Eucalyptus carbon stock estimation in subtropical regions with the modeling strategy of sample plots–airborne LiDAR–Landsat time series data

Updating eucalyptus carbon stock data in a timely manner is essential for better understanding and quantifying its effects on ecological and hydrological processes.At present,there are no suitable methods to accurately estimate the eucalyptus carbon stock in a large area.This research aimed to explore the transferability of the eucalyptus carbon stock estimation model at temporal and spatial scales and assess modeling performance through the strategy of combining sample plots,airborne LiDAR and Landsat time series data in subtropical regions of China.Specifically,eucalyptus carbon stock estimates in typical sites were obtained by applying the developed models with the combination of airborne LiDAR and field measurement data;the eucalyptus plantation ages were estimated using the random localization segmentation approach from Landsat time series data;and regional models were developed by linking LiDAR-derived eucalyptus carbon stock and vegetation age(e.g.,months or years).To examine the models’robustness,the developed models at the regional scale were transferred to estimate carbon stocks at the spatial and temporal scales,and the modeling results were evaluated using validation samples accordingly.The results showed that carbon stock can be successfully estimated using the age-based models(both age variables in months and years as predictor variables),but the month-based models produced better estimates with a root mean square error(RMSE)of 6.51 t⋅ha1 for Yunxiao County,Fujian Province,and 6.33 t⋅ha1 for Gaofeng Forest Farm,Guangxi Zhuang Autonomous Region.Particularly,the month-based models were superior for estimating the carbon stocks of young eucalyptus plantations of less than two years.The model transferability analyses showed that the month-based models had higher transferability than the year-based models at the temporal scale,indicating their possibility for analysis of carbon stock change.However,both the month-based and year-based models expressed relatively poor transferability at a spatial scale.This study provides new insights for cost-effective monitoring of carbon stock change in intensively managed plantation forests.

Effect of decarburization annealing temperature and time on the carbon content, microstructure, and texture of grain-oriented pure iron

In this study,the effect of decarburization annealing temperature and time on the carbon content,microstructure,and texture of grain-oriented pure iron was investigated by optical microscopy and scanning electron microscopy with electron-backscatter diffraction. The results showed that the efficiency of decarburization dramatically increased with increasing decarburization temperature. However,when the annealing temperature was increased to 825°C and 850°C,the steel's carbon content remained essentially unchanged at 0.002%. With increasing decarburization time,the steel's carbon content generally decreased. When both the decarburization temperature and time were increased further,the average grain size dramatically increased and the number of fine grains decreased; meanwhile,some relatively larger grains developed. The main texture types of the decarburized sheets were approximately the same: {001}<110> and {112~115}<110>,with a γ-fiber texture. Furthermore,little change was observed in the texture. Compared with the experimental sheets,the texture of the cold-rolled sheet was very scattered. The best average magnetic induction(B_(800)) among the final products was 1.946 T.

Study on Response Time of SPE Carbon Monoxide Sensor

The influence of structural design and the parameters of the working electrode on the response time of a solid polymer electrolyte (SPE) carbon monoxide sensor has been studied. Results show that the response time is mainly determined by the RC time constant of the catalyst layer and also related with the working electrode potential.

Role of carbon nanotracers in lymph node dissection of advanced gastric cancer and the selection of preoperative labeling time

BACKGROUND The incidence of gastric cancer is high.The number of dissected lymph nodes was an independent factor affecting prognosis.Although preoperative labeling is helpful in lymph nodes resection,there are no guidelines for when to perform preoperative labeling.AIM To investigate the role of nanocarbon in lymph node dissection during gastrectomy,and to discuss the relationship between the timing of preoperative injection of carbon nanoparticles and the extent of lymph node dissection.METHODS A prospective analysis was performed on the clinical data of 307 patients with advanced gastric cancer who underwent laparoscopic surgery in the General Surgery Department of Weifang People’s Hospital between June 2018 and February 2021.The patients were randomly divided into experimental group and control group based on whether they received preoperative nanocarbon injection or not.The experimental group was divided into different groups according to the preoperative labeling time.The number of dissected lymph nodes and the number of lymph nodes with black staining were compared in each group after surgery,and the role of nanocarbon in the number of dissected lymph nodes,pathological staging,and the relationship with prognosis were discussed.RESULTS The average number of dissected lymph nodes in the experimental group was higher than that in the control group.In the experimental group,the number of lymph node dissections and number of black-staining lymph nodes in the nanocarbon-labeling group at 2 d and 1 d before surgery were higher than in the labeling group on the day before surgery(P<0.05).CONCLUSION Preoperative nanocarbon labeling can safely and effectively guide lymph node dissection.To improve the detection rate of lymph nodes is conducive to subsequent comprehensive anti-tumor therapy.

