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1.
Gunga HC Suthau T Bellmann A Friedrich A Schwanebeck T Stoinski S Trippel T Kirsch K Hellwich O 《Die Naturwissenschaften》2007,94(8):623-630
Both body mass and surface area are factors determining the essence of any living organism. This should also hold true for
an extinct organism such as a dinosaur. The present report discusses the use of a new 3D laser scanner method to establish
body masses and surface areas of an Asian elephant (Zoological Museum of Copenhagen, Denmark) and of Plateosaurus engelhardti, a prosauropod from the Upper Triassic, exhibited at the Paleontological Museum in Tübingen (Germany). This method was used
to study the effect that slight changes in body shape had on body mass for P. engelhardti. It was established that body volumes varied between 0.79 m3 (slim version) and 1.14 m3 (robust version), resulting in a presumable body mass of 630 and 912 kg, respectively. The total body surface areas ranged
between 8.8 and 10.2 m2, of which, in both reconstructions of P. engelhardti, ∼33% account for the thorax area alone. The main difference between the two models is in the tail and hind limb reconstruction.
The tail of the slim version has a surface area of 1.98 m2, whereas that of the robust version has a surface area of 2.73 m2. The body volumes calculated for the slim version were as follows: head 0.006 m3, neck 0.016 m3, fore limbs 0.020 m3, hind limbs 0.08 m3, thoracic cavity 0.533 m3, and tail 0.136 m3. For the robust model, the following volumes were established: 0.01 m3 head, neck 0.026 m3, fore limbs 0.025 m3, hind limbs 0.18 m3, thoracic cavity 0.616 m3, and finally, tail 0.28 m3. Based on these body volumes, scaling equations were used to assess the size that the organs of this extinct dinosaur have. 相似文献
2.
化工园区接警处警与应急值守系统的研究 总被引:2,自引:2,他引:0
本文分析了目前常用的接警处警系统,针对化工园区安全管理的工作需要,研究化工园区综合接警中心接警处警工作的特点和要求,分析化工园区接警中心工作体系和功能要求,设计开发了化工园区接警处警与应急值守系统。文中对系统体系架构、系统建设关键问题和所需的支持系统进行了详细介绍。该系统集成了地理信息系统的功能,提供化工园区事故接警、通知和处置功能,应用重大危险源监管信息系统、应急预案综合管理系统、综合监控系统等业务系统作为数据支持,为化工园区接警中心管理园区突发事件、实现事故快速反应和及时应对提供技术支持。 相似文献
3.
In Canadian oil sands mining operations, bitumen is extracted from oil sands using the hot water extraction process, which produces tremendous amounts of tailings. Currently, these tailings are disposed of in large ponds, in which coarse particles settle out relatively quickly and fine particles remain suspended in water and settle very slowly. After years of settling, the fine particles form a stable suspension in water known as mature fine tailings (MFTs). Long-term storage of the MFT is costly and poses a major environmental liability.Oil sands companies are now actively investigating different approaches to replace or reduce the use of oil sands tailings ponds. Filtration of the tailings to produce “dry tailings” for stacking is now being investigated as an alternative by a number of companies. Fast water drainage is a critical step for the filtration process. In this paper, we use simple laboratory-scale filtration tests to evaluate the filterability of the oil sands tailings and to generate a parameter that can be used in filtration scale-up. It was found that the filterability of the original coarse oil sands tailings was relatively low. However, after the fines are flocculated with the coarse particles to form uniform flocs the filterability was improved by several orders of magnitude. The results demonstrate that filtration of the flocculated coarse tailings to produce the “dry” stackable tailings may be viable. 相似文献
4.
