猪粪快速好氧堆肥过程中氧气浓度的变化

采用自主设计开发的氧气测量设备,测定堆体不同部位的氧气浓度,从而对猪粪堆肥过程中氧气浓度的变化、通风对氧气浓度的影响、堆体不同部位氧气浓度的差异进行了分析。结果表明,堆肥过程中氧气浓度呈升高的趋势,中后期氧气浓度增加比前期明显;停止通风后10min内氧气消耗速率最快,这后消耗速度较慢;堆体四周和顶部氧气浓度较高,中部较低。     

遮荫条件下绞股蓝光合作用特点的研究

在夏季遮荫条件下栽培绞股蓝的净光合速率日变化呈现不典型的双峰曲线,第1峰值出现在11：00时,达13．8μmolCO2·m^-2·S^-1日净光合速率达到176．97μmol CO2·m^-2,是强光下栽培的3．1倍;净光合速率和光量子通量密度呈正相关,相对湿度对净光合速率的影响小．强光下栽培绞股蓝。光合作用“午休”现象明显,净光合速率日变化呈现双峰曲线,第1峰值出现在10：00时,为3．0μmol CO2·m^-2·s^-1．第2峰值出现在14：00时,为1．25μmol CO2·m^-2·s^-1;相对湿度与净光合速率成正相关,对净光合速率的影响大．当光量子通量超过700μmol·m^-2·s^-1时,净光合速率与光量子通量密度呈负相关．在影响该植物蒸腾速率的诸多因子中,蒸腾速率和气孔导度之间的相关性最为显著．因此绞股蓝属于高度耐荫而怕光的植物．人工栽培应重点考虑光照因子．     

蚊子花的组织培养与快速繁殖

1植物名称蚊子花（Lopezia cordata Hornem．）。 2材料类别茎段和顶芽。 3培养条件基本培养基为MS。（1）芽诱导培养基：1／2MS（MS大量元素用量减半）;（2）增殖培养基：MS＋6-BA0．2mg·L^-1（单位下同）＋NAA0．2;（3）生根培养基：I／2MS＋NAA0．5。以上培养基中均加入6g·L^-1琼脂和30g·L^-1蔗糖,pH5．9—6．0。培养室中温度为（24＋1）℃,光照时间为16h·d^-1,光照强度约为60μmol·m^-2·s^-1。     

光系统Ⅱ电子受体p－BQ及DMBQ的耗氧的动态变化

对苯醌（ｐ—ＢＱ）及二甲基对苯醌（ＤＭＢＱ）作为类囊体膜中光系统ＩＩ电子受体时，可同时作为电子递体促进耗氧反应，这个过程在低浓度下即可发生。因耗氧的速率较放氧速率低，所以在氧变化动力学测量开始阶段，耗氧过程为放氧过程所掩盖。ｐ－ＢＱ为４０μｍｏｌ／Ｌ时耗氧活力与放氧活力之比为０．１６，在３００μｍｏｌ／Ｌ时，比值为０．５５。因此，在计算光系统ＩＩ电子传递活力时，不可忽略耗氧活力。耗氧速率随浓度增加而增加。在相同浓度下促进耗氧速率的关系为：而耗氧速率达到饱和的浓度则是：实验表明ｐ－ＢＱ作为电子递体参与耗氧反应的位置不先于ＤＣＭＵ抑制位置。     

温度升高对高光强环境下蛋白核小球藻(Chlolorella pyrenoidosa)光能利用和生长的阻抑效应

以蛋白核小球藻（Cholorella pyrenoidosa）为实验材料,研究了温度变化对不同光照水平下蛋白核小球藻的光能利用和生长的影响,以明确光照强度对微藻的光能利用和生长的影响是否因温度不同而发生变化。实验中共设置了3个光照强度水平（50,150,300μmol·m^-2s^-1）和2个温度水平（15℃,25℃）。实验结果表明,不同光照水平下小球藻叶绿素荧光的非光化学淬灭（NPQ）大小与温度有关,光照强度为150,300μmol·m^-2s^-1时,温度升高使小球藻叶绿素荧光NPQ提高,并且光照强度越高小球藻叶绿素荧光NPQ增大越多,50μmol·m^-2s^-1光照强度下温度升高对叶绿素荧光NPQ没有影响。实验发现,25℃培养温度下小球藻的光合电子传递速率（ETR）随光照强度增高而上升的速率要低于15℃时小球藻ETR上升的速率;随着光照强度增高,温度升高使小球藻ETR降低程度增大。实验结果还表明,15℃时小球藻培养液叶绿素a浓度随光照强度升高而增高,300μmol·m^-2s^-1培养光强下具有最高的叶绿素a浓度。但在25℃时,光照强度升高叶绿素a浓度并不一定增高,300μmol·m^-2s^-1光照强度下的叶绿素a浓度比150μmol·m^-2s^-1光照强度下要低。本研究表明,温度升高增大了高光照水平下蛋白核小球藻对光能的热耗散,使光照增强对小球藻生长的促进作用减弱。由于温度升高对小球藻光能利用和生长的阻抑作用,小球藻生长的适宜光照水平因温度升高而降低。     

