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排序方式: 共有224条查询结果,搜索用时 15 毫秒
1.
Virginija Sacevičienė Milda Jucienė Vaida Dobilaitė Valentina Krylova Skirma Žalenkienė Nijolė Dukštienė Raimondas Bliūdžius 《应用聚合物科学杂志》2019,136(21):47523
The aim of this work was to investigate the physical and mechanical performance of architectural polyester (PES)–poly(vinyl chloride) (PVC) membranes exposed to different artificial aging conditions. Two commercially available architectural membranes were chosen as research objects. The durability of the PES/PVC fabrics was evaluated by the loss in mechanical performance, scanning electron microscopy, and X-ray diffraction analysis in order to understand the effect of the degradation agents on the surface of the membranes. The mechanical performance of the PES/PVC membranes was unchanged. Scanning electron microscopy images of the tested materials showed initial cracks after aging. The X-ray fluorescence analysis showed that at the time of aging, the amount of Cl and Si decreased slightly, while Ti decreased by half, and Ca by volume increased twice. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47523. 相似文献
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This article represents the result of experimental research on transient heat transfer in a multilayered (heterogeneous) wall. Our non-steady thermal transmission simulation is based on a finite-difference calculation method. The value of a Fourier number shows the similarity of thermal variation in conditional layers of an enclosure. Most scientists recommend using no more than a value of 0.5 for the Fourier number when performing calculations on dynamic (transient) heat transfer. The value of the Fourier number is determined in order to acquire reliable calculation results with optimal accuracy. To compare the results of simulation with experimental research, a transient heat transfer calculation spreadsheet was created. Our research has shown that a Fourier number of around 0.5 or even 0.32 is not sufficient (\({\approx }17\,\%\) of oscillation amplitude) for calculations of transient heat transfer in a multilayered wall. The least distorted calculation results were obtained when the multilayered enclosure was divided into conditional layers with almost equal Fourier number values and when the value of the Fourier number was around 1/6, i.e., approximately 0.17. Statistical deviation analysis using the Statistical Analysis System was applied to assess the accuracy of the spreadsheet calculation and was developed on the basis of our established methodology. The mean and median absolute error as well as their confidence intervals has been estimated by the two methods with optimal accuracy (\({F}_{\mathrm{oMDF}}= 0.177\) and \(F_{\mathrm{oEPS}}= 0.1633\) values). 相似文献
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The accurate prediction of the visual comfort zone in an indoor environment is difficult as it depends on many parameters. This is especially the case for large compact urban areas in which the density and shadow from neighboring buildings can limit the accessible daylighting in indoor spaces. This paper investigates the satisfaction range for illuminance regarding indoor air temperature in office buildings and the significant parameters affecting this range in six office buildings in Tehran, Iran. Lighting comfort has been evaluated by a subjective survey (509 total responses) and field measurement. The questionnaires were filled out in 146 and 109 rooms in summer and winter, respectively. The results show that the illuminance should not be less than 550 lx, while illuminance between 600 and 650 lx provides the highest satisfaction level. The satisfaction with lighting level is affected by individual parameters such as age, type of activity, and environmental parameters such as window orientation, external obscurations, and season. A relationship was observed between lighting level satisfaction and thermal condition acceptance, and the overall comfort depends more on thermal conditions than the lighting level. 相似文献
5.
Edita Zubrytė Danutė Kaušpėdienė Romas Ragauskas Rima Binkienė Aušra Selskienė 《分离科学与技术》2020,55(16):2855-2868
ABSTRACT A non-hazardous groundwater treatment waste (GWTW) was examined as a low-cost sorbent for Pb(II) and Cu(II) ions. The content of the dominant elements in GWTW was as follows: 78% Fe2O3, 7.4% P2O5, 7.4% CaO and 5.2% SiO2. The removal of Pb(II) and Cu(II) was fast, and more than 67–95% of ions were accumulated by GWTW during the first 3 min. The sorption capacity of GWTW depends on solution pH, concentration and temperature. Equilibrium data fitted well with Langmuir–Freundlich and Langmuir-partition models. The inherently formed nano-adsorbent could be utilized for the treatment of water contaminated with Pb(II) and Cu(II) ions. 相似文献
6.
