High-resolution crustal structure of the Yinchuan basin revealed by deep seismic reflection profiling:implications for deep processes of basin

The Yinchuan basin, located on the western margin of the Ordos block, has the characteristics of an active continental rift. A NW-striking deep seismic reflection profile across the center of Yinchuan basin precisely revealed the fine structure of the crust. The images showed that the crust in the Yinchuan basin was characterized by vertical stratifications along a detachment located at a two-way travel time（TWT） of 8.0 s.The most outstanding feature of this seismic profile was the almost flat Mohorovicˇic′ discontinuity（Moho） and a high-reflection zone in the lower crust. This sub-horizontal Moho conflicts with the general assumption of an uplifted Moho under sedimentary basins and continental rifts, and may indicate the action of different processes at depth during the evolution of sedimentary basins or rifts.We present a possible interpretation of these deep processes and the sub-horizontal Moho. The high-reflection zone, which consists of sheets of high-density, mantlederived materials, may have compensated for crustal thinning in the Yinchuan basin, leading to the formation of a sub-horizontal Moho. These high-density materials may have been emplaced by underplating with mantlesourced magma.

Comprehensive Multi-Level Exploration of Buried Active Faults:an Example of the Yinchuan Buried Active Fault

The paper introduces the steps and methods of multi-approach, multi-level exploration of buried faults in thick Quaternary sediment regions by taking the test exploration of the Yinchuan active fault as example. Based on the comprehensive analyses of previous data, we choose the Xinqushao Village of Xingqing District of Yinchuan City as the test site for the comprehensive exploration. Firstly, we adopted shallow seismic investigation with group intervals of 10m, 5m and lm to gradually trace layer by layer the master fault of the Yinchuan buried fault from a deep depth to a shallow depth where drilling could be used. Then, with composite geological profile drilling, we determined the precise location and dip angle of the fault. The drilling show the buried depth of the upper offset point is 8.3m. Finally, large-scale trenching revealed that the actual buried depth of the upper offset point of the fault is 1.5m from the ground surface and there are paleoearthquake events of 5 stages. Combined with the preliminary result of corresponding sample age, we conclude the Yinchuan buried fault is a mid to late Holocene active fault.

Wetland Ecotourism Development Research-- In the Case of Yinchuan National Wetland Park

Wetland ecotourism is a special form of ecological tourism,and is also an effective way of protecting wetland ecosystem and developing wetland resource.Wetland resources of Yinchuan are rich,and its wetland ecotourism resource condition is very superior.Taking Yinchuan National Wetland Park as the object of empirical study,SWOT analysis is conducted in this paper.By internal and external environmental analysis matrix method,the feasibility of developing wetland tourism in Yinchuan is obtained.Taking"ecological security as the bottom line,ecological culture as the core,and ecological civilization as the goal"as the development ideas,and community participation,policy and fund as the safeguard mechanisms,and improving ecotourism service facility,upgrading tourism product and enriching tourism format as the development ways,ecotourism development model of Yinchuan National Wetland Park is established,in order to realize the sustainable development of wetland ecotourism in Yinchuan.

Yinchuan: The Nature, Culture, Planning Policies and Urban Development

While Yinchuan is not a typical city in China,the process by which its environment,culture and policies have affected its development is typical.The process of urban expansion in Yinchuan reflects the urban development of China in general (or a mirror can reflect China’s development history and policies evolution).Industrial development,local policy orientation,the natural environment,and other factors have both accelerated and restrained the direction and rate of expansion experienced by Yinchuan.The future urban development of Yinchuan can be conducted from three perspectives,including its city planning,and from regional and international perspectives.These perspectives should be applied to encourage city betterment and ecological restoration,new-type urbanization and rural revitalization,regional coordination and cooperation,healthy,livable,intelligent development,and a culturally inclusive atmosphere.

