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Speciesα-diversity promotes butβ-diversity restricts aboveground biomass in tropical forests,depending on stand structure and environmental factors

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Journal of Forestry Research 2023年第5期34卷 889-901页

作者： Umar aftab Abbasi Eskil Mattsson Sarath Premalal Nissanka Arshad Ali Forest Ecology Research Group College of Life SciencesHebei UniversityBaoding 071002People’s Republic of China IVL Swedish Environmental Research Institute Aschebergsgatan 4441133 GothenburgSweden Gothenburg Global Biodiversity Centre(GGBC) GothenburgSweden Department of Crop Science Faculty of AgricultureUniversity of PeradeniyaPeradeniyaSri Lanka

Forest plays a vital role in the global biogeochemical cycles through a high rate of carbon sequestration and harboring ***,local species diversity is declining while also becoming increasingly homogenized across *** eff ects of local biotic processes(e.g.,speciesα-diversity and stand structural heterogeneity)and environmental factors on aboveground biomass(AGB)have been widely tested,there is a huge knowledge gap for the eff ect of regional biotic processes(i.e.,taxonomic and functionalβ-diversity)in ***,we hypothesized that regional and local environmental factors along with biotic processes jointly regulate AGB through species shifts in tropical *** piecewise structural equation modeling(pSEM),we linked climatic water availability,soil fertility,stand structural heterogeneity(either tree DBH inequality,height inequality,or stand density),speciesα-diversity,taxonomic or functionalβ-diversity(and its two components;β-turnover andβ-richness),and AGB across 189 inventory plots in tropical forests of Sri *** fertility and climatic water availability shaped local and regional biotic *** structural heterogeneity promoted speciesα-diversity but declinedβ-diversity(but increasedβ-taxonomic turnover).Speciesα-diversity and stand structural heterogeneity promoted AGB whereas taxonomic and functionalβ-diversity declined(butβ-taxonomic turnover increased)*** relationships of AGB with speciesα-diversity andβ-diversity varied from signifi cant to nonsignifi cant positive depending on the specifi c combinations of stand structural heterogeneity metrics *** study shows that local biotic processes could increase AGB due to the local and regional niche complementarity eff ect whereas the regional biotic processes could restrict AGB due to the regional selection or functional redundancy eff ect under favorable environmental *** argue that biotic homogenization,as well as drought conditions,ma

关键词： Biodiversity Biotic homogenization Climate Forest functioning Soil Tree size

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A system dynamics model for billion trees tsunami afforestation project of Khyber Pakhtunkhwa in Pakistan:Model application to afforestation activities

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Journal of Mountain Science 2019年第11期16卷 2640-2653页

作者： Naila NAZIR Aqsa FAROOQ Sajjad AHMAD JAN aftab AHMAD Department of Economics University of PeshawarKhyber Pakhtunkhwa 25000Pakistan Department of Economics Edwardes CollegePeshawar Saddar 25000Pakistan Global Change Impact Study Center Ministry of Climate Change10-Mauve AreaG-8/1IslamabadPakistan

As part of the global effort to plant billion trees,an afforestation project is launched in Pakistan in Khyber Pakhtunkhwa(KP)province to conserve existing forests and to increase area under forest *** present study is designed to build a Systems'model by incorporating major activities of the Billion Tree Tsunami Afforestation Project(BTTAP)with special focus on afforestation activities to estimate the growth in forest area of *** of complete dataset was a *** fix the model,the raw data taken from the project office has been *** Commission Form 1-Phase I&II helped us with additional *** relied on the data available for one and half period of the project as rest of the data is subject to the completion of the *** results show that the project target to enhance area under forest differs from the target to afforest area under the *** system dynamics'model projection shows that the forest area of KP would be 23.59 million hectares at the end of the BTTA project,thus having an increase of 3.29%instead of 2%that has been initially ***,the results show that the progress to meet the target in some afforestation classes is slow as compared to other *** forestry,plantation on communal lands and owners'plantation need special focus of the *** would affect 0.02 million hectares area of the *** model under study may be used as a reference model that can be replicated to other areas where billion tree campaigns are going on.

关键词： Billion trees project Afforestation System dynamic model Forest area Deforestation Pakistan

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Effect of auxins on axillary and de novo shoot regeneration from in vitro shoot cultures derived from forced epicormic buds of teak (Tectona grandis L.)

