油菜素内酯提高植物抗逆性研究进展

油菜素内酯类(BRs)在农、林业生产上被广泛应用,近十多年来,有大量关于BRs提高植物抗逆性的研究报道.对油菜素内酯类(BRs)物质提高植物的抗旱性、抗湿性、抗寒性、抗热性、抗盐性、抗药性和抗病性等抗逆性作用以及对植物衰老的调节作用的研究进展进行了综述.     

Observations of ozone formation in power plant plumes and implications for ozone control strategies

Data taken in aircraft transects of emissions plumes from rural U.S. coal-fired power plants were used to confirm and quantify the nonlinear dependence of tropospheric ozone formation on plume NO(x) (NO plus NO(2)) concentration, which is determined by plant NO(x) emission rate and atmospheric dispersion. The ambient availability of reactive volatile organic compounds, principally biogenic isoprene, was also found to modulate ozone production rate and yield in these rural plumes. Differences of a factor of 2 or greater in plume ozone formation rates and yields as a function of NO(x) and volatile organic compound concentrations were consistently observed. These large differences suggest that consideration of power plant NO(x) emission rates and geographic locations in current and future U.S. ozone control strategies could substantially enhance the efficacy of NO(x) reductions from these sources.     

Foam solar sea power plant

In the accompanying report Beck suggests a new type of open-cycle system for obtaining power from the ocean's thermal gradient. A modification of this open-cycle plant which will ensure a high efficiency, and also a low capital cost per unit power output, is described here.     

Defensive function of herbivore-induced plant volatile emissions in nature

Herbivore attack is known to increase the emission of volatiles, which attract predators to herbivore-damaged plants in the laboratory and agricultural systems. We quantified volatile emissions from Nicotiana attenuata plants growing in natural populations during attack by three species of leaf-feeding herbivores and mimicked the release of five commonly emitted volatiles individually. Three compounds (cis-3-hexen-1-ol, linalool, and cis-alpha-bergamotene) increased egg predation rates by a generalist predator; linalool and the complete blend decreased lepidopteran oviposition rates. As a consequence, a plant could reduce the number of herbivores by more than 90% by releasing volatiles. These results confirm that indirect defenses can operate in nature.     

Ocean thermal gradient hydraulic power plant

Solar energy stored in the oceans may be used to generate power by exploiting ploiting thermal gradients. A proposed open-cycle system uses low-pressure steam to elevate vate water, which is then run through a hydraulic turbine to generate power. The device is analogous to an air lift pump.     

cDNA-AFLP技术在植物抗逆性相关基因表达研究中的应用

cDNA-AFLP技术是以mRNA反转录的cDNA为模板进行AFLP分析,在保留AFLP多态性丰富、稳定性高、无需了解序列信息等优点的同时,集中显示了基因组表达序列的多态性差异,可对生物体转录组进行全面、系统的分析,并已成功地用于基因差异显示、表达基因遗传连锁作图和基因克隆等方面。文章综述了cDNA-AFLP在植物抗逆性相关基因表达特性分析及基因分离方面的应用。     

矿质营养与植物病害机理研究进展

矿质营养不仅影响着植物的正常生长发育,且以多种方式直接或间接地影响着植物对病害的抗性。从矿质营养与病原菌的侵染,与酚类化合物代谢,与活性氧代谢,与碳氮化合物代谢,与内源激素代谢5方面综述了矿质营养对植物病害的侵染和繁殖的影响。     

Environmental impact of a geothermal power plant

The Wairakei plant discharges approximately 6.5 times as much heat, 5.5 times as much water vapor, and 0.5 times as much sulfur, per unit of power produced, as would a modern coal plant in New Zealand. It also contaminates the Waikato River with H(2)S, CO(2), arsenic, and mercury at concentrations that have adverse but not calamitous effects. Designed and built at a time when environmental sensibilities were less acute and geothermal technology was less developed, Wairakei produces an overall environmental impact that would be neither acceptable nor necessary in a new plant. Despite its imperfections, however, the Wairakei plant has been under development or in operation for more than 20 years without presenting any serious environmental problems for the local population. Reinjection of the hot waste water, an as yet unproven procedure for liquid-dominated fields, would reduce the plant's environmental impact sharply. Ground subsidence is not a severe problem at Wairakei but may prove to be one at the nearby Broadlands field. There are several environmental characteristics that are unique to geothermal power: (i) pollutant formation may be independent of the power productionc rate; (ii) effluent pathways may change abruptly; (iii) preoperational testing and wild bores contribute significantly to the overall impact; and (iv) waste water may be discharged at temperatures high enough so that utilization of the waste heat becomes both practical and imperative.     

植物根系形态建成研究进展

根系的形态建成对植物生长发育的好坏发挥着十分重要的作用.本文概述了植物侧根形成和生长过程中侧根原基的起始、形成、生长点的活化和侧根的伸长过程,分析了根毛形成和生长过程中根毛细胞命运的特异化、根毛的初始化和伸长的过程及其相关基因的作用.     

Carbon dioxide compensation points in related plant species

Both high and low C0(2) compensation concentrations were found in the plant genera-Panicum, Cyperus, and Euphorbia. Within each genus, however, high and low compensations were found in different subgenera. Thus, they may not be genetically closely related. No significant differences in CO(2) compensation were found among 100 genetic lines of Triticum aestivum L. or among 20 lines of Hordeum vulgare L.     

