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Developmental environment contributes to rapid trait shifts among newly colonized subterranean habitats
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作者 Nathan E.Swanson Andrew G.Gluesenkamp +1 位作者 Alexandra E.Donny Suzanne E.McGaugh 《Zoological Research》 SCIE CSCD 2023年第4期808-820,共13页
Recent colonization of extreme environments provides unique opportunities to study the early steps of adaptation and the potential for rapid convergent evolution.However,phenotypic shifts during recent colonization ma... Recent colonization of extreme environments provides unique opportunities to study the early steps of adaptation and the potential for rapid convergent evolution.However,phenotypic shifts during recent colonization may also be due to plasticity in response to changes in the rearing environment.Here,we analyzed a suite of morphological and behavioral traits in paired surface,subterranean,and facultatively subterranean Mexican tetras(Astyanax mexicanus)from recent introductions in two separate watersheds outside of their native range.We found a variety of phenotypic and behavioral shifts between subterranean and surface populations that are similar to those observed in relatively ancient populations in Mexico.Despite this rapid morphological divergence,we found that most of these trait differences were due to plasticity in response to rearing environments.While most trait assays in common-garden,lab-raised fish indicated that phenotypic shifts in wild fish were the result of plasticity,we also found evidence of genetic control in several traits present in subterranean populations.Interestingly,wall-following behavior,an important subterranean foraging behavior,was greater in lab-born subterranean fish than in lab-born surface fish,suggesting rapid divergence of this trait between subterranean and surface populations.Thus,this study sheds light on the early steps of subterranean evolution,identifies potential rapid behavioral evolution,and suggests that plasticity in traits involving exploratory behavior may facilitate subterranean colonization. 展开更多
关键词 Plasticity Adaptation subterranean CAVEFISH Evolution Common garden
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Microbiota of a seepage face at the mouth of a subterranean estuary:diversity,distribution and substrate dependence
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作者 Yueming Wu Yongjun Wei +5 位作者 Juan Severino Pino Ibánhez Danqing Sun Kaiqi Lu Qianqian Wang Jian Li Shan Jiang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第8期147-157,共11页
Subterranean estuaries,i.e.,the mixing zone between terrestrial groundwater and recirculated seawater,host a wide range of microbiota.Here,field campaigns were conducted at the mouth of the subterranean estuary at the... Subterranean estuaries,i.e.,the mixing zone between terrestrial groundwater and recirculated seawater,host a wide range of microbiota.Here,field campaigns were conducted at the mouth of the subterranean estuary at the Sanggou Bay(Shandong Province,China)over four consecutive seasons at a seepage face(0−20 cm depth).The diversity of benthic microbiome was characterized via 16S rRNA gene sequencing and metagenomics,combined with physic-chemical parameters,e.g.,organic carbon,total nitrogen and sulfate contents in sediments.During spring,the dominant species were assigned to the phylum Proteobacteria.Important opportunistic species was assigned to Acidobacteria,Actinobacteria and Bacteroidetes.The key components were identified to be species of the genera Pseudoalteromonas,Colwellia and Sphingobium,indicating the involvement of sediment microbiota in the degradation of sedimentary organic carbon,particularly that of pelagic