Maize seed coatings and seedling sprayings with chitosan and hydrogen peroxide: their influence on some phenological and biochemical behaviors

Objective:To evaluate the effect of chitosan(CH) and hydrogen peroxide(H2O2) seed coatings and seedling sprinklings on two different maize varieties by measuring their phenology,the H2O2 presence,the catalase(CAT) activity,and the protein quantity.Methods:Seven groups of ten seeds for each maize variety were treated with CH(2%(20 g/L) and 0.2%(2 g/L)) or H2O2(8 mmol/L) by coating,sprinkling,or both.Germination and seedling growth were measured.One month after germination,the presence of H2O2 in seedlings in the coated seed treatments was evaluated.Protein content and CAT activity were determined under all treatments.Results:H2O2 seed coating enhanced the germination rate and increased seedling and stem length in the quality protein maize(QPM) variety.Seedlings had a higher emergence velocity under this treatment in both varieties.CH and H2O2 sprinklings did not have an effect on seedling phenology.Exogenous application of H2O2 promoted an increase of endogenous H2O2.CH and H2O2 seedling sprinkling increased the protein content in both maize varieties,while there was no significant effect on the CAT activity of treated seeds and seedlings.Conclusions:CH and H2O2 enhance some phenological and biochemical features of maize depending on their method of application.     

Influence of natural deposition plane orientation on oedometric consolidation behavior of three typical clays from southeast coast of China

The parameters obtained from oedometric consolidation tests are commonly used in the development of constitutive modeling and for engineering practice. This paper focuses on the influence of the natural deposition plane orientation on oe- dometric consolidation behavior of three natural clays from the southeast coast of China. Oedometer tests were conducted on intact specimens prepared by sampling at a series of angles relative to the natural deposition plane. For each specimen, yield stress, compressibility indexes, secondary compression, and permeability coefficients were determined. The influence of the sampling angle on these properties was investigated, revealing that yield stress, compression index, swelling index, creep index, ratio of secondary compression coefficient to compression index （Cae/JCc） and permeability coefficient were all dependent to some extent on the sampling angle. These findings indicate the role of the anisotropy due to the natural deposition on the oedometric con- solidation behavior.     

Isolation and physiological characteristics of a premature senescence mutant in rice （Oryza sativa L.）

A rice pse(t) (premature senescence, tentatively) mutant line, was isolated from 4500 independent T-DNA inserted transgenic lines. The symptoms of premature senescence appeared more severely than those of the control plants (Zhonghua 11,japonica) at the last development stage. To characterize the mutant and provide basic information on the candidate genes by mapping to a physical region of 220-kb, experiments were carried out in two phytotrons under controlled temperature of 24 ℃ and28 ℃, respectively. The content of chlorophyll, soluble protein and MDA (malondialdehyde), net photosynthesis, the antioxidant enzyme activities of SOD (superoxide dismuase) (EC 1.15.1.1) and POD (peroxidase) (EC 1.11.1.7) and the peptidase activities of leaves were measured from top to bottom according to the leaf positions at the flowering stage. Compared with the control plant,the mutant showed the following characteristics: (1) Higher net photosynthesis rate (Pn) appeared in the 1 st and 2nd leaves, contents of chlorophyll and soluble protein were also higher in the 1 st leaf; (2) The activities of SOD, POD and peptidase were higher according to the leaf position from top to bottom; (3) The symptom of premature senescence was accelerated in the mutant at 28℃treatment. The MDA content and the SOD and POD activities between the 24 ℃ and 28 ℃ treatment mutants were not significantly different. Content of chlorophyll and soluble protein of leaves mutant decreased rapidly at 28 ℃ treatment. The results show that pse(t) is sensitive to high temperature. The probable function of PSE(T) is discussed.     

Evaluation of the performance of surface treatments on concrete durability

This paper reports on a laboratory-based study carried out to evaluate the effectiveness of surface treatments on the durability of concrete and suggests a number of different evaluation methodologies for assessing the performance of various surface treatments. Durability of untreated and treated concrete specimens was evaluated by measuring chloride diffusion, charge passing capacity, air permeability and water absorption. A total of six concrete surface treatments were selected to represent different generic types, including coating, penetrant and mixed-use treatments. Results show that the concrete specimens with a coating procedure have a better long-term performance and effectiveness than the specimens with the penetrant treatments. This work also indicates that the wetting and drying cycles test can be used to assess the weatherability of the surface treatments. The ASTM C 1202 and the Autoclam air permeability test can be used to evaluate the effectiveness of surface treatments quantitatively. Further work is needed, however, to assess the longevity of the various surface treatments.     