Sulfur dioxide emissions from power plants: their effect on air quality

A modeling study of atmospheric diffusion indicates that emission from power plants contributed only a modest percentage of the yearly average concentration of sulfur dioxide at ground level in the most polluted areas of Cook County, Illinois, during 1968.     

Ozone concentrations in new jersey and new york: statistical association with related variables

The concentrations of ozone at nine measurements sites in New Jersey and New York during the period 1 May through 30 September 1973 have been examined. Daily fluctuations in the ozone concentrations at any two sites are highly correlated. The concentrations are lower with low levels of solar radiation and also with high wind speed. The average ozone concentration shows only minor differences between weekdays and weekends, despite markedly different traffic patterns.     

Modeling grain protein formation in relation to nitrogen uptake and remobilization in rice plant

Protein concentration of grain is an important quality index of rice, and formation of grain protein largely depends on pre-anthesis nitrogen assimilation and post-anthesis nitrogen remobilization in the rice plant. The primary objective of this study was to develop a simplified process model for simulating nitrogen accumulation and remobilization in plant and protein formation in rice grains on the basis of an established rice growth model. Six field experiments, involving different years, eco-sites, varieties, nitrogen rates, and irrigation regimes, were conducted to obtain the necessary data for model building, genotypic parameter determination, and model validation. Using physiological development time (PDT) as general time scale of development progress and cultivar-specific grain protein concentration as genotypic parameter, the dynamic relationships of plant nitrogen accumulation and translocation to environmental and genetic factors were quantified and synthesized in the present model. The pre-anthesis nitrogen uptake rate by plant changed with the PDT in a negative exponential pattern, and post-anthesis nitrogen uptake rate changed with leaf area index (LAI) in an exponential equation. Post-anthesis nitrogen translocation rate depended on the plant nitrogen concentration and dry weight at anthesis as well as residue nitrogen concentration of plant at maturity. The nitrogen for protein synthesis in grains came from two sources: the nitrogen pre-stored in leaves, stem and sheath before anthesis and then remobilized after anthesis, and the nitrogen absorbed directly by plant after anthesis. Finally, the model was tested by using the data sets of different years, eco-sites, varieties, and N fertilization and irrigation conditions with the root mean square errors (RMSE) 0.22%–0.26%, indicating the general and reliable features of the model. It is hoped that by properly integrating with the existing rice growth models, the present model can be used for predicting grain protein concentration and grain protein yield of rice under various environments and genotypes.     

模拟增温对华北农田土壤碳排放的影响

为研究增温效应下农田温室气体排放的变化和机制,选择华北平原的山东禹城农田生态系统国家野外科学观测研究站当地典型的冬小麦-夏玉米农田为研究对象,设计翻耕增温(CTW)处理和翻耕不增温(CTN)对照开展多年增温试验。2014年10月出苗期至2015年12月冬小麦越冬期持续增温,2016年初至2016年9月增温设备因故障关闭。结果显示,2014—2015年,冬小麦期土壤温度显著增加1.31℃(P<0.05),夏玉米期土壤温度升高0.71℃(P>0.05),而全年土壤体积含水量均值对增温无显著响应,仅越冬期土壤含水量增加明显。两年期内,增温抑制冬小麦季CO2累积排放达20.35%,以3月和5月差异表现最为明显。2014—2016年冬小麦季,CTW、CTN处理的年均CH4累积吸收量分别为1641.2、2185.7 g·hm^-2,增温抑制冬小麦季CH4吸收,但对夏玉米季CH4通量无显著作用。冬小麦季增温降低CTW处理土壤微生物生物量碳值达26.55%,而微生物生物量氮仅个别施肥和灌溉月份对增温响应显著。两年期冬小麦和夏玉米季CTW、CTN地上生物量均值分别为12.19、16.33 mg·hm^-2和16.41、21.18 mg·hm^-2,表明增温降低了地上作物生物量。研究表明,长期增温显著抑制小麦季土壤CO2释放和CH4吸收,但玉米期碳排放和吸收的响应相对较弱。增温条件下,土壤水热条件和生物量依然是限制土壤碳通量的重要因素。     

BHA,BHT对生物柴油排放和动力经济性试验

为了研究酚类抗氧化剂对燃用生物柴油/柴油内燃机的影响,在一台四缸柴油机上进行了排放及燃油经济性和动力性试验.结果表明:在抗氧化剂质量浓度较低时,BHT要比BHA、TBHQ的诱导期长,当抗氧化剂质量浓度较高时,BHA的诱导期要比BHT、TBHQ长.BHA质量浓度分别为800、1 200mg/L时,B10混合燃料比未添加抗氧化剂的B10混合燃料有效燃油消耗率分别平均降低了0.67%、1.5%;当BHT质量浓度为800、1 200mg/L时,B10混合燃料比未添加抗氧剂的B10混合燃料的有效燃油消耗率分别平均降低了2.2%、2.6%.添加抗氧化剂BHT、BHA的燃料碳烟排放比未添加BHA、BHT的燃料低,但是添加酚类抗氧化剂后的NOx排放略有增加.