稀土积累与水稻白叶枯病发生发展的关系研究

在试验生态小区的土壤中,模拟长期使用稀土产生的积累以探讨稀土积累与水稻白叶枯病发生发展的关系。研究结果表明:0.5%,1%,3%,5%,7%,10%吸附容量和40g/亩的稀土以及土壤中2000g/亩和40g/亩的稀土复合肥添加剂对水稻白叶枯病发生后的病情指数影响无显著差异。

Bioaccumulation of Nickel by Various Scenedesmus Species in Culture Solution Containing Nickel

Sixteen Scenedesmus species or strains have been employed to investigate the maximum capacity of nickel (Ni) accumulation in 10 mg/L Ni solution. The results showed that the capacity of accumulating Ni from aqueous solution in 16 Scenedesmus species or strains showed the diversity. S. quadricauda freshwater algae culture collection of the Institute of Hydrobiology (FACHB) 44 and S. quadricauda FACHB 506 performed much more capacity of Ni accumulation than other species such as Scenedesmus sp. FACHB 416 and Scenedesmus sp. FACHB 489. Sequestration of Ni ions from aqueous solution was very efficient (26.7 mg Ni/g dry weight, in the 100 mg/L Ni solution) in S. quadricauda FACHB 44. The kinetics of Ni binding indicated that Ni bioaccumulation, in algal cell of S. quadricauda FACHB 44, possessed a rapid biosorption (5 min) and an slow bioaccumulation (2-3 h). More than 70% of Ni binding in algal cell were accumulated by biosorption and the remaining 20%-30% were bioaccumulated by energy_consumed transportation. It is much more higher ratio of energy_consumed transportation in S. quadricauda FACHB 44 than in other algae. Both the transmission electron microscope (TEM) and the energy_dispersive X_ray (EDX) microanalyses also revealed the different mechanisms of bioaccumulation in the various subcellular regions: a very fast adsorption in the cell wall; and a time_dependent absorption in protoplasm, specially in starch and chromatin.

Low temperature induces oocytes p34^(cdc2) synthesis and accumulation-the acquisition of competence to resume meiosis in toad oocytes

Full grown oocytes derived from Bufo Bufo gargarizans rearing at high temperature environment (24℃),never underwent GVBD after progesterone treatment. No p34cdc2, H1 kinase activity was detected in the oocytes after progesterone stimulation or OA microinjection; Western blotting analysis showed that the level of p3cdc2, and p33 in the oocytes are significantly lower than those in the oocytes derived from the hibernating toads (below 10 ℃). 25S-Met incorporation analysis showed that when the oocytes were incubated at 6℃, synthesis of about thirty defferent polypeptides was promoted or induced, including p34cdc2 and some other p13suc1-binding proteins. All these results indicated that a low temperature environment is essential for the oocytes of Bufo Bufo gargarizans to express and store some cell cycle drivers and its regulators, and to gain the maturation competence. These results will also provide a new clue for explaining the molecular mechanisms why gametogenesis of some organisms depends on a relative low temperature and how to maintain the geographical distribution of some animals.

Environmental contamination and health hazard of lead and cadmium around Chatian mercury mining deposit in western Hunan Province,China

A field survey concerning lead and cadmium pollution in environment mediums and hair samples around the Chatian mercury mining deposit in western Hunan Province,China,was conducted to preliminarily evaluate their health hazard to local inhabitants.The results show that mining wastes,especially tailing,contain high cadmium level with the maximum of 79.92μg/g. High levels of lead and cadmium are accumulated in surface water and paddy soil,respectively,and both metals pollution occurs in brown rice.The average daily intake dose(ADD)of lead for local adults via three routes reaches up to 7.7μg/(kg·d),exceeding the provision tolerable daily intake by JECFA of 3.5μg/(kg·d),and drinking water exposure route contributes the highest daily intake.As an indicator for heavy metal exposure,the hair of local population contains Pb(5.06±3.02)μg/g.The average daily intake dose of cadmium for adults is 0.119μg/(kg·d).More attention must be paid on health risk from lead pollution compared with cadmium.