Estimation of Residence Times and Recharge Area of Groundwater in the Moulares Mining Basin by Using Carbon and Oxygen Isotopes (South Western Tunisia)

Radiogenic carbon (14C) of the DIC (Dissolved Inorganic Carbon) and oxygen-18 were used to understand the hydro- dynamic functioning of the multilayer aquifer system in the Moulares mining basin, southern Tunisia. The results of this study permits identify two groundwater types. A- an old paleoclimatic groundwater, marked by low carbon-14 (14C) activities. B - a recent groundwater, was distinguished by relatively high carbon-14 activities. In addition to these two water types, other groundwater, indicating a mixing effect, is resulting presumably from upward movement from the deeper groundwater. Based on 14C activity and the piston flow type theory the groundwater residence time varies from 5 Kyear to 35 Kyear. Carbon-14 activity and oxygen-18 in Groundwater are active since Mio-Plio-Quaternary and Upper Cretaceous aquifers lead to the identification of paleorecharged water probably during Late Pleistocene and Early to Middle Holocene. The water feedings of these aquifers are mainly provided by infiltration of precipitations, infiltration of irrigation water, lateral feeding from cretaceous relieves from the South and the North and along recent and fossil drainage networks that constitute major fresh water sources in groundwater tables.

The Efficiency of the Energy Saving Stoves in Amboseli Ecosystem-Analysis of Time, Energy and Carbon Emissions Savings

It is estimated that more than 2.5 billion people worldwide use biomass for cooking. Burning biomass is one of the major contributors to carbon dioxide (CO2) emission—a principle gas in global warming and climate change. One way of cutting down the CO2 emissions is adaptation of efficient and clean energy technologies. This study examined the efficiency of the energy saving stoves in Amboseli ecosystem by comparing the cooking time, energy use, wood fuel and carbon emissions to the traditional three stone open fire set ups. The result indicates a statistical difference in the time spent cooking on energy stoves and three stone open fire (t = 5.3055;n = 60;p = 0.00117). Energy saving stoves saved 12.7% - 33.3% of wood fuel compared to the traditional three stones set ups. Water boiling tests to determine the energy savings, revealed that energy saving stoves saved between 25.74% and 26.16% energy/joule per session in-house and outdoor settings respectively. Based on the two meals prepared per day by each household, the total Carbon Emission Savings for the 1000 local beneficiaries of energy saving stoves varied from 102,200 kg CO2 (indoor cooking) to 357,700 kg CO2 (outdoor cooking) per year. It is therefore concluded that energy saving stoves saves time, fuel wood and energy, and reduces carbon emissions. The study findings refute the claims that open fire when carefully operated can be fuel efficient and clean burning to rival energy saving stoves. To improve the performance of the energy saving stoves, it is recommended that a design modification be done to include a chimney to emit excess smoke during indoor cooking;and the stove should be fixed to the floor with mortar to minimise heat loss and breakages.

Effect of austempering time on microstructure and properties of a low-carbon bainite steel

The effect of austempering time after the bainitic transformation on the microstructure and property in a low-carbon bainite steel was investigated by metallography and dilatometry. The results showed that by prolonging the austempering time after the bainite transformation, the amount of large-size martensite/austenite islands decreased, but no significant change of the amount and morphology of bainite were observed. In addition, more austenite with a high carbon content was retained by prolonging the holding time at the bainite transformation temperature.Moreover, with a longer holding time, the elongation was improved at the expense of a small decrease in tensile strength. Finally, the Avrami equation B(RF) = 1-exp(-0.0499 × t^0.7616) for bainite reaction at 350℃ was obtained for the tested steel. The work provided a reference for tailoring the properties of low-carbon steels.

