Simulation Study of Water Quality for the Three Gorges Reservoir in Chongqing

In order to survey the degree of stability of dangerous rock slope and get reliable theoretical foundation about the slope restoration, earth stress measuring is performed in the engineering project through drilling on the slope surface. The survey is conducted by means of complete temperature compensation and automatic recording. In terms of experimental data, the computing ram of earth stress works out the magnitude, direction, inclination of the earth stress and their distribution. The result supplies theoretical base for the design and working of slope and dangerous rock control engineering, which has been proved to fine effects in the fields of society, security,environment, and economy in its practice.     

分装式低温等离子体减压保鲜技术研究

采用分装式低温等离子体减压保鲜技术贮藏果蔬.结果表明,分装式低温等离子体减压保鲜技术能有效降温(0～6℃),调节湿度(90%～95%),清除和分解环境及果蔬组织内部的乙烯等有害气体,杀灭病原体,降解残留农药.应用该技术使叶菜类及瓜果类蔬菜保鲜期分别达到90天和150天,出库后货架期长达7～10天.     

FEM Analysis of Stress Distribution Law in the Rocksalt Cavity''s Surrounding Rock

Basic on the FEM numerical analysis, the contour maps stress of rocksalt cavity's surrounding rock and the major principal stress's law changed with the depth and horizontal direction are analyzed. The influencing factors to the distribution of the stress surrounding rocksalt cavity, such as cavity's span, water pressure and the depth of rocksalt layer is also studied. The results show that major principal stress becomes big with the increase of rocksalt's depth. The cavity's influence to the stress's distribution will be clearer with the nearer to the cavity. The stress's centralization will be weaker with the accretion of water pressure in rocksalt's cavity. But the stress's centralization will be stronger, and the stress's value increases.     

工业大麻抗逆生理及分子机制研究进展

工业大麻(Cannabis sativa L.)是一种抗逆性较强的高附加值经济作物.往往种植在盐碱、山坡地等土壤环境条件相对比较恶劣的地块以充分利用土地资源.在生长过程中可能会受到盐碱、干旱、涝害、低温、高温、营养缺乏和重金属污染等逆境胁迫.为了确保产量和品质,在种植过程中一方面要根据其表型变化及时采取应对策略减少损失...     

Stress Distribution in Fixed Anchor Length of Compression Type Anchor in Soft Rock Mass

To study stress distribution in fixed anchor length of compression type rock anchor cable, field test was carried out. Strain sensors were placed in the grout paste in fixed anchor length with certain interval. Axial and radial strains of the grout were noted by test. Shear stress distribution curve along the fixed anchor length was obtained by stress-strain relationship and static equilibrium analysis. Analysis results prove that maximal shear stress on the interface can achieve upper level and move forward when the load increases; the transmission length is short; shear stress transfers forward; and three dimensional state is obvious around capacity plates in soft rock mass.     

Characterization and Quantification of Water Stress in Wheat by Soil-Induced Plant Components

Measurements of transpiration rate (TR), leaf diffusive resistance (LDR), leaf water potential (LWP), and canopy minus air temperature (Tc-Ta) were made over four differentially irrigated plots of wheat grown at Pantnagar. The data were analysed to workout functional relationships between these plant parameters. Correlation studies yielded low values of correlation coefficients 'r'. The plotting of the data also showed wide scattering around the lines. For removing the variability of shoot environment the whole data were normalized by subtracting the values of well irrigated (unstressed) plants from the values of the stressed plants. The plotting of normalized data showed close linear relationships. The regression analysis of normalized data provides highly significant correlationships of TR Vs LDR, TR Vs LWP, TR Vs Tc, TR Vs Tc-Ta and Tc-Ta Vs LDR. It indicates that normalization of plant parameters for environmental variability is required in order to better quantify crop responses to soil water deficit.     

低温胁迫对茄子幼苗叶片光合特性的影响

以茄子702幼苗为试材,研究了低温胁迫对茄子幼苗光合特性的影响.结果表明,低温胁迫下,茄子幼苗的叶绿素含量、叶绿素a/b、净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、光饱和点(LSP)、光饱和光合速率、表观量子效率(AQY)、CO2饱和点(CSP)、羧化效率(CE)和RuBP最大再生速率均下降;光补偿点(LCP)、CO2补偿点(CCP)均上升;胞间CO2浓度(Ci)先降低后升高.以上结果表明,低温胁迫伤害了茄子幼苗的光合机构.     