origin,e.g.,phytoplankton detritus and bivalve pseudo-feces.During spring,the microbial community was statistically similar along the depth profiles and among the three sampled stations.Similar spatial distributions were obtained in the remaining seasons.By contrast,the dominant species assemblages varied significantly among seasons,with key genera being Thioprofundum and Nitrosopumilus during summer and autumn and Thioprofundum and Ilumatobacter during winter.Network analysis revealed a seasonal shift in benthic nitrogen and sulfur metabolism associated with these variations in microbial community composition.Overall,our findings suggested that macro elements derived from pelagic inputs,particularly detrital phytoplankton,shaped the microbial community compositions at the seepage face,resulting in significant seasonal variations,while the influence of terrestrial materials transported by groundwater on the sediment microbiota at the seepage face found to be minor. 展开更多
关键词 subterranean estuary MICROBIOTA seepage face seasonal variation SUBSTRATE
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Spatial distribution and export of nutrients and metal elements in the subterranean estuary of Daya Bay
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作者 Zhaoxi Liu Mingchen Ge +4 位作者 Qianqian Wang Xuejing Wang Kai Xiao Gang Li Hailong Li 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第8期77-86,共10页
Subterranean estuaries(STE)are important seawater-groundwater mixing zones with complex biogeochemical processes,which play a vital role in the migration and transformation of dissolved materials.In this study,we firs... Subterranean estuaries(STE)are important seawater-groundwater mixing zones with complex biogeochemical processes,which play a vital role in the migration and transformation of dissolved materials.In this study,we first investigated the spatial distributions of dissolved inorganic nitrogen(DIN),dissolved inorganic phosphorous(DIP),dissolved inorganic silicon(DSi)and metal elements(As,Ba,Cr,Cu,Fe,Mn,Ni,Pb,and Zn)in STE including upper intertidal,seepage face and subtidal zones.We then estimated submarine groundwater discharge(SGD)and associated nutrient and metal element fluxes.From the generalized Darcy’s law method,SGD was estimated to be 30.13 cm/d,which was about 7 times larger than the inflow(4.16 cm/d).The nutrient and metal fluxes from SGD were estimated to be(5.33±4.99)mmol/(m^(2)·d)for DIN,(0.22±0.03)mmol/(m^(2)·d)for DIP,(16.20±2.05)mmol/(m^(2)·d)for DSi,(1325.06±99.10)μmol/(m^(2)·d)for Fe,(143.41±25.13)μmol/(m^(2)·d)for Mn,(304.06±81.07)μmol/(m^(2)·d)for Zn,(140.21±13.33)μmol/(m^(2)·d)for Cu,(84.49±2.94)μmol/(m^(2)·d)for Pb,(37.38±5.51)μmol/(m^(2)·d)for Ba,(27.88±3.89)μmol/(m^(2)·d)for Cr,(10.10±6.33)μmol/(m^(2)·d)for Ni,and(6.25±3.45)μmol/(m^(2)·d)for As.The nutrient and metal fluxes from SGD were relatively higher than those from the inflow,suggesting that nearshore groundwater acted as the sources of nutrients and metal elements discharging into the sea.The environmental potential pollution of coastal seawater was evaluated by pollution factor index(Pi),comprehensive water quality index(CWQI),and ecological risk index(ERI).Pb mainly caused potential danger of nearshore environment with considerable contamination(Pi=5.78±0.19),heavy pollution(CWQI=4.09)and high ecological risk(ERI=18.00).This study contributed to better understanding the behavior of nutrients and metal elements and improving the sustainable management of STE under the pressure of anthropogenic activities and climate change. 展开更多
关键词 subterranean estuaries submarine groundwater discharge NUTRIENTS metal elements pollution assessment Daya Bay
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Subterranean-SAE 算法的条件立方攻击
