Soil Organic Carbon Loss under Different Slope Gradients in Loess Hilly Region

Based on field runoff plots observation and sample analysis, the effect of slope gradient on soil organic carbon loss was studied under natural rainfall conditions in loess hilly region. The results showed that with slope gradient increasing （from10° to 30°）, the changing trend of soil erosion intensity （A） was A20°〉A30°〉A15°〉A10°〉A25°, suggesting that slope gradient between 20° and 25° was a critical degree ranger to exist. Soil organic carbon loss was mainly influenced by soil erosion intensity, appearing the same trend as did soil erosion intensity with increasing slope gradient. Soil erosion results in organic carbon enrichment in sediment. Average enrichment ratios of five runoff plots varied from 2.27 to 3.74, and decreased with increasing erosion intensity and slope gradient. The decrease of surface runoff and soil erosion is the key to reduce soil organic carbon loss.

Unburned Carbon Loss in Fly Ash of CFB Boilers Burning Hard Coal

The unburned carbon loss in fly ash of circulating fluidized bed (CFB) boilers, most of which are burning active fuels such as lignite or peat, is normally very low. However, most CFB boilers in China usually burn hard coals such as anthracite and bituminous coal and coal wastes, so the carbon content in the fly ash from these boilers is higher than expected. This paper investigates the source of unburned carbon in the fly ash of CFB boilers burning hard coal through a series of field tests and laboratory investigations. The char behavior during combustion, including fragmentation and deactivation, which is related to the parent coal, has an important impact on the carbon burnout in CFB boilers. The research shows that char deactivation occurs during char burnout in fluidized bed combustion, especially for large particles of low rank coal. The uneven mixing of solids and air in the core region of the furnace also causes poor burnout of carbon in CFB fly ash. An index describing the volatile content (as dry ash free basis) over the heating value is proposed to present the coal rank. The coal combustion efficiency is shown to be strongly connected with this coal index. Several changes in the CFB boiler design are suggested to reduce the unburned carbon loss in the fly ash.

Erosion and covered zones altered by surface coverage effects on soil nitrogen and carbon loss from an agricultural slope under laboratorysimulated rainfall events

Soil erosion,one of the most serious environmental concerns,might remove topsoil and essential element from terrestrial land.However,few attentions have been given to investigating how soil erosion regimes affect soil carbon and nitrogen loss.Therefore,this study investigated the effects of surface coverage rates(83%,67%,50%,33%,17%and 0%)and two positions(up-and downslope)on erosion regimes and its associated soil nitrogen and carbon loss under a sequence of six rainfalls(R1-R6).These results showed that the sediment concentrations with 33%(R4)and 17%(R5)coverage downslope were significantly lower than those with coverage upslope,whereas there was no significant difference between the runoff rates of the two slopes.Thus,surface coverage at different positions induced two soil erosion regimes(deposition-and transport-dominated processes).Dynamics of the DON and DIN concentrations indicated different release processes of soil nitrogen into runoff.The DON contributed to a substantial amount of soil nitrogen loss,which accounted approximately 81%of the organic form.The SBOC is significantly correlated with sediment-enriched clay particles from the deposition-dominated processes and is higher than that from the transport-dominated processes.The DOC is significantly correlated with Rr for transport-dominated processes.These results illustrated the critical role of erosion regimes in soil organic carbon loss in dissolved or sediment-bound form.It is concluded that erosion/covered zones altered by surface coverage could produce transport-and deposition-dominated erosion regimes and consequently affect soil carbon and nitrogen loss.In addition,these results demonstrated that surface coverage pattern may efficiently control soil erosion and soil carbon and nitrogen loss.