Major Accumulations of Life and Main ＂Pain Points＂ in the Seas and Oceans

Because of permanent matter and energy accumulation in the sea marginal biotopes, communities of organisms adapted to these specific conditions are developed. Terms contour biotopes and contourobiont＇s communities were proposed. These habitats are populated by a great variety of organisms with numerical superiority of early stages of development of hydrobionts. Therefore, contour biotopes are responsible for the reproduction of many species of plants and animals, including commercialiy ~rnportant species of invertebrate and fish. But as a result of natural physical and chemical processes, the same habitats accumulate many substances that are harmful to living organisms, especially for early ontogenetic stages. So here formed main hotspots, critical ecological zones in seas and oceans, which need to be monitored in the first place. Understanding of the key role of contour biotopes and communities in marine ecological processes development is an ecological imperative. Making of ecological diagnoses, prediction of possible departures from the ecological norm and prevention of serious negative events in the marine environment needs special consideration of contour biotopes and their inhabitants, which are underestimated in traditional marine biological and ecological investigations.

陕蒙交界地区碎屑岩风化成因浅析

陕蒙交界地区基岩均具强风化,由此造成当地环境恶化、下游地区生态破坏和灾害积累。其形成机理应与岩石本身的物质组成、自然地理环境、地质构造状况、水文地质条件及其物理化学条件有关。而南部地区,由于上述诸因素的差别,基岩风化微弱。

An Array Extension Method in a Noisy Environment

An array extension method in a noisy environment was proposed to improve angular resolution and array gain. The proposed method combines the FOC （fourth-order cumulants） technique with the ETAM （extended towed array measurements） method to extend array aperture and suppress Gaussian noise, First, successive measurements of a virtual uniform linear array were constructed by applying lburth-order cumulants to measurements of uniform linear array; Gaussian noise in these measurements was also eliminated. Then, the array was extended by compensating phase differences using the ETAM method, Finally, the synthetic aperture was extended further by the fourth-order cumulants technique. The proposed FOC-ETAM-FOC method not only improves angular resolution and array gain, but also effectively suppresses Gaussian noise. Furthermore, it inherits the advantages of the ETAM method. Simulation results showed that the FOC-ETAM-FOC method achieved better angular resolution and array gain than the ETAM method. Furthermore this method outperforms the ETAM method in Gaussian noise environment.

早全新世生境改善促进中国北方农牧交错带的农业起源

中国北方农牧交错带农业起源的机制尚不明晰.内蒙古高原中部地处中国北方农牧交错带的核心区,是探索中国北方旱作农业起源机制的关键区域.本研究以代表内蒙古自治区新石器文化开端的裕民文化为研究对象,对裕民、坝南遗址中的沉积剖面(YM、BN1和BN2)开展石英光释光(OSL)测年,建立了各剖面的年龄-深度框架.在此基础上,通过对裕民遗址的植物浮选和炭化种子的鉴定、各剖面的多指标分析,系统探讨了中国北方农业起源与气候变化之间的关系.结果显示,裕民遗址记录的该区域农业起源的时间明显滞后于降水显著增加的早全新世,但与8.4ka前后该区域植被显著增加的时间一致.通过进一步与裕民文化圈周边高分辨率古环境记录的比对,证实了区域农业起源与气候变化的“异步”现象.自全新世伊始,随着水热条件的逐渐转好,区域生态环境逐步改善,促使地表由贫瘠的砂质层逐渐转变为富含有机质的土壤.早全新世区域生态环境的改善,为8.4ka前后中国北方旱作农业的起源提供了适宜的环境基础.早全新世的“环境积累效应”在中国北方农业起源中发挥了重要的作用,本研究将为未来气候变化背景下的区域农业管理提供参考.

