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171.
Abstact Ecological city is the advanced mode of harmonious development of city. Constant improvement is being made in the development of ecological city. However, building ecological city is an enormous project that calls for a huge amount of capital. The government fund is far from adequate. This paper probes into the fund issue and discusses in detail the mechanism of investment and financing in building ecological city from various aspects such as diversification of the investment subjects and the modes of financing. 相似文献
172.
Abstract There is an obvious departure from the regional equilibrium of developments between the upper and lower reaches of the Pearl River in Guangdong, which resulted in “the effects of contra-geography-grads development”. It is mainly because the upriver mountainous areas have been deeply stuck in industrialization delay and marginalization plights, so that nearly 40 million local people have conceived a dream to get rid of “the vicious circle of poverty” by speeding up industrial development. But the problem is that such industrialization efforts on a large scale in mountainous areas are encountering the bottleneck of environmental capacity that strictly limits industrial emissions along the upper reaches of any water system. As a solution, an institutional arrangement called “the Local Area Quotas for Industrial Emis-sions along the Pearl River” is put forward supposed to give corresponding compensation to the rights of industrial development yielded by some areas with lower environmental capacity through the distribution and trading of IDQs. 相似文献
173.
In this article, we introduce China’s major forest types and discuss the historical development of forest management in China,
including actions taken over the last decade toward achieving SMF. Major challenges are identified, and a strategy for SFM
implementation in China is presented. China’s forests consist of a wide variety of types with distinctive distributional patterns
shaped by complex topography and multiple climate regimes. How to manage this wide array of forest resources has challenged
forest managers and policy-makers since the founding of the country. Excessive exploitation of China's forest resources from
the 1950s to the late 1990s contributed to environmental problems and calamities, such as floods, soil erosion, and desertification.
At the start of the new millennium, the Chinese government decided to shift its emphasis from timber production towards the
achievement of sustainable forest management (SFM). With a series of endeavors such as the implementation of the “Six Key
Forestry Projects” and the reform of forest tenure policies, and the adoption of a classification system for China's forests,
a beginning has been made at reversing the trend of environmental degradation that occurred throughout the latter half of
the last century. At the same time, huge challenges remain to be tackled for the development of forestry in China. 相似文献
174.
The maintenance of a timely, reliable and accurate spatial database on current forest ecosystem conditions and changes is
essential to characterize and assess forest resources and support sustainable forest management. Information for such a database
can be obtained only through a continuous forest inventory. The National Forest Continuous Inventory (NFCI) is the first level
of China’s three-tiered inventory system. The NFCI is administered by the State Forestry Administration; data are acquired
by five inventory institutions around the country. Several important components of the database include land type, forest
classification and ageclass/ age-group. The NFCI database in China is constructed based on 5-year inventory periods, resulting
in some of the data not being timely when reports are issued. To address this problem, a forest growth simulation model has
been developed to update the database for years between the periodic inventories. In order to aid in forest plan design and
management, a three-dimensional virtual reality system of forest landscapes for selected units in the database (compartment
or sub-compartment) has also been developed based on Virtual Reality Modeling Language. In addition, a transparent internet
publishing system for a spatial database based on open source WebGIS (UMN Map Server) has been designed and utilized to enhance
public understanding and encourage free participation of interested parties in the development, implementation, and planning
of sustainable forest management. 相似文献
175.
采用重量法用滤筒替代滤膜进行测定水中悬浮物的比对实验,实验结果表明:滤筒测定水中悬浮物比滤膜测定水中悬浮物更具有易恒重、测定误差小、准确度高、快速、简便、成本低等优点,适合水质监测应用。 相似文献
176.
微酸多年卧孔菌产漆酶条件优化及其在染料脱色中的应用 总被引:4,自引:0,他引:4
微酸多年卧孔菌(Perenniporia subacida)产漆酶能力对生物漂白等研究具有重要意义.通过单因子和正交试验确定了微酸多年卧孔菌(菌株号:Dai 8224)的最适产酶条件:麦芽糖20 g/L,酵母浸粉5 g/L,pH 5.4,Cu2+2.0 mmol/L,培养温度24℃,转速160 r/min,接种量1.5%(V/V),此时酶活最高可达1.945 U/mL.单独使用微酸多年卧孔菌漆酶粗酶液对染料具有很好的脱色效果.该菌株对于50 mg/L杂环类染料中性红的脱色率可达98.3%,对偶氮染料刚果红的脱色率次之,为91.57%,对亚甲基蓝和铬天青的脱色率也都在80%以上.此外,其催化中性红脱色的最佳底物浓度为60 mg/L,脱色率达到99.42%,其中,生物降解作用占55.92%,菌体吸附作用占43.5%.结果表明该菌对多种染料脱色具有较大的应用潜力.图4表3参31 相似文献
177.
