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Standardization of proton-induced x-ray emission technique for analysis of thick samples

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Chinese Physics B 2015年第9期24卷 171-176页

作者： shad Ali Johar Zeb Abdul Ahad Ishfaq Ahmad m.Haneef Jehan Akbar Department of Physics Hazara University National Center of Physics (NCP)

This paper describes the standardization of the proton-induced x-ray emission（PIXE） technique for finding the elemental composition of thick samples. For the standardization, three different samples of standard reference materials（Srms） were analyzed using this technique and the data were compared with the already known data of these certified Srms. These samples were selected in order to cover the maximum range of elements in the periodic table. Each sample was irradiated for three different values of collected beam charges at three different times. A proton beam of 2.57 me V obtained using 5UDH-II Pelletron accelerator was used for excitation of x-rays from the sample. The acquired experimental data were analyzed using the GUPIXWIN software. The results show that the Srm data and the data obtained using the PIXE technique are in good agreement.

关键词： standardization thick samples PIXE analysis

Effect of magnetite content on Bond work index and preconditioning: Case study on Chadormalu iron ore mine

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Journal of Central South University 2018年第4期25卷 795-804页

作者： Hossein INANLOO ArABI shad F SErESHKI m ATAEI m KArAmOOZIAN Department of mining Petroleum and Geophysics Shahrood University of Technology

Grinding is one of the most costly operations in the mechanical breaking and *** of the breakage characteristics and preconditioning is important to increase the grinding *** of the seismic,mechanical and breakage properties of iron oxides are very important parameters for investigating the rock fragmentation by blasting and comminution processes in iron ore *** this paper,at first,geomechanical and seismic properties of the oxide ores(magnetite and hematite)in the Chadormalu iron ore mine were *** results showed that the percentage of magnetite has a direct relationship with uniaxial compressive strength,tensile strength and P and S wave’s velocities and has an inverse relationship with Poisson ratio and ***,to study breakage and preconditioning characteristics in the iron ores,two samples with different magnetite percents were blasted by detonation *** results showed that with higher percentage of magnetite,the number of fractures induced by blasting *** work index and magnetite percent were investigated in the 430 blasts in the *** investigation not only confirmed the small scale blasting results,but also showed that increasing the magnetite percent up to 50%noticeably reduces Bond work index and energy consumption in the grinding ***,the relationship between muck pile fragmentation and magnetite percentage were studied for several blasts that had the same blast pattern parameters and similar geology *** results also confirmed precedents conclusions regarding magnetite percent and preconditioning relationship.

关键词： iron oxides geomchanical parameter preconditioning magnetite percent energy consumption

Factors influencing mercury accumulation in three species of forage fish from Caddo Lake, Texas, USA

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Journal of Environmental Sciences 2010年第8期22卷 1158-1163页

作者： matthew m Chumchal ray W Drenner David r Cross K David Hambright Department of Biology Texas Christian University 2800 S. University Dr Department of Psychology Texas Christian University 2800 S. University Dr Program in Ecology and Evolutionary Biology Biological Station and Department of Zoology 730 Van Vleet Oval University of Oklahoma

most studies that have examined mercury （Hg） contamination of fish have focused on game species feeding near the top of the food web, while studies that examine forage fish that feed near the base of the food web are rare. We conducted a survey of Hg contamination in three species of forage fish, brook silverside （Labidesthes sicculus）, threadfin shad （Dorosoma petenense） and gizzard shad （Dorosoma cepedianum）, from Caddo Lake, Texas, USA and found species-specific differences in Hg concentrations. We examined total length, age, trophic position （determined using δ15N）, and growth rate of forage fish as factors that could have influenced within-and between-species differences in Hg concentration. Total length and age were the best predictors of within-species differences in Hg concentration. Between-species differences in Hg concentrations were most strongly influenced by trophic position.

关键词： mercury trophic position forage fish

氮沉降背景下土壤微生物对入侵植物乌桕叶绿素荧光特征的影响

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生态学报 2021年第23期41卷 9377-9387页

作者：方海富冯为迅罗来聪高宇王佰慧 shad Nasir 魏启轩邹瑜苏思思张令江西农业大学林学院江西省森林培育重点实验室江西特色林木资源培育与利用2011协同创新中心南昌330045

植物入侵会造成入侵地生态系统功能和稳定性的破坏。与原产地种源相比,入侵种源植物在生理学特性方面有所不同,使其在资源利用和抵抗环境胁迫具有较强的竞争优势。叶绿素荧光特性与植物光合作用效率密切相关,对植物生长具有重要作用。... 详细信息