Study on Multi-effect Time Parameters of Ergonomic Validity Index in Low-carbon Residential Kitchen

In the study on functional low-carbon ergonomic validity in buildings,ergonomic validity is different from resource validity which is easy for quantitative analysis. To eliminate the complexity and uncertainty impacts of human factors on quantitative study,it proposes a method of building a parameter of ergonomic validity—multi-effect time by using cardiotachometer to record heart rate change,being used to evaluate the functional low-carbon ergonomic validity targeting at the ontological characteristics of kitchen. This method is used to determine the physical consumption intensity( multi-effect) through heart rate incremental relation based on the principles of physiology and ergonomics,and to confirm the ergonomic validity of environmental factors by the time to complete standard work as well as multi-effect quantitative analysis. The test results show that,under the kitchen operating conditions,the multi-effect( ME) can properly reflect the real-time status of the operator and is easily operated; the parameters obtained are not significantly related to the physiological status of the operator,and multi-effect time( MT) is sensitive to the physical consumption brought about to the operator due to kitchen environmental factors; thus,it can be taken as an objective index,which is simple and easy to operate in residential kitchen functional low-carbon evaluation.

多时间尺度下电力消费碳排放区域动态演进及收敛性分析

为了协调推进全国及各重大战略区域的减排降碳工作,加快实现碳达峰和碳中和的目标,通过碳核算技术指南法对区域电力消费碳排放量进行核算,并应用泰尔指数分析区域间的碳排放差异.在此基础上,使用三维非参数核密度估计法研究区域电力消费碳排放量的动态演变特征,并通过变异系数和空间面板模型进行σ收敛和绝对β收敛分析.研究以甘肃省为例,结果表明,甘肃省电力消费碳排放总体呈上升趋势,同时各地区之间的差异逐渐减小;在动态演进方面,随着时间推移区域内部的两极分化特征整体趋于减弱,差异化程度逐渐降低;在收敛特性方面,各时间尺度下均不存在σ收敛,但均存在绝对β收敛.

碳移除下全球地表气温峰值出现时间的主要影响因子:能量平衡模型研究

碳移除是21世纪末实现巴黎气候协定温度目标的关键手段。在其开展后,全球地表气温将在随后的若干年达峰。目前,耦合模式比较计划第六阶段(CMIP6)开展碳移除试验的数值模式较少,限制了科学界对碳移除下全球地表气温峰值出现时间的理解。本文发现,基于强迫—响应能量框架的两层能量平衡模型能够很好地重现出:1)大气CO_(2)浓度变化对全球地表气温的影响;2)碳移除过程中全球地表气温的峰值出现时间。因此,该模型可作为CMIP6碳移除试验的补充,能够胜任峰值出现时间的影响因子研究。该能量平衡模型的结果显示,在碳移除过程中,不考虑深层海洋的情况下,对全球平均地表气温的峰值出现时间影响最大的因子为平衡气候敏感度,其次为地表热容量;当深层海洋存在时,影响最大的因子为深层海洋热容量,其次为平衡气候敏感度,之后为地表热容量。这些因子主要通过改变碳移除开始时地表净能量收入的大小来影响全球地表气温峰值的出现时间。相比不考虑深层海洋的情况,深层海洋的存在可以略微提前全球温度峰值出现的时间,并使得碳移除后CO_(2)强迫对地表净能量的下降幅度的贡献较大。

考虑碳排放与交付时间敏感的渠道选择研究

为了研究消费者对碳排放和交付时间具有双重敏感性的市场环境下,制造商选择传统单一零售渠道或网上零售渠道的策略,本文构建了由制造商和传统零售商组成的传统单一零售渠道和网上直销双渠道两种供应链结构,对比分析两种模型的均衡定价策略及供应链成员的最优利润,探讨在消费者具有双重敏感性下,零售商与制造商的渠道偏好。研究发现,双渠道的碳减排水平总是比单渠道的高。当消费者偏好于网上直销渠道,且消费者的双重敏感性及双渠道中渠道竞争均较小时,零售商愿意接受较高的批发价格并且偏好传统单一零售渠道;反之,零售商更偏好网上直销双渠道。当消费者偏好于网上直销渠道时,制造商会选择网上直销双渠道模型。当消费者不偏好网上直销渠道,且消费者双重敏感性及双渠道中渠道竞争均较小时,制造商才会选择传统单一零售渠道模型;否则,即使消费者不偏好网上渠道,双重敏感性及竞争有一项较大时,制造商也会选择网上直销双渠道。

