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11.
A germination experiment of pre-treated seeds of Melia azedarach was conducted in the nursery of Forestry and Wood Technology Discipline, Khulna University, Bangladesh. Matured seeds of
Melia azedarach were collected from healthy trees of National Botanical Garden, Bangladesh and were treated with five pre-sowing treatments
(control, immersion in cold water, immersion in hot water, scarification with sand paper, and immersion in concentrated H2SO4) on seed germination. Results revealed that the germination rates of pre-sowing treated seeds were significantly increased
compared to those in control, except for cold water treatment. The highest germination success (80%) was found in scarification
with sand paper, followed by 74% and 69% in immersion in H2SO4 and hot water treatment, respectively. Germination started on 8–11 days and completed on 20–21 days of the germination period
in all cases. Analysis of variance showed the significance difference in germination success among the treatments but no significance
difference in germination period among the treatment. Hot water treatment may be recommended on seed germination of the species
in rural Bangladesh. 相似文献
12.
Shorea robusta Gaertn.f.(Sal)is one of the important timber-yielding plants in India,which dominates the vegetation of Terai landscape of Uttar Pradesh state in India forming various communities based on its associations.The present study deals with delineation,mapping and characterization of various communities of Sal(Shorea robusta)forests in Terai landscape of Uttar Pradesh,India ranging across over 16districts.Field survey and visual interpretation based forest vegetation type classification and mapping was carried out as part of the project entitled‘Biodiversity characterization at landscape level using remote sensing and GIS’.Indian Remote Sensing-P6(Resourcesat-1)Linear Imaging Self Scanner-III satellite data was used during the study.The total area covered by different Sal forests was found to be approximately2256.77 km2.Sal communities were identified and characterized based on their spectral properties,physiognomy and phytosociological characteristics.Following nine Sal communities were identified,delineated and mapped with reasonable accuracy viz.,Chandar,Damar,dry plains,moist plains,western alluvium,western alluvium plains,mixed moist deciduous,mixed dry deciduous and Siwalik.It is evident from the area estimates that mixed moist deciduous Sal is the most dominant community in the region covering around(1613.90 km2),other major communities were found as western alluvium plains Sal(362.44 km2),mixed dry deciduous Sal(362.44 km2)and dry plains Sal(107.71 km2).The Terai landscape of Uttar Pradesh faces tremendous anthropogenic pressure leading to deterioration of the forests.Community level information could be used monitoring the status as well as for micro level conservation and planning of the Sal forests in Terai Landscape of Uttar Pradesh. 相似文献
13.
Matin MA Rafi MA 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2006,53(Z1):26-28
All animal diseases have the potential to affect human lives adversely by reducing the quantity and/or quality of food (meat, milk, etc.), secondary livestock products (hides, skins and fibres) and animal power (traction and transport). The importance of the livestock sector is growing more rapidly than any other agricultural sector in Pakistan. In the past, livestock production in Pakistan has been affected because of transboundary animal diseases like rinderpest, foot and mouth disease and peste des petits ruminants disease, posing a serious threat to the livestock industry in Pakistan. The continuing persistence of rinderpest has been of grave concern for the entire region including Pakistan. The export of livestock products managed to retain its growth with relaxation of restrictions imposed by the Gulf states in the year 2001 only. Pakistan has been provisionally declared a rinderpest free country in 2003, as a result of a vigorous eradication programme. 相似文献
14.
15.
Matin Mahmoudifard Ahmad Mousavi Shoushtari Maryam Shanehsaz 《Fibers and Polymers》2014,15(9):1797-1803
Nanofibrous membranes are intensively applied to fabricate advanced intelligent devices like highly sensitive sensors due to their flexibility, high porosity, high surface area and good mechanical and chemical stability. In this work, fluorescent cadmium telluride (CdTe) quantum dots (Q.Ds) were synthesized and then uniformly embedded in poly vinyl alcohol (PVA) nanofibers by electrospinning technique to serve as reversible quenching fluorescence-based sensor to detect the traces of benzene, toluene and xylene vapors selectively at room temperature. Fluorescence analysis suggested that Q.Ds preserve their original fluorescent property in solid nanofiber as if they were in solution. Scanning electron microscopy images showed the uniform diameter of nanofibers. In addition, Fluorescence and transmission electron microscopy (TEM) measurements confirmed the uniform distribution of the Q.Ds into nanofibers structures. The main mechanism of quenching based sensor was designated as electron transfer from thiogalycolic acid (TGA) — capped Q.D surface to target volatile organic compounds (VOC’s) vapors. Fabricated sensor showed selectively sensing upon trace of different target vapors due to the difference in the electronegativity of various VOC’s molecules. For example exposure to more electron withdrawing toluene molecules induces severe quenching effect on fluorescence intensity of Q.D (about 25 %) over xylene exposure. Moreover, it was observed that reducing the diameter of nanofibers enhanced the sensitivity of sensor. 相似文献
16.