Black carbon (BC) is known as a strong sorbent for the sorption of planar hydrophobic organic compounds (HOCs), but there is very little information about the sorption of nonplanar HOCs on BC. In this study, the sorption of di-(2-ethyl-hexyl) phthalate (DEHP), one kind of nonplanar phthalate acid ester (PAE), by environmental BC collected from river sediments and pure BC (char-wood, char-stalk and soot-ash) was investigated. Strong and nonlinear sorption was observed for the sorption of DEHP on both pure BC and environmental BC with the Freundlich exponent ranging from 0.55 to 0.75 except for soot-ash, and the measured K(BC) (BC-water partition coefficient) of DEHP was about one order of magnitude higher than its organic carbon-water partition coefficient. There was a significant difference in sorption capacity among the environmental and pure BC. The presence of di-methyl phthalate (DMP) could significantly decrease the sorption of DEHP on BC, especially for environmental BC. In addition, the contribution of BC to the total sorption of DEHP on original river sediments was more than 50% when the equilibrium concentration of DEHP was less than 10 μg L(-1). This study indicated that ortho-substituted nonplanar PAEs could also be strongly sorbed by BC, and the difference in sorption among the BC samples revealed that it is important to take the source of BC into account when assessing its effects on the fate of HOCs in aquatic environment. 相似文献
178.
Averrhoa carambola L., a high-biomass tropical tree, has recently been shown to be a strong accumulator of cadmium (Cd) and has great potential for Cd phytoextraction. In the present study, field studies and a controlled-environment experiment were combined to establish the extent of variation in Cd tolerance and accumulation at the cultivar level using 14 to 19 cultivars of A. carambola. The results indicated that all cultivars tested could accumulate Cd at high but different levels, and that Cd tolerance also varied greatly between these cultivars. It is confirmed that the high Cd tolerance and accumulation capacity are species-level and constitutional traits in A. carambola. However, no correlation was detected between tolerance index and accumulation of Cd in different cultivars, suggesting that the two traits are independent in this woody Cd accumulator. More importantly, cultivar Wuchuan Sweet (WCT) was shown to have the highest Cd-extraction potential; it yielded a high shoot biomass of 30 t ha(-1) in 230 d, and extracted 330 g ha(-1) Cd in the aerial tissues grown in Cd-contaminated field soil, which accounted for 12.8% of the total soil Cd in the top 20 cm of the soil profile. 相似文献
179.
Stringent quarantine measures during the Coronavirus Disease 2019 (COVID-19) lockdown period (January 23, 2020 to March 15, 2020) have resulted in a distinct decrease in anthropogenic source emissions in North China Plain compared to the paralleled period of 2019. Particularly, 22.7% decrease in NO2 and 3.0% increase of O3 was observed in Tianjin, nonlinear relationship between O3 generation and NO2 implied that synergetic control of NOx and VOCs is needed. Deteriorating meteorological condition during the COVID-19 lockdown obscured the actual PM2.5 reduction. Fireworks transport in 2020 Spring Festival (SF) triggered regional haze pollution. PM2.5 during the COVID-19 lockdown only reduced by 5.6% in Tianjin. Here we used the dispersion coefficient to normalize the measured PM2.5 (DN-PM2.5), aiming to eliminate the adverse meteorological impact and roughly estimate the actual PM2.5 reduction, which reduced by 17.7% during the COVID-19 lockdown. In terms of PM2.5 chemical composition, significant NO3? increase was observed during the COVID-19 lockdown. However, as a tracer of atmospheric oxidation capacity, odd oxygen (Ox = NO2 + O3) was observed to reduce during the COVID-19 lockdown, whereas relative humidity (RH), specific humidity and aerosol liquid water content (ALWC) were observed with noticeable enhancement. Nitrogen oxidation rate (NOR) was observed to increase at higher specific humidity and ALWC, especially in the haze episode occurred during 2020SF, high air humidity and obvious nitrate generation was observed. Anomalously enhanced air humidity may response for the nitrate increase during the COVID-19 lockdown period. 相似文献
180.
Alnadari Fawze Bassey Anthony Pius Abdin Mohamed Salama Mohamed Abdelbaset Nasiru Mustapha Muhammad Dai Zhuqing Hu Yuhang Zeng Xiaoxiong 《Journal of Polymers and the Environment》2022,30(9):3582-3597
Journal of Polymers and the Environment - In this study, carboxymethyl chitosan with gum Arabic (CG) based novel functional films containing Cinnamomum camphora seeds extract (CCSE) at varying... 相似文献