中国乡村旅游客源市场研究

随着中国工业化、城市化进程的发展,越来越多的人选择到乡村去旅游,这是人们释放心理压力、回归大自然的需求,因此乡村旅游发展非常迅速。2006年我国把旅游主题确定为“乡村旅游年”,这更加说明了乡村旅游的重要性。从乡村旅游客源市场作为研究出发点,简要介绍了乡村旅游的背景和概念,研究了乡村旅游客源市场现状,最后给出了市场推广的主体与媒介。     

Temporal and Spatial Relationships Between Watershed Land Use and Salt Marsh Disturbance in a Pacific Estuary

Historical and recent remote sensing data can be used to address temporal and spatial relationships between upland land cover and downstream vegetation response at the watershed scale. This is demonstrated for sub-watersheds draining into Elkhorn Slough, California, where salt marsh habitat has diminished because of the formation of sediment fans that support woody riparian vegetation. Multiple regression models were used to examine which land cover variables and physical properties of the watershed most influenced sediment fan size within 23 sub-watersheds (1.4 ha to 200 ha). Model explanatory power increased (adjusted R(2) = 0.94 vs. 0.75) among large sub-watersheds (>10 ha) and historical watershed variables, such as average farmland slope, flowpath slope, and flowpath distance between farmland and marsh, were significant. It was also possible to explain the increase in riparian vegetation by historical watershed variables for the larger sub-watersheds. Sub-watershed area is the overriding physical characteristic influencing the extent of sedimentation in a salt marsh, while percent cover of agricultural land use is the most influential land cover variable. The results also reveal that salt marsh recovery depends on relative cover of different land use classes in the watershed, with greater chances of recovery associated with less intensive agriculture. This research reveals a potential delay between watershed impacts and wetland response that can be best revealed when conducting multi-temporal analyses on larger watersheds.     

Enhancement of the anaerobic hydrolysis and fermentation of municipal solid waste in leachbed reactors by varying flow direction during water addition and leachate recycle

Poor performance of leachbed reactors (LBRs) is attributed to channelling, compaction from waste loading, unidirectional water addition and leachate flow causing reduced hydraulic conductivity and leachate flow blockage. Performance enhancement was evaluated in three LBRs M, D and U at 22 ± 3 °C using three water addition and leachate recycle strategies; water addition was downflow in D throughout, intermittently upflow and downflow in M and U with 77% volume downflow in M, 54% volume downflow in U while the rest were upflow. Leachate recycle was downflow in D, alternately downflow and upflow in M and upflow in U. The strategy adopted in U led to more water addition (30.3%), leachate production (33%) and chemical oxygen demand (COD) solubilisation (33%; 1609 g against 1210 g) compared to D (control). The total and volatile solids (TS and VS) reductions were similar but the highest COD yield (g-COD/g-TS and g-COD/g-VS removed) was in U (1.6 and 1.9); the values were 1.33 and 1.57 for M, and 1.18 and 1.41 for D respectively. The strategy adopted in U showed superior performance with more COD and leachate production compared to reactors M and D.     

加强饮服业环境污染防治与管理的探讨

文章就饮服行业环境污染状况、成因、危害及如何防治污染与加强行政管理进行了分析阐述     

经济欠发达地区的可持续发展战略

在人类面临多种生存危机的今天，经济欠发达地区应重视发展中“不可持续”观念和行为，控制人口数量，提高人口质量，规范政府行为，树立一种全新、科学和适度的富裕观，并通过有节制，保护性地发展生产，走上可持续发展的轨道。     

Assessment of metal availability in smelter soil using earthworms and chemical extractions

