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31.
Gamergates (i.e. mated reproductive workers) are mostly known from ant species within the Ponerinae. We report here the discovery of gamergates in two species of the subfamily Myrmicinae. Until now, mated reproductive females in colonies of myrmicine species have been considered morphologically distinct from the worker caste. However, in two species of the myrmicine Metapone (Metapone madagascarica and a newly discovered, not yet described Metapone species) all workers have six ovarioles and a spermatheca; and some of them are mated. There are no morphological differences between mated and non-mated workers. Field observations and laboratory studies indicate that colonies of the Metapone species can reproduce with gamergates only.  相似文献   
32.
Although amphibians are highly vocal, they generally emit only a limited number of acoustic communication signals. We report here the extraordinarily rich vocal repertoire of Amolops tormotus, a ranid species in China. These frogs produce countless vocalizations, some of which share features of birdsong or primate calls, e.g., ultrasonic frequency components, multiple upward and downward FM sweeps, and sudden onset and offset of selective harmonic components within a call note. Frame-by-frame video analysis of the frog's calling behavior suggests the presence of two pairs of vocal sacs that may contribute to the remarkable call-note complexity in this species. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00114-002-0335-x.  相似文献   
33.
In this study, an inventory of air pollutant emission estimates from major air polluting sources in Turkey for period between 1985 and 2005 with 5-year intervals were estimated. Inventory covers anthropogenic sources of five major air pollutants of particulate matter, sulfur dioxide, carbon monoxide, nitrogen oxides and non-methane volatile organic compounds. Their break-down with respect to main activity sectors were shown and their distribution by the largest industrial source categories were worked out as annual estimates. This inventory and its analysis point to serious environmental implications of air pollutants and a need to develop a policy plan for reducing these emissions.  相似文献   
34.
Independent teams undertook environmental monitoring of particular concentrations of major construction projects forming part of Hong Kong’s U.S. $20 billion airport infrastructure programme located in dense urban areas. The team combination of environmental specialists with experienced civil engineers enabled pragmatic mitigation measures to be developed and accepted by the construction personnel with the result that potentially significant adverse impacts were averted. The authors discuss the mechanism and success of this innovative approach.  相似文献   
35.
生物质利用现状   总被引:29,自引:0,他引:29  
生物质能的使用是实现能源可持续发展的有效措施之一,因此其研究意义重大。本文在阐述生物质、生物质能定义和优点的基础上,对我国的生物质资源量及其利用的主要技术手段进行了分析。同时也对生物质利用所面临的主要问题进行了介绍,并提出了一些解决方案。认为现阶段我国生物质的利用应该注意国家政策的支持、基础研究的深入和宣传力度的加强。  相似文献   
36.
生态建设的生态效益转换的经济效益的转换速度,转换数量,转换成本,转换难易等直接影响生态建设的活力,效率和可持续发展,将生态效益转换的经济效益生态经营在其中起到关键作用,本文开创性探讨生态经营起因,内涵,功能,内容,技术,方法,手段等,为培育欠发达地区生态经营意识,能力,增强可持续发展能力指明了方向。  相似文献   
37.
Hydrogen storage and transportation or distribution is closely linked together. Hydrogen can be distributed continuously in pipelines or batch wise by ships, trucks, railway or airplanes. All batch transportation requires a storage system but also pipelines can be used as pressure storage system. Hydrogen exhibits the highest heating value per weight of all chemical fuels. Furthermore, hydrogen is regenerative and environment friendly. There are two reasons why hydrogen is not the major fuel of toady’s energy consumption: First of all, hydrogen is just an energy carrier. And, although it is the most abundant element in the universe, it has to be produced, since on earth it only occurs in the form of water. This implies that we have to pay for this energy, which results in a difficult economic task, because since the industrialization we are used to consuming energy for free. The second difficulty with hydrogen as an energy carrier is the low critical temperature of 33 K, i.e. hydrogen is a gas at room temperature. For mobile and in many cases also for stationary applications the volumetric and gravimetric density of hydrogen in a storage system is crucial. Hydrogen can be stored by six different methods and phenomena: high pressure gas cylinders (up to 800 bar), liquid hydrogen in cryogenic tanks (at 21 K), adsorbed hydrogen on materials with a large specific surface area (at T < 100 K), absorbed on interstitial sites in a host metal (at ambient pressure and temperature), chemically bond in covalent and ionic compounds (at ambient pressure), oxidation of reactive metals e.g. Li, Na, Mg, Al, Zn with water. These metals easily react with water to the corresponding hydroxide and liberate the hydrogen from the water. Finally, the metal hydroxides can be thermally reduced to the metals in a solar furnace.  相似文献   
38.
段国玉 《环境科学与管理》2007,23(9):129-130,141
中水回用作为一项保护环境、节约资源的措施,将有力地促进城市的可持续发展和加速生态城市的建设,是解决中国水资源危机的有效途径之一.文章着重对住宅小区的中水回用系统进行了经济技术分析.  相似文献   
39.
电子废弃物的特点   总被引:16,自引:2,他引:16  
电子废弃物资源化研究是一项新型而紧迫的课题,它具有数量多、危害大、潜在价值高、回收利用困难的特点,必须对电子废弃物予以高度关注。  相似文献   
40.
室内空气中甲醛和苯系物检测与净化   总被引:2,自引:0,他引:2  
通过对哈尔滨市装饰装修竣工一年内的60户室内空气污染物检测分析,结果表明:室内空气甲醛超标64.1%,苯超标54.1%,甲苯超标35.6%,二甲苯超标30.6%.采用臭氧法,光催化氧化法和药剂法三种方法对室内空气污染物甲醛和苯进行净化效果实验研究,评价其净化效果,比较了三种方法的优劣.  相似文献   
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