Joint effects of microwave and chromium trioxide on root tip cells of Vicia faba

The mutagemc effects of microwave and chromium trioxide （CrO3） on Vicia faba root tip were studied. Micronucleus assay and chromosomal aberration assay were used to determine the mitotic index, the micronucleus frequency and chromosomal aberration frequency of Vicia faba root tip cells induced by microwave and CrO3. The results showed that the micronucleus frequency decreased, and that the mitotic index and chromosomal aberration frequency showed linear dose responses to CrO3, in treatment of microwave for 5 s. In microwave of 25 s, the mitotic index decreased, the micronucleus frequency and chromosomal aberration frequency increased with increase of CrO3 concentration. We concluded that microwave and CrO3 had antagonistic effect on the mitotic index of Vicia faba root tip cells, but had synergetic effect on micronucleus frequency and chromosomal aberration frequency of Viciafaba root tip cells.     

Emergy-analysis based approaches to develop circular economy in the Three Gorges Reservoir area

The eco-environment and the condition of economic development in the Three Gorges area were evaluated with emergy indices calculated with the statistic data of the years from 1997 to 2005. The rising environmental loading ratio indicates an increasing pressure of economic activities on the environment and the economic development achieved at the cost of over-exploitation of resources and environment deterioration. The net emergy yield ratio implies that the economic system of this area was a self-contained, resource-export-oriented type at a relatively low level of technology. The emergy sustainability index of about 6 implies the economy of this area was under developed but had a potential to grow. According to the results of the emergy analysis, circular economy should be taken as the economic model of this region's development. This economic system should be water-resource-oriented and more open, make combined use of local and extraneous resources, and have an updated systematic structure with emphasis on emergy recirculation.     

Relationship between malt qualities and β-amylase activity and protein content as affected by timing of nitrogen fertilizer application

The effects of different timing of N fertilizer application at the same rate on grain β-amylase activity, protein concentration, weight and malt quality of barley were studied. Grain β-amylase activity and protein concentration were significantly higher in treatments where all top-dressed N fertilizer was applied at booting stage only or equally applied at two-leaf stage and booting stage than in the treatment where all top-dressed N fertilizer was applied at two-leaf age stage only. On the other hand, grain weight and malt extract decreased with increased N application at booting stage. There were obvious differences between barley varieties and experimental years in the grain and malt quality response to the timing of N fertilizer application. It was found that grain protein concentration was significantly and positively correlated with β-amylase activity, but significantly and negatively correlated with malt extract and Kolbach index. The effect of grain protein concentration on malt quality was predominant over the effect of grain β-amylase activity.     

Dynamical Behavior of Nonlinear Viscoelastic Timoshenko Beams with Damage on a Viscoelastic Foundation

Based on convolution-type constitutive equations for linear viscoelastic materials with damage and the hypotheses of Timoshenko beams with large deflections, the nonlinear equations governing dynamical behavior of Timoshenko beams with damage on viscoelastic foundation were firstly derived. By using the Galerkin method in spatial domain, the nonlinear integro-partial differential equations were transformed into a set of integro-ordinary differential equations. The numerical methods in nonlinear dynamical systems, such as the phase-trajectory diagram, Poincare section and bifurcation figure, were used to solve the simplified systems of equations. It could be seen that simplified dynamical systems possess the plenty of nonlinear dynamical properties. The influence of load and material parameters on the dynamic behavior of nonlinear system were investigated in detail.     

