Nitric acid pressure leaching of limonitic laterite ores:Regeneration of HNO3 and simultaneous synthesis of fibrous CaSO4·2H2O by-products

An innovative technology,nitric acid pressure leaching of limonitic laterite ores,was proposed by our research team.The HNO3 regeneration is considerable significance for the improvement of the proposed technology and its commercial application,but it has not been systematically investigated.Herein,regenerating HNO3 from Ca(NO3)2 solution with low-cost H2SO4,and simultaneous synthesis of fibrous CaSO4·2H2O by-products were studied.As a theoretical basis,the solubility of CaSO4·2H2O in HNO3 medium is studied.It is concluded that the solubility of CaSO4·2H2O increases with increasing temperature or increasing HNO3 concentration,which has considerable guiding significance for the subsequent experimental research and analysis.Then,the effects of various factors on the residual Ca^2+ concentration of filtrate,the regenerated HNO3 concentration and the morphology of synthesized products are investigated using ICP-AES and SEM.And the effect mechanism is also analyzed.The results indicate the regenerated HNO3 concentration reaches 116 g/L with the residual Ca^2+ concentration being 9.7 g/L at the optimum conditions.Moreover,fibrous CaSO4·2H2O by-products with high aspect ratios(length,406.32μm;diameter,14.71μm;aspect ratio,27.62)can be simultaneously synthesized.

A comparative study on different regeneration processes of Pt-Sn/γ-Al2O3 catalysts for propane dehydrogenation

Three different regeneration processes including hydrogen or nitrogen purging and coke-burning treatment were used to restore the Pt-Sn/γ-AlOcatalysts, through which propane dehydrogenation reaction was performed in a consecutive reaction-regeneration mode. It was found that the catalyst using hydrogen regeneration showed the best stability compared with those regenerated by nitrogen purging and coke-burning treatment, suggesting that hydrogen regeneration is an effective approach for maintaining the performance of Pt-Sn/γ-AlOcatalysts in propane dehydrogenation reaction. The effect of different regeneration atmospheres on the metal active center and the coke deposition was investigated by XRD,TEM, N-physisorption, TPO, TG and Raman technologies, and the results revealed that hydrogen or nitrogen regeneration resulted in little impact on the size and structure of metal active center, retaining the effective Pt Sn phase over the catalyst. Moreover, hydrogen regeneration not only removed the low dense components of the coke, but also altered the property of the residual coke through hydrogenation, leading to a higher mobility of coke, and thus a higher accessibility of the metal active centers. Whereas nitrogen regeneration only removed the low dense components of the coke. Although coke-burning regeneration caused a thorough coke removal, the catalyst subjected to repeated redox exhibited poor stability due to metal agglomeration, phase segregation and the resulting large PtSn particle and core-shell structure with a Sn-rich surface.

A novel catalytic method for the regeneration of carbonyl compounds from oximes using aluminum nitrate and NaBr as catalyst

A wide variety of aldoximes and ketoximes were regenerated to corresponding carbonyl compounds with Al（NO3）3·9H2O in presence of catalytic amounts of NaBr in CH2Cl2 at room temperature.

C6H10S2O联合Nano-CaCO3对铅染毒小鼠海马学习记忆功能的影响

评价 C6H10S2O联合Nano-CaCO3对铅染毒小鼠的海马学习记忆功能产生的影响,以指导铅染毒相关问题的处理。方法 选择齐齐哈尔医学院动物实验中心提供的20-30g 健康雌性 KM 小鼠,健康清洁级,分为正常对照组、模型对照组、C6H10S2O 组、Nano-CaCO3组、联合治疗组,其中后四组均为铅染毒模型。五组的饲养条件相同,方法 /剂量建立铅染毒模型,提供对应治疗方法,通过评估体质量与血液中铅元素含量、NO含量和ACHE活力、水迷宫、新物体识别测量的结果,判断治疗效果。结果 与空白对照组比较,模型对照组的体质量显著降低(P<0.05),血铅含量显著增加(P<0.05);与模型对照组比较,C6H10S2O组和联合治疗组小鼠的体质量显著提高(P<0.05),而血铅含量仅在联合治疗组显著减少(P<0.05);其他三组的体质量和血铅含量均无统计学差异(P>0.05)。与模型对照组比较,联合治疗组的跨越隐匿平台次数和平台象限游泳路程显著增加(P<0.05);与Nano-CaCO3组比较,联合治疗组的跨越隐匿平台次数和平台象限游泳路程也显著增加(P<0.05)。五组在NO含量和ACHE活力、认知指数方面的对比,差异均不存在统计学意义(P>0.05)。结论 C6H10S2O联合Nano-CaCO3可以减少铅含量,提高体质量,对空间学习能力有一定影响,但对认知能力、学习记忆能力不存在显著影响。

