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1.
城市污泥中氯苯类化合物(CBs)的堆肥处理研究   总被引:6,自引:1,他引:6  
将城市污泥与稻草、木屑、玉米秸秆进行不同方式的堆肥处理,应用气相色谱-质谱仪(GC/MS)对堆肥中的5种氯苯类化合物(CBs)进行分析,为城市污泥的农业利用提供依据。结果表明,不同方式污泥堆肥中CBs的总含量(ΣCBs)在0.035~5.608 mg/kg之间,依次为广州污泥稻草-翻堆>广州污泥稻草+菌种-翻堆>广州污泥稻草-连续通气>佛山污泥稻草-翻堆>广州污泥稻草-间隙通气>佛山污泥木屑-间歇通气>西安污泥玉米秸秆-自然通风>佛山污泥木屑-翻堆。各污泥堆肥中主要以个别化合物为主,其种类有所不同。ΣCBs的降解率为30.39%~92.34%,以佛山污泥木屑堆肥降解效果最好。适当的堆肥处理可以有效地降低污泥中的CBs。  相似文献   

2.
堆肥法处理含油污泥的研究   总被引:2,自引:0,他引:2  
通过添加稻草和有机肥对含油污泥进行了115 d的堆肥处理,动态监测了堆制过程中总石油烃含量、温度、C/N/P比例及功能微生物数量变化,测定了堆制前后石油组分和生物毒性,探讨了堆肥法处理降解油泥的效果。结果表明,堆肥处理后油泥中的总石油烃含量从123±1 g kg-1降低至71.7±0.7 g kg-1,降解率达42%,是未堆肥对照处理的2.5倍;堆体在第21天达到最高温度50℃;堆肥处理的C/N/P比例变化呈现下降趋势;堆肥过程中油泥中烃降解菌和芳烃降解菌与堆制前比较增加了近2个数量级。此外,含油污泥经堆肥法处理后生物毒性降低,EC50从1.77±0.28 mg m l-1提高至2.76±0.38 mg m l-1。  相似文献   

3.
根据2009—2014年在长江中下游薯区实施的68个氮、磷、钾肥料用量田间试验结果,建立了基于养分丰缺指标法——肥料效应函数的甘薯氮、磷、钾施肥指标体系。结果表明:施用氮肥、磷肥、钾肥均对甘薯具有极显著的增产效果(P<0.01);植薯土壤水解性氮含量的“高”、“低”指标分别为170 mg/kg和100 mg/kg,有效磷含量的临界指标为17 mg/kg,土壤速效钾含量“高”、“低”的指标分别为110 mg/kg和30 mg/kg;高产田块甘薯的氮、磷、钾肥最佳经济推荐施用量分别为N 125 kg/hm2、P2O5160 kg/hm2和K2O 182 kg/hm2,中低产田块的氮、磷、钾肥最佳经济推荐施用量分别为N 155 kg/hm2、P2O5120 kg/hm2和K2O 220 kg/hm2。  相似文献   

4.
伍海兵  马想  梁晶 《土壤》2023,55(4):911-917
为改善城市土壤团粒结构,以上海典型搬迁地土壤为研究对象,通过室外培养试验,研究了不同用量厨余垃圾沼渣堆肥和化学改良剂分别单施以及混施对土壤水稳定性团聚体、团粒结构形成的影响。结果表明:20%、30%沼渣堆肥单施处理可显著增加搬迁地土壤0.5~1.0、1.0~2.0 mm粒径大团聚体以及0.106~0.25 mm粒径微团聚体质量分数(P<0.05),而显著降低<0.106 mm粒径微团聚体质量分数(P<0.05)。化学改良剂β-环糊精单施处理可显著增加土壤微团聚体总量(P<0.05);3 kg/m3用量硫酸钙、氧化铁单施处理均可显著促进土壤大团聚体的形成(P<0.05)。沼渣堆肥和化学改良剂混施处理较单施处理显著增加土壤>2.0、0.25~0.5 mm粒径大团聚体质量分数(P<0.05),而降低<0.106 mm粒径微团聚体质量分数(P<0.05)。在沼渣堆肥处理中,以20%沼渣堆肥添加量对土壤团粒结构改良效果最佳;在化学改良剂处理中,以3 kg/m3硫酸钙处理对土壤团粒结构改良效果最佳,其次是3 kg/m3氧化铁处理。WG20+SMmix处理(20%沼渣堆肥+化学改良剂混施)对搬迁地土壤团粒结构改良效果最佳,团粒结构达19.03%,较CK(对照组)、SMmix(化学改良剂混施)、WG20(20%沼渣堆肥)处理分别提高了94.0%、73.5%和26.0%。  相似文献   