高温胁迫对蝴蝶兰幼苗叶绿素荧光参数的影响

为了探究高温胁迫对蝴蝶兰幼苗叶片光合机构的影响,将蝴蝶兰幼苗置于38℃处理4天,以25℃为对照,测定了蝴蝶兰幼苗叶绿素荧光参数的变化。结果表明：随着高温胁迫时间的延长,蝴蝶兰叶片叶绿素总含量、最大光化学效率(Fv/Fm)、有效光量子产量(ΦPSⅡ)、表观光合电子传递速率(ETR)、光化学猝灭系数(qP)持续下降,而丙二醛(MDA)含量、初始荧光(Fo)、非光化学猝灭系数(qN)不断上升。与胁迫前相比,胁迫后期的上述指标均存在显著差异。由此表明,高温胁迫下蝴蝶兰幼苗PSⅡ反应中心出现了可逆失活或损伤,使光合原初反应过程受阻,显著降低了原初光能转换效率,从而引起严重的光抑制,极大地减弱了光合电子传递活性,使反应中心积累过剩光能,对光合机构和叶绿素造成光氧化破坏,但蝴蝶兰幼苗能在一定程度上通过热耗散途径来减轻伤害。     

应用数字图像技术对不同株型夏玉米进行高温胁迫诊断

以受高温胁迫程度不同的夏玉米为研究对象,利用数码相机获取玉米吐丝-授粉期冠层的数字图像,同时利用叶绿素荧光仪探测植株受胁迫的程度,研究利用数码相机的可见光光谱进行夏玉米受逆境胁迫程度诊断的可行性。结果表明,红光标准化值与叶片叶绿素荧光值(Fv/Fm)成负相关关系(r=-0.35),而绿光标准化值、蓝光标准化值均与Fv/Fm成正相关关系,其相关系数r分别为0.57、0.70。由此可以得出,绿光标准化值、蓝光标准化值能反映夏玉米受胁迫程度,其中蓝光标准化值是能够较好地反映夏玉米受高温胁迫程度的光谱参数。     

用高光谱数据诊断水分胁迫下棉花冠层叶片氮素状况的研究

利用ASD地物光谱仪,获取北疆棉花冠层关键生育时期的高光谱数据,应用一阶微分光谱,衍生出基于光谱位置变量的分析方法,以红边积分面积(SDr)为自变量,冠层全氮(TN)含量为因变量,做相关分析,结果表明:红边积分面积变量与冠层TN含量呈显著的相关性,相关系数是0.7394(n=40),利用构建的相关模型可以较为精确地估测棉花两个品种新陆早6号与8号冠层叶片的全氮含量,均方差(RMSE)分别为0.3859和0.4272。研究认为面积变量具有预测棉花冠层全氮含量的应用潜力。     

高温、强光胁迫对苹果果皮组织APX活性的影响

通过对自然条件下苹果树冠不同方位和不同日烧程度果实APX活性的比较,以及在果实上施用外源抗氧化剂,研究了高温和强光胁迫下果实APX活性的变化规律。结果表明：树冠不同方位果实APX活性有明显差异,树冠西南、南和西面三个方位果实表皮组织APX活性均极显著地高于其他方位,这与自然条件下不同方位果实对高温和强光的适应性有直接关系。在一定高温胁迫范围内,APX活性随果实日烧程度增强而上升,但超过一定限度,其活性显著下降,说明过度高温和强光下APX本身也受到伤害。果实喷施不同外源抗氧化剂能提高APX活性,其中以SA处理效果最显著,比对照提高了534．87％。由此可见,适当施用外源抗氧化剂可提高果实APX的活性,从而提高果实的抗氧化能力。     

