BMA—IL型平板玻璃防霉液的研制

根据我们曾提出的玻璃表面的电势在水对玻璃侵蚀过程中可以有效屏蔽离子交换、降低离子交换速率的机理,用复合高价阳离子金属盐与弱酸混合制备了BMA-IL型玻璃防霉液.实验证明,该防霉液可以有效地延缓玻璃表面霉变,将有很大的应用前景.     

建筑密封材料老化机理探讨

本文结合各类密封材料的交联反应过程和热老化、氙灯老化试验结果,对其耐久性的老化反应机理进行了探讨。     

护坡植物根系与岩体相互作用的力学特性

通过野外原位拉拔试验，选取灌木铁仔、黄荆、羊蹄甲和禾本科金发草等4种植物，按着生点基岩风化程度不同，测定植株的抗拔力、单根的力学特性和生物指标，研究护坡植物根系与岩体相互作用的力学特性。试验结果表明：受根系构型、受力单根的极限抗拉力及作用根系数量的影响，其单根极限抗拉力随根径的增加而增大，之间有很好的幂函数关系；随植物类型不同，单根的拉力-伸长率关系不同，且极限伸长率随着根径的不同而变化，羊蹄甲与黄荆的拉力-伸长率为线性关系，遵从胡克定律，而灌木铁仔的拉力-伸长率为对数函数关系，羊蹄甲与黄荆根系的极限伸长率表现为随根径增大而降低，铁仔根系的极限伸长率与根径的关系表现出单峰形曲线；在地茎或株高相近的情况下，灌木的抗拔力随基岩风化程度的加剧而增大，在基岩风化程度相近的情况下，抗拔力随地茎、株高及地下生物量的增加而增大，之间具有很好的指数关系；草本植物金发草生物指标与抗拔力之间无明显的数学关系，与基岩问的力学作用不明显。探明根系力学作用特性随植被与基岩类型改变而改变的特征，可为岩石边坡植被护坡工程构造设计及植被类型选择提供必要的参考。     

Phytolith‐rich biochar: A potential Si fertilizer in desilicated soils

Silicon (Si) is beneficial to plants since it increases photosynthetic efficiency, and alleviates biotic and abiotic stresses. In the most highly weathered and desilicated soils, plant phytoliths make up the reservoir of bioavailable Si. The regular removal of crop residues, however, substantially decreases this pool. Si supply may therefore be required to sustain continuous cropping. Available Si fertilizers are costly and usually poor in soluble Si. Biochar produced from the pyrolysis of phytolith‐rich biomass is thus a promising alternative Si source for plants. Taking into account the challenges of increasing food demand and environmental concerns, we evaluate the global potential of biochar produced from major crop residues and manures in terms of phytogenic Si (PhSi) supply. Crop residues contribute to 80% of the global production of biomass dry matter (8,201 Tg/year) of which 3,137 Tg/year are potentially available after pyrolysis, giving a potential application rate of 1.7 T ha^?1 year^?1 for highly weathered soils in the tropics. The potential PhSi supply from crop biochar amounts to 102 Tg Si/year. On its own, rice straws produce 57.7 Tg PhSi/year, accounting for 56.6% of the potential annual PhSi production. The Si release from crop biochar depends on inter altere feedstock type, pyrolysis temperature, soil pH, and buffer capacity. Furthermore, the amplitude of plant Si uptake and mineralomass depends on plant species, soil properties, and processes. These factors interact and can exert a decisive influence on the effectiveness of phytolithic biochar in releasing Si into highly weathered soils. We conclude that the use of phytolithic biochar as a Si fertilizer offers undeniable potential to mitigate desilication and to enhance Si ecological services due to soil weathering and biomass removal. This potential must be explored, as well as the conditions for using biochar in the field.     

岩溶泉补给地表溪流二氧化碳脱气作用研究

碳酸盐岩风化作用(即岩溶作用)能够吸收大气二氧化碳(CO_2),形成溶解无机碳(DIC,dissolved inorganic carbon),被认为是一种重要的陆地碳汇,其在全球碳收支平衡和未来陆地增汇中可能会有重要贡献。然而,目前对岩溶碳汇的稳定性还存在争议,一些学者认为岩溶地下水出露地表后会发生CO_2脱气,对岩溶碳汇通量估算带来不确定性。本文以广西桂林长流水表层岩溶泉补给的溪流(约2.7km长)为例,利用水化学和同位素质谱仪测试技术,研究了溪水水化学指标和溶解无机碳同位素(δ~(13)C_(DIC))沿流程变化,探讨了溪流CO_2脱气过程、通量及其影响因素,以更好地了解岩溶碳汇的稳定性。结果表明:从泉口向下游,在陡坡地段(C1～C14段,长约270m,坡度约10°),溪水pH值、方解石饱和指数和δ~(13)C_(DIC)沿流程分别升高了0.9、0.9和1.8‰,而CO_2分压、电导率、Ca~(2+)浓度和DIC浓度分别下降了85%、34μS/cm、0.2mmol/L和0.7mmol/L,说明溪水发生了显著的CO_2脱气,并伴随碳酸钙沉淀。而在平缓地段(C18～C26段,长约2.1km,坡度1°),溪水各水化学指标和δ~(13)C_(DIC)变化较小,指示CO_2脱气作用较弱。这些发现表明溪流CO_2脱气受到了地形决定的水动力条件控制。另外,在下游渠段,受支流汇入影响,溪水pH值和方解石饱和指数有所降低,在一定程度上抑制了CO_2脱气。溪流CO_2脱气能够抵消部分岩溶作用固定的大气CO_2量,但是在长流水这一高地势、低流量且有碳酸钙沉积的环境下,其抵消的量也仅占29%。对于在低缓地区受流量很大的岩溶泉/地下河补给的河流,其CO_2脱气作用对岩溶碳汇的影响有限,加之受可能增强的水生光合生物固碳效应影响,岩溶碳汇应具有很高的稳定性。     

