size, textural and surface characteristics influence some major technological properties of high siliceous aluminosilicate zeolite and sillicoaluminophosphate （SAPO） microporous materials. A comparative study was furnished for measuring surface characteristics, particle size and particle size distribution using particle size analyzer （PSA） and scanning electron microscope （SEm）. The PSA is capable of measuring particle diameter in micron range. The results of these techniques for estimation of particle size were compared and correlated statistically. Student t-test and variance ratio test （F-test） methods were performed for the significance of results by the analysis of variance （ANONA） and multiple-range tests. Textural and surface characteristics were evaluated by Brunauer, Emmett ＆ Teller （BET） volumetric technique and v-αs plotting method. The textural results shows that the external surface area and micropore volume of microporous materials were higher than those of the high siliceous zeolites and its zeotype materials.

关键词： Synthesis High siliceous zeolites microporous materials Particle size distribution micropore volume SEm

Hibernation with rhythmicity:the circadian clock and hormonal adaptations of the hibernating Asiatic toads(Bufo gargarizans)

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Integrative Zoology 2022年第4期17卷 656-669页

作者： Zhigang XIE Ibrahim m.ahmad Lirong ZUO Feng XIAO Yongpeng WANG Dongming LI Zhejiang Academy of Agricultural Sciences HangzhouChina College of Chemistry and Life Science Zhejiang Normal UniversityJinhuaChina ministry of Education Key Laboratory of molecular and Cellular Biology Key Laboratory of Animal PhysiologyBiochemistry and Molecular Biology of Hebei ProvinceCollege of Life SciencesHebei Normal UniversityShijiazhuangChina

Hibernation is one of the fundamental strategies in response to cold environmental *** hibernation,the endocrine and circadian systems ensure minimal expenditure of energy for *** circadian rhythms of key hormones,melatonin(mT),corticosterone(CORT),triiodothyronine(T3),and thyroxine(T4),and the underlying molecular regulatory mechanisms of hibernation have been well determined in mammals but not in ***,a terrestrial hibernating species,Asiatic toad(Bufo gargarizans),was employed to investigate the plasma CORT,mT,T3,and T4;and the retina,brain,and liver mRNA expression of the core clock genes,including circadian locomotor output cycles kaput(Clock),brain and muscle ARNT-like 1(Bmal1),cryptochrome(Cry)1 and 2,and period(Per)1 and 2,at 7-time points over a 24-h period under acute cold(1 day at 4℃),and hibernation(45 days at 4℃).Our results showed that the circadian rhythms of the core clock genes were rather unaffected by acute cold exposure in the retina,unlike the brain and *** contrast,during hibernation,the liver clock genes displayed significant circadian oscillations,while those in the retina and brain stopped ***,plasma CORT expressed circadian oscillations in both groups,and T3 in acute cold exposure group,whereas T4 and mT did *** results reveal that the plasma CORT and the liver sustain rhythmicity when the brain was not,indicating that the liver clock along with the adrenal clock synergistically maintains the metabolic requirements to ensure basic survival in hibernating Asiatic toads.

关键词： Asiatic toad circadian rhythm clock genes cold exposure hibernation metabolic hormones

Fermentation, formulation and evaluation of PGPR Bacillus subtilis isolate as a bioagent for reducing occurrence of peanut soil-borne diseases

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Journal of Integrative Agriculture 2019年第9期18卷 2080-2092页

作者： Abdel-Gayed m.ahmad Abo-Zaid G.Attia matar S.mohamed Hafez E.Elsayed Onion Garlic and Oil Crops Research DepartmentPlant Pathology Research InstituteAgricultural Research CenterGiza 12619Egypt Bioprocess Development Department Genetic Engineering and Biotechnology Research InstituteCity of Scientific Research and Technological ApplicationsNew Borg El-Arab CityAlexandria 21934Egypt Chemical Engineering Department Faculty of EngineeringJazan UniversityJazan 45142Saudi Arabia Plant Protection and Biomolecular Diagnosis Department Arid Lands Cultivation Research InstituteCity of Scientific Research and Technological ApplicationsNew Borg El-Arab CityAlexandria 21934Egypt

