【目的】硅能够缓解一些植物的非生物胁迫症状,但是硅能否缓解鸭茅的铝毒症状并不清楚。为明确硅缓解铝胁迫下鸭茅植株生长发育的调节机理。【方法】试验选取中国西南地区主栽鸭茅品种,德纳塔(Donata)、安巴(Amba)、宝兴(Baoxing)和牧友...【目的】硅能够缓解一些植物的非生物胁迫症状,但是硅能否缓解鸭茅的铝毒症状并不清楚。为明确硅缓解铝胁迫下鸭茅植株生长发育的调节机理。【方法】试验选取中国西南地区主栽鸭茅品种,德纳塔(Donata)、安巴(Amba)、宝兴(Baoxing)和牧友(Potomac)为供试植物,利用水培试验研究了不同添加量的外源硅(0、2 m M)对铝(0、10、30、50和100μM)胁迫下鸭茅(Dactylis glomerata L.)植株生长、形态构建及对铝离子吸收的影响。【结果】(1)外源加硅2 m M明显缓解了铝胁迫下鸭茅植株生长的受抑症状,在一定程度上增加了鸭茅根系干重及枝条干重,并改变了根冠比和叶片重量比的变化趋势;(2)外源加硅明显降低了鸭茅根系和茎叶吸收和积累铝的水平,并显著增加了鸭茅的总根体积、根毛数量和根系伸长率。(3)外源加硅对缓解铝离子胁迫下的根系形态参数根系长度、表面积及体积均具有一定的调节作用。【结论】硅有利于促进铝胁迫下鸭茅植株健康形态的重新构建,并降低植株对铝离子的吸收,从而降低植株的中毒症状。展开更多
A multi-parameter nonlinear elasto-plastic constitutive model which can fully capture the three typical features of stress-strain response, linearity, plasticity-like stress plateau and densification phases was develo...A multi-parameter nonlinear elasto-plastic constitutive model which can fully capture the three typical features of stress-strain response, linearity, plasticity-like stress plateau and densification phases was developed. The functional expression of each parameter was determined using uniaxial compression tests for aluminum alloy foams. The parameters of the model can be systematically varied to describe the effect of relative density which may be responsible for the changes in yield stress and hardening-like or softening-like behavior at various strain rates. A comparison between model predictions and experimental results of the aluminum alloy foams was provided to validate the model. It was proved to be useful in the selection of the optimal-density and energy absorption foam for a specific application at impact events.展开更多
Longitudinal and transverse mechanical properties and energy absorption properties of foam-filled square tubes under quasi-static loading conditions were studied.The foam-filled thin-walled square tube was fabricated ...Longitudinal and transverse mechanical properties and energy absorption properties of foam-filled square tubes under quasi-static loading conditions were studied.The foam-filled thin-walled square tube was fabricated with aluminum tube as its shell and closed-cell Al-Mg alloy foam as its core.The results indicated that the plateau region of the load-displacement curve exhibited a marked fluctuant serration which was clearly related to the formation of folds.The longitudinal deforming mode of foam-filled square tube was the same as that of the empty tube,but the fold number of foam-filled square tube was more than that of the empty tube.The longitudinal compression load and energy absorption value of foam-filled square tube were higher than the sum of that of aluminum foam (alone) and empty tube (alone) due to the interaction between tube and filler.In transverse direction,the compression load and energy absorption ability of foam-filled square tubes were significantly lower than those in longitudinal direction.展开更多
The dry modification of aluminum hydroxide powders with phosphoric acid and the effects of modification of technological conditions on thermal stability, morphology and oil absorption of aluminum hydroxide powders wer...The dry modification of aluminum hydroxide powders with phosphoric acid and the effects of modification of technological conditions on thermal stability, morphology and oil absorption of aluminum hydroxide powders were investigated. The results show that the increase of mass ratio of phosphoric acid to aluminum hydroxide, the decrease of mass concentration of phosphoric acid and prolongation of mixing time are favorable to the improvement of thermal stability of aluminum hydroxide; when the mass ratio of phosphoric acid to aluminum hydroxide is 5:100, the mass concentration of phosphoric acid is 200 g/L and the mixing time is 10 min, the initial temperature of loss of crystal water in aluminum hydroxide rises from about 192.10 to 208.66 ℃, but the dry modification results in the appearance of agglomeration and macro-aggregate in the modified powders, and the oil absorption of modified powders becomes higher than that of original aluminum hydroxide.展开更多