Losses of Soil Organic Carbon and Nitrogen and Their Mechanisms in the Desertification Process of Sandy Farmlands inHorqin Sandy Land

Soil organic carbon(SOC)and total nitrogen(N)concentrations from bulk soils and soil particle size fractions in the different extent of desertified farmlands(potential, light, medium, severe, and most severe desertified farmlands)were examined to quantitatively elucidate losses of carbon and nitrogen and its mechanisms in the desertification process. Particle size fractions(2 -0.1 mm, 0.1 - 0.05 mm, <0.05 mm)were obtained by granulometric wet sieving from 30 sandy soils(0 - 15cm depth)of different desertified extent. It was shown that soil physical stability index(St)in most severe desertified farmlands was 5 -7% and St in other farmlands was less than 5 %, which contributed to very low soil organic matter content. This was the intrinsic cause that sandy farmlands in Horqin sandy land was subject to risk of desertification. Desertification resulted in considerable losses of SOC and N. Regression analysis indicated that SOC and N content reduced 0.169 g kg-1 and 0.0215 g kg-1 respectively with one percent loss of soil silt and clay content. Losses of SOC and N were mostly the removal of fine particle size fractions(silt and clay, and a less extent very fine sand)from the farmlands by wind erosion, which were rich in organic matter and nutrients, as well as the depletion of organic C and N associated with coarse particles(>0. 05 mm)in desertification process. The concentrations of C and N associated with sand(2 - 0.1 mm and 0.1 - 0.05 mm)significantly decreased with increase of desertified extent. Silt and clay associated C and N concentrations, however, were less changed, and in contrast, were higher in soils under most severe desertified extent than in soils under potential and severe desertified extent. The percentage of distribution in sand(>0.05 mm)associated C and N significantly increased with increase of desertified extent, suggesting that stability of SOC decreased in the desertification process.

Evaluation of the Bending Loss of the Hollow Optical Fiber for Application of the Carbon Dioxide Laser to Endoscopic Therapy

Since carbon dioxide laser is excellent for incision, hemostasis, coagulation, and vaporization of soft tissues, it has been widely applied in clinical treatments as the laser knife. In these days, flexible thin hollow optical fibers transmitting mid-infrared light have been developed, and the application of carbon dioxide laser to endoscopic therapy has become possible. However, it is expected that the irradiation effect is influenced by the change in the laser power at the tip of the hollow optical fiber due to the change in the transmittance by the bending loss. The purpose of this research is to quantitatively evaluate the change in the output power and therapeutic effect by bending the hollow optical fiber in a gastrointestinal endoscope. The change in the transmittance of the hollow optical fiber due to the insertion of the fiber into the endoscope and bending of the head of the endoscope was measured. Then, the relationship between the irradiated laser power and the incision depth for a porcine stomach was investigated. As the results, the most significant decrease in the transmittance of the hollow optical fiber was caused by the insertion of the fiber into the instrument channel of the endoscope, and bending of the head of the endoscope with the angle of 90° decreased the output laser power and incision depth by 10% and 25%, respectively. Therefore, it was confirmed that the bending loss of the hollow optical fiber due to the bending of the head of the endoscope had no significant influence on the endoscopic therapy using the carbon dioxide laser.

Responses of Carbon Sink of Ecosystem Vegetation to Land Use Changes in Kunming City

[Objectives]To analyze the relationship between the land use pattern and the carbon sequestration level of the ecosystem vegetation in Kunming City,and to provide a certain reference for optimizing the land ecological use pattern and scientific carbon reduction and sequestration.[Methods]Based on remote sensing data,meteorological data,vegetation data and soil data,the Carnegie-Ames-Stanford Approach(CASA)was adopted to estimate the vegetation net primary productivity(NPP)in Kunming during 2005-2020,and then the vegetation carbon sink was calculated through the plant mortality model.Besides,it established the land use transfer matrix of Kunming City,and analyzed the change characteristics of the carbon sink of ecosystem vegetation in Kunming City under the influence of land use changes.[Results]During 2005-2020,the water area,construction land and unused land area in Kunming increased by 43.52,710.51 and 2.8 km 2,respectively;farmland,woodland and grassland decreased by 269.72,140.20 and 347.03 km 2,respectively;farmland,woodland,grassland,water area,construction land and unused land caused a total of 58212.72 t of vegetation net carbon sink loss in land conversion,accounting for 14.88%,25.23%,11.95%,10.58%,37.09%,and 0.26%,respectively.[Conclusions]This study is expected to help to improve the ecological carbon sequestration capacity of Kunming and promote the sustainable development of land resources.