5.
城市污泥堆肥过程中有机污染物的变化   总被引:5,自引:0,他引:5  
根据国内外研究资料,综述了城市污染在堆肥处理过程中氯代酚(CPs)、PCDD/Fs、多环芳烃(PAHs)类、氯苯类(PCBs、CBs)等有机污染物的变化,提出将城市污泥进行堆肥处理,可以不同程度降解其中各种有机污染物,达到农用的目的。有机污染物降解的效果与其种类和性质、污泥的性质、环境因素(包括微生物类型和数量、C/N比、水分含量、温度、通气状况)等有关。  相似文献   

6.
蚯蚓堆肥是废弃物资源化利用的有效途径,为明确规模化蚯蚓处理废弃物过程中碳(C)、氮(N)、磷(P)元素的物质变化规律与环境效益,以工厂化蚯蚓处理牛粪模式为对象,分析各环节物料的属性变化、气体排放规律和养分向堆体下方土壤迁移情况,并量化环境影响值。研究结果显示,蚯蚓处理过程中,固体物料全C、C/N和C/P均表现出降低的趋势,全N含量有所提高,pH和全P无明显变化;蚯蚓粪成品C/N、NH4+和NH4+/NO3-的范围均达到堆肥腐熟的标准。随着蚯蚓堆肥过程的进行,CH4和N2O的排放速率呈降低的趋势,CO2和NH3分别在蚯蚓处理中期和初期排放达到最高;C、N通过气体形式损失率分别为25.2%和10.9%。堆放牛粪后,土壤全N和全P含量主要在0~20 cm深度有所增加,平均增幅分别为23.8%和12.0%;NH4+和NO3-含量在不同土层均有所提高;有效P含量在0~10 cm深度增幅达到3倍以上。蚯蚓处理牛粪的全球变暖潜势、富营养化潜势、酸化潜势分别为181.1 kg CO2 eq/t、0.24 kg PO4 eq/t和1.29 kg SO2 eq/t,整体优于传统的好氧堆肥和厌氧发酵模式。研究结果可为蚯蚓处理过程中的品质控制、气体减排和污染防控提供理论参考,并为蚯蚓堆肥处理废弃物模式的工厂化应用推广提供  相似文献   

7.
CaCl2和6-BA溶液处理对枣果软化褐变及相关酶活性的影响   总被引:4,自引:1,他引:4  
试验探讨了鲜枣贮藏过程中果肉软化褐变与PG活性、PPO活性的关系以及采前CaCl2和6-BA溶液处理对采后枣果果肉软化褐变、PG活性、PPO活性的影响。结果表明,枣果采后硬度逐渐下降且与贮藏时间呈极显著负相关,PG活性在贮藏期间呈起伏变化,与枣果软化无显著相关性。 随贮藏时间延长果肉褐变指数逐渐增大,PPO活性逐渐升高,PPO活性与果肉软化褐变的发生相一致。采前用1% CaCl2、15 mg/kg 6-BA以及1% CaCl2+15 mg/kg 6-BA对枣果进行喷雾处理,能降低采后枣果的PG活性和PPO活性,抑制果肉硬度的下降和果肉的褐变进程。1% CaCl2处理可使赞皇大枣贮藏末期的果肉硬度比对照增加1.2 kg/cm2;1% CaCl2+15 mg/kg 6-BA处理可使赞皇大枣贮藏末期的果肉硬度增加1.5 kg/cm2。15 mg/kg 6-BA处理对枣果软化褐变及PG活性、PPO活性有一定影响,但效果不及CaCl2处理。  相似文献   