Epidemiological Analysis of Asymptomatic SARS-CoV-2 Novel Coronavirus Infection Cases in Yinchuan City of Ningxia

Objective:To analyze the epidemiological characteristics of asymptomatic SARS-CoV-2 novel coronavirus infection cases in Yinchuan City,Ningxia.Methods:Cases of asymptomatic SARSCoV-2 novel coronavirus infections discovered in Yinchuan City from February 2020 to April 2020 were taken as the research subjects,epidemiological and laboratory examination data were collected,and statistics and analysis were conducted.Results:Among the 10 cases of asymptomatic infection,6 were males and 4 were females,with an average age of(34.3±2.1)years;2 cases had a history of living in Hubei,8 cases had a history of close contact with confirmed cases;6 cases had no other underlying diseases while the other 4 cases were accompanied by one or more underlying diseases;6 cases were diagnosed as asymptomatic infection by serum-specific IgM antibody detection;4 cases were diagnosed as asymptomatic infection by throat swab testing;there were 4 cases with alanine base transferase level higher than the normal range,2 cases with aspartate aminotransferase level higher than the normal range,and 3 cases with D-dimer level out of the normal range.Conclusion:The asymptomatic SARS-CoV-2 novel coronavirus infection has certain clinical characteristics;it is infectious and has insidious characteristics.Even if medical observation is dismissed,monitoring is still needed to prevent the pandemic from rebounding.

Lithospheric structure and faulting characteristics of the Helan Mountains and Yinchuan Basin： Results of deep seismic reflection profiling

The Helan Mountains and Yinchuan Basin （HM-YB） are located at the northern end of the North-South tectonic belt, and form an intraplate tectonic deformation zone in the western margin of the North China Craton （NCC）. The HM-YB has a complicated history of formation and evolution, and is tectonically active at the present day. It has played a dominant role in the complex geological structure and modem earthquake activities of the region. A 135-km-long deep seismic reflection profile across the HM-YB was acquired in early 2014, which provides detailed information of the lithospheric structure and faulting characteristics from near-surface to various depths in the region. The results show that the Moho gradually deepens from east to west in the depth range of 40-48 km along the profile. Significant differences are present in the crustal structure of different tectonic units, including in the distribution of seismic velocities, depths of intra-cmstal discontinuities and undulation pattern of the Moho. The deep seismic reflection profile further reveals distinct structural characteristics on the opposite sides of the Helan Mountains. To the east, The Yellow River fault, the eastern piedmont fault of the Helan Mountains, as well as multiple buried faults within the Yinchuan Basin are all normal faults and still active since the Quaternary. These faults have controlled the Cenozoic sedimentation of the basin, and display a ＂negative-flower＂ structure in the profile. To the west, the Bayanhaote fault and the western piedmont fault of the Helan Mountains are east-dipping thrust faults, which caused folding, thrusting, and structural deformation in the Mesozoic stratum of the Helan Mountains uplift zone. A deep-penetrating fault is identified in the western side of the Yinchuan Basin. It has a steep inclination cutting through the middle-lower crust and the Moho, and may be connected to the two groups of faults in the upper crest. This set of deep and shallow fault system consists of both strike-slip, thrust, and normal faults formed over different eras, and provides the key tectonic conditions for the basin-mountains coupling, crustal deformation and crust-mantle interactions in the region. The other important phenomenon revealed from the results of deep seismic reflection profiling is the presence of a strong upper mantle reflection （UMR） at a depth of 82-92 km beneath the HM-YB, indicating the existence of a rapid velocity variation or a velocity discontinuity in that depth range. This is possibly a sign of vertical structural inhomogeneity in the upper mantle of the region. The seismic results presented here provide new clues and observational bases for further study of the deep structure, structural differences among various blocks and the tectonic relationship between deep and shallow processes in the western NCC.

中国西部典型城市大气污染物浓度变化特征及与其他区域差异性分析

为了解中国西部城市银川大气污染物浓度变化特征及其与其他区域的差异性,对银川2016—2023年空气质量和大气污染物浓度进行分析。结果表明:2016—2023年银川环境空气质量改善明显,空气质量综合指数从5.87下降到4.35,降幅达25.9%。2023年可吸入颗粒物(PM_(10))、细颗粒物(PM_(2.5))、SO_(2)、NO_(2)、CO年均值分别较2016年下降24.2%、33.3%、73.1%、2.9%、39.1%。季节雷达特征图显示,银川春季PM_(10)污染较突出,与沙尘有关;夏季污染程度最轻,冬季污染最重。除O_(3)外,采暖季SO_(2)、CO、PM_(2.5)、PM_(10)、NO_(2)分别比当年非采暖季高41.7%~359.1%、81.3%~150.0%、28.9%~134.8%、3.7%~146.2%、16.7%~86.2%,表明供暖对冬季大气污染物浓度贡献显著。2016—2023年银川大气污染物浓度与全国以及其他重点区域的变化趋势大致相同。O_(3)污染逐渐凸显;PM_(2.5)浓度与全国和宁夏接近;SO_(2)、NO_(2)和CO浓度较高,成为制约PM_(2.5)和O_(3)浓度下降的主要因素;PM_(10)浓度受周边沙尘影响较大。