环保型改性纳米碳酸钙降滤失剂的合成与性能评价

纳米碳酸钙在钻井液中具有降滤失及封堵作用、且环保,但分散性差、易团聚,导致效果不理想。使用硅烷偶联剂对纳米碳酸钙进行表面改性,再通过自由基共聚法将抗温、抗盐单体接枝到改性纳米碳酸钙表面,得到改性纳米碳酸钙降滤失剂SDNPJ-2,采用红外光谱(FTIR)、热重分析进行表征,同时对比评价其综合性能,通过对膨润土基浆粒径、zeta电位分析,滤饼扫描电镜(SEM)分析,考察SDNPJ-2在黏土颗粒上的吸附特征,研究改性纳米碳酸钙降滤失剂在水基钻井液中的降滤失机制。结果表明:SDNPJ-2可抗230℃高温;1%SDNPJ-2可分别使4%膨润土基浆、25%盐水基浆、10%CaCl_(2)基浆150℃/(16 h)老化后的API滤失量降低70%、89%和85%,可抗氯化钠250000 mg/L、抗氯化钙100000 mg/L,降滤失效果优于国外同类目前最优产品Driscal D;生化需氧量(BOD_(5))为558 mg/L、BOD_(5)/COD(化学需氧量)达22.6%,可生物降解;SDNPJ-2通过酰胺基团吸附于黏土表面、改善其分散性,优化体系粒径级配、通过物理堆积有效封堵滤饼和地层孔隙,两方面协同达到优良的降滤失效果。

活化调控的龙眼壳多孔碳材料结构和吸波性能

生物质材料是一种来源丰富、廉价易得的可再生资源,通过在生物质材料中构筑多层级结构制备生物质碳材料是目前吸波材料领域研究的热点。为制备轻质、宽频、高效的生物碳基吸波材料,以龙眼壳为原料,通过活化碳化的方式制备龙眼壳多孔碳材料(LSPC),通过X-射线衍射、拉曼光谱、扫描电镜等表征多孔碳材料的微观结构,并采用矢量网络分析仪对其吸波性能进行分析,考察了磷酸(H3PO4)、氢氧化钾(KOH)和氧化锌(ZnCl_(2))对龙眼壳多孔碳材料结构和吸波性能的影响。结果表明:活化使得龙眼壳多孔碳结晶度下降、缺陷增多,形成了较多的异质界面和活化中心,增强了材料的极化损耗。与未活化的龙眼壳多孔碳相比,H3PO4活化处理使得多孔碳材料的孔壁变薄、孔结构更为明显;KOH活化多孔碳材料不仅保留了龙眼壳连续的孔结构,而且孔壁出现了类似脊椎的波浪起伏结构;ZnCl_(2)活化制得的龙眼壳多孔碳材料仅在原有的光滑截面形成许多小孔;综合分析表明,活化处理改善了龙眼壳多孔碳材料的吸波性能,其中以氢氧化钾活化制备的龙眼壳多孔碳材料吸波性能最佳,其反射损耗达到-43.57 dB,分别是LSPC-H3PO4的2.03倍和LSPC-ZnCl_(2)的3.02倍;活化处理不同程度地改善了龙眼壳多孔碳材料的有效吸收带宽。对微观形貌关联的电磁损耗行为分析表明,活化促进了龙眼壳多孔碳材料中多层级孔结构的生成,有效降低了龙眼壳多孔碳材料的有效介电常数,改善了材料的阻抗匹配;同时,龙眼壳多孔碳材料可通过传导损耗、偶极极化、界面极化、多重反射等多重损耗机制衰减电磁波。