Reservoir Characteristics and Genetic Mechanisms of the Mesozoic Granite Buried Hills in the Deep‐water of the Qiongdongnan Basin,Northern South China Sea

Due to its structure,rock and mineral composition,fluid and other factors,the granite Buried Hill Reservoir is highly heterogeneous with a complex longitudinal structure and a reservoir space made up of a combination of dissolution pores and fractures.This paper is based on current understanding of tectonic evolution in the northern part of the South China Sea,in conjunction with the seismic phase characteristics.It is determined that the meshed fault system was formed by three stages of movement-tectonic compression orogeny during the Indochinese epoch,strike-slip compression-tension during the Yanshanian Period,early fracture extension activation during the Himalayan-which controlled the distribution of the Buried Hill Reservoir.Drilling revealed two types of buried hills,faulted anticline and fault horst,their longitudinal structure and the reservoir space type being significantly different.The mineral composition,reservoir space and diagenetic characteristics of the reservoir rocks and minerals were analyzed by lithogeochemistry,micro section and logging etc.,it thus being determined that the Mesozoic rocks of the Songnan Low Uplift in the Qiongdongnan Basin are mainly composed of syenogranite,granodiorite,monzogranite,which is the material basis for the development of the Buried Hill Reservoir.The content of felsic and other brittle minerals is more than 70%,making it easy for it to be transformed into fractures.At the same time,the weathering resistance of granodiorite and monzogranite is weaker than that of syenogranite,which is easily weathered and destroyed,forming a thick sand gravel weathering zone.With increasing depth of burial,weathering and dissolution gradually weaken,the deep acidic fluid improving the reservoir property of internal fractures and expanding the vertical distribution range of the reservoirs.The research results lay a foundation for the exploration of Buried Hill in the deep-water area of the Qiongdongnan Basin.     

北京怀柔云蒙山地区花岗岩风化过程的地球化学基因

地球化学基因是近两年提出的一种新的地球化学示踪技术,本文选择北京怀柔云蒙山地区两个邻近的花岗岩风化剖面(编号为B和C)来分析岩性地球化学基因和金矿化地球化学基因的属性特征。剖面B样品的化学蚀变指数CIA变化为51.3~58.9,WIG的范围为89.4~68.6,属于初始风化程度;剖面C样品的CIA变化为52.4~78.4,WIG的范围为84.8~25.3,属于中等风化程度。这种邻近剖面风化程度的明显差异表明微环境对岩石风化产物的影响是显著的。相对于剖面底部新鲜花岗岩而言,岩性地球化学基因相似度在剖面B和C中的范围分别为85%~100%和90%~100%,金矿化地球化学基因相似度范围分别为85%~100%和80%~100%。当相对于剖面顶部土壤样品时,岩性地球化学基因相似度在剖面B和C中的范围分别为80%~100%和90%~100%,金矿化地球化学基因相似度范围分别为85%~100%和80%~100%。依据≥80%的基因相似度标准(区分基因是否相似),尽管两个剖面在风化程度上存在明显差异,但岩性地球化学基因和金矿化地球化学基因在两个剖面内部均表现出良好的遗传性和继承性,且在两个剖面之间体现出同源风化产物之间具有良好的相似性。相对于理想金矿石(其金矿化基因为12020202020)而言,金矿化相似度在剖面B和C中的范围分别为25%~50%和30%~50%。依据≥40%的金矿化相似度(即样品与理想金矿石的金矿化相似度)作为存在金矿化异常的标准,在两个剖面中均可识别出厚度约1 m左右的矿化异常层位。因此,金矿化基因除了具有地球化学基因的属性(遗传性、继承性、相似性)外,其金矿化相似度(即相对于理想金矿石的相似度)也有可能作为金矿勘查中的一个地球化学综合指标。     

红层泥岩边坡快速风化特性研究

红层泥岩边坡的快速风化是一个普遍存在而又未完全解决好的问题。选择典型工点，对红层泥岩边坡的快速风化进行原位监测试验，结果表明：红层泥岩边坡的快速风化是从表面向内进行的，且集中在表层10cm的深度内，气温的变化和降雨对泥岩边坡表层的快速风化有重要的影响。对泥岩岩块进行长时间的风化崩解试验，结果也证实日气温和含水量基本恒定时泥岩岩块的风化速度缓慢。采用泥岩岩块温度变化试验和有限元分析方法得出：红层泥岩表层处于高温状态时的降雨是其快速风化剥落的主要外因，这为红层泥岩边坡的生态治理提供了理论依据。     

Schmidt hammer rebound hardness tests for the characterization of ancient fired clay bricks

This article presents results of non-destructive Schmidt hammer tests performed on ancient fired clay bricks sampled from historical masonry. These tests were carried out in order to evaluate, and compare, the different degrees of degradation, depending on the bricks’ specific exposures and locations within a wall. The results indicate that this technique is sensitive enough to distinguish sample locations and measure weathering differences, even for different surfaces of a particular sample. For each case study, referenced surfaces were tested for bricks from a facade or interior wall. Each surface was tested with a Schmidt hammer type LB at ten different points of measurement, and these measurements were repeated ten times. For each impact at a particular point, a mean rebound value was calculated to provide an index of the degree of brick-surface microweathering.