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作者 刘勇 陈思维 +2 位作者 张莎莎 向泽军 曾祥勇 《密码学报》 CSCD 2022年第1期45-59,共15页
美国国家标准与技术研究院(NIST)于2018年开始征集轻量级认证加密和哈希算法标准,其中Subterranean 2.0密码套件是晋级到第二轮的32个候选算法之一.Subterranean-SAE是Subterranean 2.0密码套件中的一种认证加密工作模式.2019年,刘富康... 美国国家标准与技术研究院(NIST)于2018年开始征集轻量级认证加密和哈希算法标准,其中Subterranean 2.0密码套件是晋级到第二轮的32个候选算法之一.Subterranean-SAE是Subterranean 2.0密码套件中的一种认证加密工作模式.2019年,刘富康等人对4轮空白轮(4 blank rounds)的Subterranean-SAE算法进行了基于条件立方的密钥恢复攻击,此攻击有效的前提假设是:当条件变量满足条件时输出代数次数为64,否则为65.但刘富康等人并没有验证该假设是否成立.借助三子集可分性理论,本文首次提出了在初始状态未知场景下评估输出代数次数的新技术,并将该技术成功应用于4轮空白轮Subterranean-SAE算法.实验结果表明,4轮空白轮Subterranean-SAE算法32个输出比特的代数次数上界为63,因此刘富康等人的密钥恢复攻击实际为区分攻击.进一步,本文提出降低立方维数、扩展立方变量选取范围的策略,并成功改进了Subterranean-SAE算法条件立方的搜索方法.利用此方法我们共搜索到24组33维立方并以此构造条件立方攻击,攻击的数据和时间复杂度分别为2^{41.8}和2^{124}.本文的条件立方攻击能够通过实验验证其有效性,并且能够正确恢复128比特密钥.在nonce不重用场景下,这是首次实现4轮缩减轮数Subterranean-SAE算法的全密钥恢复攻击.值得注意的是,本文缩减轮数的攻击并不会对Subterranean-SAE算法构成实质安全性威胁,但有助于加深对其安全性的理解. 展开更多
关键词 subterranean 2.0密码套件 subterranean-SAE 条件立方攻击 三子集可分性
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Evaluation of the virulence of entomopathogenic fungus, Isaria fumosorosea isolates against subterranean termites Coptotermes spp.(Isoptera:Rhinotermitidae) 被引量:2
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作者 J.J.Jessica T.L.Peng +2 位作者 A.S.Sajap S.H.Lee S.A.Syazwan 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第1期213-218,共6页
The entomopathogenic fungus Isaria fumosorosea Wize, formerly known as Paecilomyces fumosoroseus is reported as a promising biocontrol agent for controlling subterranean termites, particularly those belonging to the f... The entomopathogenic fungus Isaria fumosorosea Wize, formerly known as Paecilomyces fumosoroseus is reported as a promising biocontrol agent for controlling subterranean termites, particularly those belonging to the family Rhinotermitidae. In Malaysia, the family Rhinotermitidae includes two species of subterranean termites with extremely high economic importance; namely Coptotermes curvignathus Holmgren, and the Asian SLubterranean Termite (Coptotermes gestroi Wasmann). To comprehend the potential control of this soil-dwelling fungus against these subterranean termites in Malaysia, an investigation was carried out by testing the pathogenecity of 11 isolates against these termite species. All isolates showed pathogenic potential against the termite (Mortality rate of C. curvignathus:84.4%; C. gestroi:67.3%). IsolatePF49 was the most effective against both species of termites and was further tested for its virulence and mycosis.The LC_(50) values of PF49 against C. curvignathus and C.gestroi were 7.55×103 and 1.09×102 conidia/ml,respectively. The average number of days required to complete the mycosis process in C. curvignathus and C.gestroi were 4.7 and 8 days, respectively. These fungi are believed useful for protecting living trees, plants, wood,wood structures, and other cellulosic materials susceptible to termite infestation and damage. 展开更多
关键词 Biological control ENTOMOPATHOGENIC fungus subterranean TERMITES Lethal concentration
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The Utilization of Real-Time High Resolution Monitoring Techniques in Karst Carbon Sequestration:A Case Study of the Station in Banzhai Subterranean Stream Catchment 被引量:1
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作者 HE Shi-Yi KANG Zhi-Qiang +1 位作者 LI Qing-Yan WANG Ling-Ling 《Advances in Climate Change Research》 SCIE 2012年第1期54-58,共5页