8.
李勋光  李小平 《土壤》1992,24(6):302-305
本文以作物经济产量减产指标及可食部分的卫生质量标准为依据,确定了下蜀黄土发育的黄棕壤中砷的临界含量范围是:全-As为40.8-64.7mg/kg;1 NHCl-As为11.6-14.0mg/kg;0.5NNa2CO3-As为9.8-11.0mg/kg。其确定值为:全-As50.9mg/kg;1 NHCl-As12.6mg/kg;0.5NNa2CO3-As10.5mg/kg。它们均高于红壤、棕壤和褐土,表明各土壤砷的临界值具有明显的区域性分异。  相似文献   

9.
在红壤自然状况下,模拟了施肥沟,对红壤不同污泥施肥处理的N素释放特性进行了研究。试验结果表明,干污泥配比在10%~20%时,碱解氮、铵态氮和硝态氮累计释放量分别为:25.71%~33.48%,9.57%~14.85%和4.08%~7.65%。堆肥污泥配比在20%~33%时,其累计释放量分别为13.55%~15.65%,2.03%~4.23%和3.11%~5.37%。干污泥处理的释放量大于堆肥污泥处理的释放量,释放过程变化较堆肥污泥剧烈,铵态氮和硝态氮均有明显峰值,铵态氮最大含量532.98±10 mg/kg,释放量最大达10.95%;硝态氮含量最大为149.2±14 mg/kg,释放量最大时为3.32%。无论是从氮的肥效角度,还是氮释放的环境风险角度考虑,污泥堆肥处理后施肥方式均优于干污泥处理施肥方式。  相似文献   

10.
城市污泥与调理剂混合堆肥过程中有机质组分的变化   总被引:5,自引:4,他引:1  
【目的】研究城市污泥堆肥过程中各项有机质组分及碳、 氮在堆肥过程中的形成与转化,以期改善堆肥的生物有效性,促进其土地利用。【方法】在工厂规模化下,以城市污泥、 蘑菇渣锯末以及返混料按照6∶3∶1的质量比混合形成堆肥物料,辅以强制通风措施和翻抛,进行为期18 d的高温堆肥试验。堆肥期间定期采样,测定指标包括温度、 C/N值、 pH、 含水率、 有机质降解率、 水溶性组分、 半纤维素、 纤维素和木质素,研究堆肥期间不同阶段堆肥物料中有机质组分的动态变化。【结果】堆体温度随着发酵时间的延长呈现先升高后降低的趋势,最高温度达到71.3℃; 含水率由60.7%降低到51.4%,pH呈现先升高后降低的趋势,总体处于6.0~7.5之间; 总有机碳含量持续下降,氮素含量表现为高温期持续下降随后呈上升的趋势; 初始阶段,堆肥物料中四种成分含量分布为: 水溶性组分纤维素半纤维素木质素,至堆肥结束变化为: 纤维素水溶性组分木质素半纤维素,经过堆肥之后水溶性组分及半纤维素含量分别由39.5%和20.1%下降为27.9%和14.4%,纤维素含量由初始的21.8%上升至29.5%,木质素含量相对稳定不变。物料经过堆肥化处理后达到腐熟标准,水溶性组分和半纤维素含量分别降低了38.6%和38.8%,纤维素和木质素含量在高温期分别降解了11.7%和18.5%; 物料总量降低了9.8%。水溶性组分的主要降解阶段为高温期,期间降解部分占总降解量的65.5%; 半纤维素的主要降解阶段为稳定期,稳定期降解部分占总降解量的69.1%,且有继续降解的趋势; 纤维素和木质素仅在高温期有少量降解; 氮素则表现为高温期铵态氮的损失及稳定期硝态氮的积累。【结论】堆肥化处理在实现污泥减量化基础上,污泥中有机质得到了稳定化,有利于城市污泥的土地利用。  相似文献   