Three-dimensional S-wave velocity structure of the crust and upper mantle for the normal fault system beneath the Yinchuan Basin from joint inversion of receiver function and surface wave

A series of parallel normal faults are distributed in the Helan Mountain-Yinchuan Basin tectonic belt,where a historical M8.0 earthquake occurred.It is rare that such a great earthquake occurs in a normal fault system within the continent.To deeply understand the fine structure of the normal fault system,we deployed 104 broadband temporary stations near the system,collected data from permanent stations and other temporary stations nearby,and obtained the high-precision threedimensional S-wave velocity structure beneath 206 stations via joint inversion of receiver function and surface wave.A typical graben-in-graben feature bounded by four major faults was identified in the Yinchuan Basin.We analyzed the seismicity in the normal fault system and found a seismic strip in the southern part of the basin,where there are significant changes in the sedimentary thickness,which is speculated to be the southern boundary of the normal fault system.There are significant differences in the crustal thickness and velocity structure in the crust on both sides of the boundary between the Helan Mountain and the Yinchuan Basin,and a low-velocity zone was identified in the upper mantle beneath this boundary,which could be related to the fact that the Helan Mountain-Yinchuan Basin tectonic belt is located between the Alxa Block and the Ordos Block.The M8.0 Yinchuan-Pingluo earthquake occurred at the junction of four major faults in the Yinchuan Basin,which was located in the high-velocity zone near the velocity transition zone at the basin-mountain boundary.The low-velocity zone in the upper mantle beneath this boundary may have promoted the nucleation of this earthquake.Based on evidence from geological drilling,micro seismicity,the regional stress field,and the velocity models obtained in this study,it is inferred that the eastern piedmont fault zone of the Helan Mountain was the seismogenic fault of the 1739 M8.0 Yinchuan-Pingluo earthquake.

Characteristics of the three-dimensional deep electrical structure in the Helan Mountains-Yinchuan Basin and its geodynamic implications

Located in the north segment of the North-South seismic belt where the Alxa block(AB)and the Ordos block(OB)contact,the Helan Mountains-Yinchuan Basin(HLM-YCB)constitutes a typical normal faulting basin-mountain structure on the Chinese mainland.The 1739 M8.0 Pingluo earthquake occurred in the Yinchuan fault depression basin with such a basinmountain structure.Data on five magnetotelluric profiles encompassing distinct segments of the HLM-YCB were utilized for three-dimensional(3D)joint inversion in order to collect fine 3D electrical structure information at a crustal and upper mantle scale across the entire region.The electrical structure between the main blocks in the HLM-YCB and adjacent areas is characterized by east-west horizontal blocks OB,YCB,and HLM,which are divided by the Yellow River fault(F5)with the HLM eastern piedmont fault(F2)as electrical boundary zones on the east and west sides.The two main block units,AB and OB,exhibit an obvious layered resistivity structure.Besides,the HLM-YCB is characterized by a typical basin-mountain structure with the mountains as a high-resistivity body and the basin as a low-resistivity body,and in the northern YCB a large-scale lowresistivity structure exists,extending to the upper mantle,probably derived from the upwelling of mantle-derived materials.It is speculated from a combination of recent 3D crustal movement field information and other data that the HLM-YCB is an active tectonic zone formed via regional tensile action.The formation of the HLM-YCB lies in the interaction of the Tibetan Plateau(TP),AB,and OB and abnormal mantle activities beneath the YCB.The HLM-YCB reflects the joint action of upwelling and diffluence caused by the underplating of hot materials from the deep mantle with gravity and the redistribution of regional tectonic stress on the earth’s surface,which may be the main dynamic reason for the 1739 M8.0 Pingluo earthquake.

