Non-cyanide Copper Plating on Steel Substrate in Alkaline Tartrate Bath

以酒石酸盐为络合剂,胺化合物为辅助络合剂,研究钢铁基体上碱性无氰镀铜工艺,探讨了搅拌、镀液温度、PH、ρ(Cu2+)和添加剂对镀层外观的影响。考察了镀液的深镀能力和抗fE2+、fE3+、zn2+及Sn4+杂质能力以及镀层与铁基体的结合力。实验结果表明:可以在宽广的工艺条件下获得光亮的铜镀层;阴极电流效率随温度、PH和ρ(Cu2+)提高而增大,在实验确定的工艺条件下ηκ为82%左右;镀液深镀能力达91%;计时电位曲线试验结果表明,基体上的钝化膜在沉积初期被破坏而处于活化状态,使得铜镀层与钢铁基体有足够的结合力。The process of non-cyanide copper electroplating on steel substrate was developed using tartrate as complexing agent and amine compound as assistant complexing agent.The effects of agitation,bath temperature,pH,ρ(Cu2+) and additive on deposit appearance were studied.The bath covering power,the ability of anti-impurities to Fe2+,Fe3+,Zn2+,Sn4+ and adhesion of copper to steel substrate were tested.The results show that,in this bath the bright copper coating can be electrodeposited under wide condition ranges;the current efficiency is about 82% and is increased with the increasing of bath temperature,pH and ρ(Cu2+);the covering power of the bath is 91%.Chronopotentiometric curves prove that the passivation films on steel substrate could be spoiled at the early stage of electrodeposition and the substrate could be activated and therefore adhesion is strong enough between copper deposit and the substrate.广东省教育部产学研结合专项资金项目(2006D90404019);福建省科技计划重点项目(2008H0086);国家自然科学基金项目(20873114

Co-regulation of rainfall amount and timing on soil carbon mineralization in a typical salt marsh of the Yellow River Delta,China

Studying the effects of rainfall regimes such as rainfall amount and timing on soil carbon mineralization is of great importance for our understanding the mechanisms underlying the stability and accumulation of soil carbon in coastal salt marshes. In this study,we examined the responses of soil carbon mineralization (CO_2 and CH_4 fluxes) from undisturbed soil columns to rainfall events in different seasons (dry and wet seasons) with filed experiments in a primary Suaeda salsa region in the Yellow River Delta salt-marsh wetland,which is far away from the coast and not affected by tides. The results showed that rainfall amount and timing had a significant interaction in affecting soil CO_2 flux rates. During the dry season,large rainfall events significantly reduced soil CO_2 flux rates but had no significant effect in the wet season,which might be closely related to the significant increase in soil water content and salinity. Rainfall amount,rainfall timing and their interactions had no significant effect on soil CH_4 efflux rates. Rainfall timing and rainfall amount did not affect CH_4 /CO_2. CH_4 /CO_2 increased with increasing soil water content and salinity. Soil water content and soil salinity showed similar increases to increasing rainfall amount. Our results suggested that the changing rainfall regime under climate change in the future would have a great impact on soil carbon mineralization and carbon sink function by regulating soil water and salt migration in this region

Effects of tidal action on methane emissions over a salt marsh in the Yellow River Delta, China

Salt marshes are coastal wetlands that are considered to be a potential natural source of methane ( CH_4 ). By controlling the production, oxidation, and transport of CH_4 in soils, tidal action drives the episodic and high-magnitude emissions of CH_4 from coastal wetlands. Using the eddy covariance technique, we measured the CH_4 fluxes, environmental factors,and tidal dynamics in a salt marsh in the Yellow River Delta in China. We aimed to investigate the dynamics of CH_4 emissions in the growing season and to analyze the effect of tidal action on CH_4 emission. The results showed that the mean daily methane was 0.063 mg m~(-2) h~(-1),ranging from -0.36 to 0.57 mg m~(-2) h~(-1),during the growing season. Tidal flooding and the wet stage after tides are the significant sources of CH_4. Drying and wetting cycles induced by short-term tides resulted in pulsed CH_4 emissions. Therefore, the soil drought and wetting induced by increasing temperatures and precipitation distribution under climate change will positively impact CH_4 emissions and the carbon cycle in the region.</p