WTO“稀土案”与中国自然资源出口管制的完善 总被引:1,自引:0,他引:1
陈斌彬 《中国人口.资源与环境》2017,(1):120-127
举世瞩目的 WTO"稀土案"于2014年8月7日终落帷幕。同先前的"原料案"一样,中国还是难逃败诉的命运。上诉机构支持申诉方的大部分指控,再次否决了《1994年关税与贸易总协定》(General Agreement on Tariffs and Trade of 1994,以下简称GATT)第20条对中国《入世议定书》的可适用性,从而确认中国对稀土、钨、钼三种原材料采取的出口税及配额等管制措施违背了WTO相关规则和入世所作的特殊承诺。作为自然资源的进出口大国,在自然资源贸易纠纷(特别是出口管制问题)不断"升温"和WTO争端解决机制运用愈来愈频繁的今天,中国应认真总结和反思这场"稀土保卫战"失利带来的经验教训,以从源头上破解中国出口管制措施在WTO体制下遭遇的法律困境,避免今后类似案件败诉的重现。基于此,本文综合应用案例分析、文本分析、历史分析和比较分析等方法对"稀土案"争讼的焦点和争端解决机构(DSB)的裁决意见做了详尽的透析,结果发现此案中DSB的审理不同程度存在着解释僵化、无视中国缔约真意及主观随意、前后矛盾等失范之处,对中国颇为不公。不过,该案也从另外一方面暴露出中国出口管制立法的疏漏与实施缺陷。是故,本文建议中国:1请求部长级会议/总理事会对GATT与《入世议定书》关系做出统一解释,并单独将出口税承诺纳入减让表;2重视DSB既有的裁决思路,根据WTO规则修改相关出口管制法规;3加强资源开采的法律管控,提高资源税的征收标准;4确保对内外资源需求企业的管制一致,优化出口许可管理,努力从WTO法和国内法两个层面推动现行自然资源出口秩序的完善,使中国今后对自然资源的出口管制既能符合WTO规则又能达致确保本国经济可持续性发展之目的。 相似文献
5.
A method to estimate the impact of clear-cutting on nutrient concentrations in boreal headwater streams 总被引:1,自引:0,他引:1
Large-scale forestry operations, like clear-cutting, may impair surface water quality if not done with environmental considerations in mind. Catchment and country level estimates of nutrient loads from forestry are generally based on specific export values, i.e., changes in annual exports due to the implemented forestry operations expressed in kg ha−1. We introduce here a specific concentration approach as a method to estimate the impact of clear-cutting on nutrient concentrations and export in headwater streams. This new method is potentially a more dynamic and flexible tool to estimate nutrient loads caused by forestry, because variation in annual runoff can be taken into account in load assessments. We combined water quality data from eight boreal headwater catchment pairs located in Finland and Sweden, where the effect of clear-cutting on stream water quality has been studied experimentally. Statistically significant specific concentration values could be produced for total nitrogen, nitrate, ammonium, and phosphate. The significant increases in the concentrations of these nutrients occurred between 2 and 6 years after clear-cutting. Significant specific concentration values could not be produced for total phosphorus and total organic carbon with the whole dataset, although in some single studies significant increases in their concentrations after clear-cutting were observed. The presented method enables taking into account variation in runoff, temporal dynamics of effects, and the proportional size of the treated area in load calculations. The number of existing studies considering large site-specific variation in responses to clear-cutting is small, and therefore further empirical studies are needed to improve predictive capabilities of the specific concentration values. 相似文献
6.
Nazli Yesiller James L. Hanson Jason T. Cox Danielle E. Noce 《Waste management (New York, N.Y.)》2014,34(5):848-858
This investigation was conducted to evaluate experimental determination of specific gravity (Gs) of municipal solid waste (MSW). Water pycnometry, typically used for testing soils was adapted for testing MSW using a large flask with 2000 mL capacity and specimens with 100–350 g masses. Tests were conducted on manufactured waste samples prepared using US waste constituent components; fresh wastes obtained prior and subsequent to compaction at an MSW landfill; and wastes obtained from various depths at the same landfill. Factors that influence specific gravity were investigated including waste particle size, compaction, and combined decomposition and stress history. The measured average specific gravities were 1.377 and 1.530 for as-prepared/uncompacted and compacted manufactured wastes, respectively; 1.072 and 1.258 for uncompacted and compacted fresh wastes, respectively; and 2.201 for old wastes. The average organic content and degree of decomposition were 77.2% and 0%, respectively for fresh wastes and 22.8% and 88.3%, respectively for old wastes. The Gs increased with decreasing particle size, compaction, and increasing waste age. For fresh wastes, reductions in particle size and compaction caused occluded intraparticle pores to be exposed and waste particles to be deformed resulting in increases in specific gravity. For old wastes, the high Gs resulted from loss of biodegradable components that have low Gs as well as potential access to previously occluded pores and deformation of particles due to both degradation processes and applied mechanical stresses. The Gs was correlated to the degree of decomposition with a linear relationship. Unlike soils, the Gs for MSW was not unique, but varied in a landfill environment due both to physical/mechanical processes and biochemical processes. Specific gravity testing is recommended to be conducted not only using representative waste composition, but also using representative compaction, stress, and degradation states. 相似文献
7.