煤流-潮流协同的矿山供电系统低碳优化运行

双碳目标的提出对我国矿山绿色高效开采提出了更高的需求。为此,该文提出煤流-潮流协同的矿山供电系统优化调度方法。首先,基于煤流在采煤工作面、带式运输机、储煤筒仓等环节的连续性特征,抽象出运输煤流和节点功率耦合的运输设备模型;其次,整合煤流运输安全约束与配网潮流约束,建立煤流-潮流协同的运行优化模型;最后,以矿山用能的经济性和碳减排为目标,考虑主网实时碳计量水平,调节采煤时间、煤流速度、运输流量与设备用能,生成煤流运输和矿山电网低碳调度的优化方案。以山西某矿山供电系统为实例,验证所提模型与方法的有效性。仿真结果表明,所提模型与方法能够有效降低矿山生产的吨煤电耗、用能成本及碳排放量,实现了煤流-潮流协同的矿山低碳化经济运行。

机场群场面碳排放时空特征和驱动因素分析

以减少场面碳排放为目标,为航空器滑行路径优化提供理论依据,对川渝地区机场群场面碳排放量的时空特征及驱动因素进行了分析,并提出相应的减排策略。基于历史航班数据采用局部空间关联指数时间路径模型对机场群场面碳排放的时空特征进行了分析,得出机场群场面碳排放的空间结构动态趋势;利用对数平均狄氏指数分解法对天府机场场面碳排放的驱动因素进行驱动效应分析,得到场面碳排放受客均座位数和城市连通数作用显著的结论。所提方法为机场场面滑行路径优化以及航班时刻的合理调整提供了理论研究基础,也可为机场相关单位提供节能减排策略的依据。

考虑需求响应及不确定性的综合能源优化调度

如何在区域综合能源系统中建立有效的需求侧模型,对于需求响应政策的实施至关重要。为提高用户参与需求响应积极性,引入实时定价机制,同时考虑系统的经济低碳性和电气热用户的用能满意度,构建兼顾系统和用户利益的综合需求响应主从博弈模型。针对用户参与需求响应的不确定性,引入贝叶斯方法更新负荷曲线。算例分析表明,所提博弈模型及贝叶斯方法能够有效平衡系统和用户之间的利益,提高了综合需求响应的可靠性。

稳定段曝气时间对高负荷接触稳定法碳捕获影响及微生物群落结构分析

为探究高负荷接触稳定法(HiCS)中稳定段曝气时间(ts)对废水碳捕获的影响,分析不同ts下HiCS系统的碳捕获率及污泥性质的差异,同时分析微生物群落结构差异。结果表明:当ts为1.0、2.0、3.0 h时,碳捕获率分别为43.0%、42.4%、39.2%,显著高于ts为0.5、4.0 h的20.3%和25.3%;污泥粒径较小且分布集中、微观结构粗糙多孔,有利于污泥和有机物接触絮凝。微生物群落结构分析表明,与接种污泥相比,ts为0.5 h的HiCS污泥中变形菌门(Proteobacteria)和拟杆菌门(Bacteroidetes)的相对丰度由24.7%、25.8%上升至40.0%、30.8%。FAPROTAX功能预测结果显示,与碳循环代谢相关的微生物丰度最高,占比达到60%以上,其相对丰度受ts影响显著,在1.0~3.0 h时高于0.5、4.0 h时。

基于全局时序因子分析的中国区域绿色技术创新环境评价

为探究绿色技术创新环境水平及其提升路径,基于2017—2021年中国31个省份的数据样本,从区域层面构建绿色技术创新环境评价指标体系,引入全局时序因子分析法识别其中实际起作用的主要维度,对绿色技术创新环境水平进行评分,并用蝴蝶模型对比区域间差异。结果表明:基本公共服务、城市发展、政策效率、资源供给与绿色生活是影响绿色技术创新环境的4个主要维度;各区域绿色技术创新环境水平整体差异大,资源供给与绿色生活和城市发展方面差异最显著。建议通过政策引导、加大投入、扩大开放等措施实现资源跨区域流动,提升绿色技术创新环境。