碳中和背景下中美欧印2035年碳减排力度及经济代价探究

根据《巴黎协定》共同时间框架,2025年前各缔约方要提交面向2035年的新一轮国家自主贡献(NDC)。2035年的减排雄心将是连接当前NDC与长期碳中和承诺的重要纽带,对全球能否最终实现2℃/1.5℃温升控制目标具有重要意义。该研究聚焦美国、欧盟这两个碳排放量最大的发达经济体和中国、印度这两个碳排放量最大的新兴经济体,从衔接NDC与碳中和承诺的角度预估四大排放体2035年潜在的碳减排力度,并利用碳配额分配体系和可计算一般均衡模型探究对2℃/1.5℃支持情况以及减排经济代价。结果显示:(1)从NDC迈向碳中和,2035年中国单位GDP二氧化碳排放可能比2005年下降73%~77%,美国碳排放可能比2005年下降61%~67%,欧盟碳排放可能比1990年下降65%~70%,印度单位GDP二氧化碳排放可能比2005年下降51%~58%。(2)上述碳减排力度有可能支持全球2035年走上2℃温控目标碳排放路径,但若要支持走上1.5℃路径,美国和欧盟2035年要达到零碳乃至负碳排放,中国碳排放要降至50亿t左右。(3)在不合作情景下,2035年中国实现上述碳减排力度面临的GDP损失为0.36%~0.58%,与美国(0.36%~0.52%)相当,略低于欧盟(0.49%~0.80%),印度所处发展阶段相对滞后,GDP损失更易受碳减排力度影响(0.26%~0.81%);增强合作有助于以更低的经济代价实现碳减排,2035年四大排放体整体GDP损失有望从0.39%~0.65%下降至0.21%~0.41%。建议尽快深化面向2035年减排目标和实施路径的研究,进一步推动国家间应对气候变化合作交流,以助力全球实现巴黎气候目标。

装备典型材料循环盐雾加速腐蚀行为与机理研究

目的研究装备典型材料在循环盐雾试验条件下的加速腐蚀行为与机理,建立快速分析和表征碳钢腐蚀性能的试验方法。方法通过实施模拟海洋大气环境腐蚀效应及作用特点的循环盐雾加速腐蚀试验,采用SEM、XRD及电化学测试等手段,表征和分析样品腐蚀质量损失、腐蚀形貌、腐蚀产物成分、腐蚀电压、腐蚀电流密度及阻抗等腐蚀性能随暴露时间的变化规律,归纳碳钢的加速腐蚀行为和电化学机理。结果碳钢样品腐蚀质量损失动力学符合幂函数规律,腐蚀速率整体呈现先升高、再降低的变化趋势。腐蚀产物为疏松外层与相对致密内层组成的准双层结构,整体呈现从疏松剥落到逐渐增厚致密的变化过程,成分以铁的氧化物和羟基氧化物为主。极化曲线拟合的腐蚀电流密度呈现先波动增加、后减小的变化趋势,腐蚀电位则围绕中枢值上下波动。电化学阻抗谱由2个容抗弧组成,后期容抗弧中低频区的直线表示出Warburg阻抗的典型特征。结论循环盐雾加速腐蚀试验能够较为全面地描述碳钢材料的加速腐蚀行为与机理,为进一步研究装备典型材料室内外腐蚀试验相关性提供条件。