The karst process acts as carbon sequestration for atmospheric CO_2.The amount of karst carbon sequestration (KCS) depends on the discharge of karst catchment and inorganic carbon concentration of the water body.Based... The karst process acts as carbon sequestration for atmospheric CO_2.The amount of karst carbon sequestration (KCS) depends on the discharge of karst catchment and inorganic carbon concentration of the water body.Based on the data from the monitoring station on Banzhai subterranean stream located in Maolan National Nature Reserve of Guizhou province,the process and influence factors of KCS have been analyzed.It shows that the amount of KCS is about 353 t C per year in the catchment of Banzhai subterranean stream,and there is good linear relationship between the strength of KCS and discharge of the stream at various time scales.Therefore,how to monitor the discharge accurately is the key to the estimation of KCS.And stations with real-time monitoring function are very important for KCS calculation because of strong seasonal variability of the karst water cycle. 展开更多
关键词 karst carbon sequestration monitoring Banzhai subterranean stream discharge RAINFALL HCO3^-
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RESEARCH ON THE SPATIAL STRUCTURE OF KARST MASSIF——Taking the Basin of the Houzhai Subterranean Stream in Puding Country for Example
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作者 张兆干 张建新 +1 位作者 杨剑民 申屏 《Chinese Geographical Science》 SCIE CSCD 1998年第3期65-72,共0页
Eight spatial structure types are determined through morphology, hydrogeology, hydrology and impulse response in karst districts, with the well studied Houzhai subterranean stream in Puding, Guizhou Province as a samp... Eight spatial structure types are determined through morphology, hydrogeology, hydrology and impulse response in karst districts, with the well studied Houzhai subterranean stream in Puding, Guizhou Province as a sample research area. These types contain peak forest basin, peak forest laterite platform, resurrected peak forest basin, old peak forest funnel depression, peak forest funnel, peak forest funnel depression, peak cluster valley and peak forest doline. In the area, each of them has its respective surface and subterranean structural feature, and morphology, hydrogeology, hydrology and impulse response as well. The difference of responses of subsurface system in different spatial structure types are obtained by time series analysis, frequency spectrum research and decline curve calculation of material current. According to the analysis of the aquifer feature, the upper reaches of suburfall stream is dominated by pipeline flow, the lower reaches is characterized by braided fissure flow drainage system and mixed characteristic exists in the middle reaches. The result of the impulse test shows that the large ascending range of stage in the test on swash condition is in fissure system. However, in pipeline type, especially in the subterranean stream where there is waterfall or incomplete fill of underground water, the ascending range of stage is one quantity level less than the impulse range of stage at some fissure types, showing that change range of stage can indicate the spatial structure characteristics of certain area upper the station. The main direction of karst geomorphic evolution there is positive course except in the west area. It can be seen that karst geomorphological evolution direction can change when discharge datum plane influences some part of a relatively large drainage. In certain time unit, the upper reaches are controlled by old datum plane and the lower reaches by new datum plane. Two opposite geomorphological evolution directions can exist in one drainage. 展开更多
关键词 KARST MASSIF SPATIAL STRUCTURE geomorphic evolution subterranean STREAM Puding
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Molecular identification of Taenia mustelae cysts in subterranean rodent plateau zokors(Eospalax baileyi)