Emine Kaplanoglu Igor Kolotilin Rima Menassa Cam Donly 《International journal of molecular sciences》2022,23(7)
Plant-mediated RNA interference (RNAi) holds great promise for insect pest control, as plants can be transformed to produce double-stranded RNA (dsRNA) to selectively down-regulate insect genes essential for survival. For optimum potency, dsRNA can be produced in plant plastids, enabling the accumulation of unprocessed dsRNAs. However, the relative effectiveness of this strategy in inducing an RNAi response in insects using different feeding mechanisms is understudied. To investigate this, we first tested an in vitro-synthesized 189 bp dsRNA matching a highly conserved region of the v-ATPaseA gene from cotton mealybug (Phenacoccus solenopsis) on three insect species from two different orders that use leaf-chewing, lacerate-and-flush, or sap-sucking mechanisms to feed, and showed that the dsRNA significantly down-regulated the target gene. We then developed transplastomic Micro-tom tomato plants to produce the dsRNA in plant plastids and showed that the dsRNA is produced in leaf, flower, green fruit, red fruit, and roots, with the highest dsRNA levels found in the leaf. The plastid-produced dsRNA induced a significant gene down-regulation in insects using leaf-chewing and lacerate-and-flush feeding mechanisms, while sap-sucking insects were unaffected. Our results suggest that plastid-produced dsRNA can be used to control leaf-chewing and lacerate-and-flush feeding insects, but may not be useful for sap-sucking insects. 相似文献
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Danguolė Raklevičienė Regina Losinska Danguolė Švegždienė 《Microgravity science and technology》2011,23(2):227-233
Responses of cress (Lepidium sativum L.) seedling leaves to separate and simultaneous illumination with red (660 nm) and far-red (735 nm) light were studied under
fast clinorotation (50 rpm) and usual gravity (1g) conditions. The monochromatic light emitting diodes (LEDs) have been used
for illumination of seedlings from above. The growth and spatial orientation of leaves and the location of presumable gravisensors
in petioles were analysed. Clinorotation in the dark promoted the radial expansion of leaf lamina and unfolding of leaves.
It was shown that clinorotation in red light inhibited significantly the elongation of petioles as compared with that under
the action of gravity force. Simultaneous red and far-red illumination promoted the growth of petioles under clinorotation,
but did not affect the orientation of laminas, which remained the same as of the 1-g control ones. Red light, applied separately
and simultaneously with far-red light, guided the bending of laminas as well as the unfolding of leaf petioles in both usual
and clinorotation conditions. Histological and cytological analyses of petioles revealed the presence of movable amyloplasts
in endodermic cells in proximal region of petioles. Comparison of intracellular positioning of amyloplasts in petioles of
leaves grown under clinorotation and the action of gravity allows a presumption that these plastids may be identified as gravisensors
of garden cress leaves. The obtained data imply that clinorotation and exposition to monochromatic red light or simultaneous
illumination by red and far-red light affect the elongation of petioles of cress seedling leaves. Spectral components guide
the unfolding of laminas in a gravity-independent manner. 相似文献
9.
Rima G Satgé J Dagiral R Lion C Sentenac-Roumanou H Fatôme M Roman V Laval JD 《Metal-Based Drugs》1999,6(1):49-60
The present review describes the work carried out during the last 20 years in the field of the radioprotective activity and toxicity of several classes of organosilicon and organogermanium compounds (i.e. metallathiazolidines, metalladithioacetals, metallatranes and germathianes). 相似文献
10.
A. Survila Z. Mockus R. Juškėnas V. Jasulaitienė 《Journal of Applied Electrochemistry》2001,31(10):1109-1116
Optimal conditions for Sn and Co codeposition were achieved in slightly acid citrate solutions containing no excess of ligand. Sn–Co coatings were deposited with amounts of Co ranging from 15 to 86 mass %. Bright deposits were obtained when the Co content exceeded 76%. These coatings may be considered as solid solutions of tin in -Co and -Co. The -Sn phase is predominant in the case of coatings containing less Co. Voltammograms of the partial processes of Sn(II) and Co(II) reduction may be described quantitatively with the proviso that SnL2– and CoLH– are electrically active complexes. 相似文献