The effects of K and Al in K-deficient and complete nutrient solutions on the growth and nutrient uptake of rice were studied in the work. The effect of Al on the growth of roots and above-ground part of rice was asso...The effects of K and Al in K-deficient and complete nutrient solutions on the growth and nutrient uptake of rice were studied in the work. The effect of Al on the growth of roots and above-ground part of rice was associated with the concentration of Al in solution. A low level (0.1 mmol L-1) of Al promoted but a high level (1 mmol L-1) of Al inhibited the growth of both the root and the aerial part of rice, and the magnitude of K concentration in the nutrient solution also had an appreciable impact on this. Thus, in the low-Al solution, the plant treated with K2 (80 mg K L-1) produced much longer roots, showing the presence of interaction between Al and K; in the high-Al solution the K-treated plant had more and longer roots and a considerably greater dry weight of the above-ground pat compared with the plant deficient in K, showing the alleviating effect of K+ on Al toxicity.The mechanism of the Al-K interaction affecting the rice aerial part growth is not yet known, but part of the reason might be that the excessive amount of Al inhibited the uptake of some nutrients such as Ca and Mg and reduced their transfer to the plant aerial organs, whereas K showed its compensating effect on this; therefore, K could relieve Al toxicity at a high level of Al and promoted rice growth at a lOw level of Al.展开更多
The development of gold and cobalt-copper-nickel deposits in Kamchatka threatens the loss of biodiversity in spawning rivers and lakes and has negative effects on coastal ecosystems. To reduce pollution by mining wast...The development of gold and cobalt-copper-nickel deposits in Kamchatka threatens the loss of biodiversity in spawning rivers and lakes and has negative effects on coastal ecosystems. To reduce pollution by mining wastes, filters with dried marine alga Saccharina bongardiana in combination with zeolite and pumice are recommended. Combined Saccharina-based sorbents remove heavy metal ions more effectively, increasing adsorption capacity by five times compared to mineral （pumice） sorhents. As a result of desorption, a tenfold increase of the solution concentration is reached after the first sorption cycle. Valuable elements （Ni, Co, Cu etc.） can then be extracted from concentrates by any known method. It increases economic efficiency of the mining industry due to recycling of non-ferrous metals. Saccharina-based sorbents can be also utilized for purification of polluted natural waters. It may serve as environmental protection measure and provide for ecological safety of the unique natural environment of Kamchatka and its bioresources.展开更多
A group of Zn-Al layered double hydroxides (LDHs) were synthesized at different temperatures from 25-90 °C in order to investigate the influence of synthesis temperature on characteristics of the LDHs and their p...A group of Zn-Al layered double hydroxides (LDHs) were synthesized at different temperatures from 25-90 °C in order to investigate the influence of synthesis temperature on characteristics of the LDHs and their phosphate adsorption behaviour. The results reveal that an increase in the synthesis temperature generally improves the specific surface area of the sample and the phosphate adsorption capacity. The significantly enhanced crystallin- ity of the Zn-Al-30, synthesized at 30 °C, leads to a remarkable decrease in the specific surface area and consequently a poor phosphate adsorption capacity. It is suggested that the surface adsorption plays an important role in the phosphate uptake by the Zn-Al LDHs. Zn-Al-70 presents a relatively higher crystallinity and a lower specific surface area, compared with Zn-Al-60 and Zn-Al-80, but the highest phosphate adsorption capacity, indicating that surface adsorption is only one of the pathways for phosphate removal. The phosphate adsorption by the Zn-Al follows a pseudo-second-order kinetic equation. The adsorption isotherms fit Langmuir models, and the maximum a dsorption capacities of the Zn-Al-25, Zn-Al-50 and Zn-Al-70 are estimated to be 17.82, 21.01 and 27.10 mg·g-1 adsorbent, respectively.展开更多
