中国化石能源消费碳排放与经济增长关系研究

化石能源过度消费导致的气候变化问题引发了全世界对经济发展模式的关注,论文运用计量经济学方法研究了中国化石能源消费碳排放与经济增长的关系,测算了中国1953-2010年化石能源消费引起的碳排放总量,建立了碳排放总量和国内生产总值的时序计量经济模型,通过协整检验、误差修正模型、基于VAR模型的脉冲响应函数、因果关系检验,分析了二者之间的长短期关系,结果表明:1953-2010年,我国的化石能源消费碳排放总量和国内生产总值之间存在长期均衡的协整关系和短期动态调整机制,通过短期调节,可以自动实现二者之间的长期均衡。当期GDP对碳排放总量的当期波动有显著性影响,每增加1%的GDP便会增加0.719%的碳排放量,上期误差对碳排放总量的当期波动调整幅度较大,单位调整比例为-0.102。利用脉冲响应函数波形图对碳排放量与经济增长之间的影响及响应进行了20期的详细刻画,揭示了二者之间复杂的短期动态关系。1953-2010年,存在从碳排放总量到GDP的单向Granger因果关系,碳排放是经济增长的Granger原因,而经济增长不是碳排放的Granger原因,说明从过去58 a的整体状况来看,高碳排放推动了经济增长,而经济增长并未导致明显的碳排放增加。研究结果将对中国制定节能减排和碳减排政策提供依据和支撑。     

基于能源消费的浙江省碳排放影响因素实证研究

本文运用协整和Granger因果检验方法,实证了在1995-2013年间浙江省碳排放与经济增长、能源效率、对外贸易、城市化和人口增长的现实关系。研究表明:浙江省碳排放与经济增长之间呈现"弱脱钩"关系,对外贸易、经济增长和人口增长对碳排放有正向驱动效应,而能源效率和城市化水平对碳排放有负向驱动效应。Granger因果关系上,对外贸易、经济增长、城市化水平和人口增长是引起浙江省碳排放变化的Granger原因,且仅存在单向影响机制,能源效率与碳排放互为Granger因果关系。     

农业碳排放与经济增长实证研究

本文选取甘肃省2001-2011年的数据,通过相应的计量分析方法,研究了农业碳排放和经济增长之间的关系。研究表明甘肃省农业碳排放量和强度逐年增长,但增长速度处于阶段性下降状态,同时经济增长和化肥、农药等农业碳源导致的碳排放强度之间存在一定的协整关系,并对此给出了降低农业碳排放量的建议。     

能源消费、能源效率与中国经济增长的协整分析研究

利用协整理论和基于误差修正模型的Granger因果关系检验分析了中国能源消费、能源效率和经济增长的关系。协整检验表明这三者之间存在长期协整关系,GDP和能源消费之间存在双向因果关系,而GDP和能源效率之间不存在因果关系。进一步脉冲响应函数分析结果表明,能源消费和GDP在长期内存在较强的双向正向效应;中国GDP在长期内对能源效率将会产生较强的正向效应,而能源效率则对GDP存在微弱的负向效应。     

森林碳汇与经济增长的长期均衡及短期动态关系研究——基于中国1998—2010年省级面板数据

森林是重要的陆地生态系统,森林碳汇与经济增长的长期均衡及短期动态关系的研究,有利于探求森林生态系统平衡发展及经济可持续增长的有效路径。测度中国30 个省份1998—2010 年的森林碳汇,采取面板数据的单位根检验、协整检验、误差修正模型的因果关系检验、脉冲响应等计量技术,考察并预测森林碳汇与经济增长间的动态关系。实证结果表明:森林碳汇与经济增长之间存在协整关系,并存在短期修正效应,当经济可持续增长偏离长期均衡时,将以19%的力度调整至均衡状态,且Granger 因果关系检验及VAR面板模型结果验证了森林碳汇与经济增长的正的双向互动关系;脉冲响应函数显示,经济增长对森林碳汇发展的稳健性产生微弱的正向冲击,而森林碳汇发展在短期对经济增长的稳定性产生显著的正向生态冲击。据此,提出了加大财政对碳汇森林的政策扶持、树种与造林模式相结合、建立并完善碳汇计量与监测机制、完善投融资渠道、加强森林管理等促进我国森林生态系统持续发展的对策建议。     

浙江省碳排放与经济增长的脱钩关系及驱动因素研究

运用IPCC参考方法、Tapio脱钩模型、协整分析和Granger因果检验,研究了浙江碳排放特征及其驱动因素.结果表明:碳排放量呈增长趋势,碳排放强度呈下降趋势,多数年份碳排放与经济增长之间呈"弱脱钩"状态;经济增长、外贸和人口增长对碳排放正向驱动,能源效率和城市化对碳排放负向驱动;经济增长、外贸、城市化和人口增长是引起碳排放增长的单向Granger原因,能源效率与碳排放互为Granger原因.     

