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991.
中国高等植物干质量热值特点 总被引:9,自引:0,他引:9
植物干质量热值是植物干物质完全燃烧所释放的能量值,反映了植物光合作用中固定太阳辐射能的能力。文章收集国内已有的129科、460属、1110种维管植物的干质量热值数据,并加上作者自测的8种苔藓植物干质量热值进行统计分析和差异性检验,分析国内高等植物干质量热值特点。结果显示,植物不同器官的平均GCV为繁殖体(19677.23J·g-1)>叶(19518.22J·g-1)>枝(19455.91J·g-1)>皮(19183.12J·g-1)>干(19122.49J·g-1)>根(18701.44J·g-1);群落中不同组分平均GCV的排序是乔木层(19672.48J·g-1)>灌木层(19218.62J·g-1)>凋落物层(18689.86J·g-1)>草本层(17682.47J·g-1)>苔藓层(15645.44J·g-1);在不同生活型的植物中,挺水植物(18492.67J·g-1)>浮水植物(16381.25J·g-1)>沉水植物(14589.09J·g-1);平均GCV多年生草本GCV(17903.28J·g-1)>一年生草本(17652.74J·g-1);常绿型木本植物各器官均大于落叶型木本植物,针叶树种各器官均大于阔叶树种;从不同气候型来看,高纬度地区的温带大陆性季风气候以及高寒大陆性气候的植物平均GCV较高,低纬度的热带季风气候区的植物比亚热带季风气候区的高,温带大陆性半干旱气候区内最低。 相似文献
992.
运用GC-MS、紫外光谱及三维荧光光谱扫描技术考察了石化污水处理厂“水解酸化—厌氧处理—好氧处理”工艺的各单元出水中有机污染物的变化情况。总进水中检出84种主要有机污染物,主要含有烃类27种,酚类5种,醛、酯、醇和酮类化合物共24种,胺类4种,腈、有机酸及其他杂环化合物14种,另有10种物质未定性;该工艺的COD累积去除率达87.66%, 64种有机污染物被完全去除,17种有机污染物去除率可达90%以上,接触氧化池出水中主要含杂环化合物和少量醛、醇、酯类化合物。 相似文献
993.
Ya Ma Yan Cui Xiaoxi Zuo Shanna Huang Keshui Hu Xin Xiao Junmin Nan 《Waste management (New York, N.Y.)》2014,34(10):1793-1799
A process for reclaiming the materials in spent alkaline zinc manganese dioxide (Zn–Mn) batteries collected from the manufacturers to prepare valuable electrolytic zinc and LiNi0.5Mn1.5O4 materials is presented. After dismantling battery cans, the iron cans, covers, electric rods, organic separator, label, sealing materials, and electrolyte are separated through the washing, magnetic separation, filtrating, and sieving operations. Then, the powder residues react with H2SO4 (2 mol L?1) solution to dissolve zinc under a liquid/solid ratio of 3:1 at room temperature, and subsequently, the electrolytic Zn with purity of ?99.8% is recovered in an electrolytic cell with a cathode efficiency of ?85% under the conditions of 37–40 °C and 300 A m?2. The most of MnO2 and a small quantity of electrolytic MnO2 are recovered from the filtration residue and the electrodeposit on the anode of electrolytic cell, respectively. The recovered manganese oxides are used to synthesize LiNi0.5Mn1.5O4 material of lithium-ion battery. The as-synthesized LiNi0.5Mn1.5O4 discharges 118.3 mAh g?1 capacity and 4.7 V voltage plateau, which is comparable to the sample synthesized using commercial electrolytic MnO2. This process can recover the substances in the spent Zn–Mn batteries and innocuously treat the wastewaters, indicating that it is environmentally acceptable and applicable. 相似文献
994.
Jian-Bing W Du-Ning X Xing-Yi Z Xiu-Zhen L Xiao-Yu L 《Environmental monitoring and assessment》2006,121(1-3):595-611
A total of 292 soil samples were taken from surface soil (0–20 cm) of a typical small watershed–Tongshuang in the black soil region of Heilongjiang province, northeast China in June 2005 for examining the concentration of soil organic carbon (SOC). Spatial variability of SOC in relation to topography and land use was evaluated using classical statistics, geostatistics and geographic information system (GIS) analyses. The objective of this study was to provide a scientific basis for land management targeting at improving soil quality in this region. Classical statistical analysis results indicated that the variability of SOC was moderate (C
V = 0.30). Slope position and land use types were discriminating factors for its spatial variability. Geostatistics analyses showed that SOC had a strong spatial autocorrelation, which was mainly induced by structural factors. Mean concentration of SOC in surface soil was 2.27% in this watershed, which was a very low level in the northern black soil region of northeast China. In this small watershed, present soil and water conservation measures played an important role in controlling soil loss. But SOC's restoration was unsatisfactory. Nearly three-quarters of the area had worrisome productivity. How to improve SOC concentration targeting at soil fertility is a pressing need in the future. 相似文献
995.