A dendritic Cu/Cu_(2)O structure with high curvature enables rapid and efficient reduction of carbon dioxide to C_(2) in an H-cell

Electrocatalytic reduction of CO_(2)(CO_(2)RR)to multicarbon products is an efficient approach for ad-dressing the energy crisis and achieving carbon neutrality.In H-cells,achieving high-current C_(2)products is challenging because of the inefficient mass transfer of the catalyst and the presence of the hydrogen evolution reaction(HER).In this study,dendritic Cu/Cu_(2)O with abundant Cu^(0)/Cu^(+)interfaces and numerous dendritic curves was synthesized in a CO_(2)atmosphere,resulting in the high selectivity and current density of the C_(2)products.Dendritic Cu/Cu_(2)O achieved a C_(2)Faradaic efficiency of 69.8%and a C_(2)partial current density of 129.5 mA cm^(-2)in an H-cell.Finite element simulations showed that a dendritic structure with a high curvature generates a strong electric field,leading to a localized CO_(2)concentration.Additionally,DRT analysis showed that a dendritic struc-ture with a high curvature actively adsorbed the surrounding high concentration of CO_(2),enhancing the mass transfer rate and achieving a high current density.During the experiment,the impact of the electronic structure on the performance of the catalyst was investigated by varying the atomic ratio of Cu^(0)/Cu^(+) on the catalyst surface,which resulted in improved ethylene selectivity.Under the optimal atomic ratio of Cu^(0)/Cu^(+),the charge transfer resistance was minimized,and the desorption rate of the intermediates was low,favoring C_(2) generation.Density functional theory calculations indicated that the Cu^(0)/Cu^(+) interfaces exhibited a lower Gibbs free energy for the rate-determining step,enhancing C_(2)H_(4) formation.The Cu/Cu_(2)O catalyst also exhibited a low Cu d-band center,which enhanced the adsorption stability of *CO on the surface and facilitated C_(2)formation.This observa-tion explained the higher yield of C_(2) products at the Cu^(0)/Cu^(+) interface than that of H_(2) under rapid mass transfer.The results of the net present value model showed that the H-cell holds promising industrial prospects,contingent upon it being a catalyst with both high selectivity and high current density.This approach of integrating the structure and composition provides new insights for ad-vancing the CO_(2)RR towards high-current C_(2) products.

Recovery and regeneration of Al_2O_3 with a high specific surface area from spent hydrodesulfurization catalyst CoMo/Al_2O_3

Aluminum recovery is a key issue for the overall recycling of valuable metals from spent catalysts. This paper focuses on the recovery and regeneration of alumina with high additional value from the spent hydrodesulfurization catalyst CoMo/Al_2O_3. The results indicate that 98.13% alumina is successfully leached from the treated spent catalysts by an alkaline leaching process under the conditions of 5 mol·L^(-1) sodium hydroxide,a liquid/solid ratio of 20 ml·g^(-1),a temperature of 160 0 C and a reaction time of 4 h. In the leaching residue, no difficult leaching compound is found and cobalt and nickel are enriched,both of which are conducive to the subsequent metal recovery step. The reaction order of aluminum leaching is 0.99. This reaction fits well with the interfacial chemical reaction model, and its apparent activation energy is calculated as 45.50 kJ mol^(-1). Subsequently, y-Al_2O_3 with a high specific surface area of 278.3 m^2·g^(-1), a mean size of 2.2 μm and an average pore size of 3.10 nm is then regenerated from the lixivium, indicating its suitability for use as a catalyst carrier. The recovery and regeneration of alumina from spent catalysts can not only significantly contribute to the total recycling of such hazardous spent catalysts but also provide a new approach for the preparation of y-Al_2O_3 with a high specific surface area using spent catalysts as the aluminum sources.