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作者 Fang ZHAO Jun-Ying MA +4 位作者 Hui-Xia CAI Jian-Ping SU Zhi-Bin HOU Tong-Zuo ZHANG Gong-Hua LIN 《Zoological Research》 CAS CSCD 北大核心 2014年第4期313-318,共6页
Cestode larvae spend one phase of their two-phase life cycle in the viscera of rodents, but cases of cestodes infecting subterranean rodents have only been rarely observed. To experimentally gain some insight into thi... Cestode larvae spend one phase of their two-phase life cycle in the viscera of rodents, but cases of cestodes infecting subterranean rodents have only been rarely observed. To experimentally gain some insight into this phenomenon, we captured approximately 300 plateau zokors(Eospalax baileyi), a typical subterranean rodent inhabiting the Qinghai-Tibet Plateau, and examined their livers for the presence of cysts. Totally, we collected five cysts, and using a mitochondrial gene(cox1) and two nuclear genes(pepck and pold) as genetic markers, we were able to analyze the taxonomy of the cysts. Both the maximum likelihood and Bayesian methods showed that the cysts share a monophyly with Taenia mustelae, while Kimura 2-parameter distances and number of different sites between our sequences and T. mustelae were far less than those found between the examined sequences and other Taeniidae species. These results, alongside supporting paraffin section histology, imply that the cysts found in plateau zokors can be regarded as larvae of T. mustelae, illustrating that zokors are a newly discovered intermediate host record of this parasite. 展开更多
关键词 ENDOPARASITES New host record Phylogenetic relationships subterranean rodent
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Characteristics Research of Immersed and Waterlogged Subterranean River System of Reservoir Areas of Hydroelectric Stations
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作者 Li Wenxing Department of Civil Engineering, Guilin Institute of Technology, Guilin 54 1004 《Journal of China University of Geosciences》 SCIE CSCD 2003年第1期79-84,共6页
The karst immersion and waterlogging is one of the typical and the m os t harmful natural disasters in southern karst areas of China. It is threat to th e local production and life for a long time. In recent years, du... The karst immersion and waterlogging is one of the typical and the m os t harmful natural disasters in southern karst areas of China. It is threat to th e local production and life for a long time. In recent years, due to the constru ction of more reservoirs, the disaster became serious. This article takes immers ion and waterlogging of Banwen's subterranean rivers in Yantan reservoir area as an example, researches the daily rainfall's reflection to the water level of re servoir depression, discusses characteristics of immersion and waterlogging of t he valley, analyzes the disaster index in detail, such as water level process, t he highest water level, sensitive rainfall, original waterlogged rainfall and de layed day numbers etc., and provides the reference as a basis to the disaster an alysis. 展开更多
关键词 reservoir areas of hydroelectric station subterranean river system immersed and waterlogged characteristic.
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Electrical Performance and Effect of Frequency Electromagnetic Waves on Subterranean Termites <i>Coptotermes curvignathus</i>Holmgren
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作者 Seno D. Panjaitan Farah Diba +1 位作者 Ferry Hadary Tsuyoshi Yoshimura 《Journal of Electromagnetic Analysis and Applications》 2014年第1期1-7,共7页