Dynamics of soil CO2 concentration and CO2 efflux in non-growing season of the Yellow River Delta wetland

土壤碳通量是全年性的过程,非生长季土壤碳通量是陆地碳循环的重要组成部分。针对非生长季地上地下CO2动态变化研究相对缺乏这一现象,对黄河三角洲湿地不同深度土壤CO2浓度及温度动态变化进行了连续3个月的监测;为揭示该地区地表CO2通量与地下CO2浓度变化之间的关系,对地表CO2通量、土壤CO2浓度及温度进行了两次同步测定。结果表明：随着土层深度的增加,土壤CO2浓度显著升高;相同深度下,秋季的土壤CO2浓度明显高于冬季。地表CO2通量和地表温度具有相似的日变化规律,二者呈极显著正相关关系,土壤呼吸温度敏感性系数（Q10）为3.49~3.74。地表CO2通量与土壤CO2浓度、土壤温度均存在极显著线性或指数关系,利用其经验模型对黄河三角洲湿地土壤秋冬季碳通量进行了估算,通过比较发现,所有模型拟合结果在季节变化上相近：最大值为0.44~0.57μmol·m~（-2）·s^-1,最小值为-0.18~0.01μmol·m~（-2）·s^-1,平均值为0.09~0.12μmol·m~（-2）·s^-1。本研究揭示了非生长季土壤碳的转化过程对滨海湿地碳循环的潜在影响

Effects of changes in precipitation on soil respiration in coastal wetlands of the Yellow River Delta

Soil moisture fluctuation caused by changes in precipitation patterns associated with global change is an important driving force for the dynamic changes of soil respiration. However, it is unclear how coastal wetlands respond to changes in precipitation patterns, and thus cause changes in the ecosystem blue carbon function. To explore the response and mechanism of soil respiration and environmental and biological factors to precipitation changes, the soil carbon flux observation system was applied to monitor wetland soil respiration rates under different precipitation treatments relying on increased and decreased precipitation fields outside the control experiment platform of the Yellow River Delta coastal wetland in 2017. The results showed that: (1) with increased precipitation, the wetland soil temperature gradually decreased; simultaneously,both precipitation increase and decrease significantly increased wetland soil moisture (P &lt; 0.05); (2) changes in precipitation significantly affected vegetation species composition, aboveground and belowground biomass allocation, and root/shoot ratio (P &lt; 0.05). A 40% and 60% precipitation increase significantly increased the wetland plant species and vegetation root shoot ratio; however,it significantly reduced the aboveground biomass of wetland vegetation. In addition,a 40% increase and 60% decrease of precipitation significantly increased the aboveground biomass of wetland vegetation; (3) there was no significant effect of precipitation changes on annual soil respiration in wetlands. Nevertheless,a 60% and 40% precipitation increase both significantly increased the soil respiration rate in wetlands during the non-flooding season (P &lt; 0.05); (4) the wetland soil respiration and moisture showed a quadratic curve (P &lt; 0.05) with the correlation coefficient decreasing with precipitation increase. Furthermore, during the wetland non-flooding season, soil respiration and temperature were exponentially correlated (P &lt; 0.05) with soil temperature sensitivity (Q10) increasing with increasing precipitation. There was no significant correlation between soil respiration and temperature during flooding periods; (5) during the flooding period,the soil respiration rate was inversely correlated with the surface water level (P&lt; 0.001).</p

Dynamics of soil CO_2 concentration and CO_2 efflux in non-growing season of the Yellow River Delta wetland

To address the issue of lacking data in the non-growing season,we conducted an experiment in a coastal wetland of the Yellow River Delta from October 29,2016 to February 9, 2017,by continuously monitoring soil CO_2 concentration and temperature at different soil depths (15,30,and 45 cm). In order to understand the dynamics of CO_2 efflux and to assess its relationship with soil CO_2 concentration,we measured CO_2 efflux in March 3-5 and March 16-18, 2017. The results showed that soil CO_2 concentration significantly increased with the increases of soil depth. At the same depth,soil CO_2 concentration was significantly higher in autumn than in winter. There was strong diurnal variation in CO_2 efflux,which was consistent with the variation of surface soil temperature. The temperature sensitivity coefficients (Q10) of soil respiration were 3.49-3.74. There was a significant positive correlation between CO_2 efflux and soil CO_2 concentration or soil temperature. Using the derived relationships,we estimated CO_2 efflux for the nongrowing season,and found that the three models produced similar magnitudes and variations, i.e.,0.44 to 0.57,-0.18 to 0.01 and 0.09 to 0.13 &mu;mol&middot;m~(-2)&middot;s~(-1) for the maximum,the minimum and the mean values,respectively. Our results demonstrated the effects of soil carbon trans- formation in non-growing season on carbon cycling of the Yellow River Delta wetland.</p