A novel application of the SAWD-Sabatier-SPE integrated system for CO_2 removal and O_2 regeneration in submarine cabins during prolonged voyages

To improve the working and living environment of submarine crews, an integrated system of CO2 removal and O2 regeneration was designed to work under experimental conditions for 50 people in a submarine cabin during prolonged voyages. The integrated system comprises a solid amine water desorption （SAWD） unit for CO2 collection and concentration, a Sabatier reactor for CO2 reduction and a solid polymer electrolyte （SPE） unit for O2 regeneration by electrolysis. The performances of the SAWD-Sabatier-SPE integrated system were investigated. The experimental results from the SAWD unit showed that the average CO2 concentration in the CO2 storage tank was more than 96% and the outlet CO2 concentration was nearly zero in the first 45 min, and less than 1/10 of inlet CO2 after 60 min when input CO2 was 0.5% （1000 L）. About 950 L of CO2 was recovered with a recovery rate of 92%-97%. The output CO2 concentration was less than 0.2%, which showed that the adsorption-desorption performance of this unit was excellent. In the CO2 reduction unit we investigated mainly the start-up and reaction performance of the Sabatier reactor. The start-up time of the Sabatier reactor was 6, 8 and 10 rain when the start-up temperature was 187.3, 179.5 and 168 ℃, respectively. The product water was colorless, transparent, and had a pH of 6.9-7.5, and an electrical conductivity of 80μs/cm. The sum of the concentration of metal ions （Ru^3＋, Al^3＋, Pb^2＋） was 0.028% and that of nonmetal ions （Cl^-, SO4^2-） was 0.05%. In the O2 regeneration unit, the O2 generation rate was 0.48 m^3/d and the quantity was 2400 L, sufficient to meet the submariners＇ basic oxygen demands. These results may be useful as a basis for establishing CO2-1evel limits and O2 regeneration systems in submarines or similar enclosed compartments during prolonged voyages.

GLS1通过激活Nrf2/HO-1轴抑制过氧化氢诱导的ARPE-19细胞氧化应激、自噬与凋亡

目的探究GLS1对过氧化氢诱导的ARPE-19细胞氧化应激、自噬与凋亡的影响及机制。方法ARPE-19细胞分为对照组、H_(2)O_(2)组、H_(2)O_(2)+Vector组、H_(2)O_(2)+GLS1组,对照组细胞不做任何处理,H_(2)O_(2)组细胞用200μmol/L H_(2)O_(2)诱导48h,H_(2)O_(2)+Vector组和H_(2)O_(2)+GLS1组细胞转染Vector和GLS1质粒后用200μmol/L H_(2)O_(2)诱导48 h,比色法测定各组细胞SOD、GSH和MDA浓度,透射电镜观察各组细胞自噬小体,流式细胞术检测各组细胞凋亡水平,Western blot检测各组细胞Nrf2、HO-1、LC3-Ⅱ、p62的表达。结果与对照组比较,H_(2)O_(2)组ARPE-19细胞SOD、GSH表达显著下降,MDA显著增加,自噬小体数目显著增加,细胞凋亡显著增加,LC3-Ⅱ表达显著上调,P62、抗核因子红系2相关因子2(nuclear factor erythroid 2-related factor 2,Nrf2)、血红素氧合酶1(heme Oxygenase-1,HO-1)表达显著下调。与H_(2)O_(2)+Vector组比较,H_(2)O_(2)+GLS1组细胞SOD、GSH表达显著增加,MDA显著降低,自噬小体数目显著减少,细胞凋亡显著减少,LC3-Ⅱ表达显著下调,P62、Nrf2、HO-1表达显著上调。结论GLS1可抑制H_(2)O_(2)诱导的ARPE-19细胞氧化应激、自噬与凋亡,其机制为激活Nrf2/HO-1信号通路。

Sulfur poisoning and regeneration of MnO_x-CeO_2-Al_2O_3 catalyst for soot oxidation

MnOx-CeO2-Al2O3 mixed oxides were prepared by impregnating manganese and cerium precursors on alumina powders via a sol- gel deposition method. The oxide catalyst exhibited a poor resistance to sulfur dioxide after the treatment in 100 ppm SO2/air at 350 °C for 50 h. The formation of manganese sulfate and especially cerium sulfate reduced the availability of surface active metal oxides, blocked the pore structure and decreased the surface area of the catalyst. These changes in chemical and structural and textural properties resulted in a severe loss in the activities of the sulfated catalyst for NO and soot oxidation. The decomposition of sulfates was almost complete during the calcina-tion in air at 800 °C for 30 min, which partially recovered the surface active sites and the catalyst surface area despite the significant sintering of metal oxides. Consequently, the NOx-assisted soot oxidation activity of the catalyst was regenerated to some extent by the oxidation treatment.