The research aimed to propose a non-destructive technology to control subterranean termites Coptotermes curvignathus Holmgren infestation based on electromagnetic waves. A portable apparatus for this technology has be... The research aimed to propose a non-destructive technology to control subterranean termites Coptotermes curvignathus Holmgren infestation based on electromagnetic waves. A portable apparatus for this technology has been built and its experiment is presented in this paper. Some electrical parameters were measured and analyzed along with their effects to the termites. The experiment using frequency range between 30 Hz - 600 kHz has been done. The average error of the apparatus by comparing the result with the direct measurement using oscilloscope was also measured. The highest error value appeared at 600 kHz with frequency error 6.05 kHz. The highest error of voltage (i.e. 0.186 Volt) appeared at 100 kHz. For safetiness, the highest magnetic field at 300 kHz was 0.1815 μT and at 500 kHz was 0.00725 μT which were safe for human. The average value of termites mortality was higher on irradiation time 120 minutes than 60 minutes respectively in all test frequency: 300 kHz, 400 kHz, 500 kHz and 600 kHz. This paper presents an important information of the electromagnatic-based technology for environmental friendly termites control in spite of using the insecticides. 展开更多
关键词 Electromagnetic Waves FREQUENCY subterranean TERMITES COPTOTERMES curvignathus TERMITES Infestation
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Relationship Between Rate of Intake and Daily Intake of Dry,Mature Subterranean Clovers by Sheep
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《畜牧与饲料科学》 1997年第S1期161-172,共2页
关键词 Relationship Between Rate of Intake and Daily Intake of Dry Mature subterranean Figure Clovers by Sheep
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塔里木盆地塔河油田逆冲背斜区奥陶系古暗河系统发育特征
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作者 张长建 蒋林 +2 位作者 文欢 吕晶 昌琪 《石油实验地质》 CAS CSCD 北大核心 2024年第2期333-341,共9页
塔里木盆地塔河油田古暗河系统研究尚处于初始阶段,主要从暗河的深浅分布、结构样式等特征开展暗河洞穴的划分,较少从构造、断裂、古地貌、地下水位等地质方面综合分析复杂暗河系统的空间发育规律,致使暗河的主次从属关系、空间叠置样... 塔里木盆地塔河油田古暗河系统研究尚处于初始阶段,主要从暗河的深浅分布、结构样式等特征开展暗河洞穴的划分,较少从构造、断裂、古地貌、地下水位等地质方面综合分析复杂暗河系统的空间发育规律,致使暗河的主次从属关系、空间叠置样式、原始连通关系难以厘清,从而制约了塔河油田开发后期的综合治理研究。为了明确塔河油田主体区逆冲背斜区奥陶系古暗河系统发育特征,利用构造断裂解析、古地貌恢复、地震属性刻画、纵断剖面解读等方法进行了S67井区古暗河的类型识别、系统划分和地质成因研究,尤其首次识别并剖析了潜流回流暗河。结果表明,S67井区处于塔河主体区岩溶台原南缘的低地势区,发育幅差较小的峰丛洼地、溶丘洼地,地表水系下切深度较浅;逆冲背斜为低角度逆冲推覆构造样式,逆冲背斜之上的网格状断裂为多层状暗河系统提供有利溶蚀通道。研究区奥陶系发育相对独立的、树枝状结构的地下水位暗河系统和潜流带暗河系统,地下水位型暗河可分为主干型、支流型和废弃型,潜流回流暗河可分为上升型、对称型。控制逆冲背斜区古暗河发育的主要因素有古地貌、地下水位、逆冲背斜构造和次级断裂网络等。 展开更多
关键词 走滑断裂 逆冲断裂 古地貌 暗河 潜流回路 地下水位 奥陶系 塔河油田
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基于开源GemPy的城市地下空间三维隐式势场建模方法研究
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作者 廖舟 李梅 《地学前缘》 EI CAS CSCD 北大核心 2024年第3期482-497,共16页
三维地质建模是城市地下空间规划和管理的重要基础工作。在地质科学大数据时代,当前三维建模逐渐转向三维隐式建模。常见的三维地质建模软件如GeoModeller、Surpac等都提供了隐式建模技术,但是上述商业软件均封装完好、并不开源。本文... 三维地质建模是城市地下空间规划和管理的重要基础工作。在地质科学大数据时代,当前三维建模逐渐转向三维隐式建模。常见的三维地质建模软件如GeoModeller、Surpac等都提供了隐式建模技术,但是上述商业软件均封装完好、并不开源。本文基于开源GemPy建模平台,重点实现了三维隐式势场建模技术与针对地层尖灭的建模方案,将算法方案加入GemPy底层建模架构,并以某城市地下空间为例,对三维地质精细化建模工程流程进行了验证。论文构建了基于研究区钻孔数据的建模数据集,采用势场法和泛克立格插值法建立城市三维地质模型,并针对城市地质中常见的地层尖灭进行了单独的布尔运算处理。为细致直观展示研究区三维地质模型地层界面的拟合情况,对共计18个工程地质层分别进行可视化。最后,对模型的精度采用分层K折交叉验证方法进行验证,并用皮尔逊相关系数(CC)等4种指标对建模效果进行衡量。对研究区的实验结果表明,基于开源GemPy的三维隐式势场地质建模方法针对城市地质构造具有一定通用性,并在精度上具有较好效果,可以为城市地下空间开发利用提供决策依据。 展开更多
关键词 三维地质建模 隐式势场法 GemPy 地层尖灭 城市地下空间
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Attenuation of arsenic in a karst subterranean stream and correlation with geochemical factors: A case study at Lihu,South China 被引量:5
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作者 Liankai Zhang Hui Yang +2 位作者 Jiansheng Tang Xiaoqun Qin Au Yik Yu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2014年第11期2222-2230,共9页