青藏高原东缘及邻区强震构造:专辑序言

青藏高原东缘由多个次级构造单元组成了独特的“多层次挤出-旋转活动构造体系”,是调节高原物质向东挤出的构造转换带,发育了高密度的活动断裂,强震频度高且强度大,而且地质地貌复杂,成为我国地震灾害问题最为突出的地区之一。近年来,伴随全国地震灾害风险普查、城市活断层探测、地震科学实验场建设、工程场地的地震安全性评价以及重大工程与城镇区的活断层鉴定与地壳稳定性评价等工作的深入开展,高精度遥感、构造地貌、古地震和第四纪年代学等方法的广泛应用,显著提升了青藏高原东缘及邻区强震构造的调查研究程度。为了及时交流这方面的最新研究成果,支撑区域防震减灾及重要工程和基础设施建设的地质安全评价等工作,《地震科学进展》编辑部组织了“青藏高原东缘及邻区强震构造”成果专辑,征集了活断层与地震、甘肃积石山地震以及相关领域的研究综述等代表性学术论文20余篇,本期《青藏高原东缘及邻区强震构造专辑Ⅰ》优选了10篇论文,后续还将推出《青藏高原东缘及邻区强震构造专辑Ⅱ》,希望这些成果可提升对区域强震活动特征与孕震构造机制的理解,并为区域强震危险性分析和有效防范强震灾害风险提供科学依据。

银西高铁黄土含水层隧道群井降水模拟研究

研究目的:银西高铁上阁村隧道穿越董志塬黄土含水层施工中出现的渗涌水,受地下水渗流影响,引起了洞身黄土含水率增加、围岩自稳性变差等问题。为解决上阁村富水黄土隧道施工难题,论文首先分析了上阁村隧道黄土含水层分布特征,其次介绍了地表降水施工辅助措施及其效果,最后应用MIDAS/GTS建立隧道工程群井降水模型,实现了不同流量以及渗透系数工况下的隧道开挖渗流模拟计算。研究结论:(1)上阁村隧道长大段落通过软塑黄土含水层,通过地表降水梳干隧道洞身范围内地下水,提高了隧道洞身黄土围岩稳定性,确保了隧道施工的安全和进度;(2)不同单井流量(80 m^(3)/d、90 m^(3)/d、100 m^(3)/d)的群井数值模拟结果表明,地下水位降深在短时间内达到了设计要求,验证了降水设计参数及效果;(3)本研究可为黄土等低渗透岩体富水隧道工程施工处置及设计提供依据。

银川盆地地热水水化学特征及形成机理

地热能绿色可持续,对于实现“双碳”目标至关重要。银川盆地是典型的寒旱区域,对热能需求巨大。针对银川盆地地热的研究基本集中于估算地热资源量,对地热水的水化学特征及形成机理研究较少。因此以运用水文地球化学、氢氧稳定同位素、放射性同位素(氚和^(14)C)测年和水岩作用模拟等方法分析银川盆地内地热水水化学特征及形成演化机制。研究结果表明银川盆地地热水水化学类型为Cl-Na型和Cl·SO4-Na型。Na^(+)在阳离子中占比最大,Cl^(-)在阴离子中占比最大。岩盐的溶解是Na^(+)的主要来源之一,另一个来源是阳离子交替吸附作用。石膏的溶解是SO_(4)^(2-)主要来源。银川盆地补给区高程为范围在2600~2900 m,平均补给高程为2762.44 m,地热水来源并非大气降水直接补给,而是贺兰山地区高海拔处的大气降水沿贺兰山东麓断裂对银川盆地地下热水进行补给,地热水最老年龄为20750 a,存在亚现代地下水的混合水,补给高程高且距离远。

银川地区含香樱桃设施栽培技术

含香樱桃在银川地区表现出花量大、果个大、颜色美、风味香等特点,具有裂果轻、耐贮运、较抗病、特耐寒等优点。从休眠期、升温期、催芽期、萌芽开花期、果实发育前期、果实着色至果实成熟期、采收期7个时期总结银川地区含香樱桃设施栽培技术,旨在为含香樱桃在银川地区的推广种植提供借鉴参考。