The optical absorption of Ti：Al2O3 single crystal has been measured at room temperature, in the wavelength region between 200 nm and 800 nm. The main absorption peaks at 491 nm and 562 nm, the weak infrared absorptio...The optical absorption of Ti：Al2O3 single crystal has been measured at room temperature, in the wavelength region between 200 nm and 800 nm. The main absorption peaks at 491 nm and 562 nm, the weak infrared absorption band with a peak at 650 nm and the strong UV absorption band below 300 nm were observed. The refractive index is discussed by using Fresnel＇s equation. In particular, the Sellmeier equation was determined in the visible region by means on non-conventional method based on the measurement of refraction by using UV-visible spectroscopy. The refractive indices decreased from 3.71 to 1.28 with wavelength in the range 400-800 nm.展开更多
文摘【目的】硅能够缓解一些植物的非生物胁迫症状,但是硅能否缓解鸭茅的铝毒症状并不清楚。为明确硅缓解铝胁迫下鸭茅植株生长发育的调节机理。【方法】试验选取中国西南地区主栽鸭茅品种,德纳塔(Donata)、安巴(Amba)、宝兴(Baoxing)和牧友(Potomac)为供试植物,利用水培试验研究了不同添加量的外源硅(0、2 m M)对铝(0、10、30、50和100μM)胁迫下鸭茅(Dactylis glomerata L.)植株生长、形态构建及对铝离子吸收的影响。【结果】(1)外源加硅2 m M明显缓解了铝胁迫下鸭茅植株生长的受抑症状,在一定程度上增加了鸭茅根系干重及枝条干重,并改变了根冠比和叶片重量比的变化趋势;(2)外源加硅明显降低了鸭茅根系和茎叶吸收和积累铝的水平,并显著增加了鸭茅的总根体积、根毛数量和根系伸长率。(3)外源加硅对缓解铝离子胁迫下的根系形态参数根系长度、表面积及体积均具有一定的调节作用。【结论】硅有利于促进铝胁迫下鸭茅植株健康形态的重新构建,并降低植株对铝离子的吸收,从而降低植株的中毒症状。
基金Projects (90716005, 10802055, 10972153) supported by the National Natural Science Foundation of ChinaProject (2007021005) supported by the Natural Science Foundation of Shanxi Province, China+2 种基金Project supported by the Postdoctoral Science Foundation of ChinaProject supported by the Homecomings Foundation, ChinaProject supported by the Top Young Academic Leaders of Higher Learning Institutions of Shanxi, China
文摘A multi-parameter nonlinear elasto-plastic constitutive model which can fully capture the three typical features of stress-strain response, linearity, plasticity-like stress plateau and densification phases was developed. The functional expression of each parameter was determined using uniaxial compression tests for aluminum alloy foams. The parameters of the model can be systematically varied to describe the effect of relative density which may be responsible for the changes in yield stress and hardening-like or softening-like behavior at various strain rates. A comparison between model predictions and experimental results of the aluminum alloy foams was provided to validate the model. It was proved to be useful in the selection of the optimal-density and energy absorption foam for a specific application at impact events.
基金Project (200412) supported by the Nippon Sheet Glass Foundation,Japan
文摘Longitudinal and transverse mechanical properties and energy absorption properties of foam-filled square tubes under quasi-static loading conditions were studied.The foam-filled thin-walled square tube was fabricated with aluminum tube as its shell and closed-cell Al-Mg alloy foam as its core.The results indicated that the plateau region of the load-displacement curve exhibited a marked fluctuant serration which was clearly related to the formation of folds.The longitudinal deforming mode of foam-filled square tube was the same as that of the empty tube,but the fold number of foam-filled square tube was more than that of the empty tube.The longitudinal compression load and energy absorption value of foam-filled square tube were higher than the sum of that of aluminum foam (alone) and empty tube (alone) due to the interaction between tube and filler.In transverse direction,the compression load and energy absorption ability of foam-filled square tubes were significantly lower than those in longitudinal direction.
基金Project(06SK2011) supported by the Science and Technology Program of Hunan Province, China
文摘The dry modification of aluminum hydroxide powders with phosphoric acid and the effects of modification of technological conditions on thermal stability, morphology and oil absorption of aluminum hydroxide powders were investigated. The results show that the increase of mass ratio of phosphoric acid to aluminum hydroxide, the decrease of mass concentration of phosphoric acid and prolongation of mixing time are favorable to the improvement of thermal stability of aluminum hydroxide; when the mass ratio of phosphoric acid to aluminum hydroxide is 5:100, the mass concentration of phosphoric acid is 200 g/L and the mixing time is 10 min, the initial temperature of loss of crystal water in aluminum hydroxide rises from about 192.10 to 208.66 ℃, but the dry modification results in the appearance of agglomeration and macro-aggregate in the modified powders, and the oil absorption of modified powders becomes higher than that of original aluminum hydroxide.
