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951.
Effectiveness of China's National Forest Protection Program and nature reserves 总被引:2,自引:0,他引:2
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Guopeng Ren Stephen S. Young Lin Wang Wei Wang Yongcheng Long Ruidong Wu Junsheng Li Jianguo Zhu Douglas W. Yu 《Conservation biology》2015,29(5):1368-1377
There is profound interest in knowing the degree to which China's institutions are capable of protecting its natural forests and biodiversity in the face of economic and political change. China's 2 most important forest‐protection policies are its National Forest Protection Program (NFPP) and its national‐level nature reserves (NNRs). The NFPP was implemented in 2000 in response to deforestation‐caused flooding. We undertook the first national, quantitative assessment of the NFPP and NNRs to examine whether the NFPP achieved its deforestation‐reduction target and whether the NNRs deter deforestation altogether. We used MODIS data to estimate forest cover and loss across mainland China (2000–2010). We also assembled the first‐ever polygon dataset for China's forested NNRs (n = 237, 74,030 km2 in 2000) and used both conventional and covariate‐matching approaches to compare deforestation rates inside and outside NNRs (2000–2010). In 2000, 1.765 million km2 or 18.7% of mainland China was forested (12.3% with canopy cover of ≥70%)) or woodland (6.4% with canopy cover <70% and tree plus shrub cover ≥40%). By 2010, 480,203 km2 of forest and woodland had been lost, an annual deforestation rate of 2.7%. Forest‐only loss was 127,473 km2 (1.05% annually). In the NFPP provinces, the forest‐only loss rate was 0.62%, which was 3.3 times lower than in the non‐NFPP provinces. Moreover, the Landsat data suggest that these loss rates are overestimates due to large MODIS pixel size. Thus, China appears to have achieved, and even exceeded, its target of reducing deforestation to 1.1% annually in the NFPP provinces. About two‐thirds of China's NNRs were effective in protecting forest cover (prevented loss 4073 km2 unmatched approach; 3148 km2 matched approach), and within‐NNR deforestation rates were higher in provinces with higher overall deforestation. Our results indicate that China's existing institutions can protect domestic forest cover. 相似文献
952.
The exothermic oxidation of 3-methylpyridine with hydrogen peroxide was analyzed by Reaction Calorimeter (RC1e) in semi-batch operation. Heat releasing rate and heat conversion were studied at different operating conditions, such as reaction temperature, feeding rate, the amount of catalyst and so on. The thermal hazard assessment of the oxidation was derived from the calorimetric data, such as adiabatic temperature rise (ΔTad) and the maximum temperature of synthesis reaction (MTSR) in out of control conditions. Along with thermal decomposition of the product, the possibility of secondary decomposition under runaway conditions was analyzed by time to maximum rate (TMRad). Also, risk matrix was used to assess the risk of the reaction. Results indicated that with the increase of the reaction temperature, the reaction heat release rate increased, while reaction time and exotherm decreased. With the increase of feeding time, heat releasing rate decreased, but reaction time and exotherm increased. With the amount of the catalyst increased, heat releasing rate increased, reaction time decreased and exothermic heat increased. The risk matrix showed that when the reaction temperature was 70 °C, feeding time was 1 h, and the amount of catalyst was 10 g and 15 g, respectively, the reaction risk was high and must be reduced. 相似文献
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954.
A 1-dodecanethiol-based phase-transfer protocol is developed for the extraction of noble metal ions from aqueous solution to a hydrocarbon phase, which calls for first mixing the aqueous metal ion solution with an ethanolic solution of 1-dodecanethiol, and then extracting the coordination compounds formed between noble metal ions and1-dodecanethiol into a non-polar organic solvent. A number of characterization techniques,including inductively coupled plasma atomic emission spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis demonstrate that this protocol could be applied to extract a wide variety of noble metal ions from water to dichloromethane with an efficiency of 96%, and has high selectivity for the separation of the noble metal ions from other transition metals. It is therefore an attractive alternative for the extraction of noble metals from water, soil, or waste printed circuit boards. 相似文献
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956.
采用数理统计、 Morlet小波分析和Mann-Kendall突变检验对乌鲁木齐河源1号冰川1959-2008年径流序列进行分析,揭示了冰川融水径流的变化趋势、 周期特征和突变特性,并对径流与气候、 冰川变化关系进行了探讨。结果表明:乌鲁木齐河源1号冰川近50 a来径流增加趋势显著,特别是在1993年发生突变后,平均径流较1993年前增加了69.4%。径流序列第一主周期为15 a,第二主周期为6 a。在13~16 a时间尺度上看,1号冰川融水径流在未来的几年将继续保持偏多趋势,但是从5~7 a和超长期时间尺度上看则相反。冰川融水径流与冰川物质平衡、 年均气温、 消融期气温及年降水量存在良好的瞬时响应关系,其中消融期气温的振动对冰川融水径流振动能量贡献最大,在气温超过2 ℃时,径流将加速增长。物质平衡变化100 mm可引起河流径流变化22.9×104 m3,1号冰川过去50 a累积物质平衡为-13 693 mm,相当于额外补给河流径流量3 135.7×104 m3,约是年径流量的16.1倍。 相似文献
957.
介绍了灰色理论之GM(2,1)模型的建模思想,并成功地应用于山东省SO_2排放总量的预测,其结果与实际情况一致性很好,表明GM(2,1)模型预测区域SO_2排放总量是可行的。 相似文献
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959.
960.
邻苯二酚1,2-双加氧酶(C12O)基因的定位、克隆和表达 总被引:3,自引:0,他引:3
射性同位素标记tfdC基因片段作探针,Southernblot杂交定位L1菌株的邻苯二酚1,2双加氧酶基因位于PstⅠ的I片段和BamHⅠ的M和N片段.低熔点琼脂糖回收PstⅠ的I段,直接克隆至表达载体pKT230上,获得重组子pKT230p.重组子转化不具开环酶活性的甲胺磷降解菌P2,获得高效的C12O酶活 相似文献