Four isolates of Bacillus subtilis coded,B4,B7,B8 and B10 were examined as biocontrol agents for their abilities and antagonistic effect on the in vitro growth of certain phytopathogenic fungi of peanut,Rhizoctonia solani and Sclerotium *** subtilis isolate B4(GenBank accession ***150884)was the highly effective one for inhibiting the fungal mycelial *** fermentation of *** isolate B4 was carried out and the maximum biomass achieved was 4.53 g L-1 at 11 *** subtilis isolate B4 was formulated and evaluated as a biofungicide to reduce peanut soil-borne diseases under greenhouse and field conditions at the side of Rizolex-T(fungicide)as *** by formulated plant growth-promoting rhizobacteria(PGPR)*** B4 and Rizolex-T in a soil infested with ***,*** and mixture of them were more effective in decreasing percentage of damping-off,root and pod rot disease incidence(%)in greenhouse and open field environment during the two seasons 2015 and *** by PGPR gave highly dry weight and number of healthy pods compared to control of fungi treatment which was nearby to dry weights of healthy pods achieved by treatments by Rizolex-T in a soil infested with ***,*** and mixture of *** PGPR *** B4 gave higher increasing of yield percentage than treatment by Rizolex-T in the two evaluated seasons 2015 and *** can conclude that the produced bioforumlated agent was more efficient as fungicide when compared with the other chemical synthesized fungicides,safe for human and the environment and economy.

关键词： peanut soil-borne diseases Bacillus subtilis biocontrol fermentation formulation

Ageing Effect on Hardness and microstructure of Al-Zn-mg Alloys

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Journal of materials Science & Technology 2000年第3期16卷 319-322页

作者： m.Iqbal, m.A.Shaikh, m.ahmad and K.A.Shoaib (Nuclear Physics Division, Pakistan Institute of Nuclear Science and Technology P.O.Nilore, Islamabad, Pakistan) Nuclear Physics Division Pakistan Institute of Nuclear Science and Technology Islamabad P.O.Nilore Pakistan

Experimental results of the investigation on the hardness of two Al-Zn-mg alloys [Al-10.0 Zn-4.0 mg and Al-8.5 Zn-3.0 mg (wt pct)] aged in the temperature range 60～310℃ for different intervals of time from 1/4 h to 168 h are presented. Both the alloys were found to show identical behaviour of hardness with ageing time. Alloy with higher Zn and mg content had higher hardness than the alloy with lower solute content. There were three ranges of temperature in which different types of precipitates formed and affected the hardness. Some of the grain boundaries were found to migrate and precipitate free zone has been observed.

关键词： Zn Ageing Effect on Hardness and microstructure of Al-Zn-mg Alloys Al

Enhanced photocatalytic activity of Ce-doped ZnO nanopowders synthesized by combustion method

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Journal of Rare Earths 2015年第3期33卷 255-262页

作者： m.ahmad E.Ahmed Fezza Zafar N.R.Khalid N.A.Niaz Abdul Hafeez m.Ikram m.Ajmal Khan 洪樟连 Department of Physics Bahauddin Zakariya University State Key Laboratory of Silicon materials Department of Materials Science & Engineering Zhejiang University Science and Technology Division University of Education

Facile and fast combustion method was used to synthesize Zn O and Ce-doped Zn O（CZO） nanocrystalline powders photocatalysts with different cerium concentrations（0.5 wt.%–10.0 wt.%） followed by calcination at 700 oC for 3 h. The prepared samples were characterized by a variety of characterization techniques such as X-ray diffraction（XRD）, scanning electron microscopy（SEm） combined with energy dispersive X-ray diffraction（EDX）, transmission electron microscopy（TEm）, UV-visible spectroscopy, BET surface area analyser and photoluminescence spectroscopy（PL）, to study the crystal structure, surface morphology, chemical composition and optical properties. It was observed from XRD results that synthesized powders had hexagonal wurtzite structure with the smallest crystallite size about 13 nm. Absorption spectra showed that cerium doping enhanced the light absorption properties towards the visible light region. Photoluminescence spectra for Ce-doped Zn O samples exhibited relatively weak near band edge（NBE） emission peaks as compared to that of pristine Zn O. The photocatalytic activities of the prepared samples were evaluated by photocatalytic degradation of Rhodamine B（Rh B） under UV light and visible light（λ≥420 nm） irradiation. The textile mill effluent containing organic matters was also treated under sunlight using photocatalysis and the reduction in the chemical oxygen demand（COD） of the treated effluent revealed a complete destruction of the organic molecules along with colour removal. The results showed that the CZO photocatalyst doped with 3.0 wt.% cerium exhibited four times enhanced photocatalytic activity compared to pure Zn O. The enhanced photocatalytic activity could be attributed to extended visible light absorption and inhibition of the electron-hole pair＇s recombination.