银川市牛奶产业当前困境与纾解对策

近五年来,银川市牛奶产业呈现扩规上档、集约集群、提质增效的良好发展态势,并逐步实现一、二、三产业融合发展。然而,在银川市牛奶产业快速发展的过程中,由于饲草、奶牛、牛奶、乳品加工和销售比例失调,银川市牛奶产业面临着产业膨胀的困境,产业链各环节之间的矛盾日益凸显。文章通过针对牧草、奶牛养殖、乳品加工、销售全产业链的调查,发现目前银川市牛奶产业面临的主要问题有:饲草供不应求,价格大幅上涨;养殖规模扩张导致牛奶阶段性供给过剩,乳品加工产能释放不足,本地乳企市场竞争力弱;乳品销售额增长不及牛奶产量增长;产业链协同机制不健全等。基于此,文章提出了调整牛奶产业发展政策、开拓乳品市场、加强饲草料供给、加大科技投入力度、完善产业链协同机制等具体对策建议。

银川盆地东南缘面子山—清水营断裂活动性

研究银川盆地的构造活动特征对于认识青藏、鄂尔多斯和阿拉善3大地块的相互作用具有重要意义。银川盆地东南缘的面子山—猪头岭一带地形高差显著,影像上线性明显,可能发育一条未知的活动断裂。本文沿面子山—清水营一线开展了野外地质调查、探槽开挖和地层年代测试等工作,结果表明:银川盆地东南缘发育面子山—清水营断裂,全长50 km,以猪头岭北为界,分为面子山断层和清水营断层两段。面子山断层以高角度正断为主,断层擦痕显示具有左旋走滑运动,走向北东,跨断层数条冲沟显示具有左旋扭动特征;而清水营断层则表现为逆断层,走向北东东,发育陡坎地貌。该断裂断错了(23.65±1.17) ka BP和(33.16±1.82) ka BP的沉积地层,表明断裂最新活动时代为晚更新世晚期。该断层的发现表明,鄂尔多斯地块的西北边界复杂,构造变形带较宽,且不严格的受控于断陷盆地的边界断裂,其构造变形已扩张到地块一侧,这可能与青藏高原持续向东北向的推挤扩展有关。

银川城市地下空间开发的地质安全风险分析

城市地下空间受地质环境的影响和制约,评价地质环境的安全成为地下空间开发的先导问题。结合银川市地下空间资源调查和区划,选择了地震(活动断裂和场地地震效应)、砂土液化、富水砂卵石层、地基承载力和地表载荷等因素作为评价因子,在分别确定各要素空间分布的基础上,进行了单因素的地质风险分析;采用层次分析和乘积标度相结合的方法,进行银川市地下空间开发的多因素地质安全风险综合评价。结果表明:银川市地下空间开发的最主要制约因素是地震和砂土液化;地质风险的强风险区面积最小,占总面积的4.10%,中风险区面积占19.69%,弱风险区面积最大,占41.07%,低风险区占35.13%。这为银川市地下空间开发建设等提供地质参考。

基于CIWOA-BP和灰色置信区间的银川市需水量预测模型

需水量预测是水资源科学配置和调度的基础,为提高其合理性,针对需水量变化的波动、不确定性特点,提出一种改进鲸鱼算法(CIWOA)优化BP神经网络与灰色置信区间估计相结合的需水量区间预测模型。利用灰色关联分析筛选需水量影响因子,输入CUBIC混沌映射和自适应权重改进的鲸鱼算法优化BP模型(CIWOA-BP),结合灰色置信区间估计建立组合区间预测模型,对银川市需水量进行模拟预测。结果表明:CIWOA-BP模型预测精度高于普通鲸鱼算法优化BP模型(WOA-BP)、遗传算法优化BP模型(GA-BP);CIWOA-BP模型与灰色置信区间的组合模型优于其与BOOTSTRAP区间估计组合,在置信度90%时需水量区间预测合理、可靠。