精胺对荇菜抗氧化酶系汞毒害的缓解作用

研究了外施不同浓度的精胺（Spm）对15μmol·L^-1汞胁迫下,荇菜（Nymphoides pehatum）叶中SOD、CAT、APX、POD保护酶的活性、O2^-产生速率、MDA、叶绿素、可溶性蛋白、游离态多胺含量的影响。结果表明：外施0．05～0．5mmol·L^-1的Spn,显著提高了汞胁迫下荇菜叶内的亚精胺、精胺水平以及叶绿素和可溶性蛋白的含量;并能提高SOD、CAT和APX的活性,降低O2^-的产生速率,减缓MDA的积累;0．05～0．5mmol·L^-1的外源Spm可增强植物抗氧化胁迫的能力,缓解汞对荇菜的毒害作用,其中0．05～0．1mmol·L^-1的外源Spm效果最佳,但当Spm浓度达到5mmol·L^-1时,却加剧了汞的毒害作用。     

光系统II电子受体p—BQ及DMBQ的耗氧的动态变化

对苯醌（ｐ－ＢＱ）及二甲基对苯醌（ＤＭＢＱ）作为类囊体膜中光系统Ⅱ电子受体时,可同时作为电子递体促进耗氧反应,这个过程在低浓度下即可发生。因耗氧的速率较放氧速率低,所以在氧变化动力学测量开始阶段,耗氧过程为放氧过程所掩盖。ｐ－ＢＱ为４０μｍｏｌ／Ｌ时耗氧活力与放氧活力之比为０．１６,在３００μｍｏｌ／Ｌ时,比值为０．５５。因此,在计算光系统Ⅱ电子传递活力时,不可忽略耗氧活力。耗氧速率随浓度增加而增     

城市污泥堆肥温度动态变化过程及层次效应

对城市污泥强制通风静态垛堆肥的温度变化规律进行了研究。结果表明,当调理剂比例较低时,堆体升温速率和降温速率都较为缓慢,堆肥处理长,堆体温度较低,当调理剂比例较高时,堆体升温速率较快,堆肥温度将在较短时间内达到灭菌稳定化所要求的高温。堆体温度在高温阶段持续的时间与调理剂比例有着密切的联系,当调理剂比例太高时,高温持续时间短,如加入适当比例的回流污泥,堆温可以在50℃以上高温阶段持续足够的时间,当堆肥原料的起始温度高于15℃,堆体一般要经历升温阶段、高温持续阶段和降温阶段,但是当堆肥原料的起始温度很低时,堆体温度还要经历一个起爆阶段。堆体内不同层次的温度有着不同的变化趋势,堆肥初始阶段,堆体下层温度高于上层温度,随后上层温度逐渐高于下层温度。     

三种农药对斑马鱼的急性毒性和生物浓缩系数

采用斑马鱼(Brachydanio rerio)为试验生物,研究了吡虫啉、三唑磷和哒螨灵的急性毒性和生物浓缩系数．通过毒性试验,获得了这3种农药对斑马鱼的24、48、72和96h LC50值．这3种农药的96h LC50值分别为281．37mg·L^-1、8．37mg·L^-1和11．66μg·L^-1．根据急性毒性数据和有关技术指南,确定生物浓缩试验浓度和持续暴露时间为14d．经0．5和5mg·L^-1吡虫啉暴露后的生物浓缩系数(BCFs)分别为1．52和0．97．经0．02和0．2mg·L^-1三唑磷暴露后的BCFs分别为9．00和8．45．经0．1和1μg·L^-1哒螨灵暴露后的BCFs分别为5600和4920．     

