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1.
文白异读是方言中的普遍现象,它的研究有助于我们全面了解某种方言的演变,本文以《方言调查字表》为模本,就涟源自马话的文白异读现象进行了整理,从声母、韵母、声调三方面描述了涟源白马话中的文白异读字,同时也从这三方面总结出了这种方言中文白异读的规律。  相似文献   

2.
小气候自记图图像数据采集的数字化处理方法   总被引:1,自引:0,他引:1  
提出一种用数字图像处理技术(digital image processing,DIP)和算法获取小气候自记图图纸上数据的方法,解决了此类图纸中弧形时间轴变成直角坐标轴的问题,并且提高了数据的获取量,基本方法是利用图象软件Imagetool中的“Point”功能获取小气候自记图图象上的记录曲线上点的像素值,然后通过我们给出的算法转换成相应的数据资料,步骤包括:自记图纸扫描、自记图纸的图像纠偏、事件数字化、时间轴的标准化、温湿度的计算、现场时间的计算、时间和数字化图形一致性生成。同时通过实例比较和分析说明了手工与DIP方法在数据取样密度和表现性能差异上的来源。图4参4。  相似文献   

3.
本文采用GC-MS结合同时溶剂浓缩(CSR)大体积不分流进样技术,建立了高效、灵敏测定环境水体中18种PAHs的检测方法.优化了提取溶剂种类、用量等参数,并确定以含多环芳烃内标的0.5 m L环己烷做溶剂作为最佳提取条件;采用GC-MS进行分析,通过在分析柱与分流不分流进样口间串接5m×0.53mm预柱的方式,使得进样体积高达50μL,以提高对多环芳烃的检测灵敏度.实验结果表明,使用大体积不分流进样技术,进样体积为50μL时,对各多环芳烃的检测相比传统不分流进样1μL,灵敏度提高了近50倍;18种多环芳烃在0.1—10μg·L-1的范围内,线性相关系数大于0.9992、精密度小于4.5%(n=8),对实际水样,加标5 ng·L~(-1)的回收率为63.5%—119.5%、加标25、50 ng·L~(-1)水平下的加标回收率为76.2%—119.5%.同时以3倍信噪比计算,各组分方法检出限(MDL)为0.010—0.068 ng·L~(-1).总体来看,采用CSR-GCMS对水体中多环芳烃的分析能够大大减少前处理过程中对样品浓缩的时间耗费,并避免低沸点多环芳烃的损失,是一种非常灵敏、高效的检测方法.  相似文献   

4.
生态系统功能与生态系统服务的概念辨析   总被引:4,自引:0,他引:4  
"生态系统功能(Ecosystem functions)"和"生态系统服务(Ecosystem services)"已成为生态学中的重要研究领域.针对国内部分研究人员对"生态系统功能"与"生态系统服务(功能)"概念和术语混淆使用的问题,在归纳总结国内外有关的重要研究的基础上,通过分别论述"生态系统功能"与"生态系统服务"的定义和内涵,辨析和阐明了生态系统"功能"与"服务"的区别与关系.生态系统功能是构建系统内生物有机体生理功能的过程,侧重于反映生态系统的自然属性,是维持生态系统服务的基础;生态系统服务是由生态系统功能产生的,是基于人类的需要、利用和偏好,反映了人类对生态系统功能的利用,是生态系统功能满足人类福利的一种表现.因此"生态系统服务功能"这一术语不准确,容易产生误解.  相似文献   

5.
通过合理利用促进珍稀濒危植物保护   总被引:4,自引:0,他引:4  
文章分别以银杏(Ginkgo biloba)、杜仲(Eucommia ulmoides)、水杉(Metasequoia glyptostroboides)、厚朴(Magnolia officinalis)、红豆杉(Taxus wallichiana)等珍稀濒危物种为例,从正反两方面阐述了采用合理利用手段能对珍稀濒危物种的保护起直接作用.提出应该改变人们竭泽而渔的消费观念;加强珍稀濒危物种的育种与栽培研究,提高产业化程度;加强"致死性"利用物种的替代性研究,减少对野生资源的毁灭性利用;加强立法执法,规范市场;注重产业化过程中的知识产权保护与国家资源流失问题等多个方面着手开展工作,最终达到实现利用与保护的和谐统一.  相似文献   