林下三七种植对坡面水土及碳氮流失的影响

【目的】探究天然降雨条件下不同坡度三七种植林地和自然林地的水土及碳氮流失特征,为林下种植模式的水土及碳、氮流失评估和控制提供理论依据和数据支撑。【方法】采用野外径流小区原位观测试验,以云南省寻甸县三七(Panax notoginseng(Burkill)F.H.Chen)种植林地为研究对象,对2020和2021年天然降雨条件下不同坡度(5°,10°,15°)三七种植林地和自然林地的水土及碳、氮流失特征进行对比分析,并在此基础上对水土及碳、氮流失量与降雨特征和坡度的关系进行探究。【结果】(1)三七种植林地平均总径流量、总土壤流失量分别为17.35 mm/a和14.91 t/(km^(2)·a),比自然林地分别增加了173.79%和249.43%,其中以15°坡面水土流失量最大,分别为24.10 mm/a和24.32 kg/(km^(2)·a)。(2)三七种植林地平均有机碳、全氮(TN)、氨氮(NH_(4)^(+)-N)、硝态氮(NO-3-N)流失量分别为740.62,75.97,9.55和7.26 kg/(km^(2)·a),比自然林地分别显著增加了251.44%,203.15%,220.47%和224.11%,其径流中TN和NH_(4)^(+)-N平均含量分别为0.77和0.33 mg/L。三七种植林地中,以侵蚀泥沙形式流失的有机碳和TN分别占各自总流失量的93.50%和82.01%,以地表径流流失的NH_(4)^(+)-N、NO-3-N分别占各自总流失量的62.09%和87.47%。(3)降雨量、降雨历时、5 min最大降雨强度(I 5)、10 min最大降雨强度(I 10)、30 min最大降雨强度(I 30)均与径流量、土壤流失量及碳、氮流失量呈显著或极显著正相关关系。坡度与水土和碳、氮流失量呈极显著正相关(P<0.01),可用二次函数拟合二者之间的关系(R^(2)>0.93)。【结论】三七种植林地土壤侵蚀强度属于微度侵蚀,最大土壤流失量远低于西南土石山区容许土壤流失量,且径流中TN、NH_(4)^(+)-N平均质量浓度分别低于Ⅲ、Ⅱ类地表水环境质量标准限值。三七种植林地水土及碳、氮流失量较自然林地显著增加,且随着坡度的增大急剧增大。建议在缓坡地段种植三七,以减少水土与养分流失。

Sn-Zn合金包覆PAN基碳纤维/聚六氟丙烯有机光纤材料的制备

采用Sn-Zn合金包覆聚丙烯腈(PAN)基碳纤维,以聚六氟丙烯为载体制备塑料光纤(POF)皮层材料,并将POF皮层材料与聚苯乙烯光纤芯材进行匹配,研究了材料在力学性能、传输损耗性、光场强度方面的变化。结果表明:Sn-Zn合金表面包覆PAN基碳纤维与聚六氟丙烯结合紧密,作为POF皮层材料的效果良好,在最常见的650 nm波长、100 m内,传输低于100 Mb/s速率数据信息的能力符合要求,光信号基本环绕着光纤芯材传播,没有过多的光信号因为皮层材质的缘故而散失,表明该皮层材料与聚苯乙烯光纤芯材的匹配性较高。

Key Variables Explaining Soil Organic Carbon Content Variations in Croplands and Non-Croplands in Chinese Provinces

Soil organic carbon (SOC) plays an important role in global carbon cycles.Large spatial variations in SOC contents result in uncertain estimates of the SOC pool and its changes.In the present study,the key variables explaining the SOC contents of croplands (CPs) and non-croplands (NCPs) in Chinese provinces were investigated.Data on SOC and other soil properties (obtained from the Second National Soil Survey conducted in the late 1970s to the early 1990s),climate parameters,as well as the proportion of the CP to the total land area (Pcp) were used.SOC content variations within a province were larger than those among provinces.Soil clay and total phosphorus content,ratio of annual precipitation to mean temperature,as well as Pcp were able to explain 75% of the SOC content variations in whole soil samples.Soil pH,mean temperature during the growing season from May to October,and mean annual wind velocity were able to explain 63% of the SOC content variations in NCP soils.Compared with NCP soils,CP soils had lower SOC contents,with smaller variations within and among provinces and lower C/N ratios.Stepwise regression showed that the soil clay content was a unique factor significantly correlated with the SOC content of CP soils.However,this factor only explained 24% of the variations.This result suggested that variables related to human activities had greater effects on SOC content variations in CP soils than soil properties and climate parameters.Based on SOC contents directly averaged from soil samples and estimated by regression equations,the total SOC pool in the topsoil (0-20 cm) of China was estimated at 60.02 Pg and 57.6 Pg.Thousands of years of intensive cultivation in China resulted in CP topsoil SOC loss of 4.34-4.98 Pg.