濒危植物绵刺光合的生理生态学特征

使用Li-6200便携式光合测定仪,测定了自然状况下绵刺的净光合速率,蒸腾速率,水分利用效率以及气象因子在9：00-19：00的日进程,以白刺等旱生植物为对照。进行了对比研究。研究结果表明,绵刺的日平均净光合速率为8.832μmol·m^-2·s^-1,小于白刺的日平均净光合速率9.449μmol·m^-2·s^-1;绵刺的水分利用效率大于白刺,在13：00之前差异最为明显;同其它沙旱生植物相比,其净光合速率和水分利用效率均介于多种旱生植物之间;绵刺的净光合速率同各个气象因子的相关均不显,水分利用效率同气温以及相对温度之间呈极显相关,与气温,相对温度以及大气CO2浓度之间存在的多元线性关系。相关方程为YWUE=6.306 0.633XRH-0.178XTA 0.0164Xco2。     

温度、盐度对强壮箭虫耗氧率和窒息点的影响

研究了不同温度、盐度下强壮箭虫的耗氧率和窒息点.结果表明:温度和盐度均对强壮箭虫的耗氧率和比耗氧率有显著影响.试验温度在5℃-25℃,强壮箭虫个体耗氧率(IO)和比耗氧率(SO)开始随温度的升高而升高,之后呈明显下降趋势.其回归方程分别为y=0.0058x3 -0.2956x2+4.415x-8.7816(R2=0.99,P＜0.05)和y=0.0011x3 -0.0546x2+0.8161x-1.6232(R2=0.99,P＜0.05),数值分别为6.30～11.71μg·ind-1·h-1和1.22 ～2.16μg· mg-1·h-1,窒息点为4.18～6.87 mg·L-1.盐度10 ～40条件下,IO和SO随盐度的升高逐渐下降,回归方程分别为y=-0.0068x2 -0.1412x+21.702(R2=0.89,P＜0.05)和y=-0.0013x2-0.0261x+4.0114( R2 =0.89,P＜0.05),数值分别为4.98～17.73μg ·ind-1·h-1和0.92～3.56 μg·mg-1 ·h-1,窒息点为4.02～6.24 mg·L-1.对强壮箭虫与其他水生动物的耗氧率和窒息点进行比较得出,强壮箭虫是一种狭氧性浮游动物.     

钾素水平对网纹甜瓜叶片光合特性及叶绿体亚显微结构的影响

在设施基质栽培条件下,研究了营养液中120、240及360 mg·L^-1 3个钾素水平对网纹甜瓜‘甜甜1号’叶片光合特性及叶绿体亚显微结构的影响.结果表明,营养液中钾素水平过低（120 mg·L^-1）或过高（360 mg·L^-1）均导致网纹甜瓜叶片净光合速率下降,使叶绿体片层结构混乱、变形和片层数减少,但对CO₂补偿点（70 μl·L^-1）、饱和CO₂（600 μl·L^-1）、光补偿点（50 μmol·m^-2·s^-1）无显著影响.适宜的钾素水平能显著提高叶片的饱和光强、羧化效率和表观量子效率,3个指标分别为1 200 μmol·m^-2·s^-1、0.1364和0.0237.在试验条件下,提高温室内基质栽培网纹甜瓜叶片光合效率的最适钾素水平为240 mg·L^-1.     

二氧化硫对小麦的氧化胁迫及其某些信号分子的调节

通过在密闭的培养箱中一次性通入不同体积浓度的SO₂气体,研究了小麦幼苗超氧自由基O2-含量和3种抗氧化酶活性的变化,探讨了信号分子水杨酸、乙烯和过氧化氢对SO₂氧化胁迫的调节作用.结果表明,当通入10和40 μl·L^-1 SO₂时,小麦叶片中O2-含量递增,过氧化物酶(POD)和过氧化氢酶(CAT)活性增强,但超氧化物歧化酶(SOD)活性降低.当SO₂浓度达到50 μl·L^-1时,POD和CAT活性也开始降低,此时叶片尖端出现坏死,叶片绿色部位滋生大量真菌.用1 mmol·L^-1水杨酸(SA)(pH6.5)浸泡小麦干种子6 h,或用10 mmol·L^-1 H₂O₂浸泡幼苗,O2-含量低于对照植株,而3种酶的活性高于对照植株,均可有效地减轻SO₂的氧化胁迫.在SO₂熏蒸下,乙烯显著抑制3种酶的活力,提高O2-的形成速率.SA与乙烯同时使用时,SA几乎完全消除了乙烯的负面作用.     