完形填空练习

The Town of Pressure and the Town of Pleasure were neighbors but had nothing in common.Residents built walls __1__ influence from the other town. In Pressure,__2__ struggled to be the very best. When women gave birth,they would __3__ to have the baby with the loudest cry,There was violent competition in every aspect of life.Becayse __4__ was the index(指     

In-situ nitrogen removal from the eutrophic water by microbial-plant integrated system

Objective： This study was to assess the influence of interaction of combination of immobilized nitrogen cycling bacteria （INCB） with aquatic macrophytes on nitrogen removal from the eutrophic waterbody, and to get insight into different mechanisms involved in nitrogen removal. Methods： The aquatic macrophytes used include Eichhornia crassipes （summer-autumn floating macrophyte）, Elodea nuttallii （winter-growing submerged macrophyte）, and nitrogen cycling bacteria including ammonifying, nitrosating, nitrifying and denitrifying bacteria isolated from Taihu Lake. The immobilization carriers materials were made from hydrophilic monomers 2-hydroxyethyl acrylate （HEA） and hydrophobic 2-hydroxyethyl methylacrylate （HEMA）. Two experiments were conducted to evaluate the roles of macrophytes combined with INCB on nitrogen removal from eutrophic water during different seasons. Results： Eichhornia crassipes and Elodea nuttallii had different potentials in purification of eutrophic water. Floating macrophyte＋bacteria （INCB） performed best in improving water quality （during the first experiment） and decreased total nitrogen （TN） by 70.2%, nitrite and ammonium by 92.2% and 50.9%, respectively, during the experimental period, when water transparency increased from 0.5 m to 1.8 m. When INCB was inoculated into the floating macrophyte system, the populations of nitrosating, nitrifying, and denitrifying bacteria increased by 1 to 2 orders of magnitude compared to the un-inoculated treatments, but ammonifying bacteria showed no obvious difference between different treatments. Lower values of chlorophyll a, CODMn, and pH were found in the microbial-plant integrated system, as compared to the control. Highest reduction in N was noted during the treatment with submerged macrophyte＋INCB, being 26.1% for TN, 85.2% for nitrite, and 85.2% for ammonium at the end of 2nd experiment. And in the treatment, the populations of ammonifying, nitrosating, nitrifying, and denitrifying bacteria increased by 1 to 3 orders of magnitude, as compared to the un-inoculated treatments. Similar to the first experiment, higher water transparency and lower values of chlorophyll a, CODMn and pH were observed in the plant＋ INCB integrated system, as compared to other treatments. These results indicated that plant-microbe interaction showed beneficial effects on N removal from the eutrophic waterbody.     

Alterations in seedling vigour and antioxidant enzyme activities in Catharanthus roseus under seed priming with native diazotrophs

An experiment was conducted on Catharanthus roseus to study the effect of seed treatments with native diazotrophs on its seedling growth and antioxidant enzyme activities. The treatments had significant influence on various seedling parameters.There is no significant influence on dry matter production with the diazotrophs, Azospirillum and Azotobacter. However, the vital seedling parameters such as germination percentage and vigour index were improved. Azotobacter treatment influenced maximum of 50% germination, whereas Azospirillum and Azotobacter were on par with C. roseus with respect to their vigour index. There was significant difference in the population of total diazotrophs. Azospirillum and Azotobacter between rhizosphere and non-rhizosphere soils of C. roseus had the same trend and were observed at various locations of the study. The activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) were increased to a significant extent due to the treatment with diazotrophs.     

硼对根用芥菜种子萌发及幼苗抗氧化能力的影响

目的:研究不同浓度的硼酸对根用芥菜种子萌发的影响。方法:以临泉花叶根用芥菜种子为材料,以不同浓度(0、10、20、100、1000、5000μmol/L)硼酸对根用芥菜种子进行浸种处理,调查了种子发芽指标,测定了萌发种子中脱氢酶和酸性磷酸酶活性以及幼苗总抗氧化能力、脯氨酸(Pro.)和丙二醛(MNDA)的含量。结果:随着硼酸浓度的升高,根用芥菜种子的发芽势、发芽率、脱氢酶活性、酸性磷酸酶活性、幼苗总抗氧化能力和Pro.含量均呈先升后降趋势,MDA含量呈先降后升趋势;当硼酸浓度为100μmol/L时,种子的发芽势、发芽率、脱氢酶活性、幼苗总抗氧化能力和Pro含量均达到最大值,MDA含量达最低值,均与其它处理差异显著;当硼酸浓度为10μmol/L时酸性磷酸酶活性达到最大值,硼酸浓度在10~1000μmol/L范围内酸性磷酸酶活性差异不显著,随后下降,但仍高于CK。结论:根用芥菜种子用100μmol/L浓度的硼酸浸种最为适宜。     