11.
【目的】以富士(Fuji)、 秦冠(Qinguan)嫁接在平邑甜茶(Malus hupehensis Rehd.)上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水(ZZ)、 低氮正常水(DZ)、 正常氮干旱(ZG)、 低氮干旱(DG)。氮素和水分均设置两个水平,分别为正常氮(6 mmol/L NO-3-N)、 低氮(0.3 mmol/LNO-3-N)、 正常供水(保持盆中砂子相对含水量为饱和含水量的80%~85%)、 干旱处理(保持盆中砂子相对含水量为饱和含水量的60%~65%)。【结果】富士和秦冠的生物量(茎和叶)、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水(ZZ)>低氮正常水(DZ)>正常氮干旱(ZG)>低氮干旱(DG),并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水(ZZ)>低氮正常水(DZ)>正常氮干旱(ZG)>低氮干旱(DG); 氮、 钾元素含量在植株各部位的分布顺序依次是叶>根>茎,磷元素则是根>叶>茎;光合氮素利用效率(PNUE)和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水(DZ)处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱(DG)处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。  相似文献   

12.
Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.  相似文献   

13.
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,  相似文献   

14.
The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.  相似文献   

15.
Abstract

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species.  相似文献   

16.
Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L?1 nitric acid (HNO3) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L?1 ammonium acetate (NH4OAc) and 1.0 mol L?1 HNO3 extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils.  相似文献   

17.
Biologically enhanced dissolution offers a method to speed removal of chlorinated solvent dense non-aqueous-phase liquid (DNAPL) sources such as tetrachloroethene (PCE) and trichoroethene (TCE) from aquifers. Bioremediation is accomplished by adding an electron donor to the source zone where fermentation to intermediates leading to acetic acid and hydrogen results. The hydrogen and possibly acetic acid are used by dehalogenating bacteria to convert PCE and TCE to ethene and hydrochloric acid. Reductive dehalogenation is thus an acid forming process, and sufficient alkalinity must be present to maintain a near neutral pH. The bicarbonate alkalinity required to maintain pH above 6.5 is a function of the electron donor: 800 mg/L of bicarbonate alkalinity is sufficient to achieve about 1.2 mM TCE dechlorination with glucose, 1.7 mM with lactate, and a much higher 3.3 mM with formate. Laboratory studies indicate that in mixed culture, formate can be used as an electron donor for complete conversion to ethene, contrary to pure cultures studies indicating it cannot. Various strategies can be used to add electron donor to an aquifer for DNAPL dehalogenation while minimizing pH problems and excessive electron donor usage, including use of injection-extraction wells, dual recirculation wells, and nested injection-extraction wells.  相似文献   

18.
Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions.  相似文献   

19.
Inoculation of wheat seedlings with the plant growth-promoting bacterium Azospirillum brasilense Cd was immobilized in alginate microbeads and, without applying any stress, significantly increased the quantity of several photosynthetic pigments, such as chlorophyll a, chlorophyll b, and the auxiliary photoprotective pigments violaxanthin, zeaxanthin, antheroxanthin, lutein, neoxanthin, and β-carotene. This resulted in greener plants with no apparent visible stress. After monitoring the quantity of photosynthetic pigments for 4 weeks, we observed that inoculated plants had higher quantities of pigments in shoot and stem. The greatest difference in the quantity of all pigments between inoculated and noninoculated plants occurred in the first week of growth. Regardless of treatment, the quantity of pigments in stems was three to four times less than the quantity of these pigments in shoots. Application of Azospirillum, either as liquid inoculant or as alginate microbeads, did not alter the positive effect of the bacteria on pigment production or the positive response of the plants towards A. brasilense Cd inoculation.  相似文献   

20.
Three slow-growing legume trees used for desert reforestation and urban gardening in the Sonoran Desert of Northwestern Mexico and the Southwestern USA were evaluated whether their growth can be promoted by inoculation with plant growth-promoting bacteria (Azospirillum brasilense and Bacillus pumilus), unidentified arbuscular mycorrhizal (AM) fungi (mainly Glomus sp.), and supplementation with common compost under regular screenhouse cultivation common to these trees in nurseries. Mesquite amargo (Prosopis articulata) and yellow palo verde (Parkinsonia microphylla) had different positive responses to several of the parameters tested while blue palo verde (Parkinsonia florida) did not respond. Survival of all tree species was over 80% and survival of mesquite was almost 100% after 10 months of cultivation. Inoculation with growth-promoting microorganisms induced significant effects on the leaf gas exchange of these trees, measured as transpiration and diffusive resistance, when these trees were cultivated without water restrictions.  相似文献   

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