计及站-网损耗分摊的区域综合能源系统碳排放流计算方法

为应对日益严重的环境和能源问题,碳减排相关研究已成为重中之重,碳排放流能够辨析碳要素的流动。以此为研究背景,提出一种计及站-网损耗分摊的区域综合能源系统碳排放流计算方法。依据双层结构热力系统等效变换规则,构建电-气-热网络统一结构模型。在此基础上,对区域综合能源系统网络损耗实现双向分摊,碳排放流损耗等效至管线两端节点,明确网络损耗对应碳排放责任的主体。针对能源站碳责任的界定问题,在考虑能源站损耗的碳排放流集线器模型基础上,推广至标准化矩阵碳排放流集线器,并采用区域综合能源系统碳排放流统一矩阵计算方法,实现站-网损耗分摊下的碳排放流计算和分析。算例结果验证了所提方法的合理性和有效性,网损的双向分摊和考虑能源站损耗的碳排放流集线器模型使发电侧和用户侧更加公平地承担对应的碳排放责任,分布式多类型可再生能源的接入有利于提高全域新能源渗透率,降低站-网综合碳排放流损耗。

炭黑N330用量对天然橡胶阻尼性能的影响

研究炭黑N330用量对天然橡胶(NR)阻尼性能的影响。结果表明:随着炭黑用量的增大,NR混炼胶的FL,Fmax和Fmax-FL增大,t90缩短;NR硫化胶的邵尔A型硬度、100%定伸应力、300%定伸应力、拉伸强度和撕裂强度增大,拉断伸长率和回弹值减小;NR硫化胶低温下的损耗因子(tanδ)峰值减小,高温下的tanδ呈增大趋势。随着温度的升高,NR硫化胶的tanδ减小,且炭黑N330用量大的NR硫化胶的tanδ减小速率大于炭黑N330用量小的NR硫化胶,表明高温下炭黑N330用量大的NR硫化胶的阻尼性能对温度变化更敏感。随着炭黑N330用量的增大,NR硫化胶的静刚度和动/静刚度比都增大,表明炭黑N330用量增大对NR硫化胶的阻尼性能有提升作用。

基于自然-经济综合视角的碳排放强度与生态盈亏多情景模拟研究——以淮海经济区为例

生态盈亏与碳排放强度是衡量生态环境质量与经济发展水平的重要指标,分析两者时空关联并预测未来演进方向对提升区域生态环境质量健康水平具有指导作用。以淮海经济区为研究对象,以2000年、2010年和2020年3期土地利用数据为基础,运用PLUS模型、双变量自相关、耦合协调度及面板计量回归模型等方法,预测并分析淮海经济区2000—2036年3种情景下碳排放强度、生态盈亏的演化特征及时空关联。结果表明:(1)常规发展情景下,淮海经济区生态性呈下降趋势,强耕地保护情景下生态性微有下降,强生态保护情景下,生态性有所上升,自然要素是主导。(2)常规发展情景下,淮海经济区碳排放量逐渐加大,强耕地保护及强生态保护情景下,则呈下降趋势;三种状态下,碳排放强度均呈下降趋势,时间轴2010—2020年降幅较大,空间序河流水系地区碳排放强度降幅较大。(3)淮海经济区碳排放强度与生态盈亏呈负相关关系,低低和低高聚类主要分布在城镇建设用地周边,高低和高高聚类分布在人类干扰较少的自然区域;高高聚类主要位于河流水系交汇区,表明水域有效降低碳排放强度的功能。(4)淮海经济区的碳排放强度与生态盈亏之间的耦合协调度呈东西高、中部低的态势,高耦合协调度主要分布于低高聚类,即自然地区域,低耦合协调度主要分布于西部平原区;科学技术、经济发展水平及二产占比对耦合协调度呈正影响,城镇化率、道路密度呈负影响。研究认为,淮海经济区当前的土地利用方式,不利于区域环境质量的改善,建议进一步强化建设用地管控、大力推进高标准农田建设和水域保护,以耕地质量提升和水域保护加强提升粮食主产区环境质量健康水平。