关键词： ZnO cerium combustion photocatalyst Rhodamine B rare earths

Practical fixed-time adaptive fuzzy control of uncertain nonlinear systems with time-varying asymmetric constraints: a unified barrier function based approach

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Frontiers of Information Technology & Electronic Engineering 2024年第9期25卷 1282-1294页

作者： Zixuan HUANG Huanqing WANG Ben NIU Xudong ZHAO Adil m.ahmad College of Engineering Bohai UniversityJinzhou 121013China College of mathematical Science Bohai UniversityJinzhou 121013China School of Information Science and Engineering Shandong Normal UniversityJinan 250014China Faculty of Electronic Information and Engineering Dalian University of TechnologyDalian 116024China Communication Systems and Networks Research Group Department of Information TechnologyFaculty of Computing and Information TechnologyKing Abdulaziz UniversityJeddahSaudi Arabia

A practical fixed-time adaptive fuzzy control strategy is investigated for uncertain nonlinear systems with time-varying asymmetric constraints and input quantization. To overcome the difficulties of designing controllers under the state constraints, a unified barrier function approach is employed to construct a coordinate transformation that maps the original constrained system to an equivalent unconstrained one, thus relaxing the time-varying asymmetric constraints upon system states and avoiding the feasibility check condition typically required in the traditional barrier Lyapunov function based control approach. meanwhile, the “explosion of complexity” problem in the traditional backstepping approach arising from repeatedly derivatives of virtual controllers is solved by using the command filter method. It is verified via the fixed-time Lyapunov stability criterion that the system output can track a desired signal within a small error range in a predetermined time, and that all system states remain in the constraint range. Finally, two simulation examples are offered to demonstrate the effectiveness of the proposed strategy.

关键词： Unified barrier function Time-varying asymmetric state constraints Fuzzy logic systems Fixed-time control Command filter

Physiological but not morphological adjustments along latitudinal gradients in a human commensal species,the Eurasian tree sparrow

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Integrative Zoology 2023年第5期18卷 891-905页

作者： Qian ZHANG mo LI Yuan YIN Shiyong GE Danjie LI Ibrahim m.ahmad Ghulam NABI Yanfeng SUN Xu LUO Dongming LI Hebei Key Laboratory of Animal Physiology Biochemistry and Molecular BiologyCollege of Life SciencesHebei Normal UniversityShijiazhuangChina Key Laboratory for ConservingWildlife with Small Populations in Yunnan Faculty of Biodiversity and ConservationSouthwest Forestry UniversityKunmingChina Ocean College Hebei Agricultural UniversityQinhuangdaoChina Hebei Collaborative Innovation Center for Eco-Environment Hebei Normal UniversityShijiazhuangChina

Human commensal species take advantage of anthropogenic conditions that are less likely to be challenged by the selective pressures of natural *** morphological and physiological phenotypes can therefore dissociate from habitat *** how these species adjust their morphological and physiological traits across latitudinal gradients is fundamental to uncovering the eco-physiological strategies underlying coping ***,we studied morphological traits in breeding Eurasian tree sparrows(ETSs;Passer montanus)among low-latitude(Yunnan and Hunan)and middle-latitude(Hebei)localities in *** then compared body mass;lengths of bill,tarsometatarsus,wing,total body,and tail feather;and baseline and capture stress-induced levels of plasma corticosterone(CORT)and the metabolites including glucose(Glu),total triglyceride(TG),free fatty acid(FFA),total protein,and uric acid(UA).None of the measured morphological parameters varied with latitude except in the Hunan population,which demonstrated longer bills than those in other ***-induced CORT levels significantly exceeded baseline levels and decreased with increasing latitude,but total integrated CORT levels did not vary with *** stress-induced significantly increased Glu levels and decreased TG levels,independent of ***,the Hunan population had significantly higher baseline CORT,baseline and stress-induced FFA levels,but lower UA levels,which differed from other *** results suggest that rather than morphological adjustments,physiological adjustments are mainly involved in coping mechanisms for middle-latitude adaptation in *** is worth investigating whether other avian species also exhibit such dissociation from external morphological designs while depending on physiological adjustments.

