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591.
基于室内超宽带信道测量研究建立了基于簇的时延抽头模型以及与距离和载频有关的新颖的路径损耗模型,建立了路径损耗同时与距离和频率的依赖关系.同时,研究发现视距和非视距接收信号幅度分别满足莱斯和瑞利分布.该模型对超宽带无线系统仿真和设计有重要的指导意义.  相似文献   
592.
593.

Herein, we report a detailed study on creating heterojunction between graphitic carbon nitride (g-C3N4) and bismuth phosphate (BiPO4), enhancing the unpaired free electron mobility. This leads to an accelerated photocatalysis of 2,4-dichlorophenols (2,4-DCPs) under sunlight irradiation. The heterojunction formation was efficaciously conducted via a modest thermal deposition technique. The function of g-C3N4 plays a significant role in generating free electrons under sunlight irradiation. Together, the generated electrons at the g-C3N4 conduction band (CB) are transferred and trapped by the BiPO4 to form active superoxide anion radicals (?O2?). These active radicals will be accountable for the photodegradation of 2,4-DCPs. The synthesized composite characteristics were methodically examined through several chemical and physical studies. Due to the inimitable features of both g-C3N4 and BiPO4, its heterojunction formation, 2.5wt% BiPO4/g-C3N4 achieved complete 2,4-DCP removal (100%) in 90 min under sunlight irradiation. This is due to the presence of g-C3N4 that enhanced electron mobility through the formation of heterojunctions that lengthens the electron-hole pairs’ lifetime and maximizes the entire solar spectrum absorption to generate active electrons at the g-C3N4 conduction band. Thus, this formation significantly draws the attention for future environmental remediation, especially in enhancing the entire solar spectrum’s harvesting.

Graphical abstract
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594.
Mitigation translocation is a subgroup of conservation translocation, categorized by a crisis-responsive time frame and the immediate goal of relocating individuals threatened with death. However, the relative successes of conservation translocations with longer time frames and broader metapopulation- and ecosystem-level considerations have been used to justify the continued implementation of mitigation translocations without adequate post hoc monitoring to confirm their effectiveness as a conservation tool. Mitigation translocations now outnumber other conservation translocations, and understanding the effectiveness of mitigation translocations is critical given limited global conservation funding especially if the mitigation translocations undermine biodiversity conservation by failing to save individuals. We assessed the effectiveness of mitigation translocations by conducting a quantitative review of the global literature. A total of 59 mitigation translocations were reviewed for their adherence to the adaptive scientific approach expected of other conservation translocations and for the testing of management options to continue improving techniques for the future. We found that mitigation translocations have not achieved their potential as an effective applied science. Most translocations focused predominantly on population establishment- and persistence-level questions, as is often seen in translocations more broadly, and less on metapopulation and ecosystem outcomes. Questions regarding the long-term impacts to the recipient ecosystem (12% of articles) and the carrying capacity of translocation sites (24% of articles) were addressed least often, despite these factors being more likely to influence ultimate success. Less than half (47%) of studies included comparison of different management techniques to facilitate practitioners selecting the most effective management actions for the future. To align mitigation translocations with the relative success of other conservation translocations, it is critical that future mitigation translocations conform to an established experimental approach to improve their effectiveness. Effective mitigation translocations will require significantly greater investment of time, expertise, and resources in the future.  相似文献   
595.
Journal of Polymers and the Environment - Bio-based non-isocyanate poly(hydroxyurethanes) (NIPUs) have recently gained significant interest due to increasing awareness of the health and...  相似文献   
596.
Compassionate conservation holds that compassion should transform conservation. It has prompted heated debate and has been criticized strongly. We reviewed the debate to characterize compassionate conservation and to philosophically analyze critiques that are recurring and that warrant further critical attention. The necessary elements of compassionate conservation relate to the moral value of sentient animals and conservation and to science and conservation practice. Although compassionate conservation has several nontraditional necessary conditions, it also importantly allows a degree of pluralism in values and scientific judgment regarding animals and conservation practice. We identified 52 specific criticisms from 11 articles that directly critique compassionate conservation. We closely examined 33 of these because they recurred regularly or included substantial questions that required further response. Critics criticized compassionate conservation's ethical foundations, scientific credentials, clarity of application, understanding of compassion, its alleged threat to conservation and biodiversity. Some criticisms, we found, are question begging, confused, or overlook conceptual complexity. These criticisms raise questions for critics and proponents, regarding, for example, equal versus differential intrinsic moral value of different sentient animals (including humans), problems of natural and human-caused suffering of wild animals and predation, and the acceptability of specific conservation practices within compassionate conservation. By addressing recurring and faulty critiques of compassionate conservation and identifying issues for compassionate conservation to address, this review provides a clearer basis for crucial ongoing interdisciplinary dialogue about ethics, values, and conservation.  相似文献   
597.
Coastal zones, which connect terrestrial and aquatic ecosystems, are among the most resource-rich regions globally and home to nearly 40% of the global human population. Because human land-based activities can alter natural processes in ways that affect adjacent aquatic ecosystems, land-sea interactions are increasingly recognized as critical to coastal conservation planning and governance. However, the complex socioeconomic dynamics inherent in coastal and marine socioecological systems (SESs) have received little consideration. Drawing on knowledge generalized from long-term studies in Caribbean Nicaragua, we devised a conceptual framework that clarifies the multiple ways socioeconomically driven behavior can link the land and sea. In addition to other ecosystem effects, the framework illustrates how feedbacks resulting from changes to aquatic resources can influence terrestrial resource management decisions and land uses. We assessed the framework by applying it to empirical studies from a variety of coastal SESs. The results suggest its broad applicability and highlighted the paucity of research that explicitly investigates the effects of human behavior on coastal SES dynamics. We encourage researchers and policy makers to consider direct, indirect, and bidirectional cross-ecosystem links that move beyond traditionally recognized land-to-sea processes.  相似文献   
598.
Environmental Science and Pollution Research - The increasing demand for using competent and inexpensive methods based on biomaterials, like adsorption and biosorption, has given rise...  相似文献   
599.
Journal of Material Cycles and Waste Management - E-waste, also known as waste from electrical and electronic equipment, is a solid waste that accumulates quickly due to high demand driven by the...  相似文献   
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