C_(6)/C_(6+)糖基碳水化合物选择性转化为糠醛的研究

糠醛是一种广泛应用在食品、医药、农药和化工等领域的重要的精细化工品。通常,半纤维素解聚到五碳糖后进一步脱水可转化为糠醛,而纤维素解聚后生成的六碳糖难于转化为糠醛。基于此,实验研究了葡萄糖(C_(6))选择性转化糠醛的影响因素,提出了可能的反应路径;比较了几种典型的C_(6)/C_(6+)糖基碳水合物转化为糠醛的差异。结果表明葡萄糖在硫酸-环丁砜体系中可转化收率为32.6%的糠醛,且糠醛在硫酸-环丁砜体系中保持6.0 h后的浓度依然较为稳定,损失率仅为4.6%。以果糖、蔗糖与纤维素为原料时,可分别得到收率为32.4%、46.5%和43.5%的糠醛。上述结果说明溶剂的性质及其对糠醛的稳定作用,糖基碳水化合物的碳链长度和结构是影响糠醛选择性生成的重要因素。

砾石覆盖下土壤侵蚀过程中有机碳转移数量特征

青藏高原对气候变化响应敏感,且具有提前的征兆,由于全球变暖的原因,冻土的融化会使冻土中所含的碳化合物以温室气体的形式排到大气中,从而进一步加剧全球变暖,本研究利用野外实地调查和采挖土壤侵蚀区的土壤到室内实验室采用模拟径流冲刷法对土壤进行实验,主要得到:(1)当坡面土壤无砾石覆盖时,随着坡度的增加,有机碳的流失量也随之增加;(2)相比没有砾石覆盖的坡面土壤,砾石覆盖度为40%和70%时的土壤有机碳流失量显著大于裸坡的有机碳流失量;(3)随着砾石覆盖度的增加,砾石体积对土壤的破坏力增强,最终使有机碳失去物理保护而迁移流失,造成土壤有机碳流失量增加。由以上结论得出,在今后的裸坡地带进行水土流失预防和治理时应注重削减坡度的方式来减缓土壤侵蚀的发生和有机碳的流失。

基于碳流追踪的含光伏储能配电网减碳贡献分配方法

配电网中分布式光伏具有分布广、间歇性强的特点,其就地消纳的特性造成配电网减碳贡献分配不均。为公平衡量分布式光伏与储能装置在配电网中的减碳作用,首先通过双向网损分摊,将实际有损网络转化为无损虚拟网络,进而得到一个时间断面下的碳排放流分布。然后,计算长时间尺度下分布式光伏的计划功率与实际功率对应的碳流分布,从而得到分布式光伏的相对碳排放强度。最后,计算不同配电网储能容量场景下分布式光伏的相对碳排放强度,并以此为依据衡量储能装置的减碳作用,从而提出一种满足公平分配原则的含光伏储能的配电网减碳贡献分配方法,并在标准算例中进行验证。

不同有机物料对滩涂盐碱地有机碳损失·重金属含量及水稻产量的影响

通过田间小区试验,研究不同有机物料(对照CK、鸡粪T_(1)、羊粪T_(2)、菌菇渣T_(3)、生物腐植酸T_(4))在等有机碳投入量下滩涂盐碱地中有机碳损失、土壤各类有机质分布及其对土壤重金属含量及水稻产量的影响。结果表明,不同有机物料施入土壤后,T_(1)、T_(2)、T_(3)、T_(4)有机碳损失率分别为64.52%、58.69%、47.04%和29.56%;未损失部分转化为土壤有机质,虽然T_(3)处理有机碳损失率较低,但土壤中的活性有机质占比低于其他处理。T_(3)、T_(4)能降低滩涂盐碱地土壤中的有效态汞、砷、镉、铅、铬含量,其中以T_(4)效果最好,T_(1)、T_(2)处理能降低汞、镉、铬有效态含量,但在一定程度上分别增加有效态砷、有效态铅含量。T_(1)~T_(4)对水稻有效穗、穗粒数有显著提高作用,较对照分别增产10.17%、14.03%、6.65%和24.52%,其中T_(4)能显著增加水稻穗粒数。由此可见,在滩涂盐碱地综合改良利用中,生物腐植酸在有机碳损失率、增加土壤活性有机质、降低土壤重金属含量及提高水稻产量方面具有较显著优势,是滩涂盐碱地改良的优良有机物料投入品。