LncRNA NALT通过调控Notch信号通路对H2O2诱导的人晶状体上皮细胞损伤的影响

目的探讨lncRNA NALT(简称NALT)对H_(2)O_(2)诱导的人晶状体上皮细胞损伤的影响及其作用机制。方法使用不同浓度H_(2)O_(2)处理人晶状体上皮SRA01/04细胞24 h,CCK-8和qRT-PCR检测细胞增殖活性及NALT表达水平。将NALT过表达质粒转染至SRA01/04细胞中,再经100μmol/L H_(2)O_(2)或联合10μmol/L Notch信号通路抑制剂DAPT干预24 h,CCK-8检测细胞增殖活性;DCFH-DA荧光探针标记法检测各组细胞ROS水平;化学法检测SOD活性和MDA含量;Annexin V-FITC/PI法检测细胞凋亡情况;Western blot检测细胞中Notch1和Hes1蛋白表达水平。结果随着H_(2)O_(2)干预浓度的增加,SRA01/04细胞增殖活性和NALT表达水平均呈剂量依赖性降低(P<0.05)。H_(2)O_(2)干预后,NALT过表达可显著提高SRA01/04细胞增殖活性和SOD活性,降低ROS、MDA及细胞凋亡水平,上调Notch1和Hes1蛋白表达水平(均P<0.05)。然而,联合DAPT干预可逆转NALT过表达对H_(2)O_(2)诱导的SRA01/04细胞损伤的保护作用。结论过表达NALT可改善H_(2)O_(2)诱导的人晶状体上皮细胞损伤,其机制可能与激活Notch信号通路有关。

Relationship Between Endopeptidase and H_2O_2 During the Aging of Wheat Leaf

The relationship between hydrogen peroxide (H 2O 2) and endopeptidase(EP) in wheat ( Triticum aestivum L. cv. Yanmai 158) leaves was studied during natural and artificial aging. Rapid accumulation of endogenous H 2O 2 and marked increase of EP activity were observed during the later phase of aging. A new EP isozyme with higher activity was detected by electrophoresis on polyacrylamide gels containing denatured heamoglobin. With the increase of exogenous H 2O 2, the activity of EP increased at first and then decreased.

Participation of H_2O_2 in Enhancement of Cold Chilling by Salicylic Acid in Banana Seedlings

The possible physiological mechanism of enhancement of cold tolerance by salicylic acid (SA) in banana seedlings ( Musa acuminata cv. Williams 8188) was explored. Measurements of leakage electrolyte after 2 d of recovery at 30/22 ℃ (day/night) following 3 d of cold stress at 7 ℃ showed that pretreatment with hydroponic solution containing SA 0.3-0.9 mmol/L as foliar spray under normal growth conditions (30/22 ℃) could significantly enhance cold tolerance of banana plants. The highest enhancing effect of SA occurred at 0.5 mmol/L and it showed the lowest leakage rate of electrolyte or smaller leaf wilting area after 2 d of recovery at normal temperature from 3 d of 7 ℃ or 5 ℃ cold stress. Higher concentrations (≥2.5 mmol/L) of SA, however, caused more electrolyte leakage, indicating that they aggravated chilling damage. Enhanced cold tolerance by SA could be related to H 2O 2 metabolism. Compared with water_treated seedlings (control), SA 0.5 mmol/L treatment inhibited activities of catalase (CAT) and ascorbate peroxidase (APX), increased peroxidase (POX) activity, but did not affect the activity of superoxide dismutase (SOD) under normal growth conditions, and these changes might lead to an accumulation of H 2O 2, whereas SA pretreatment enhanced the activities of CAT and APX, and reduced the increase in productions of H 2O 2 and thiobarbituric acid_reaction substances (TBARS) during subsequent 7 ℃ cold stress and recovery periods. Exogenous H 2O 2 treatments (1.5 -2.5 mmol/L) also increased cold tolerance of banana seedlings. Furthermore, pretreatment of banana seedlings with dimethylthiourea (a trap for H 2O 2) significantly inhibited cold tolerance induced by SA. These results suggested that endogenous H 2O 2 may be required for SA_enhanced cold tolerance. The significance of the interaction of SA, H 2O 2 and H 2O 2_metabolizing enzymes during cold stress has been discussed.