Chemical immobilization is a relatively inexpensive in situ remediation method that reduces soil contaminant solubility, but the ability of this remediation treatment to reduce heavy metal bioavailability and ecotoxicity to soil invertebrates has not been evaluated. Our objectives were to (i) assess the ability of chemical immobilization amendments (municipal sewage sludge biosolids and rock phosphate) to reduce metal bioavailability and toxicity in a toxic metal-contaminated smelter soil and (ii) evaluate soil extraction methods using Ca(NO3)2 solution or ion-exchange membranes coated with diethylenetriaminepentaacetic acid (DTPA) as surrogate measures of metal bioavailability and ecotoxicity. We treated a soil contaminated by Zn and Pb milling and smelting operations and an uncontaminated control soil with lime-stabilized municipal biosolids (LSB), rock phosphate (RP), or anaerobically digested municipal biosolids (SS) and evaluated lethality of the remediated soils to earthworm (Eisenia fetida Savigny). Lime-stabilized municipal biosolids was the only remediation amendment to successfully immobilize lethal levels of Zn in the smelter soil (14-d cumulative mortality < or = 15%). Calcium nitrate-extractable Zn in the lethal Zn smelter soil-amendment combinations was 11.5 to 18.2 mmol/kg, compared with the nonlethal LSB amended soil (0.62 mmol/kg). The Ca(NO3)2-extractable Zn-based median lethal concentration (LC50) of 6.33 mmol/kg previously developed in Zn-spiked artificial soils was applicable in the remediated smelter soils despite a 14-fold difference in total Zn concentration. Chelating ion-exchange membrane uptake among the soils was highly variable (mean CV = 39%) compared with the Ca(NO3)2-extraction (mean CV = 1.9%) and not well related to earthworm toxicity.     

提高油田伴生气回收率的研究与应用

文章阐述了陆梁油田在开发过程中采用油气混输技术、天然气发电机橇技术、锅炉烧湿气等技术,将伴生气回收率提高至92.10%;油气混输技术能够实现边缘区块油气全密闭输送;集中处理站锅炉燃烧湿气技术可增加处理站天然气外输气量,降低运行成本;小型活动天然气发电机橇的应用,可以充分利用富裕天然气降低生产成本,同时减少富裕天然气火炬放空燃烧量,收到了良好的经济效益和环境效益。     

DYNAMICS OF SIMULATED EFFECTS OF IRRIGATION OVER DRYLAND FARMING IN SASKATCHEWAN1

ABSTRACT: Irrigation development in Saskatchewan was initiated as an instrument to bring forth regional stability through drought proofing and diversification in the agricultural sector. This development has been surrounded by controversies. Particularly, some critics questioning its economic value to the farmer. In this study, irrigation on a farm is compared as a growth alternative to the expansion of dryland farming. Under relatively conservative machine replacement policies, modest family withdrawals, government subsidized irrigation loans, and relatively favorable gross operating margins, irrigation can be a profitable undertaking in the South Saskatchewan River Basin.     

青虾池塘养殖环境效率分析

为以环境友好型效率标准合理引导青虾池塘养殖生产活动,将淡水养殖对环境的影响纳入效率研究的范畴,以青虾池塘养殖为例,分别运用SBM模型和CCR模型,计算了青虾池塘养殖的环境效率和经济效率,以及各投入要素的使用情况。并运用相关分析、配对样本T检验和方差齐次性检验等技术进行比较研究。研究结果表明：当前我国青虾池塘养殖的环境效率（考虑环境因素的经济效率）仅为0476 9,而传统的经济效率（不考虑环境因素的经济效率）为0696 7,前者显著低于后者,且波动性更强。所有的要素投入都存在过量现象。除电费、虾苗和药物投入外,其他各项投入在环境效率中的过量程度均大于经济效率;具有固定成本性质的投入品,如劳动力投入和机械投入的过量程度更为严重;利用率过低致使肥料投入过量程度高于饲料投入。农户资源配置过程中忽视环境成本是根本原因,应引起高度重视     

Singular Spectrum Analysis of Hydroecological Parameter Dynamics of Lake Naroch’ in the Years 1978–2015

Singular Spectrum Analysis (SSA) has been used to decompose continuous series of data on certain characteristics of Lake Naroch’ ecosystem during the vegetative seasons of years 1978–2015 into a long-time trend, a periodic component, and a residue not amenable to decomposition. The contribution of each component to changes in this variable has been assessed. The trends accounted for 78–97% of parameter variability, and the periodic components accounted for 2.5–15%. The fluctuations of phytoplankton and zooplankton biomass dynamics were the most diverse, and the contribution of these components was the greatest (15 and 8%, respectively). The periodic components in the changes of all parameters could be divided into four groups according to period duration (17–22, 7–15, 4–7, and less than 4 years). Multidimensional factor analysis of seven biotic parameters was performed in order to identify fluctuations in the ecosystem. Five major factors accounting for 93.6% of ecosystem changes together were identified, and each factor variable was subjected to SSA analysis. The period durations were similar for the oscillatory components identified. The first factor was interpreted as a trophic status of the water body, the second was taken to be the geographical location that defines the amount of solar radiation energy available, the third was taken to be the availability of biogenic elements (phosphorus in particular), and the fourth was interpreted as specific developmental cycles of live components of the ecosystem.