黄河流域人地耦合与可持续人居环境

黄河流域是中国人地矛盾最为紧张的区域之一,承担着生态安全建设和经济社会发展的重任。自古以来人类和黄河始终处于共同进化的过程中,近年来伴随经济发展而来的生态保护压力也日益增加,流域水资源脆弱性和风险更甚,为化解人地矛盾,需探究城镇聚落和河流的动态耦合机制。在“黄河流域生态保护和高质量发展”上升为重大国家战略之际,从城乡规划、自然地理、环境考古、生态学、水文水资源、土地资源管理等多领域视角,聚焦黄河流域人地关系的空间分异和演化规律,以及资源和生态保护的困境与机遇。建成环境与自然环境的平衡是可持续发展的基础,应将黄河流域视为自然及人文环境相互影响与依存的“生命共同体”,并从系统性和交叉性、地方性和适应性等方面探讨可持续发展策略。     

基于PS-InSAR技术的黄土大厚度挖方区回弹变形规律分析

以陕北某湿陷性黄土大厚度挖方地基工程为研究对象,采用PS-InSAR技术对2018-10—2019-11间获取的16景TerraSAR-X卫星影像进行处理,获取了湿陷性黄土挖方区回弹变形信息,总结了大厚度挖方区时序回弹变形特征。结果表明,由于上部土体应力卸载,在开挖区域存在地基土回弹变形现象,选取的高密度PS点变形信息较好地反映了研究区的真实变形情况,回弹变形范围与开挖边界吻合,另外挖方厚度越大,土体开挖引起的回弹变形越大;在开挖完成后的1年监测时间内,回弹区变形量随时间呈线性变化,在最大开挖厚度处,产生最大回弹量为29.3 mm;此外,PS-InSAR技术监测到的变形量与实地水准结果吻合性较好,表明该技术在黄土大厚度挖方区回弹变形监测中具有较好的应用效果。     

肾安汤联合激素及免疫抑制剂治疗狼疮性肾炎30例

目的：探讨肾安汤联合激素及免疫抑制剂治疗狼疮性肾炎（LN）的临床疗效。方法：将60例LN患者采用随机按数字表法随机分为治疗组和对照组,每组各30例。对照组采用口服醋酸泼尼松片和静脉滴注环磷酰胺治疗,治疗组在对照组的基础上加服肾安汤治疗,2组疗程均为6个月。观察比较2组治疗前及治疗后2、4、6个月的SLEDAI评分,24h尿蛋白定量,血尿素氮（BUN)、血清肌酐（SCr）、血沉及免疫相关指标（IgG、C3、C4）情况。结果：总有效率治疗组为96.67%,对照组为76.67%,2组比较,差异有统计学意义（P<0.05）。治疗后治疗组24h尿蛋白定量、BUN和SCr水平均低于对照组,差异有统计学意义（P<0.05）。治疗后2、4、6个月2组SLEDAI评分均逐渐下降（P<0.01）,在治疗后4、6个月,治疗组SLEDAI评分低于对照组,差异有统计学意义（P<0.05）。治疗后治疗组血沉及免疫指标IgG均低于对照组（P<0.05）;2组补体C3、C4水平均比治疗前高,治疗后治疗组补体C3、C4水平均高于对照组（P<0.05）。结论：肾安汤联合激素及免疫抑制剂治疗狼疮性肾炎可以有效改善患者的症状,控制病情,减轻不良反应。     

Rift structures and its related unconformities on and adjacent the Dongsha Rise: insights into the nature of the high-velocity layer in the northern South China Sea

Marine Geophysical Research - It is curious that the typical feature of high-velocity layer (HVL) underneath the crust for the magma-rich margin was found in the magma-poor margin of the South...     

松辽坳陷湖盆环状坡折带发育特征及对沉积过程控制

借助高精度层序地层学、构造地层学、精细沉积体系分析和构造-古地貌恢复的理论和技术手段,对坳陷期松辽湖盆开展了整体性和综合性的再评价。研究认为,拗陷期影响和控制松辽盆地沉积过程的最主要因素是环古松辽湖盆发育的内环坡折带和外环坡折带。可划分为两大类型,即张扭性和压扭性。张扭型坡折以泉头组为代表,压扭型坡折在姚家组最典型。它们各自控制着不同的沉积过程。在此基础上,建立了具有典型代表意义的古松嫩平原沉积模型和古松嫩湖泊三角洲沉积模型。提出了以内、外环坡折为基础的有利勘探方向。     

断层垂直形变对强远震的响应

利用新型断层形变三维观测系统的垂直向观测结果, 研究了两年以来7.0级以上强远震在非发震断层上的同震响应特征. 结果表明,非发震断层体垂直向同震形变的延迟时间、 同震位移最大振幅、 振动持续时间等特征与地震震级、震中距等之间存在密切联系. 断层体垂直向同震形变延迟时间与震中距线性正相关,发生地震同震形变的响应速度约为5.5km/s,反映了在上层花岗岩地层中面波的传播速度;同震位移最大振幅和震中距的对数、 震级之间具有明显线性关系,震级越大,同震位移的最大振幅越大;地震震级是断层体垂直同震形变振动持续时间的主要影响因素,震级越大,同震形变振动持续时间越长. 根据断层仪观测数据推算得到的断层体垂直向同震形变延迟时间、同震位移最大振幅、振动持续时间的经验计算公式,对于地震同震形变研究具有一定意义.      