文摘The effects of K and Al in K-deficient and complete nutrient solutions on the growth and nutrient uptake of rice were studied in the work. The effect of Al on the growth of roots and above-ground part of rice was associated with the concentration of Al in solution. A low level (0.1 mmol L-1) of Al promoted but a high level (1 mmol L-1) of Al inhibited the growth of both the root and the aerial part of rice, and the magnitude of K concentration in the nutrient solution also had an appreciable impact on this. Thus, in the low-Al solution, the plant treated with K2 (80 mg K L-1) produced much longer roots, showing the presence of interaction between Al and K; in the high-Al solution the K-treated plant had more and longer roots and a considerably greater dry weight of the above-ground pat compared with the plant deficient in K, showing the alleviating effect of K+ on Al toxicity.The mechanism of the Al-K interaction affecting the rice aerial part growth is not yet known, but part of the reason might be that the excessive amount of Al inhibited the uptake of some nutrients such as Ca and Mg and reduced their transfer to the plant aerial organs, whereas K showed its compensating effect on this; therefore, K could relieve Al toxicity at a high level of Al and promoted rice growth at a lOw level of Al.
文摘The development of gold and cobalt-copper-nickel deposits in Kamchatka threatens the loss of biodiversity in spawning rivers and lakes and has negative effects on coastal ecosystems. To reduce pollution by mining wastes, filters with dried marine alga Saccharina bongardiana in combination with zeolite and pumice are recommended. Combined Saccharina-based sorbents remove heavy metal ions more effectively, increasing adsorption capacity by five times compared to mineral （pumice） sorhents. As a result of desorption, a tenfold increase of the solution concentration is reached after the first sorption cycle. Valuable elements （Ni, Co, Cu etc.） can then be extracted from concentrates by any known method. It increases economic efficiency of the mining industry due to recycling of non-ferrous metals. Saccharina-based sorbents can be also utilized for purification of polluted natural waters. It may serve as environmental protection measure and provide for ecological safety of the unique natural environment of Kamchatka and its bioresources.
基金Supported by the National Natural Science Foundation of China(50978029,51008023)
文摘A group of Zn-Al layered double hydroxides (LDHs) were synthesized at different temperatures from 25-90 °C in order to investigate the influence of synthesis temperature on characteristics of the LDHs and their phosphate adsorption behaviour. The results reveal that an increase in the synthesis temperature generally improves the specific surface area of the sample and the phosphate adsorption capacity. The significantly enhanced crystallin- ity of the Zn-Al-30, synthesized at 30 °C, leads to a remarkable decrease in the specific surface area and consequently a poor phosphate adsorption capacity. It is suggested that the surface adsorption plays an important role in the phosphate uptake by the Zn-Al LDHs. Zn-Al-70 presents a relatively higher crystallinity and a lower specific surface area, compared with Zn-Al-60 and Zn-Al-80, but the highest phosphate adsorption capacity, indicating that surface adsorption is only one of the pathways for phosphate removal. The phosphate adsorption by the Zn-Al follows a pseudo-second-order kinetic equation. The adsorption isotherms fit Langmuir models, and the maximum a dsorption capacities of the Zn-Al-25, Zn-Al-50 and Zn-Al-70 are estimated to be 17.82, 21.01 and 27.10 mg·g-1 adsorbent, respectively.
文摘The optical absorption of Ti：Al2O3 single crystal has been measured at room temperature, in the wavelength region between 200 nm and 800 nm. The main absorption peaks at 491 nm and 562 nm, the weak infrared absorption band with a peak at 650 nm and the strong UV absorption band below 300 nm were observed. The refractive index is discussed by using Fresnel＇s equation. In particular, the Sellmeier equation was determined in the visible region by means on non-conventional method based on the measurement of refraction by using UV-visible spectroscopy. The refractive indices decreased from 3.71 to 1.28 with wavelength in the range 400-800 nm.