阐述了离子色谱法测定废气中甲酸、乙酸含量的方法和步聚。甲酸、乙酸检出限分别为0.02mg/L和0.05mg/L,方法平均回收率分别为92%和95%。本方法分析速度快,所需样品量少,且无需复杂的前处理。 相似文献
996.
Jin Y. Fan Jin J. Geng Hong Q. Ren Xiao R. Wang Chao Han 《Journal of environmental science and health. Part. B》2013,48(10):844-850
Roundup® is a glyphosate-based herbicide containing a mixture of surfactants. This paper evaluates the toxic effects of Roundup® and its main constituents on the goldfish, Carassius auratus, after 7 days exposure. Fish were exposed to 0.16, 0.032 and 0.0064 mg/L of Roundup® [containing 41% isopropylamine salt of glyphosate (G.I.S) and 18% polyoxyethylene amine (POEA)], G.I.S, and POEA. Their livers were taken for determining reactive oxygen species (ROS), superoxide dismutase (SOD) activity, malondialdehye (MDA) content and acetylcholinesterase (AChE) activity. Hydroxyl radical (·OH) could be induced by exposing Roundup® at a rate of 43%–111%, G.I.S at 90%–124% and POEA at142%–157%. A decreased SOD activity was observed in fish exposed to G.I.S and POEA. The contents of MDA significantly increased when exposed to Roundup® at all concentrations, 0.16 mg/L G.I.S and 0.032 mg/L POEA. The exposure led to an inhibition of AChE in livers overall during the experimental periods. POEA was more toxic than Roundup® or G.I.S during this experiment. AChE and ·OH are supposed to be sensitive biomarkers of the exposure of Roundup® and its main constituents to C. auratus. 相似文献
997.
Xiao Sun Zuojun Liu Guilong Zhang Guannan Qiu Naiqin Zhong Lifang Wu 《Journal of environmental science and health. Part. B》2013,48(12):901-907
Traditional pesticides (TP) often do not adhere tightly to crop foliage. They can easily enter the surrounding environment through precipitation and volatilization. This can result in the pollution of the surrounding soil, water, and air. To reduce pesticide pollution, we developed a loss-control pesticide (LCP) by adding attapulgite with a nano networks structure fabricated using high energy electron beam (HEEB) irradiation and hydrothermal treatment to TP. HEEB irradiation effectively dispersed originally aggregated attapulgite through modified thermal, charge, and physical effects. Hydrothermal treatment further enhanced the dispersion of attapulgite to form nano porous networks via thermal and wet expansion effects, which are beneficial for pesticide binding. An LCP has improved retention on crop leaf surfaces. It has a higher adhesion capacity, reduced leaching and volatilization, and extended residual activity compared with the TP formulation. The treatment increases the residual activity of pesticides on crop foliage and decreases environmental pollution. 相似文献
998.
针对内蒙古农村地区高腐殖酸地下水的处理问题,分别对(pH调节)-PAC强化混凝、高锰酸钾预氧化/混凝、活性炭吸附/混凝、Fenton氧化等技术处理的可行性进行了研究,同时利用三维荧光和高效体积排阻色谱分析处理前后水中有机物的组成变化特征。有机分析结果显示,水中的有机物为腐殖酸类物质,分子量分别为1600和3500,腐殖酸类物质为水中色度的主要贡献者。原水PAC强化混凝、高锰酸钾预氧化/PAC混凝对有机物的去除效果不佳,处理前后水样DOC浓度无明显变化,而pH调节.PAC强化混凝、微米活性炭吸附和Fenton氧化均能有效去除有机物。将原水pH调节至6.5,经300mg/LPAC混凝后出水DOC降至5.99mg/L。活性炭投加量为0.6g/L时,DOC降至7.6mg/L,然后采用60mg/LPAC混凝出去高度分散而不易沉降的小颗粒活性炭。此外,当反应初始pH值为3,过氧化氢投加量为0.5%(v/v),亚铁和双氧水摩尔比为0.05时,出水DOC降至5.6mg/L,氧化后有小分子有机物生成。 相似文献
999.
1000.