“双碳”目标下农户兼业与农村生活能源消费转型

促进农村生活能源消费转型对于我国能源消费结构优化以及“双碳”目标实现具有重要意义。基于2022年实地调研数据,实证分析农户兼业对农村生活能源消费转型的影响效应及作用机制。结果表明,农户兼业对农村生活能源消费转型有显著促进作用,推动农村能源消费结构逐渐由以生物质能源为主向以商品能源为主转变。进一步机制分析显示,农户兼业通过提升家庭收入及优化收入结构、土地资本挤出、人力资本挤出和生态自觉性提升促进农村生活能源消费转型。此外,农户兼业促进农村生活能源消费转型存在代际、兼业地区和行业差异。因此,提出进一步破除城乡资源流动壁垒,完善农民工省外流动机制;加强生态文明建设,大力培育农户生态自觉性;推动乡村产业升级,促进农民收入量、质提升的对策建议。

磁性氮化碳复合材料的制备及其对磷酸化肽的富集

蛋白质的磷酸化在细胞信号传导和疾病发生发展中起着重要作用,但磷酸化的动态变化和低丰度的特点使得对其直接分析有着较大的困难。为了解决磷酸化肽难离子化、检测丰度低的瓶颈问题,本研究制备了一种磁性氮化碳复合材料,结合基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS),建立了一种对复杂样品中低丰度磷酸化肽富集与分析的方法。采用电子显微镜、红外光谱分析及X射线衍射分析等手段对合成的磁性氮化碳材料进行表征。以酪蛋白酶解产物为实验模型,发现磁性氮化碳材料能够实现对磷酸化肽的高选择性富集和高灵敏度检测,检出限为0.1 fmol。选择脱脂牛奶、人唾液和人血清为实际分析样品,发现磁性氮化碳材料对微量蛋白生物样品中磷酸化肽的分析具有较高的应用潜力。

天津某水库含嗅味物质原水应急处理方式研究

以天津某水库含嗅味物质原水为研究对象,利用小试研究了以传统混凝沉淀过滤为主体工艺的3座净水厂采用该水源进行应急供水的适宜处理方式。试验结果表明,粉末炭对原水中2-MIB和土臭素均具有较好吸附作用,其吸附效果主要受粉末炭投量和吸附时间影响,增加粉末炭投量和吸附时间可以提高二者去除率,根据去除率推算30 mg/L粉末炭吸附50 min最多可去除60 ng/L溶解态2-MIB和230 ng/L溶解态土臭素,吸附180 min最多可去除120 ng/L溶解态2-MIB和480 ng/L溶解态土臭素,2-MIB去除难度要高于土臭素;传统混凝沉淀过滤工艺可以去除大部分结合态嗅味物质,3座水厂采用厂内投加粉末炭后进行混凝沉淀过滤相对于直接混凝沉淀过滤而言,可以提高对2-MIB和土臭素的去除效果,但其效果提升主要受限于吸附时间,可应对的嗅味物质浓度较低;采用水库出口处投加粉末炭,可以增加吸附时间,明显提高2-MIB和土臭素的去除效果,该方式最终能处理的溶解态嗅味物质浓度基本与粉末炭吸附推算的浓度一致,满足安全供水需求。

浙江农业碳排放时序特征:总量、强度与结构

利用公开数据,从农业能源利用、农用物资投入、水稻种植和畜禽养殖4个层面构建碳排放量的测度指标体系,对浙江省及其各市域2010~2020年农业碳排放量进行测度,并对碳排放强度和碳排放源内部结构进行时序分析,研究发现全省或市域范围农业碳排放量和排放强度均呈下降趋势,从排放源内部结构来看,多数地市以畜禽养殖为主要碳排放源,不同市域碳排放结构存在一定的差异。研究的政策涵义在于制定碳减排政策时要充分考虑不同地市农业产业结构的差异,水稻种植、农用物资投入和农业能源利用应成为今后一定时期浙江农业碳减排的重要领域。