The ROCK pathway inhibitor Y-27632 mitigates hypoxia and oxidative stress-induced injury to retinal Müller cells

Rho kinase （ROCK） was the first downstream Rho effector found to mediate RhoA-induced actin cytoskeletal changes through effects on myosin light chain phosphorylation. There is abundant evidence that the ROCK pathway participates in the pathogenesis of retinal endothelial injury and proliferative epiretinal membrane traction. In this study, we investigated the effect of the ROCK pathway inhibitor Y-27632 on retinal Müller cells subjected to hypoxia or oxidative stress. Müller cells were subjected to hypoxia or oxidative stress by exposure to CoCl2 or H2O2. After a 24-hour treatment with Y-27632, the 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium bromide assay was used to assess the survival of Müller cells. Hoechst 33258 was used to detect apoptosis, while 2′,7′-dichlorodihydrofluorescein diacetate was used to measure reactive oxygen species generation. A transwell chamber system was used to examine the migration ability of Müller cells. Western blot assay was used to detect the expression levels of α-smooth muscle actin, glutamine synthetase and vimentin. After treatment with Y-27632, Müller cells subjected to hypoxia or oxidative stress exhibited a morphology similar to control cells. Y-27632 reduced apoptosis, α-smooth muscle actin expression and reactive oxygen species generation under oxidative stress, and it reduced cell migration under hypoxia. Y-27632 also upregulated glutamine synthetase expression under hypoxia but did not impact vimentin expression. These findings suggest that Y-27632 protects Müller cells against cellular injury caused by oxidative stress and hypoxia by inhibiting the ROCK pathway.

A Novel Technology for Post-Treating of Porous Silicon Thick Films in H_2O_2

The solution of H 2O 2 is proposed to post-treat thick porous silicon (PS) films.The prepared PS film as the cathode is applied about 10mA/cm 2 current in mixture of ethanol,HF,and H 2O 2 solutions,which is expected to improve the stability and the smoothness of the surface and the mechanical property of the thick porous silicon films.The microstructure of the PS thick films with thicknesse of 20μm and 70μm has been studied.The SEM images show significant improved smoothness on surface of PS films,and XRD spectra suggest the formation of oxide layer after post-treating in H 2O 2.

Comparison of the Effects of H_2O_2 and Salicylic Acid on Alternative Respiratory Pathway in Aged Potato Tuber Slices

The influences of exogenous H 2O 2 and salicylic acid (SA) treatments on the alternative respiratory pathway (ARP) in aged potato (Solanum tuberosum L.) tuber slices were compared. The results showed that both H 2O 2(5.0 mmol/L) and SA (0.1 mmol/L) treatments had a significant inducing effect on ARP capacity (V alt ) and its ratio to total respiration (V alt /V t) in potato slices aged for 24 h. With a monoclonal antibody against the alternative oxidase (AOX), Western blotting results showed that both H 2O 2 and SA treatments increased the AOX expression levels in aged potato tuber slices. However, the results of oxygen isotope discrimination experiments showed that H 2O 2 had no influence on the in vivo ARP activity (ρV alt ) and its contribution to V t(expressed as ρV alt /V t) in potato slices aged for 24 h, but SA had a significant influence on the ρV alt and ρV alt /V t values of the aged potato tuber slices. These results indicate that there are differences between the effects of H 2O 2 and SA on ARP in plant tissues. Both of them possess the ability to induce ARP capacity through inducing AOX expression. However, SA can simultaneously stimulate the operation of ARP, but H 2O 2 can not.