Dynamics of soil CO2 concentration and CO2 efflux in non-growing season of the Yellow River Delta wetland

土壤碳通量是全年性的过程,非生长季土壤碳通量是陆地碳循环的重要组成部分。针对非生长季地上地下CO2动态变化研究相对缺乏这一现象,对黄河三角洲湿地不同深度土壤CO2浓度及温度动态变化进行了连续3个月的监测;为揭示该地区地表CO2通量与地下CO2浓度变化之间的关系,对地表CO2通量、土壤CO2浓度及温度进行了两次同步测定。结果表明：随着土层深度的增加,土壤CO2浓度显著升高;相同深度下,秋季的土壤CO2浓度明显高于冬季。地表CO2通量和地表温度具有相似的日变化规律,二者呈极显著正相关关系,土壤呼吸温度敏感性系数（Q10）为3.49~3.74。地表CO2通量与土壤CO2浓度、土壤温度均存在极显著线性或指数关系,利用其经验模型对黄河三角洲湿地土壤秋冬季碳通量进行了估算,通过比较发现,所有模型拟合结果在季节变化上相近：最大值为0.44~0.57μmol·m~（-2）·s^-1,最小值为-0.18~0.01μmol·m~（-2）·s^-1,平均值为0.09~0.12μmol·m~（-2）·s^-1。本研究揭示了非生长季土壤碳的转化过程对滨海湿地碳循环的潜在影响

开垦对滨海湿地生态系统 CO2 交换的影响

Coastal wetlands are considered as significant sink for global C and contributors to global “ blue carbon” resources, with high primary productivity, a low soil organic matter decomposition rate, a low CH4 generation rate, and the ability to trap and bury significant amounts of allochthonous carbon. Reclamation changes soil physical and chemical properties and plant community species composition, which change carbon sequestration and emission processes, and ultimately affect the carbon sink function of coastal wet land. However, it is still not clear how carbon exchange and carbon sink respond to biological and environmental factors and their inter actions caused by reclamation in coastal wetland. Overall, clarifying the influence mechanism of reclamation on ecosystem CO2 ex change is of great significance to assessment and predict carbon sink capacity of coastal wetlan

Long-term Ecological Research Support Protection of Coastal Wetland Ecosystems

滨海湿地具有较高的生物多样性,是重要经济鱼类资源的产卵场、索饵场和越冬场,也为湿地鸟类提供食物和栖息环境,是地球上生态系统服务价值最高的生态系统类型。同时,滨海湿地也是人类活动最为集中的地区之一,已成为全球变化的生态脆弱带和环境变化敏感区。中国科学院黄河三角洲滨海湿地生态试验站(以下简称"黄河三角洲站")围绕我国滨海和河口湿地环境保护与生态建设国家战略科技需求,致力于滨海湿地生态环境保护与可持续发展,以陆-海相互作用过程、湿地保护与可持续利用为主线,基于长期定位监测和野外控制试验,量化了滨海湿地生态系统碳汇现状、规律及其驱动机制,明确了水文过程与水盐运移对滨海湿地碳循环过程的影响;揭示了滨海湿地生态系统结构与功能对气候变化和人类活动的响应与适应规律;构建了退化滨海湿地生态修复技术体系,提出了"健康滨海湿地"理论与技术模式,研发了滨海湿地生态修复关键技术,实现滨海湿地保护与利用的协同发展,丰富和发展具有区域特色的滨海湿地生态学。这些研究成果不仅为黄河三角洲湿地生态保护与修复提供基础数据、科学依据和关键技术,弥补了我国特别是北方河口三角洲湿地长期观测研究的不足,也使得黄河三角洲站成为国内外无可替代的滨海湿地生态系统科学研究基地,为提升我国滨海与河口湿地研究的理论水平和促进区域可持续发展提供重要科技支撑平台