Matin Mahmoudifard Ahmad Mousavi Shoushtari Afshin Mohsenifar 《Fibers and Polymers》2012,13(8):1031-1036
CdTe quantum dot/PVA (poly vinyl alcohol) composite nanofiber was successfully fabricated by eletrospinning process. CdTe quantum dots were uniformly dispersed and stabilized into solid nanofiber structure. Spectrofluorometer analysis revealed whenever Q.D??s enter to the PVA solution, due to the aggregation of Q.D??s red shift happens; however, when blend Q.D-PVA solution changes to nanofiber form via electrospining, this shift phenomenon offsets and original fluorescence properties of Q.D??s does not degraded due to excellent individual dispersion of Q.D in the nanofibers structure. It is also turned out that the proportion of Q.D??s incorporated in the composite solution of electrospining has strong influence on the nanofiber morphology. Addition of Q.D??s to PVA solution causes remarkable changes in the conductivity and solution viscosity, therefore different nanofiber morphologies can be obtained as evidenced by scanning electron microscopy. Furthermore, differential scanning calorimetric (DSC) revealed addition of small amount of Q.D??s to the electrospining solution causes strenuous improvement in crystalinity and heat of nanofiber fusion. Fluorescence and transmission electron microscopy (TEM) measurements confirmed the evenly dispersion of the Q.D??s into nanofibers structures. 相似文献
17.
为研究孟加拉干旱区灌溉方式、株距及其交互作用对甘蔗分蘖数量、可榨甘蔗数量、甘蔗产量以及蔗糖含量的影响 ,在孟加拉第 11农业生态区的洪积平原上进行了为期 3年的栽培试验 .试验株距分别为 30 ,4 5,6 0和 75cm ,试验灌溉方式为天然降雨配合点灌和漫灌 .试验区按裂区试验法进行布置 ,灌溉方式则按小区布设 ,株距试验布置在主试验区 .试验结果表明 ,灌溉方式、栽植株距以及它们之间的交互作用对甘蔗产量、含糖量有显著影响 .就株距而言 ,4 5cm的株距可以获得最高的甘蔗产量(75 81t·hm- 2 ) .同样 ,在雨养、点灌及漫灌三种灌溉方式中 ,漫灌的甘蔗产量最高 (91 2 7t·hm- 2 ) .最好的栽培技术组合为 4 5cm株距配合漫灌 ,甘蔗分蘖数、可榨甘蔗数、甘蔗产量、产糖量以及投入产出比分别高达 2 0 3× 10 3株·hm- 2 ,115 53× 10 3株·hm- 2 ,10 1 6 4t·hm- 2 ,8 45t·hm- 2 和 5 52∶1 相似文献
18.
This study was conducted to investigate the influence of waterlogging on availability of nutrients in paddy soils. The five soils were incubated under a waterlogged condition at 30 °C for 12 weeks. The EC, Eh, pH, NH4, K, Na, Ca, Mg, Cl, P, Fe, and Mn of soil solutions were monitored over the waterlogged period. The Eh values generally dropped to the lowest point within 14 days of waterlogging, then increased, and reached equilibrium after 8 weeks of waterlogging. The soil pH decreased in the first 2–4 weeks of waterlogging. The EC values increased partly due to dissolution of soluble salts in the first 2 weeks. The concentrations of soluble NH4 were significantly increased with waterlogging, reached maximum values at week 4–6, and then declined to the initial level. Waterlogging increased the concentration of soluble K, Ca, Mg, Fe, and Mn ions, the magnitudes of changes were greatly affected by soil properties. Increases in soluble Na, K, Ca, and Mg were attributed to the increase in solubility of insoluble salts and increase in competition for the exchange sites. Increases in soluble Fe and Mn induced by waterlogging were attributed to the dissolution of Fe and Mn oxides under reduced conditions. 相似文献
19.
Seed morphology, germination and seedlings growth of Acacia auriculiformis were studied. The experiment was conducted in the nursery of Forestry and Wood Technology Discipline, Khulna University,
Bangladesh. Matured seeds of the species were collected from healthy trees of road side plantation from different areas of
Khulna District, Bangladesh and treated with five pre-sowing treatments (control, immersion in cold water, immersion in hot
water, scarification with sand paper and immersion in concentrated H2SO4). The average length, breadth and thickness were found to be (0.58±0.017) cm, (0.44±0.007) cm and (0.20±0.089) cm, respectively.
Germination was conducted in polybags with a mixture of top soil, coconut husk, coarse sand, and fine sand in a ratio of 3:4:1:1.
Results reveal that pre-sowing treatments influences the germination rates of seeds that significantly increase the percentage
germination compared with those in control (43%) and cold water treatment (52%). The highest germination success rate was
found 83% in hot water treatment followed by 78% in scarification with sand paper, and 75% with immersion in H2SO4. Germination started from 7 to 12 days and completed between 28 and 35 days period in all treatments. ANOVA showed the significant
difference (p<0.05) among the treatments in seed germination, but no significant difference among treatment with regard to starting day,
closing day and total germination period. In case of height and diameter growth, seedlings originated from the seeds with
hot water treatment shows significantly higher in wet season (from May to July). Hot water treatment can be recommended on
seed germination of the species in rural Bangladesh. 相似文献
20.
Metacontrast and saccadic suppression 总被引：1，自引：0，他引：1
A vertical slit of light illuminated during horizontal saccadic eye movements appeared as a horizontally extended smear when stimulation was terminated before the saccade ended. However, on trials for which duration of illumination of the slit was extended into the period after the saccade, the smear appeared shorter and dimmer, and a clear image of the slit was seen. With further increases in duration, no smears were seen at the highest luminance of the slit employed, although smears were more than 2 log units above threshold when flashes were brief. This saccadic suppression is discussed in terms of metacontrast, with the accumulated luminance in the period after the saccade primarily responsible for masking the effects of the stimulation received during the movement of the eye. 相似文献