6.
基于河流环境与生物指标,构建了适用于以农田和城镇等土地利用格局为主的平原地区河流健康综合评价指数(River health comprehensive assessment index,RHCAI),该指数主要由河流水文、河流形态、河岸带状况、水体理化参数以及水生生物5大类指标构成.考虑到生物因子对河流干扰的敏感性和准确性较高,利用层次分析法适当提高了生物指标的权重.以辽北地区辽河、浑河及其支流为例,利用RHCAI对其健康状况进行了评价,结果表明,该区域河流的健康状态处于"一般"到"亚健康"水平,在被评价河流中,卧龙湖入湖河流的得分最高,接近"健康"水平,而北沙河、蒲河、柳河与东马莲河的健康状态相对较差.河流是淡水资源的重要载体,对其健康状态的科学评价可以为河流的生态修复、水资源的合理开发利用及流域的可持续发展决策提供重要的科学依据和有益借鉴.  相似文献   

7.
蚯蚓的开发利用研究进展   总被引:4,自引:0,他引:4  
蚯蚓与人类的关系十分密切,其用途广泛,除作为传统的中药外,还可提取"蚓激酶"、"氨基酸",作为轻工业的原料,生产美肤剂化妆品,亦可作为现代畜牧业、渔业的优良饲料和饵料以及人类的美味佳肴.除此之外,人们还利用蚯蚓来改良土壤,培肥地力,有的还用它处理城市垃圾、治理环境污染等.  相似文献   

8.
缺乏共同语言与理解,是适当利用志愿举措的最重要障碍之一.因此,这份"问答指南"提供了对正在使用的不同类型志愿举措的综述,和一份进一步信息源的清单.  相似文献   

9.
本文介绍济钢"九五"期间实施以优化工艺结构、产品结构和提高资源、能源利用率为核心内容的炼铁全精料、炼钢全精炼、全连铸、轧钢全一火成材和增加高炉喷煤量的"四全一喷",钢渣和含铁尘泥闭路利用、煤气闭路利用、工业用水闭路利用、余热蒸汽闭路利用的"四闭路",实现节能、降耗、减污、增效的有机统一和实际成果.提出了济钢在今后五年创建"节能清洁型工厂"的基本思路和目标,以及实现目标的主要措施.  相似文献   

10.
缺乏共同语言与理解,是适当利用志愿举措的最重要障碍之一.因此,这份"问答指南"提供了对正在使用的不同类型志愿举措的综述,和一份进一步信息源的清单.  相似文献   

11.
A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.  相似文献   

12.
Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.  相似文献   

13.
Protected areas (PAs) are often implemented without consideration of already existing PAs, which is likely to cause an overrepresentation of certain biophysical conditions. We assessed the representativeness of the current PA network with regard to the world's biophysical conditions to highlight which conditions are underprotected and where these conditions are located. We overlaid terrestrial and marine PAs with information on biophysical conditions (e.g., temperature, precipitation, and elevation) and then quantified the percentage of area covered by the PA network. For 1 variable at a time in the terrestrial realm, high temperature, low precipitation, and medium and very high elevation were underrepresented. For the marine realm, low and medium sea surface temperature (SST), medium and high sea surface salinity (SSS), and the deep sea were underrepresented. Overall, protection was evenly distributed for elevation across the terrestrial realm and SST across the marine realm. For 2 variables at a time, cold and very dry terrestrial environments had mostly low protection, which was also the case for low SST and low and medium SSS across most depths for marine environments. Low protection occurred mostly in the Sahara and the Arabian Peninsula for the terrestrial realm and along the Tropic of Capricorn and toward the poles for the marine realm. Although biodiversity measures are of prime importance for the design of PA networks, highlighting biophysical gaps in current PAs adds a frequently overlooked perspective. These gaps may weaken the potential of PAs to conserve biodiversity. Thus, our results may provide useful insights for researchers, practitioners, and policy makers to establish a more comprehensive global PA network.  相似文献   

