Nitrogen cycling in western India as revealed by nitrogen isotopes,and the historic production of saltpetre

Saltpetre (KNO₃) manufacture was a principal monopoly industry in early Modern India when the United Kingdom governed the social and economic systems. The process represented microbial transformation of excrementitious livestock and human wastes deposited around habitats, resulting in formation of salt efflorescence at an economic scale. Low caste people collected these wastes for extraction and production of rough saltpetre under the administrative control of British India. Stable isotope composition (δ¹⁵N and δ¹⁸O) was used to trace details of the microbial transformation processes, often involving the isotopic fractionation of nitrogen and oxygen. Marked elevation in δ¹⁵N and δ¹⁸O values for nitrates in soils and deposits, relative to those of primary organic nitrogen in diets and water sources, characterizes the unique processes of historic saltpetre manufacture in British India.     

Invasive cordgrass (Spartina spp.) in south‐eastern Australia induces island formation,salt marsh development,and carbon storage

Invasive vegetation species can lead to major changes in the geomorphology of coastal systems. Within temperate estuaries in the southern hemisphere, especially Australia and New Zealand, the cordgrass Spartina spp. has become established. These species are highly invasive, and their prolific growth leads to the development of supratidal environments in formerly intertidal and subtidal environments. Here, we quantified the impact of Spartina invasion on the geomorphology and sequestration capacity of carbon in the sediments of Anderson Inlet, Victoria, Australia. Spartina was first introduced to the area in the 1930s to aid in land reclamation and control coastal erosion associated with coastal development. We found that Spartina now dominates the intertidal areas of the Inlet and promotes accretion (18 mm/year) causing the formation of over 108 ha of supratidal islands over the past 100 years. These newly formed islands are calculated to potentially contain over 5.5 million tonnes of CO₂ equivalent carbon. Future management of the inlet and other Spartina‐dominated environments within Australian presents a dilemma for resource managers; on the one hand, Spartina is highly invasive and can outcompete native tidal marshes, thereby warranting its eradication, but on the other hand it is likely more resilient to rising sea levels and has the potential for carbon sequestration. Whether or not the potential advantages outweigh the significant habitat change that is anticipated, any management strategies will likely require additional research into costs and benefits of all ecosystem services provided by Spartina including in relation to nutrient cycling, shoreline stabilisation, and biodiversity as well as in response to the longevity of carbon found within the sediments.     

格尔木盐湖化工产业集群发展研究

产业集群的发展壮大是提升城市竞争力的最有效途径。本文对格尔木盐湖化工产业集群的发展阶段进行了初步判断,在此基础上,分析了格尔木盐湖化工产业集群的发展状况,提出了加快发展产业集群的具体对策建议。     

Experimental interpretation of the presence of female genitalia in Early Bronze Age ‘frying pan'-type ceramics from the Cyclades*

Α new, testable, interpretation of the function of Aegean Early Bronze Age ‘frying pan' ceramics that combines some previously suggested uses is presented experimentally. The proposed function involves a well-documented natural phenomenon responsible for the rapid change in colour of a natural salt marsh or salt pan surface due to the explosive population growth of the extremophile Archaea Halobacterium salinarium when the salt concentration approaches saturation. The cyclical nature of the appearance of red pigmentation on the salt marsh surface every late summer or every few weeks in a domestic ‘frying pan' presents an obvious analogy with the female menstruation cycle and provides an explanation for the fact that several ceramic vessels used for this purpose bear the characteristics of the female body. Furthermore, the resulting red pigment lends itself for use as a cosmetic colorant.     

基于电阻率成像法的莫高108窟墙体内水盐运移过程分析

非均质的砂砾石层是莫高窟壁画的主要墙体,但砂砾石层的非均质性如何在水盐运移过程中发挥作用却还不清楚。为此,通过在108窟西壁面上1 m×1 m和2 m×2 m范围的三维高密度电阻率成像监测,发现在这些区域上,墙体电阻率的空间分布都是非均匀的,低阻值区域在空间位置、大小和形状上都会随时间而变化。这明确说明在构成墙体的非均质砂砾石层内存在着重要的水分饱和与非饱和过程(再分配过程),正是这一不断重复的饱和与非饱和过程促进了墙体内水分的运移和盐分在一些特定区域的聚集。研究成果对全面认识莫高窟墙体内的水盐运移机理,减轻和防治壁画盐害都具有重要意义。     