The ontogeny of physiological response to light intensity in early stage spiny lobster (Jasus edwardsii) larvae

Early stage phyllosoma larvae of the spiny rock lobster Jasus edwardsii were examined for swimming speed, feeding, oxygen consumption and nitrogen excretion as instantaneous performance indicators when exposed to different irradiance levels. Swimming speed was measured in recently hatched Stage I larvae while all other parameters were measured in larvae from hatch to mid-Stage V. The swimming speed of recently hatched Stage I phyllosoma increased logarithmically between light intensities of 2.9 x 10(14) and 1.8 x 10(16) quanta s(-1) cm(-2) indicating that, within this range, swimming activity was only suppressed at the lowest irradiance level. Larvae examined under dark (no light) conditions showed lower feed intake, oxygen consumption and nitrogen excretion than larvae under low (7.7 x 10(12) q s(-1) cm(-2)) and high (3.9 x 10(14) q s(-1) cm(-2)) light intensities, and this was a consistent pattern observed throughout development from hatch to Stage V. There was no difference in feeding, oxygen consumption and nitrogen excretion between larvae exposed to low and high light intensities. However, from mid-Stage I to mid-Stage V, the metabolic feeding efficiency (feed intake:oxygen consumption ratio) was consistently higher in larvae exposed to low light intensity than in phyllosoma assessed in the dark and under high irradiance. A light intensity of about 7.7 x 10(12) quanta s(-1) cm(-2) and no higher than 3.9 x 10(14) quanta s(-1) cm(-2) is recommended to stimulate feeding and optimise metabolic feeding efficiency in early larval stages of J. edwardsii.     

甲醇抑制时重组毕赤酵母发酵的特性研究

本文对毕赤酵母进行了恒化培养研究。以甲醇为唯一碳源时,在稀释率较低时(D<0.048 h^-1),连续培养系统操作很稳定。但在稀释率高时(D>0.048h^-1),连续培养系统的定态点不止一个,实验不能维持,故采用比生长速率恒定的分批流加培养进行研究。结果表明,毕赤酵母的生长符合Andrew普遍化底物抑制模型。综合考虑水蛭素的生成、底物的消耗,在生产中维持甲醇浓度为限制性浓度(0.5 g/L),且维持比生长速率为0.02 h^-1时,水蛭素Hir65的比生成速率达到最大值0.2 mg/(g·h)且甲醇的比消耗速率为0.04 g/(g·h)。     

Oxygen consumption and body temperature of active and resting honeybees

We measured the energy turnover (oxygen consumption) of honeybees (Apis mellifera carnica), which were free to move within Warburg vessels. Oxygen consumption of active bees varied widely depending on ambient temperature and level of activity, but did not differ between foragers (>18 d) and middle-aged hive bees (7-10 d). In highly active bees, which were in an endothermic state ready for flight, it decreased almost linearly, from a maximum of 131.4 microl O(2) min(-1) at 15 degrees C ambient temperature to 81.1 microl min(-1) at 25 degrees C, and reached a minimum of 29.9 microl min(-1) at 40 degrees C. In bees with low activity, it decreased from 89.3 microl O(2) min(-1) at 15 degrees C to 47.9 microl min(-1) at 25 degrees C and 14.7 microl min(-1) at 40 degrees C. Thermographic measurements of body temperature showed that with increasing activity, the bees invested more energy to regulate the thorax temperature at increasingly higher levels (38.8-41.2 degrees C in highly active bees) and were more accurate. Resting metabolism was determined in young bees of 1-7 h age, which are not yet capable of endothermic heat production with their flight muscles. Their energy turnover increased from 0.21 microl O(2) min(-1) at 10 degrees C to 0.38 microl min(-1) at 15 degrees C, 1.12 microl min(-1) at 25 degrees C, and 3.03 microl min(-1) at 40 degrees C. At 15, 25 and 40 degrees C, this was 343, 73 and 10 times below the values of the highly active bees, respectively. The Q(10) value of the resting bees, however, was not constant but varied in a U-shaped manner with ambient temperature. It decreased from 4.24 in the temperature range 11-21 degrees C to 1.35 in the range 21-31 degrees C, and increased again to 2.49 in the range 30-40 degrees C. We conclude that attempts to describe the temperature dependence of the resting metabolism of honeybees by Q(10) values can lead to considerable errors if the measurements are performed at only two temperatures. An acceptable approximation can be derived by calculation of an interpolated Q(10) according to the exponential function (V(O(2))=0.151 x 1.0784(T(a))) (interpolated Q(10)=2.12).     