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Forestry Studies in China 2012年第3期14卷 180-186页

作者： Akram MUHAMMAD aftab FAHEEM Department of Botany University of the PunjabLahorePunjab 54590Pakistan

Akram MUHAMMAD, aftab FAHEEM＊Abstract In this presentation, we report on de novo and axillary shoot regeneration and rooting of shoots maintained over a long term, from cultures of Tectona grandis L. Shoot-tips of teak shoots forced from epicormic buds were used as the starting material for axenie shoot-culture establishment. Long term maintenance of such axenic shoot cultures was carried out by regular sub-culturing on MS media supplemented with N6-benzyleadenine （BA, 8.8 μmol·L^-1） and indole-3-butyric acid （IBA, 2 μmol·L ^1） for 24 months. Vigorously growing shoot tips （2-3 cm long） were inoculated on the MS basal medium supplemented with different concentrations （0, 1, 2, 4, 6, 8 or 10 ***-L-~） of either [BA or a-naphthaleneacetic acid （NAA） for rooting. Axillary and de novo shoots were de- veloped from axillary and cut basal ends of shoots, respectively. Shoots growing on auxins were further sub-cultured （every 15 days） and maintained for 45 days. The greatest number of de novo （5.06） as well as axillary shoots （2.85） was observed on the MS medium supplemented with 10 μmol-L^-1 NAA or 8 μmol·L^-1 IBA, respectively, after 45 days. The combinations of both IBA （μmol·L^-1）＋ NAA （μmol·L^-1） were tested at different concentrations （4 ＋ 4, 6 ＋ 6, 8 ＋ 8） supplemented to a half strength MS basal medium with 0.1% activated charcoal for rooting of decapitated and non-decapitated de novo and axillary shoots. Rooting from non-decapitated de novo shoots was highest （93.33%） with a mean number of roots of 4.61 on this medium, supplemented with 6 μmol·L^-1 IBA ＋ 6 gmol.L l NAA, after 36 days of initial culture. Individual auxin, however, was not effective for root induction. Rooted shoots were acclimatized in a green house and after four weeks plantlets were transferred to the field.

关键词： auxins de novo shoots epicormic buds in vitro teak

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An efficient method for clonal propagation and in vitro establishment of softwood shoots from epicormic buds of teak(Tectona grandis L.)

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Forestry Studies in China 2009年第2期11卷 105-110页

作者： Muhammad AKRAM Faheem aftab Department of Botany University of the PunjabQ. A. Campus

Softwood shoots were produced from 40 cm long stem segments placed horizontally in flat trays containing sterilized sand under natural light or shade conditions for subsequent rooting and micropropagation studies in teak （Tectona grand＆ L.）. Higher number of shoots （6.17） per log was produced under natural light as compared to shade conditions. Forcing was also better in natural light as compared to shade in terms of shoot length, number of nodes or leaves. For rooting, 2-4 cm long softwood shoots were excised and treated with either indole-3-butyric acid （IBA） or α-naphthyl acetic acid （NAA） at 0, 1000, 2000 or 3000 μmol.L^-1 each or with combinations （1000 ＋ 1000, 2000 ＋ 2000 or 3000 ＋ 3000 μmol.L^-1） and then placed in flat trays containing autoclaved sand at 25 ± 2℃ in 16 h photoperiod at 35 μmol.m^-2.s^-1. After 28 days, softwood cuttings treated with IBA ＋ NAA （3000 ＋ 3000 μmol.L^-1） had highest rooting percentage （89.3%） with 5.5 mean roots. Shoot apex and nodal explants of softwood cuttings were pretreated with 0.1% （w/v） ascorbic acid, boric acid, activated charcoal, citric acid, glutamine or polyvinylpolypyrollidone （PVP） for 24 h to remove phenolic compounds before surface disinfestation. Glutamine （G1） and PVP were equally effective resulting in 60% establishment of shoot apices on MS medium supplemented with 10 μmol.L^-1 6-benzylaminopurine （BAP）＋ 5 μmol.L^-1 NAA. Using shoot apices, highest （42.80） number of multiple shoots with 54.33 mm shoot length were obtained on MS ＋ BAP （8.8 ***.L 1）＋ IBA （2 μmol.L^-1） after 45 days. Shoots were successfully rooted and acclimatized to greenhouse conditions.