Long Term Evolution of Solar Meridional Circulation and Phase Synchronization Viewed Through a Symmetrical Kuramoto Model

The solar-cycle oscillations of the toroidal and poloidal components of the solar magnetic field in the northern solar hemisphere have a persistent phase difference of about \(\pi \). We propose a symmetrical Kuramoto model with three coupled oscillators as a simple way to understand this anti-synchronization. We solve an inverse problem and reconstruct natural frequencies of the top and bottom oscillators under the conditions of a constant coupling strength and a non-delayed coupling. These natural frequencies are associated with angular velocities of the meridional flow circulation near the solar surface and in the deep layer of the solar convection zone. A relationship between our reconstructions of the shallow and the deep meridional flow speed during recent Solar Cycles 21?–?23 is in agreement with estimates obtained in helioseismology and flux-transport dynamo modeling. The reconstructed top oscillator speed presents significant solar-cycle like variations that agree with recent helioseismical reconstructions. The evolution of reconstructed natural frequencies strongly depends on the coupling strength. We find two stable regimes in the case of strong coupling with a change of regime during anomalous solar cycles. We see the onset of a new transition in Solar Cycle 24. We estimate the admitted range of coupling values and find evidence of cross-equatorial coupling between solar hemispheres not accounted for by the model.     

The Impact of Irrigation on Bacterial Community Composition and Diversity in Liaohe Estuary Wetland

In this study, the sequencing of 16S ribosomal DNA was used to characterize the soil bacterial community composition and diversity in Liaohe estuarine wetland. Soil samples were taken from different locations in the wetland dominated by reed. Moreover, the soil quality parameters were evaluated (pH, moisture, organic matter, total nitrogen, available nitrogen, total phosphorus, available phosphorus). The results showed that the organic matter and nutrient contents were significantly higher in irrigated wetland than those in natural wetland. Major phylogenic groups of bacteria in soil samples including Proteobacteria, Acidobacteria, Gemmatimonadetes, Actinobacteria and Cyanobacteria were analyzed and we found that Proteobacteria was the most abundant in the community, and the phylum Acidobacteria was more abundant in irrigated wetland. Beta diversity analyses indicated that the soil bacterial community was mainly affected by sampling sites rather than seasons. In general, the bacterial community in natural wetland was not significantly different with that in artificial irrigated wetland. Artificial hydraulic engineering irrigated according to the water requirement rule of reed, increased the production of reeds, changed the way of wetland soil material input, but the diversity of bacterial community kept stable relatively.     

Effects of Anthropogenic Disturbance on Sediment Organic Carbon Mineralization Under Different Water Conditions in Coastal Wetland of a Subtropical Estuary

The changes in soil organic carbon(C) mineralization as affected by anthropogenic disturbance directly determine the role of soils as C source or sink in the global C budget. The objectives of this study were to investigate the effects of anthropogenic disturbance(aquaculture pond, pollutant discharge and agricultural activity) on soil organic C mineralization under different water conditions in the Minjiang River estuary wetland, Southeast China. The results showed that the organic C mineralization in the wetland soils was significantly affected by human disturbance and water conditions(P 0.001), and the interaction between human disturbance activities and water conditions was also significant(P 0.01). The C mineralization rate and the cumulative mineralized carbon dioxide-carbon(CO_2-C)(at the 49th day) ranked from highest to lowest as follows: Phragmites australis wetland soil aquaculture pond sediment soil near the discharge outlet rice paddy soil. This indicated that human disturbance inhibited the mineralization of C in soils of the Minjiang River estuary wetland, and the inhibition increased with the intensity of human disturbance. The data for cumulative mineralized CO_2-C showed a good fit(R~2 0.91) to the first-order kinetic model C_t = C_0(1 – exp(–kt)). The kinetic parameters C_0, k and C_0 k were significantly affected by human disturbance and water conditions. In addition, the total amount of mineralized C(in 49 d) was positively related to C_0, C_0 k and electrical conductivity of soils. These findings indicated that anthropogenic disturbance suppressed the organic C mineralization potential in subtropical coastal wetland soils, and changes of water pattern as affected by human activities in the future would have a strong influence on C cycling in the subtropical estuarine wetlands.     

Reconstruction of the North–South Solar Asymmetry with a Kuramoto Model

This paper applies a Kuramoto model of coupled oscillators to investigate the north–south (N–S) solar asymmetry and properties of meridional circulation. We focus our study on the asymmetry of the 11-year phase, which is slight but persistent: only two changes of sign (around 1928 and 1968) are observed in the past century. We present a model of two non-linear coupled oscillators that links the hemispheric phase asymmetry of sunspots with the asymmetry of the meridional flow. We use a Kuramoto model with evolving frequencies and constant symmetric coupling to show how asymmetry in meridional circulation could produce a persistent phase lead of one solar hemisphere over the other. We associate the natural frequencies of the two oscillators with the velocities of the meridional flow cells in the northern and southern hemispheres. We assume the respective circulations to be independent and estimate the value of the relevant cross-equatorial coupling by the coupling coefficient in the Kuramoto model. We find that a persistent N–S asymmetry of sunspots and the change of the leading hemisphere could indeed both be the result of the evolving frequencies of meridional circulation; the necessary asymmetry of the meridional flow may be small; and the cross-equatorial coupling has an intermediate range value. Possible applications of these results in solar dynamo models are discussed.