14.
Summary The adaptation of defensive secretions to their target organisms was examined for the abdominal gland secretions ofBledius furcatus, B. spectabilis andB. arenarius. Therefore the target organisms of the secretion of theseBledius species (i.e. their predators) had to be identified. At the collection sites examined these were the earwigLabidura riparia, the antCataglyphis bicolor, the flyLispe candicans, different carabids of the generaPogonus, Dichirotrichus, Dyschirius, Bembidion andCalathus and the wading birdsHaematopus ostralegus andCalidris alba. The secretion of the abdominal glands contains the toxin ptoluquinone dissolved in either-dodecalactone and 1-undecene (B. furcatus andB. spectabilis) or in octanoic acid and octyloctanoate (B. arenarius). The ratio of these solvents is species-specific. Application experiments using some of the natural insect predators (L. riparia, C. bicolor, Pogonus, Di. gustavii, Dyschirius) revealed that these solvent ratios provided a more effective deterrent than other possible ratios. Thus by combining the solvents in certain ratios, the capability of cuticular penetration and therefore the effectiveness of the defensive secretions are adapted to their natural targets.  相似文献   

15.
The politics of development includes subtexts of choice, as underpinned by community consensus (or lack of it), against the larger backdrop of a liberal democracy, with its intricate power structures that influence the choice of concepts and often lead to complicity rather than consent. A dilemma exists between the understanding of field-level practitioners and that of academics, whose understandings of progress differ. Progress can (and often does) imply long-term change across generations whereas development is often more a matter of crisis management and delivering tangible results to end-users. This makes it a bone of contention across political systems, irrespective of local or global dynamics. Development can emerge as a tool to be wielded for power and further political mileage at the expense of progress. Progress cannot be studied as a counterpoint to development as the sense of history is often missing in development interventions. Development tends to be piecemeal as its very logic often stems from the rationale of power. This is not to suggest, however, that development is only about politics; it is definitely more than the politics of everyday life and involves all of civil society that requires its critical and immediate attention. In this sense, it has become a priority for politicians with an underlying agenda designed to out-manouevre dissent and all statements of protest.  相似文献   

16.
An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.  相似文献   

17.
As landscapes continue to fall under human influence through habitat loss and fragmentation, fencing is increasingly being used to mitigate anthropogenic threats and enhance the commercial value of wildlife. Subsequent intensification of management potentially erodes wildness by disembodying populations from landscape-level processes, thereby disconnecting species from natural selection. Tools are needed to measure the degree to which populations of large vertebrate species in formally protected and privately owned wildlife areas are self-sustaining and free to adapt. We devised a framework to measure such wildness based on 6 attributes relating to the evolutionary and ecological dynamics of vertebrates (space, disease and parasite resistance, exposure to predation, exposure to limitations and fluctuations of food and water supply, and reproduction). For each attribute, we set empirical, species-specific thresholds between 5 wildness states based on quantifiable management interventions. We analysed data from 205 private wildlife properties with management objectives spanning ecotourism to consumptive utilization to test the framework on 6 herbivore species representing a range of conservation statuses and commercial values. Wildness scores among species differed significantly, and the proportion of populations identified as wild ranged from 12% to 84%, which indicates the tool detected site-scale differences both among populations of different species and populations of the same species under different management regimes. By quantifying wildness, this framework provides practitioners with standardized measurement units that link biodiversity with the sustainable use of wildlife. Applications include informing species management plans at local scales; standardizing the inclusion of managed populations in red-list assessments; and providing a platform for certification and regulation of wildlife-based economies. Applying this framework may help embed wildness as a normative value in policy and mitigate the shifting baseline of what it means to truly conserve a species.  相似文献   

18.
Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza‐Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land‐use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon‐dense (domed pole forest) areas. New carbon‐based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development.  相似文献   

19.
20.
Abstract: In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies—recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)—differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in‐migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.  相似文献   

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