The Historic Port of El Real de Salinas in Campeche, and the Role of Coastal Resources in the Emergence of Capitalism in Yucatán, México

The emergence of capitalism in the peninsula of Yucatán is generally presented as a process resulting from the capitalization of the agricultural sector and the export of products from its sugar, cotton, and henequén plantations in the nineteenth century. In addition to these products, the peninsula also had a dynamic coastal economy in which the harvesting of salt and the extraction of logwood (Haematoxylum campechianum), played a major role and contributed to the flow of goods to international markets. We present a preliminary archaeological survey and historical documentation of El Real de Salinas, a salt-producing port on the north coast of Campeche, which was also involved in the extraction of other coastal products and closely linked to the inland plantation system.

Performance and Risks of Salt-Accumulating Renders in Relation to Their Moisture Transport Properties

Salt-accumulating renders are usually applied in several layers with different specific properties of moisture transport. An extensive experimental programme was carried out to establish a relationship between those properties of individual layers and the performance of combined systems on a salt-laden substrate. Each of the 20 renders was characterized separately in absorption and drying tests, vacuum saturation tests, dry cup tests, mercury intrusion porosimetry, and ultrasound wave velocity measurements. Each of the 12 combined render systems was applied on a brick, which was then saturated with a concentrated NaCl solution by free capillary uptake. Subsequently the assembly was closed at the bottom and subjected to an accelerated drying test (50° C and 15% relative humidity). Moisture and salt profiles over the depth were taken regularly during 1 month. The results reveal very different degrees of effectiveness and levels of risk for the substrate, which are related to the moisture transport properties.     

殷都制盐业的探索

盐是人类赖以生存的基本物质之一。商代王都人口众多,对盐的需求量甚大,在当时生产和交通条件都不发达的情况下,单靠从商都之外运入,恐怕难以满足。今天的豫北地区在商代虽然比现在温暖湿润,生态环境良好,但仍然存在某些盐碱性土壤。因此,殷都食盐除了从山东、山西以及四川等地区输入外,普通百姓也可能就地取材,制造土盐,以满足自身生存的需要。     

典型硫酸盐环境中砖质文物的脱盐与加固材料

中国保存有众多砖质文物建筑,目前这些文物多处于户外环境中,面临严重盐害导致的掏蚀损毁问题。因而,研究兼具脱盐功能的加固材料成为砖质文物等保护的一种创新思路,加固材料的研制和工艺技术的开发是其重点和难点,具有重大的社会需求和急迫性。为此,本工作从可溶性盐的破坏机制出发,研究出一种双组分无机加固材料,加固方法是Ba(OH)_2甲醇溶液与H_2C_2O_4、H_3PO_4乙醇溶液交替滴加,并模拟可溶性盐(NaCl、KCl、Na_2SO_4)分布的典型环境,进行加固、除盐,借助X射线衍射仪(XRD)、X射线荧光光谱仪(XRF)和无线阻尼抗钻仪等现代科学仪器,追踪盐的流出与转化过程。结果表明,本材料不仅能够加固模拟样品,同时能对最具破坏性的盐Na_2SO_4实现不可逆转化,生成重晶石的主要成分BaSO_4,加固与脱盐一次完成,是一种具有实际应用潜力的新材料。     

大雁塔盐害及劣化模拟试验研究

易溶盐富集是陕西西安大雁塔砖体表面风化、结构破坏、强度衰减的主要原因。为分析盐害对大雁塔砖体结构、强度的影响机理,采用以饱和硫酸钠溶液为介质,对大雁塔砖体进行易溶盐结晶循环模拟劣化试验。在Na₂SO₄反复结晶、溶解过程中,测定试样的质量、波速及单轴抗压强度等指标,分析其变化规律。结果表明,在盐害作用下,试验砖体表现出与塔体表面类似的风化破坏现象;Na₂SO₄晶体在试样孔隙内不断发育,晶体挤压效应导致孔隙率增大,内部结构破损;质量、波速、单轴抗压强度随循环的次数呈先增加后减小的变化规律。砖体对盐害耐受力约为砖体质量的0.5%。