海南省能源消费和碳排放预测研究

以海南省1993—2012年能源消费总量、人口、国民生产总值和工业比重作为研究对象,应用协整理论建立它们之间的关系,并预测不同经济增长情景下2015—2020年海南省能源消费总量和能源消费结构。在此基础上,借助相关方法预测碳排放量,最后根据海南的实际情况提出减排政策建议。     

城镇化、居民生活能源消费与生活碳排放之间关系的实证研究

利用中国1995年－2012年居民生活能源消费数据,通过协整检验、格兰杰因果关系检验等方法对城镇化、居民生活能源消费与碳排放之间关系进行了实证研究,结果发现：城镇化、居民生活能源消费与碳排放存在长期均衡关系;城镇化程度的提高会降低CO2排放;生活能源消费的增加是CO2排放提高的重要原因。居民生活能源消费与CO2排放之间存在着双向格兰杰因果关系。提出稳步推进新型城镇化进程、合理进行生活能源消费、调控城乡居民生活能源消费等建议。     

上海市能耗与GDP大气污染的协整关系研究

采用计量经济学中的协整理论考察上海市能源消费量与经济增长、废气排放量、二氧化硫排放量之间的关系。结果显示,上海市能源消费只与经济增长、废气排放量之间存在长期协整关系,并建立了相应的长期均衡方程及误差修正模型。另外,对1978～2003年的能源消费与经济增长之间进行Granger因果关系检验,提出实现上海市经济-能源-环境和谐发展的措施。     

人均GDP、能源强度与碳排放的面板数据分析

利用2000年-2009年中国各省市的面板数据,考察了人均GDP与能源强度对碳排放的影响。在单位根检验的基础上,对这三个变量进行了协整关系检验,实证结果显示,三个变量间存在长期的均衡关系,并以碳排放为被解释变量,能源强度和人均GDP分别作为解释变量进行回归分析。能源强度和人均财富的提高都会增加二氧化碳的排放量。     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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Single and joint effects of pesticides and mercury on soil urease

The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.     

Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China

A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field ＞ tree land ＞ fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT ＞1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.     

Sorption of 1-naphthol by plant cuticular fractions

The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment,but sorption mechanism is still not fully understood.In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction.Toward this end,cuticular materials were isolated from the fruits of tomato by chemical method.The tomato cuticle sheet consisted of waxes (6.5 wt%),cuticular monomer (69.5 wt%),and polysaccharide (24.0 wt%).Isotherms of l-naphthol to the cuticular fractions were nonlinear (N value (0.82-0.90)) at the whole tested concentration ranges.The KodKow ratios for bulk cuticle (TC1),dewaxed cuticle (TC2),cutin (TC4),and desugared cuticle (TC5) were larger than unity,suggested that tomato bulk cuticle and cutin are much powerful solption medium.Sorption capability of cutin (TC4) was 2.4 times higher than the nonsaponifiable fraction (TC3).The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar (H-bonding) interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material.There was a linear negative trend between K_(oc) values and the amount of polysaccharides or fraction's polarities ((N O)/C);while a linear positive relationship between K_(oc) values and the content of cutin monomer (linear R~2=0.993) was observed for present in the cuticular fractions.Predominant sorbent of the hydrophobic organic compounds (HOCs) in the plant cuticular fraction was the cutin monomer,contributing to 91.7% of the total sorption of tomato bulk cuticle.     

Alterations of organ histopathology and metallolhionein mRNA expression in silver barb, Puntius gonionotus during subchronic cadmium exposure

Common silver barb,Puntius gonionotus,exposed to the nominal concentration of 0.06 mg/L Cd for 60 d,were assessed for histopathological alterations(gills,liver and kidney),metal accumulation,and metallothionein(MT)mRNA expression.Fish exhibited pathological symptoms such as hypertrophy and hyperplasia of primary and secondary gill lamellae,vacuolization in hepatocytes,and prominent tubular and glomerular damage in the kidney.In addition,kidney accumulated the highest content of cadmium,more than gills and liver.Expression of MT mRNA was increased in both liver and kidney of treated fish.Hepatic MT levels remained high after fish were removed to Cd-free water.In contrast,MT expression in kidney was peaked after 28 d of treatment and drastically dropped when fish were removed to Cd-free water.The high concentrations of Cd in hepatic tissues indicated an accumulation site or permanent damage on this tissue.     

Seed selections for crystallization of calcium phosphate for phosphorus recovery

Seed induces and promotes the crystallization of calcium phosphate, and acts as carrier of the recovered phosphorus （P）. In order to select suitable seed for P recovery from wastewater, three seeds including Apatite （AP）, Juraperle （JP） and phosphate-modified Juraperle （M-JP） were tested and compared. Batch and fixed-bed column experiments of seeded crystallization of calcium phosphate were undertaken by using synthetic wastewater with 10 mg/L P phosphate. It shows that AP has bad enduring property in the crystallization process, while JP has better performance for multiple uses, and M-JP is a hopeful seed for P recovery by crystallization of calcium phosphate.