关键词： capture stress corticosterone human commensal species latitudinal gradients plasma metabolites

Seasonal variations in gonad morphology and hypothalamic GnRH-I and GnIH in Eurasian Tree Sparrow,a multi-brooded passerine

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Avian Research 2022年第3期13卷 369-378页

作者： Limin Wang Ghulam Nabi Li Zhang Dan Liu mo Li Juyong Li Kaixin Shi Ibrahim m.ahmad Yuefeng Wu John C.Wingfield Dongming Li ministry of Education Key Laboratory of molecular and Cellular Biology Key Laboratory of Animal PhysiologyBiochemistry and Molecular Biology of Hebei ProvinceCollege of Life SciencesHebei Normal UniversityShijiazhuang050024China Department of Neurobiology Physiology and BehaviorUniversity of Californi1DavisCAUSA

The hypothalamic-pituitary-gonadal(HPG)axis ubiquitously regulates seasonal reproduction,following the rhythmicity of a suite of environmental *** display prominent seasonal variations in gonad size regulated by two hypothalamic peptides,gonadotropin-releasing hormone-1(GnRH-I)and gonadotropin-inhibiting hormone(GnIH).How multi-brooded avian species adjust GnRH-I and GnIH to regulate gonadal morphology seasonally remains largely ***,we studied the variations in the hypothalamic immunoreactivity(ir)of GnRH-I and GnIH,gonadal proliferation,and apoptosis in a typical multi-brooded species,the Eurasian Tree Sparrow(Passer montanus),across the pre-breeding(PB),first breeding(FB),second breeding(SB),pre-basic molt(Pm),and wintering stages(WS).Our results showed that both sexes had higher preoptic area(POA)-GnRH-I-ir but lower paraventricular nucleus(PVN)-GnIH-ir neurons during the breeding stages(FB and SB)relative to other life-history stages,with no significant differences between two *** testes and ovaries were significantly larger during the breeding *** volume increased during the two broods due to anincreased diameter of seminiferous ***,there were more testicular apoptotic cells in PB and WS stages than in breeding stages,and in PB stage than in Pm *** had higher POA-GnRH-I expression than females during the breeding stages,but both sexes had comparable PVN-GnIH expression throughout the annual *** sexes of the sparrows may undergo a similar pattern of life-history stage-dependent variation in the hypothalamic GnRH-I,GnIH,and gonadal morphology,except that during breeding stages,males may display higher expression of POA-GnRH-I relative to *** higher expression of POA-GnRH-I-ir in breeding male sparrows may be critical for male-dependent parental care.

关键词： Eurasian Tree Sparrow Gonads Hypothalamus Reproduction Seasonality

Effects of constant light and dark conditions on the locomotor activity,body mass,and body temperature rhythms of Eurasian Tree Sparrows(Passer montanus)

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Avian Research 2023年第3期14卷 435-442页

作者： Lirong Zuo Ibrahim mahmad Yuanyuan Liu Limin Wang Shu Fang Dongming Li Hebei Key Laboratory of Animal Physiology Biochemistry and Molecular BiologyCollege of Life SciencesHebei Normal UniversityShijiazhuang050024Hebei ProvinceChina Hebei Collaborative Innovation Center for Eco-Environment Hebei Normal UniversityShijiazhuang050024China

Light is an essential environmental cue influencing the endogenous circadian clocks that regulate behavioral and physiological processes in *** extensive research on the circadian rhythms of avian behavior and physiology,the mechanisms by which they adapt and adjust to abnormal photoperiod conditions,such as artificial light,have yet to be fully ***,the circadian rhythms of the body mass,activity,and core and peripheral body temperatures of the Eurasian Tree Sparrow(Passer montanus,ETS)-a diurnal passerine-were examined under three different lighting conditions:constant light(LL),constant darkness(DD),and normal light-dark cycles(LD).Our results showed that the activity,body mass,core,tarsometatarsus,and eye temperatures of the ETSs varied significantly with treatment,time,and the interaction between treatment and time;however,there was no significant change in body mass in response to the interaction between time and *** LD conditions,the ETSs exhibited significant circadian rhythms in activity and core,tarsometatarsus,and eye *** LL conditions,only the core temperature exhibited significant *** DD conditions,there were no significant circadian rhythms in activity,body mass,and eye temperature;however,the core and tarsometatarsus temperatures remained *** results indicate that the core body temperature rhythm of ETS is endogenous and can be maintained under abnormal *** contrast,the activity and body surface temperature,uncoupled from the core body temperature under abnormal photoperiod conditions,strongly depend on *** results differ from those of other diurnal avian species,suggesting a unique coping mechanism of ETS in response to an abnormal photoperiod.

关键词： Eurasian Tree Sparrow Activity Body mass Body temperature Circadian rhythm