银川市夏季臭氧污染特征及敏感性分析

对2022年7月银川市夏季臭氧(O_(3))污染特征及生成敏感性进行分析,以期为银川市O_(3)污染防控提供科学策略。结果表明:观测期间银川市出现O_(3)超标日共9 d,日最大8 h滑动平均质量浓度平均值较非超标日高32.6%,NO_(2)峰值较非超标日升高近20%;太阳辐射增强、高温低湿等气象特征容易导致O_(3)超标风险增大;银川市挥发性有机物(VOCs)中烷烃、含氧挥发性有机物(OVOCs)、卤代烃占比较高,但对O_(3)生成潜势(OPF)的贡献则呈现出烷烃>烯烃>芳香烃>OVOCs>炔烃>卤代烃的趋势,间/对-二甲苯、2-甲基-1,3-丁二烯、乙烯是O_(3)防控的关键VOCs物种;观测期银川市气团以中老化状态(94.3%)为主,其中机动车尾气对VOCs贡献率最大,为33.3%,燃烧源和工业排放贡献率相当,均为21.4%;7月银川市O_(3)生成主要受VOCs控制,现阶段VOCs减排是银川市O_(3)污染防控的有效途径。

有机肥替代氮肥对银北灌区盐化灌淤土理化性质及玉米生长的影响

次生盐渍化已成为宁夏银北灌区灌淤土壤退化的主要形式,制约着宁夏农业持续高质量发展。为了给宁夏地区盐化灌淤土的施肥管理及提高作物产量提供科学依据,以银北灌区典型盐化灌淤土为研究对象、玉米品种先玉335为指示品种,研究了不同施肥水平对盐化灌淤土土壤理化性质及玉米生长的影响。结果表明,各施肥处理均能有效地增加盐化灌淤土的速效养分含量,进而优化玉米产量构成要素,提高玉米产量。各施肥处理除常规施肥处理(施N 375.0 kg/hm^(2)、P_(2)O_(5)100.0 kg/hm^(2)、K_(2)O 100.0 kg/hm^(2))的玉米总根长、根表面积最高外,有机肥替代常规施肥量50%氮肥(施N 187.5 kg/hm^(2)、P_(2)O_(5)100.0 kg/hm^(2)、K_(2)O 100.0 kg/hm^(2)、有机肥7.3 t/hm^(2))处理的土壤理化性质及玉米生长指标最高。与对照不施肥相比,该处理下土壤有机质、速效氮、速效磷、速效钾分别增加了34.5%、25.9%、120.5%、23.7%,玉米穗长、穗粗、穗粒数、产量分别增加了40.5%、15.2%、80.5%、104.8%,秃尖长降低了78.0%;与常规施肥处理相比,该处理下土壤有机质、速效氮、速效磷、速效钾分别增加了36.5%、21.4%、13.7%、8.6%,玉米穗长、穗粗、穗粒数、产量分别增加了0.6%、1.9%、5.3%、3.1%,秃尖长降低了57.7%。综合分析,不同施肥水平均可改善盐化灌淤土理化性质进而提升玉米产量,且以有机肥替代部分氮肥施用的处理效果较好,其中以有机肥替代常规施肥量50%氮肥的施肥水平效果最好。

心理契约视角下银川市公立医院医生工作满意度提升路径研究

[目的]调查银川市公立医院医生心理契约与工作满意度现状,并从心理契约视角分析提升公立医院医生工作满意度的路径。[方法]于2022年6月采用简单随机抽样方法抽取银川市某三级甲等公立医院329名医生进行公立医院医生心理契约、工作满意度问卷调查。采用独立样本t检验和单因素方差分析研究不同人口学特征在医生心理契约和工作满意度得分上是否存在差异;采用多元线性回归分析心理契约及各维度对医生工作满意度及各维度的影响。[结果]银川市公立医院医生心理契约总得分为(3.91±0.48)分,心理契约总体履行情况呈中等偏上水平,医生工作满意度总得分为(3.49±0.45)分,总体上处于一般水平。心理契约对工作满意度有显著正向影响(β=0.731,P<0.001),对人际关系影响最大的因素是医院关系责任(β=0.263,P<0.001),对工作本身影响最大的因素是医院理念责任(β=0.340,P<0.001),对工作条件、报酬与福利影响最大的因素是医院交易责任(β=0.297,0.148,P<0.05),对培训与晋升影响最大的因素是医院发展责任(β=0.406,P<0.001),对领导与管理影响最大的因素是医院关系责任(β=0.300,P<0.001)。[结论]公立医院医生心理契约及各维度对工作满意度及各维度有显著的正向影响,要关注医院交易、发展、关系、理念责任的履行情况,增强医生归属感和认同感,激发工作积极性,提高工作满意度。