Reiner Jaakson 《Journal of the American Water Resources Association》1973,9(6):1225-1233
ABSTRACT: Water-based outdoor recreation constitutes an important benefit in many multiple-use projects. One problem frequently encountered, however, is the fluctuation of the water-level in a reservoir, especially if draw-downs occur during the summer recreation season. The Trent Canal in Ontario, Canada, forms a unique recreation waterway of some 240 miles of canal and navigable lakes and rivers. For the control of the water in the canal, the Canadian Federal government manages 44 reservoir-lakes as water-storage sites to augment the flows in the canal. While most disputes in water allocation for recreation generally involve recreation uses versus other, non-recreation uses, in the case of the Trent Canal and its reservoir-lakes the dispute in water allocation exists between two competing recreation-uses: for recreation boating on the Canal and its waterway, and for recreation use of the reservoir-lakes. Each use has its own duty-of-water in terms of requirements, or water conditions, for its optimum use. On the reservoir-lakes, by far the largest recreation user-group, is made up of the owners of private shoreline summer cottages (cabins). Draw-downs on the reservoir-lakes, in some cases as much as 13 feet, hence constitute a negative externality imposed by the canal, especially since water-level lowering takes place continuously throughout the summer. In-depth interviews conducted with over 100 cottage-owners indicate four main conclusions. First, the previous user assumptions of the extent of the negative effect of water-level fluctuation on recreation had been exaggerated. Only in extreme draw-downs during infrequent dry years would draw-down constitute a serious imposition. Second, water-level fluctuation does constitute a form of inconvenience to the private riparian recreation property owners, but it does not generally reduce the quantity of recreation use of the reservoir-lakes. Third, there is evidence that reservoir-lake users have learned to adapt successfully to water-level draw-downs. Fourth, the shoreline physiography of the location of a riparian owner strongly influences the way in which draw-down affects attitudes and opinions. The complex jurisdictional split of the land and water resources of the region points to the need to establish a Trent Canal Authority, to oversee the proper use and development of the canal, its waterway, and the reservoir-lakes. 相似文献
8.
Kylefors K 《Journal of environmental management》2003,68(4):367-376
Landfills generate emissions in the form of gas and leachate. The emissions are often measured within monitoring programmes. It is likely that the requirements of such monitoring programmes can be extended in the future, particularly in light of the increased interest in specific organic substances. Multivariate data analyses (MVDA) have been used to evaluate the possibility of predicting the content of specific organic substances from more common analyses. The results indicate that this is possible for a specific leachate. MVDA can also be used to reduce the number of analyses performed within existing monitoring programmes while retaining information about all the variables formerly included in the programmes. 相似文献
9.
Specific Conductance and pH as Indicators of Watershed Disturbance in Streams of the New Jersey Pinelands, USA 总被引:2,自引:0,他引:2
/ We used linear regression to independently and jointly relate specific conductance and pH measured at New Jersey Pinelands stream sites to the percentage of altered land in a watershed. Percentage altered land included developed and agricultural land uses and represented watershed disturbance for a given site. Median values calculated for a 2-year period (September 1992 through August 1994) characterized pH and specific conductance at the study sites. We found the relationships between the median values for both water-quality measures and percentage altered land for a site to be consistent across subregion and dominant altered-land use. Our results also demonstrated that the water-quality/altered-land relationships developed using median values were similar to relationships developed using data from any single-sample period within the entire study period. Individually, pH and specific conductance explained 48% and 56%, respectively, of the variability in watershed disturbance among study sites. The joint use of pH and specific conductance explained 79% of the watershed disturbance variability among sites. The joint use of these easily obtained water-quality measures can provide a quick assessment of instream water-quality impacts from upstream watershed disturbance at any Pinelands stream site. Additionally, a range in pH and specific conductance, and hence a range in ambient water quality, can be predicted for a given altered-land percentage or a change in existing altered-land conditions. 相似文献
10.
森林资源在生态系统的保护中有着多方面的功能,保护森林资源对于环境保护、经济发展和科学研究有着重要意义。我国森林资源破坏严重,其中重要原因之一就是有关森林资源保护法律中存在着许多不完善之处。本文指出我国《森林法》关于法律责任规定存在的问题,提出了违法砍伐林木者应当承担远期保护责任的立法建议。 相似文献