Moringa oleifera extract enhances sexual performance in stressed rats

Aphrodisiacs are required to improve male sexual function under stressful conditions. Due to the effects of oxidative stress and dopamine on male sexual function, we hypothesized that Moringa oleifera leaves might improve male sexual dysfunction induced by stress. Therefore, the effects on various factors playing important roles in male sexual behavior, such as antioxidant effects, the suppression of monoamine and phosphodiesterase type 5 (PDE-5) activities, serum testosterone and corticosterone levels, and histomorphological changes in the testes, of a hydroethanolic extract of M. oleifera leaves were investigated. Various doses of extract including 10, 50, and 250 mg/kg body weight (BW) were given orally to male Wistar rats before exposure to 12 h-immobilization stress for 7 d. The results demonstrated that the extract showed both antioxidant and monoamine oxidase type B (MAO-B) suppression activities. At 7 d of treatment, the low dose of extract improved sexual performance in stress-exposed rats by decreasing intromission latency and increasing intromission frequency. It also suppressed PDE-5 activity, decreased serum corticosterone level, but increased serum testosterone, numbers of interstitial cells of Leydig and spermatozoa. The increased numbers of interstitial cells of Leydig and spermatozoa might have been due to the antioxidant effect of the extract. The increased sexual performance during the intromission phase might have been due to the suppression of MAO-B and PDE-5 activities and increased testosterone. Therefore, M. oleifera is a potential aphrodisiac, but further research concerning the precise underlying mechanisms is still needed.     

白术粗多糖对樱桃谷鸭免疫器官的影响

目的:本试验选择白术多糖来研究其对樱桃谷肉鸭免疫器官的影响,为白术多糖在畜禽业的应用提供依据。方法:本试验选用480只1日龄樱桃谷肉鸭,随机平均分成6组,每组4个重复,其中A为对照组,饲喂基础日粮;B、C、D、E为试验组,在基础日粮中分别添加不同梯度(0.2%、0.4%、0.6%和0.8%)的白术多糖;F为抗生素添加组。整个饲养试验分为两个阶段,1～14日龄为第一阶段,15～28日龄为第二阶段。结果:在1～14日龄阶段,A组脾脏指数(1.17)显著(P<0.05)高于D组(0.76),D组胸腺指数(5.67)显著(P<0.05)高于其他各组;F组法氏囊指数(3.15)显著(P<0.05)高于E组(1.83)。D组的淋巴细胞增殖反应(0.59)显著高于(P<0.05)其他各组。在15～28日龄阶段,各组间的脾脏指数、胸腺指数和法氏囊指数差异均不显著(P>0.05)。D组淋巴细胞增殖反应(0.47)显著(P<0.05)高于其他各组。结论:白术多糖对1～14日龄阶段的樱桃谷鸭脾脏、胸腺和法氏囊等免疫器官的发育有一定促进作用。     

形态学参数对100米比赛成绩的影响

为了探讨形态学参数(身高、体重、罗勒指数、克托莱指数、BMI)对运动员100 m比赛成绩的影响,根据平均成绩(10.87 s),将女子100 m历史上突破11秒的71名运动员分为2组:FG(Faster Group)和SG(SlowerGroup),分析其形态学参数对比赛成绩的影响.结果表明,女子100 m运动员的身高、体重、罗勒指数、克托莱指数、BMI与比赛成绩不存在显著性相关(P>0.05);FG与SG在形态学参数上不存在显著性差异(P>0.05);形态学参数对100 m比赛成绩的影响不存在性别差异,步态参数对100 m比赛成绩的影响存在性别差异.     

淡水培养对桐花树种胚萌发和幼苗生长的影响

在室外自然光照条件下用淡水和人工海水(自然海盐比水为8g.Kg-1)处理培养红树植物桐花树(Aegiceras corniculatum)种胚90d,测定了种胚萌发和幼苗生长状况.结果表明:淡水处理桐花树种胚能够较早生根,且初次萌根率较高.两种处理下桐花树种胚的萌苗率随时间的变化趋势相似,且两种处理间没有显著性差异.淡水处理在幼苗前期有利于根长的伸长,而人工海水处理在幼苗中、后期有利于根数的增加.90d时,淡水处理的茎高和茎生物量分别比人工海水处理的高32.90%和50.00%,均具有显著差异性;而幼苗的胚轴、叶、根的生物量、单株生物量和根冠比及根系活力均不存在显著差异.试验表明:桐花树种胚在淡水环境里能够正常萌发,其幼苗生长良好.     