植物入侵会造成入侵地生态系统功能和稳定性的破坏。与原产地种源相比,入侵种源植物在生理学特性方面有所不同,使其在资源利用和抵抗环境胁迫具有较强的竞争优势。叶绿素荧光特性与植物光合作用效率密切相关,对植物生长具有重要作用。氮沉降加剧是全球变化的一个重要因子,土壤微生物对植物吸收利用土壤养分至关重要。通过施用细菌抑制剂(链霉素)和真菌抑制剂(扑海因)选择性抑制的土壤微生物活性,开展乌桕盆栽实验,在模拟氮沉降背景下,研究不同微生物群落如何影响入侵乌桕叶绿素荧光特性,有助于理解入侵植物的进化特征和入侵机制,为有效防控入侵植物并降低其对生态系统危害提供理论依据。以原产地地和入侵地两个种源乌桕(Triadica sebifera)为研究对象,在氮沉降条件下,通过调控土壤细菌和真菌,探讨两个种源乌桕叶绿素荧光参数差异。结果显示:氮沉降显著增加乌桕相对叶绿素含量(SPAD)、光系统II的最大量子产率(F_(v)/F_(m))、非光化学猝灭(NPQ)和半饱和光强(I_(k))。入侵种源乌桕比原产地具有较低SPAD。氮沉降与细菌抑制剂共同作用显著增强了F_(v)/F_(m)、NPQ和I_(k),显著减弱了光能利用率(α)和SPAD。细菌抑制剂减缓了本地种源乌桕α,真菌抑制剂促进本地种源乌桕I_(k),抑制入侵种源乌桕I_(k),细菌和真菌抑制剂可显著降低原产地乌桕α。氮沉降与生物抑制剂可显著作用于乌桕叶片SPAD。氮沉降、土壤微生物和不同乌桕种源可共同作用于光系统Ⅱ实际光合量子产率Y(Ⅱ),α和潜在最大相对电子传递速率(ETr_(max))。因此,氮沉降与生物抑制剂对乌桕叶绿素荧光特性具有协同作用,入侵种源乌桕对土壤微生物控制的响应不明显,在微生物控制条件下依然具有较强的适应能力,因而具有较强的入侵能力。

关键词：叶绿素荧光参数氮沉降细菌真菌植物入侵

Temperature Based Spatiotemporal Growth monitoring of rice Plant from Germination-ripening Stage Using remote Sensing and GIS Techniques

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Advances in remote Sensing 2018年第1期7卷 1-14页

作者： S. m. H. raza S. A. mahmood H. Batool T. J. shad S. Alvi F. Waseems m. Atif Butt S. Shehzad Hassan Ali Imam mirza remote Sensing and GIS Group Department of Space Science University of the Punjab Quaid-e-Azam Campus Lahore Pakistan Department of Geography University of the Punjab Quaid e Azam Campus Lahore Pakistan

rice (Oryza sativa) is the second staple food largely grown and widely consumed in Pakistan. About 10% of the total crop area of Pakistan is cultivated by rice that takes a part in value addition of almost 1.3% - 1.6% in the total Gross Domestic Product (GDP). Due to global warming, temperature has a profound impact on rice crop phenology. Low temperature is the main factor of delay in rice plant growth and very high temperature results in stressed and short heighted plant so the crop sown in a region at the same time is not ready to harvest at same hours but a delay is observed. The study area under investigation was district Sheikhupura, Nankana, Lahore, Gujranawala and Hafizabad, which are famous for rice productivity. Landsat 7, 8 freely available thermal dataset are used to calculated pixel based temperature values to evaluate growth using agricultural growth indicators. The total covered area was 13,480 km2 in which 484 km2 area was marked as less growth rate area with low temperature values due to water body and excess of vegetation over there. About 7960 km2 area is marked as good for growth experiencing optimum temperature for rice plant. Approximately 4944 km2 area is marked as stressed rice plant area experiencing high temperature values adjacent to urban population. An attempt is made here to map this effect of temperature-based growth variability of the rice plant across the study area.

关键词： Climate Gross Domestic Product (GDP) Global Warming Phenology Temperature

Assessing recent gradual upsurge of marine captured Hilsa stock(Tenualosa ilisha)in Bangladesh

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Aquaculture and Fisheries 2019年第4期4卷 156-165页

作者： Ehsanul Karim Qun Liu ming Sun Partho Protim Barman Shanur Jahedul Hasan m.Enamul Hoq College of Fisheries Ocean University of ChinaQingdao 266003China Bangladesh Fisheries research Institute(BFrI) Mymensingh 2201Bangladesh

The anadromous Hilsa shad(Tenualosa ilisha)fishery is the prime single species fishery of Bangladesh that driven by open access system which was selected for this *** purpose of this study was to assess the mSY(maximum Sustainable Yield)in order to review the effectivity of the ongoing management policy of this *** this reason,time series maritime or downstream catch-effort data of the Bay of Bengal were assembled from the Department of Fisheries,***,CPUE and other population parameters were estimated through Surplus Production models(SPms)using computer software packages of CEDA,ASPIC and *** biological reference points of mSY from the best fitted CEDA package was 282,100 t(r^(2)=0.822)for the normal assumptions of the Schaefer and Pella-Tomlinson *** values from the ASPIC packages(324,100 t and 263,500 t;for Fox and Schaefer model)and Schaefer model from TropFishr(345,486t)were larger than the catch in 2017(278,948 t).The values of F ratio(F/FmSY)for all SPms were found less than 1 and B ratio(B/BmSY)were greater than 1 that clearly indicate the gradual upsurge of the Hilsa *** on the above findings of BrPs,it also proves the effectivity of the current“Hilsa fishery management action plan”by the authorities.

关键词： Tenualosa ilisha SPm(surplus production model) CEDA(catch and effort data analysis) ASPIC(A surplus production model incorporate covariates) TropFishr