Role of Salix reinii patches in spatio-temporal patterns of cohabitants on a Japanese volcano

Shrub patches often support the colonizers particularly under stressful and/or disturbed environments.The intensities of stresses and disturbances on mountains are often related to an elevation gradient and are decreased by shrub patches(canopy and litter).We aim to clarify these relationships by using shrub patches at different elevations on a volcano.We monitored all shoots in plots established inside and outside of patches of Salix reinii(Salicaceae)and their related environments,such as temperature,light,moisture and chemistry,at three elevations on Mount Koma(1131 m a.s.l.),northern Japan,from early spring in 2005 to summer in 2006.The patch structures were evaluated by area,branch density and litter thickness.The structures of shrub patches did not differ among the elevations.The patches increased the diversity of rare species,by an overall increase in plant species richness.The moisture,nitrogen and phosphate contents in the patches were higher than outside of patches.The effects of shrub patches on the cohabitants were overall positive,although the effects were negative on seedling abundance,shoot survival and flowering.These results suggest that the growth patterns of shrub patches determine the plant community structures and facilitate plant diversity.

Blooming of bacteria and algae is a biokiller for mass-extinction of Devonian coral-stromatoporoid reef ecosystems

Studies of rock slices showed that there were many kinds of symbioses between bacteria and algae and corals-stromatoporoids in the coral-stromatoporoid reefs from the Devonian Ganxi section of Sichuan and the Dushan section of Guizhou in South China. They included encrustations, microborings, bioclaustration, etc. In the host corals-stromatoporoids invaded by bacteria and algae were many residues of dead soft issue in the infected parts, where the skeletal structures were injured. Therefore, we considered there were direct interactions between corals-stromatoporoids and bacteria and algae in coral-stromatoporoid reefs, which included that bacteria and algae blocked growth of corals-stromatoporoids and the latter had the ability of self-healing. And the bacteria and algae usually was the active side. In the Middle Devonian with normal seawater condition, corals and stromatoporoids had the ability to resist the invasion of bacteria and algae, and the host coral-stromatoporoids would not be killed; but in the Late Devonian with deterioration of seawater quality, the ability of bacteria and algae infection increased while corals-stromatoporoids' ability to resist infection declined, and therefore the host corals-stromatoporoids would be dead. Hence we suggested that the invading of bacteria and algae was a possible biokiller for mass-extinction of the Devonian coral-stromatoporoid reefs ecosystem. Beyond that, blooming of bacteria and algae and its triggering cumulative environmental effects played an important role in the reduction and extinction of metazoan in the Late Devonian. Furthermore, it can be used as a useful example to learn the trend and the reasons for the disease and decrease of modern coral reefs.

Volatile organic compounds sensing based on Bennet doubler-inspired triboelectric nanogenerator and machine learning-assisted ion mobility analysis

Ion mobility analysis is a well-known analytical technique for identifying gas-phase compounds in fastresponse gas-monitoring systems.However,the conventional plasma discharge system is bulky,operates at a high temperature,and inappropriate for volatile organic compounds(VOCs)concentration detection.Therefore,we report a machine learning(ML)-enhanced ion mobility analyzer with a triboelectric-based ionizer,which offers good ion mobility selectivity and VOC recognition ability with a small-sized device and non-strict operating environment.Based on the charge accumulation mechanism,a multi-switched manipulation triboelectric nanogenerator(SM-TENG)can provide a direct current(DC)bias at the order of a few hundred,which can be further leveraged as the power source to obtain a unique and repeatable discharge characteristic of different VOCs,and their mixtures,with a special tip-plate electrode configuration.Aiming to tackle the grand challenge in the detection of multiple VOCs,the ML-enhanced ion mobility analysis method was successfully demonstrated by extracting specific features automatically from ion mobility spectrometry data with ML algorithms,which significantly enhance the detection ability of the SM-TENG based VOC analyzer,showing a portable real-time VOC monitoring solution with rapid response and low power consumption for future internet of things based environmental monitoring applications.