Evaluation of the antioxidant property and effects in <Emphasis Type="Italic">Caenorhabditis elegans</Emphasis> of Xiangxi flavor vinegar,a Hunan local traditional vinegar

Xiangxi flavor vinegar (XV) is one of Hunan Province’s traditional fermented vinegars. It is produced from herb, rice, and spring water with spontaneous liquid-state fermentation techniques. In this study, we investigated the antioxidant property of XV by analyzing its antioxidant compounds, its free radical scavenging property in vitro and in vivo, and its effects on antioxidant enzyme activity and apoptosis in Caenorhabditis elegans. The results showed that XV is rich in antioxidants. In particular, ligustrazine reached 6.431 μg/ml. The in vitro 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH^?), hydroxyl radical (^?OH), and superoxide anion radical (O ₂ ^?? ) scavenging rates of XV were 95.85%, 97.22%, and 63.33%, respectively. The reactive oxygen species (ROS) content in XV-treated C. elegans decreased significantly (P<0.01) compared to the control group. Glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) activities were remarkably increased (P<0.01) in C. elegans after XV treatment. In addition, XV could upregulate CED-9 protein expression and downregulate CED-3 protein expression in C. elegans. These results prove that XV is rich in antioxidants and scavenges radicals in vitro efficiently. XV inhibits apoptosis in C. elegans probably by scavenging ROS and increasing the activities of its antioxidant enzymes.     

水杨酸对盐胁迫下西瓜种子萌发特性的影响

采用培养皿发芽法,研究了水杨酸浸种对盐胁迫下西瓜种子萌发和幼苗生长的影响。结果表明,300mmol/L NaCl溶液浸种显著降低了西瓜种子的发芽率、发芽势、发芽指数和活力指数及胚根长和胚芽鲜重;1.0mmol/L以下浓度水杨酸浸种使盐胁迫下西瓜种子萌发和幼苗生长量随水杨酸浓度提高而显著增加;2.0 mmol/L水杨酸浸种对盐胁迫下西瓜种子萌发和幼苗生长无明显影响,3.0 mmol/L水杨酸浸种进一步降低了盐胁迫下西瓜种子萌发和幼苗生长量。结果说明,较低浓度水杨酸浸种可缓解盐胁迫对西瓜种子萌发和幼苗生长的抑制作用,减轻西瓜种子萌发期盐胁迫伤害的最适水杨酸浓度为1.0 mmol/L。     

遮光对光皮桦苗木存活率及生长效应分析

本研究设遮光度40％、60％、80％和ck（全光照）4种处理,探讨光因子对光皮桦苗木存活率、适合度和生长的影响。研究表明,全光照条件下,死亡最高时期出现在播种后第11～60d（6月11日～7月30日）,死亡率高达84．5％,适合度仅为0．0358。遮光度40％和60％两种处理,死亡最高时期出现时间相近,死亡率前者高于后者,分别达71．1％和62．0％,适合度分别达0．1329、0．1740。当遮光度达到80％时,死亡最高时期出现时闻不明显,死亡期延续时间较长,其苗木死亡率（62．8％）、适合度（0．1700）与60％遮光度处理差异不明显。随遮光度增大,苗高、地径、生物量等主要生长指标亦明显增大。生产中采用60％～80％遮光度给光皮样幼苗遮荫可有效地提高光皮桦的苗木存活率和生长规格。     

论活动在语文教学中的协同效应

中学语文教学应该遵循心理学和教育学原理 ,并运用协同学理论 ,立足课堂 ,拓宽渠道 ,本着“激趣、导活、落实、创新”的教学思想 ,开展符合中学生认知心理的丰富多彩的活动 ,这样就能够有效地促进语文教学 ,最大限度地帮助学生获取知识、发展智力、形成能力。