镇江内江湿地不同演替阶段植物群落小气候日动态

2005年5月,选择镇江内江湿地具有代表性的裸地、虉草群落和芦苇群落,分别代表植被群落的不同演替阶段,测定不同群落、不同层次的光照强度、气温、土温和空气相对湿度,研究其植物群落小气候的日动态.结果表明,随演替由裸地到虉草群落到芦苇群落进行,群落内光照强度、气温和土壤温度均明显降低,日变幅减小.其中,日均光照强度由1 204.7 μmol·m^-2·s^-1降至141.28 μmol·m^-2·s^-1,日均变幅由1 126μmol·m^-2·s^-1降至265 μmol·m^-2·s^-1;日均气温由32.2 ℃降至24.9 ℃,日均变幅由12.75 ℃降至4.8 ℃;日均土温由21.83 ℃降至19.47 ℃,日均变幅由4.5 ℃降至2.1 ℃.群落内空气相对湿度明显升高(由58.95%增至87.3%）,变幅减小(由29.75%降至5.15%）.生境具有早期的开放性和后期的封闭性,小气候环境朝着更为阴、凉、湿的环境变化,且波动性减弱,稳定性增强.各群落内的光强、气温、湿度及土温之间均存在一定相关,但不同演替阶段各因子间相关程度各异.     

Respiratory and metabolic effects of decreased osmolality in conscious rats

We investigated the respiratory and metabolic effects of decreased osmolality, and the potential roles of angiotensin II (ANG II) and the subfornical organ (SFO) in mediating these effects, in conscious Sprague-Dawley (SD) rats. Gastric water loading was induced either by oral gavage or an externalized indwelling stomach tube (20 mL x kg(-1) distilled water at body temperature). Repeated measurements after oral gavage were obtained with and without water loading and with and without ANG II receptor block (saralasin, 1.3 microg x kg(-1) x min(-1) iv). At 15 min after water loading by oral gavage, ventilation (V, 1.14+/-0.08 L x kg(-1) x min(-1)) and tidal volume (10.7+/-0.6 mL x kg(-1)) were transiently higher (P < 0.05), at a time when plasma osmolality was decreased (-8+/-1 mOsm), compared with gavage tube alone (0.95+/-0.08 L x kg(-1) min(-1) and 9.1+/-0.7 mL x kg(-1), respectively). However, water loading via stomach tube did not stimulate V; only during the 60-s period of water infusion did V increase briefly, but this was due to increased respiratory frequency. Dye indicators demonstrated that oral gavage exposes upper airway and esophageal afferents to water, presumably accounting for respiratory stimulation. Lesions of the SFO did not affect respiration or metabolism. A decrease in osmolality, associated with both water loading techniques, caused a sustained increase in oxygen consumption (Vo2 ) and a decrease in the V/Vo2 ratio. ANG II receptor block reduced the Vo2 response and prevented the decrease in V/Vo2 following water loading by oral gavage, but did not affect the transient stimulation of V. Unlike larger mammals, decreased osmolality does not stimulate respiration in the SD rat.     

Effect of glyphosate-based herbicide on acetylcholinesterase activity in tadpoles, Hoplobatrachus rugulosus

This study focused on the effects of a glyphosate-based herbicide on activity of the neuron enzyme, acetylcholinesterase (AchE), in the tadpole stage (stage 35-39) of the East Asian Bullfrog, Hoplobatrachus rugulosus. There were 4 herbicide concentration treatments consisting of glyphosate-based herbicide added at 21, 24, 27 and 30 microl to 1L de-chlorinated water in glass containers (10x15x20 cm). There were 4 replicates per treatment, each replicate using 20 tadpoles. The toxicity results were compared with tadpoles in distilled water as a control treatment. After 24, 48, 72 and 96 hours exposure to glyphosate-based herbicide concentrations, LC50 values of 25.21, 24.66, 24.16 and 23.63 microl/L, respectively, were recorded. AChE activities decreased significantly and markedly with herbicide concentration. Such inhibition of AChE activity by this glyphosate-based herbicide indicates the potential of such herbicides to disrupt ecological communities in water near where the herbicides are applied.     

Variation in microbial population during composting of agro-industrial waste

Two compost piles were prepared, using two ventilation systems: forced ventilation and ventilation through mechanical turning. The material to compost was a mixture of orange waste, olive pomace, and grass clippings (2:1:1 v/v). During the composting period (375 days), samples were periodically taken from both piles, and the enumeration of fungi, actinomycetes, and heterotrophic bacteria was carried out. All studied microorganisms were incubated at 25 and 55 °C after inoculation in appropriate growth media. Fungi were dominant in the early stages of both composting processes; heterotrophic bacteria proliferated mainly during the thermophilic stage, and actinomycetes were more abundant in the final stage of the composting process. Our results showed that the physical and chemical parameters: temperature, pH, moisture, and aeration influenced the variation of the microbial population along the composting process. This study demonstrated that composting of these types of wastes, despite the prolonged mesophilic stage, provided an expected microbial variation.