关键词： epicormic buds glutamine PVP phenolics Tectona grandis L. tissue culture softwood shoots

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Retraction notice to“Why would sea-level rise for global warming and polar ice-melt?”[Geosci Front 10(2019)481-494]

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Geoscience Frontiers 2020年第3期11卷 1093-1093页

作者： aftab alam Khan Department of Geology University of DhakaDhaka1000Bangladesh

This article has been retracted at the request of the Editor in Chief of the journal,as the author did not follow ethics in publication and plagiarized contents from online resources and published papers without due *... 详细信息

关键词： please journal polar

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Analysis of Eigenvalues for Molecular Structures

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Computers, Materials & Continua 2022年第10期73卷 1225-1236页

作者： Muhammad Haroon aftab Kamel Jebreen Mohammad Issa Sowaity Muhammad Hussain Department of Mathematics and Statistics The University of LahoreLahore54000Pakistan Department of Mathematics An-Najah National UniversityNablusP400Palestine Department of Mathematics Palestince Polytechnic UniversityHebronP766Palestine Department of Mathematics Comsats University IslamabadLahore CampusLahore54000Pakistan

In this article,we study different molecular structures such as Polythiophene network,PLY(n)for n=1,2,and 3,Orthosilicate(Nesosilicate)SiO4,Pyrosilicates(Sorosilicates)Si2O7,Chain silicates(Pyroxenes)(SiO3)n,and Cyclic silicates(Ring Silicates)Si3O9 for their cardinalities,chromatic numbers,graph variations,eigenvalues obtained from the adjacency matrices which are square matrices in order and their corresponding characteristics *** convert the general structures of these chemical networks in to mathematical graphical *** transform the molecular structures of these chemical networks which are mentioned above,into a simple and undirected planar graph and sketch them with various techniques of *** matrices obtained from these simple undirected graphs are *** also label the molecular structures by assigning different *** graphs have also been studied for *** a connected graph,the eigenvalue that shows its peak point(largest value)obtained from the adjacency matrix has multiplicity ***,the gap between the largest and its smallest eigenvalues is interlinked with some form of“connectivity measurement of the structural graph”.We also note that the chemical structures,Orthosilicate(Nesosilicate)SiO4,Pyrosilicates(Sorosilicates)Si2O7,Chain silicates(Pyroxenes)(SiO3)n,and Cyclic silicates(Ring Silicates)Si3O9 generally have two same *** matrices have great importance in the field of computer science.

关键词： Vertex degree edges eigenvalues characteristics polynomials adjacency matrices graphical model genetics polythiophene silicates

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Performance comparison of IEC 61850-90-5 and IEEE C37.118.2based wide area PMU communication networks

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Journal of Modern Power Systems and Clean Energy 2016年第3期4卷 487-495页

作者： Ikbal ALI Mohd Asim aftab S.M.Suhail HUSSAIN Department of Electrical Engineering Faculty of Engineering and TechnologyJamia Millia Islamia(A Central University)Jamia NagarNew Delhi 110025India

Dynamic operation and control of power system is being increasingly done with the help of phasor measurement unit(PMU) based wide area monitoring and control system. The data communication requirements for the PMU based applications are well addressed by IEEE C37.118.2 standard. However, IEC 61850 is now becoming a leading standard for power utility automation needs. A new part of IEC 61850, IEC 61850-90-5, specifying the IEEE C37.118.1 based synchrophasors data transfer according to IEC 61850, will lead to IEC 61850-90-5 based PMU communication networks. A novel IEC 61850-90-5 compliant communication model of PMU is proposed in this paper. We also present a comparative performance analysis of the PMU communication networks supporting the new synchrophasor standard for data transfer, i.e. IEC61850-90-5, and the existing standard, i.e. IEEE C37.118.2, for end to end(ETE) delay requirements for a modified IEEE 30 bus test system.