温度胁迫对豇豆种子萌发生理指标的影响

以3个豇豆品种为材料,采用完全随机设计,重复3次,设置低温15℃、常温25℃(对照)和高温35℃3个处理,进行种子萌发实验。确定供试种子批种子活力正常后,在萌发种子胚根长到1 cm时,分胚根和子叶两个部位取样测定其可溶性蛋白质含量(TSP)、丙二醛(MDA)含量及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)活性等生理指标。结果表明:温度胁迫使胚根中TSP含量均较常温显著或极显著降低,子叶中的TSP含量在低温处理下极显著高于对照,而在高温下与之相反;温度胁迫下,各豇豆品种胚根和子叶中MDA含量均较显著或极显著高于对照;SOD活性变化与之相反,但品种间有差异。胚根POD活性在低温下极显著高于对照,在高温下却显著或极显著低于对照,而子叶中与之相反。子叶中CAT活性在低温下上升,高温下下降,而胚根中均上升。因此,低温和高温都明显阻碍豇豆种子萌发,但生理基础上不完全一致,且胚根和子叶的反应有明显差别,其中比较一致的是种胚萌发时MDA含量升高和SOD活性下降,反应不一致的有TSP含量、POD活性及CAT活性变化。     

Tolerance of Drought and Temperature Stress in Relation to Increased Antioxidant Enzyme Activity in Wheat

An experiment was conducted with three wheat genotypes differing in their sensitivity to moisture and/or temperature stress to study the relationship of the chloroplast antioxidant system to stress tolerance. Both moisture stress and temperature stress increased glutathione reductase and peroxidase and decreased membrane stab-iltty, chlorophyll content and chlorophyll stability index in all genotypes. Under moisture stress. DL 153–2 showed the highest membrane stabihty index, chlorophyll content, chlorophyll stability index, glutathione reductase activity and peroxidase activity. However, under elevated temperature conditions, HD 2285, and to a lesser extent DL 153–2, showed higher membrane stability, chlorophyll content and chlorophyll stability index and activities of glutathione reductase and peroxi-dase. Raj 3077, which is sensitive to both drought and temperature stress, showed the lowest membrane stability, chlorophyll content and chlorophyll stability index and glutathione reductase and perosidase activity under elevated temperature as well as drought conditions. Thus, it can be concluded that tolerance of the genotype to moisture and/or temperature stress is closely associated with its antioxidant enzyme system.     

程序降温过程中吲哚乙酸对生菜种子抗低温胁迫的影响

种子是植物越冬的重要生存策略,种子低温保存是种质资源保存的主要方式.选取含水生菜种子作为研究对象,利用程序降温仪制造不同的降温速率(3℃/h和60℃/h),研究吲哚乙酸(IAA)对种子抗寒性的影响.结果表明,相比于快速降温(60℃/h),慢速降温(3℃/h)有利于生菜种子内源IAA的积累.外源施加IAA可以降低程序降温(经慢速降温后更显著)过程中生菜种子的冷冻伤害,其中以200 μm的IAA对种子进行预处理效果最显著.无论降温速率如何,生菜种子遇到低温胁迫后SOD活性和脯氨酸含量会显著增加.外源施加IAA浓度越高,对SOD活性产生抑制作用,而IAA对脯氨酸含量有促进作用.降温速率以及外源IAA浓度也会对冷相关的ICE 1、HOS 1基因的相对表达量产生影响.     

抽穗扬花期高温胁迫对不同耐热性水稻生理指标的影响

高温热害对水稻生产造成了巨大的损失,其危害机理研究刚刚起步。为了研究不同耐热性水稻在高温胁迫下主要生理指标的变化情况,对其生理指标与耐热性的关系进行分析。结果表明:不同品种的水稻,耐热性存在差异,可以通过耐热系数筛选不同的耐热品种;高温胁迫对不同耐热性水稻的生理指标有较大的影响,绝大多数的生理指标随高温处理时间延长,表现出先增大,达到峰值后下降的趋势;耐热性强的水稻品种,各个生理指标的峰值出现的较晚,耐热性差的品种,较早达到峰值;耐热系数和生理指标相关分析表明耐热系数除与MDA含量呈正相关关系外,与各生理指标上呈负相关关系,其中与CAT酶活性相关系数到达了-0.75222**。高温胁迫下,水稻水稻生理指标会发生很大的变化;每个生理指标基本都有峰值出现,表明生物体高温热害是应激物质等调节存在反馈机制;高温胁迫时生理指标变化与耐热性有一定的相关性。     