尿素/H_2O_2溶液同时脱硫脱硝机理研究

在填料塔上对尿素/H2O2溶液同时脱硫脱硝进行了实验研究。结果表明,尿素溶液对SO2具有很高的去除效率,但对NOx的去除受到多种因素的影响。实验主要研究了H2O2浓度、吸收反应温度、溶液pH值等因素对脱硝效率的影响,并确定了最佳实验条件,在此条件下脱硫脱硝效率分别达到100%和52.6%。同时,采用化学分析法和气相色谱法对尿素溶液同时脱硫脱硝的反应产物进行分析,推导出尿素/H2O2溶液同时脱硫脱硝的反应机理和总化学反应方程式。该技术可用于对现有湿法脱硫技术的改造,使其同时具有脱硫脱硝功能。

应用~2H、^(18)O同位素示踪华北平原石家庄包气带土壤水入渗补给及年补给量确定

采集2个不同深度包气带土壤水2 H、18 O同位素剖面ZK1,ZK2,应用天然稳定同位素2 H、18 O示踪的方法,研究了华北山前冲积平原石家庄地区包气带土壤水入渗补给的历史演化特征。结果显示,研究区内,以0.05m为取样间隔,δ2 H、δ18 O值可以明显指示出大气降水及灌溉水入渗补给时间—剖面深度位置的年际对应关系。ZK2的δ2 H、δ18 O值随着埋深的增大出现周期性的波动,具有分层现象的岩性差异并不明显,说明ZK2剖面以活塞流的入渗方式补给地下水。在0~3.90m深度,δ2 H、δ18 O值显示降水和灌溉水的入渗补给时间为2011年10月至2001年11月。18 O峰值位移法计算补给量的结果显示,降水、灌溉水通过包气带补给地下水的垂向运移速度为38.5~65.0cm/a,年均入渗补给量为131.3~185.3mm。同时,对比2003年及2005-2007年降水量数据,说明少雨年份农业灌溉用水量的大小对当地地下水的入渗补给量起着关键性作用。

铁屑/焦炭/H_2O_2法预处理焦化废水的试验研究

采用铁屑/焦炭/H2O2法对焦化废水进行处理,通过单因素试验法考察了铁炭比、铁炭用量、H2O2用量、废水pH以及反应时间对处理效果的影响,并确定了最适工艺条件。结果表明,铁屑/焦炭/H2O2法与常规的铁屑内电解法相比,可显著提高焦化废水的预处理效果,并缩短反应时间。铁屑/焦炭/H2O2法处理焦化废水的最适条件为:铁炭比为4,铁炭用量为300mg/L铁屑+75mg/L焦炭,H2O2用量为1000mg/L,pH为3,反应时间20min。在此条件下,COD、色度、NH3-N和CN-的去除效率分别可达61.2%、74.0%、56.2%和74.3%,B/C比由处理前的0.189提高到0.387,处理水可生化性良好。铁屑/焦炭/H2O2可作为焦化废水的一种有效的预处理方法。

O_3、O_3/H_2O_2降解TNT的实验研究

利用自制装置 ,实验研究了不同反应条件下 ,O3 、O3 /H2 O2 对 TNT的降解规律。结果表明 ,O3 对 TNT具有一定降解功效 ,提高体系的 p H值或添加 H2 O2 均利于 TNT的降解。O3 降解 TNT,可能产生抗氧化性更强的中间产物及其积累 ,而 O3 /H2 O2 作用过程中则没有发生。p H从 1升到 1 2 ,利于 O3 对 TNT降解 ,但超过 1 2时 ,对 O3 作用的影响不再明显 ,p H的最适范围是 1 0～ 1 2 ;O3 /H2 O2作用时 ,1 0为其 p H的临界值 ,当提高或降低 p H都会降低其对 TNT降解能力。维持体系的 p H稳定 ,有利于 O3 降解 TNT,但对 O3 /H2 O2 作用功效的影响不明显。尽管温度对 O3 、O3 /H2 O2 降解 TNT功效的影响较小 ,但温度的提高不利于两者功效的发挥 ,尤其是

H_2O_2和Ca^(2+)对受低温胁迫香蕉幼苗抗冷性的影响

研究表明 ,香蕉幼苗喷施H2 O2 或CaCl2 或二者结合使用 ,能提高其POD活性 ,降低膜渗漏率 ,增加可溶性糖含量及减缓叶绿素降解 ,从而提高抗寒力 ,二者结合表现出协同效应。H2 O2 对提高POD活性 ,降低膜渗漏率和减缓Chl.b降解的效果优于CaCl2 ;CaCl2 则在提高可溶性糖含量和减少Chl.a降解方面占优。相关性分析表明 ,POD活性与膜渗漏率的负相关性达到显著水平 ,高POD活性有利于减少低温下膜渗漏。