关键词： Phasor measurement unit IEC 61850-90-5 IEEE C37.118.2 End-to-end delay

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Experimental Investigation on the Mechanical Properties of Natural Fiber Reinforced Concrete

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Journal of Renewable Materials 2022年第5期10卷 1307-1320页

作者： Ismail Shah Jing Li Shengyuan Yang Yubo Zhang aftab Anwar School of Architecture and Civil Engineering Yunnan Agricultural UniversityKunming650000China Key Laboratory of Crop Growth and Intelligent Agriculture of Yunnan Province Yunnan Agricultural UniversityKunming650000China

Recently,addition of various natural fibers to high strength concrete has aroused great interest in the field of building *** is because natural fibers are much cheaper and locally available,as compare to synthetic *** in view,this current research conducted mainly focuses on the static properties of hybridized(sisal/coir),sisal and coir fiber-reinforced *** types of natural fibers sisal and coir were used in the experiment with different lengths of 10,20 and 30 mm and various natural fiber concentrations of 0.5%,1.0%,and 1.5%by mass of cement,to investigate the static properties of sisal fiber reinforced concrete(SFRC),coir fiber reinforced concrete(CFRC)and hybrid fiber reinforced concrete(HFRC).The results indicate that HFRC has increased the compressive strength up to 35.98%with the length of 20 mm and with 0.5%concentration,while the CFRC and SFRC with the length of 10 mm and with 1%concentration have increased the compressive strength up to 33.94%and 24.86%,*** another hand,the split tensile strength was increased by HFRC with the length of 20 mm and with 1%concentration,CFRC with the length of 10 mm and with 1.5%concentration,and SFRC with the length of 30 mm and with 1%concentration have increased up to 25.48%,24.56%and 11.80%,respectively,while the HFRC with the length of 20 mm and with 0.5%concentration has increased the compressive strength of concrete but has decreased the split tensile strength up to 2.28%compared to ***,using the HFRC with the length of 20 mm and with 1%concentration provide the maximum output in terms of split tensile strength.

关键词： Sisal fiber reinforced concrete coir fiber reinforced concrete hybrid fibers compressive and tensile strength

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Interaction of point defects with twin boundaries in Au: A molecular dynamics study

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Chinese Physics B 2013年第9期22卷 496-504页

作者： Fayyaz Hussain Sardar Sikandar Hayat Zulfiqar Ali Shah Najmul Hassan Shaikh aftab Ahmad Department of Physics The Islamia University of Bahawalpur Department of Physics Hazara University

The molecular dynamics simulation technique with many-body and semi-empirical potentials （based on the embedded atom method potentials） has been used to calculate the interactions of point defects with （1 1 1）, （1 1 3）, and （1 2 0） twin boundaries in Au at different temperatures. The interactions of single-, di-, and tri-vacancies （at on- and off-mirror sites） with the twin interfaces at 300 K are calculated. All vacancy clusters are favorable at the on-mirror arrangement near the （1 1 3） twin boundary. Single- and di-vacancies are more favorable at the on-mirror sites near the （1 1 l） twin boundary, while they are favorable at the oft-mirror sites near the （1 2 0） twin boundary. Almost all vacancy clusters energetically prefer to lie in planes closest to the interface rather than away from it, except for tri-vacancies near the （1 2 0） interface at the off-mirror site and for 3.3 and 3.4 vacancy clusters at both sites near the （1 1 1） interface, which are favorable away from the interface. The interaction energy is high at high temperatures.

关键词： molecular dynamics twin boundaries vacancy clusters gold

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Biodegradation of Leather Waste by Enzymatic Treatment

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过程工程学报 2006年第3期6卷 462-465页

作者： Muhammad Nauman aftab Abdul Hameed Ikram-ul-Haq 陈润生 Dept. Biol. Sci. Quaid-i-Azam Univ.IslamabadPakistan Bioinformatics LabInstitute of BiophysicsChinese Academy of SciencesBeijing 100101China Graduate University of Chinese Academy of SciencesBeijing 100049China Dept. Biol. Sci. Quaid-i-Azam Univ.IslamabadPakistan Dept. Botany Government College Univ.LahorePakistan Bioinformatics Lab Institute of BiophysicsChinese Academy of SciencesBeijing 100101China

The treatment of shavings,trimmings and splits of leather waste from tanneries has a potential to generate value-added products. In this study enzymatic treatment of leather waste was performed. This method utilizes alkaline protease produced by Bacillus subtilis in our laboratory by submerged fermentation. Optimum conditions of pH,time duration,temperature and concentration of enzyme were determined for maximum degradation of leather waste. The amount of degradation was measured by the release of amino acid hydroxyproline. Amino acid composition in the hydrolysate obtained by the enzyme hydrolysis was determined. This relative simple biotreatment of leather waste may provide a practical and economical solution.

关键词： leather waste biodegadation Bacillus subtilis alkaline protease

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