亚精胺处理青稞幼苗对NaCl胁迫作用的缓解

以青稞（Hordeum vulgare L. var. nude）幼苗叶片为试材,以200mmol/L NaCl对其进行盐胁迫,研究了外源亚精胺（Spd）预处理对NaCl胁迫下青稞幼苗叶片相对含水量（RWC）、叶绿体色素与水溶性蛋白质含量的影响。在NaCl胁迫的前两天,NaCl+Spd处理组用含0.5mmol/L Spd的1/2Hoagland营养液进行水培和叶面喷施含0.02%土温-80的0.5mmol/L Spd溶液;对照组（CK）和NaCl处理组,用1/2的Hoagland营养液进行水培,叶面喷施含0.02%土温-80的蒸馏水。随着200mmol/L NaCl胁迫的进行,青稞幼苗叶片RWC、叶绿体色素与水溶性蛋白质含量均明显降低,Spd预处理显著延缓了它们的下降。表明Spd预处理缓解了NaCl胁迫对青稞幼苗造成的伤害,具有防衰抗盐的保护作用     

水分胁迫抑制水稻光合作用的机理

水分胁迫降低了水稻的光合速率。轻度水分胁迫下，气孔的限制是光合速率下降的主要原因；而严重水分胁迫下，叶肉细胞光合能力的降低是光合速率下降的主要原因。顺肉细胞光合能力的降低可能是由于光合量子效率、羟化效率、光合电子传递速率及光合磷酸化活力的下降所致。     

烟草(Nicotiana tabacum)非生物胁迫抗性分子机制研究进展

非生物胁迫影响烟草的生长发育,是制约作物产量和品质的重要因素。本综述阐述了非生物胁迫对烟草的影响以及最新的信号调控机制,包括干旱、盐、低温胁迫。在此基础上,综合分析了某些信号基因可能介导两因素甚至多因素调控过程,以及一些转录因子参与植物对冻害、干旱、盐害等非生物胁迫的应答调控,证明其对植物非生物胁迫的调控往往是多效性的。从分子水平上解析烟草在各种胁迫条件下的适应机制,对烟草种质资源保存、抗逆育种以及提高产量具有重要意义,为进一步研究植物的非生物胁迫应答提供理论依据。     

低温胁迫下丛枝菌根真菌对玉米幼苗形态、生长和光合的影响

为了解丛枝菌根真菌对玉米抗寒性的作用及其机理,利用盆栽试验,研究了低温胁迫下丛枝菌根（ AM）真菌接种处理对玉米幼苗形态、生长和光合特征的影响。研究显示,低温胁迫下,与非AM真菌接种处理玉米相比,接种玉米具有更大的叶片大小和更高的地上生物量。低温胁迫降低了玉米叶片净光合速率（ Pn）、气孔导度（ Gs）和蒸腾速率（Tr）,增加了叶片胞间CO2浓度（Ci）。接种丛枝菌根真菌的玉米Pn、Gs和Tr高于不接种植株,而Ci低于不接种植株。低温胁迫下,玉米叶片初始荧光（Fo）升高,而可变荧光（Fv）、最大荧光（Fm）、最大光化学效率（Fm／Fv）和潜在光化学效率（ Fv／Fo）均下降。无论常温或低温,接种AM真菌玉米叶片Fm和Fv高于非接种植株,同时,接种真菌玉米的叶片Fm／Fv和Fv／Fo也均高于不接种植株。研究结果表明,低温能够对玉米幼苗的生长和光合生理造成严重伤害;低温胁迫下,接种AM真菌能够通过其对玉米植株的保护和促进作用改善玉米的生长,以及对叶片光合系统的保护作用提高玉米的光合能力,增强玉米幼苗的抗寒能力。     

两种不同耐热性菜豆品种在高温胁迫下叶绿素a荧光参数的差异

以两个耐热性不同的菜豆品种85-CT（耐热）和BBL-47（热敏感）为试材,研究其在不同高温胁迫强度下叶绿素a荧光参数的差异,结果表明：两个品种的叶绿素荧光Fv/Fm及Fv/Fo、电子传递速率（ETR）、均随高温胁迫时间延长呈下降趋势,但耐热品种85-CT下降幅度较热敏感品种BBL-47平缓,BBL-47随高温胁迫时间延长,其叶绿素a荧光诱导动力学曲线中的第二峰（M峰）消失。