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481.
Niu J Chen J Martens D Quan X Yang F Kettrup A Schramm KW 《Environmental pollution (Barking, Essex : 1987)》2003,123(1):39-45
Photolysis of polycyclic aromatic hydrocarbons (PAHs) sorbed on surfaces of spruce [Picea abies (L.) Karst.] needles under sunlight irradiation was investigated. PAHs were produced by combustion of polyvinyl chloride (PVC), wood, high-density polyethylene (HDPE), and styrene in a stove. The factors of sunlight irradiation on the surfaces of spruce needles were taken into consideration when investigating the kinetic parameters. The photolysis of the 18 PAHs under study follows first-order kinetics. The photolysis half-lives range from 15 h for dibenzo(a,h)anthracene to 75 h for phenanthrene. Photolysis of some PAHs on surfaces of spruce needles may play an important role on the fate of PAHs in the environment. 相似文献
482.
Since the early 1970s the Bureau of Land Management (BLM) and the Forest Service have emphasized the monitoring approach in managing their rangelands. After a 5-year period of intensive monitoring, stocking rate and other management actions are typically adjusted, depending on whether a definite downward or upward trend in range condition is observed. Examining the Afton Allotment on BLM land in southcentral New Mexico, we demonstrate serious flaws in the monitoring approach and other BLM grazing policies. Monitoring reflects past management but does not consider the future. Perverse incentives for permittees to maximize permit value rather than sustain the forage base still remain in place. The Range Reform '94 proposals by the U.S. Department of the Interior do not address these incentives and other flaws in public land policy. We would reform federal grazing land policy by coupling grazing fees to grazing intensity. Ranchers choosing conservative sustainable grazing intensities would pay low fees, whereas those choosing heavy grazing intensities would be charged higher rates. We would also implement other reforms: making livestock grazing permits transferable to other uses, discontinuing subsidies, eliminating restrictions on nonuse, offering incentives for public land investment, and establishing a biodiversity fund.This paper was supported by the New Mexico Agricultural Experiment Station, Las Cruces and was part of project 1-5-27417. 相似文献
483.
Karl J. C. Harries 《Natural resources forum》1998,22(1):1-13
At common law, the legal nature of a mining royalty between private parties will decide the respective rights of payor and recipient. In some circumstances, it will also determine whether the interest of the recipient will prevail or may be lost and ignored. Industry practices, even those of long standing, that are contrary to the law will not change the law or its effect to meet such concerns. This paper looks at the development of the mining royalty between private parties in Canada and the effect of the realization by recipients that contractual royalties, as opposed to royalties that are interests in the lands or product to which they relate, can be lost in certain circumstances. Suggestions are made for some features that may assist in transforming an otherwise contractual royalty into a real property interest. Some of the concerns for both payor and recipient with respect to the implementation of such suggestions are also discussed.
The article has two appendices attached. Appendix A is an extract from an article by the author discussing the concept of payment of a royalty in kind which is relevant to such suggestions. Appendix B contains some of the more lengthy explanatory notes referred to in the text of the article. 相似文献
The article has two appendices attached. Appendix A is an extract from an article by the author discussing the concept of payment of a royalty in kind which is relevant to such suggestions. Appendix B contains some of the more lengthy explanatory notes referred to in the text of the article. 相似文献
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489.
DNA-dependent RNA polymerases of archaebacteria are distinct from those of eubacteria both in structure and in function. They show similarities to those of the eukaryotic cytoplasm. Extremely thermophilic anaerobic sulfur-respiring archaebacteria isolated from solfataric waters represent four different families, the Thermoproteaceae, the “stiff filaments”, the Desulfurococcaceae and the Thermococcaceae, of a novel order, Thermoproteales. Together with the Sulfolobales, they form the second branch of the urkingdom of the archaebacteria besides that of the methanogens and extreme halophiles. Thermoplasma appears isolated. 相似文献
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