Arsenic (As) pollutants generated by human activities in karst areas flow into subterranean streams and contaminate groundwater easily because of the unique hydrogeological characteristics of karst areas. To elucida... Arsenic (As) pollutants generated by human activities in karst areas flow into subterranean streams and contaminate groundwater easily because of the unique hydrogeological characteristics of karst areas. To elucidate the reaction mechanisms of arsenic in karst subterranean streams, physical-chemical analysis was conducted by an inductively coupled plasma mass spectrometer and an X-ray fluorescence spectrometer. The results show that inorganic species account for most of the total arsenic, whereas organic arsenic is not detected or occurs in infinitesimal amounts. As(III) accounts for 51.0% ± 9.9% of the total inorganic arsenic. Arsenic attenuation occurs and the attenuation rates of total As, As(III) and As(V) in the Lihu subterranean stream are 51%, 36% and 59%, respectively. To fully explain the main geochemical factors influencing arsenic attenuation, SPSS 13.0 and CANOCO 4.5 bundled with CanoDraw for Windows were used for simple statistical analysis and redundancy analysis (RDA). Eight main factors, i.e., sediment iron (SFe), sediment aluminum (SAI), sediment calcium (SCa), sediment organic matter (SOM), sediment manganese (SMn), water calcium (WCa^2+), water magnesium (WMg^2+), and water bicarbonate ion (WILCOX) were extracted from thirteen indicators. Their impacts on arsenic content rank as: SFe〉SCa〉WCa^2+〉SAl〉wHCO3^-〉SMn〉SOM〉WMg^2+. Of these factors, SFe, SAl, SCa, SOM, SMn, WMg^2+ and WCa&2+ promote arsenic attenuation, whereas WHCO3^- inhibits it. Further investigation revealed that the redox potential (Eh) and pH are adverse to arsenic removal. The dramatic distinction between karst and non-karst terrain is that calcium and bicarbonate are the primary factors influencing arsenic migration in karst areas due to the high calcium concentration and alkalinity of karst water. 展开更多
关键词 Karst subterranean stream Sediment Arsenic Geochemical factors Redundancy analysis
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Tunnel geometry of the subterranean termite Reticulitermes grassei (Isoptera: Rhinotermitidae)in response to sand bulk density and the presence of food 被引量:1
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作者 TANIA NOBRE LINA NUNES DAVID E. BIGNELL 《Insect Science》 SCIE CAS CSCD 2007年第6期511-518,共8页
The cryptic habits of subterranean termites restricts detailed analysis of their foraging patterns in situ, but the process is evidently dominated by tunnel constructions connecting the nest with woody resources disco... The cryptic habits of subterranean termites restricts detailed analysis of their foraging patterns in situ, but the process is evidently dominated by tunnel constructions connecting the nest with woody resources discovered within the territory of each colony. In this study, tunnel formation and orientation were studied experimentally in the termite Reticulitermes grassei (Clement), using 2-dimensional laboratory foraging arenas con- taining fine sand as the substratum. The building of exploratory tunnels over a 10-day period and the geometry of the resulting network are described. Fractal analysis showed that tunnel geometry had a fractal dimension, regardless of the total length tunnelled whether foragers encountered the food source or not. The bulk density of the sand in the arenas affected the distances tunnelled, with higher density reducing construction, but did not affect tunnel geometry. Tunnels were not discernibly orientated with respect to the positioning of the food source, even in a situation where termites had failed to find the food source at a distance of less than 50 mm, suggesting that volatiles from wood are not attractants. 展开更多
关键词 foraging gallery fractal analysis Reticulitermes grassei search pattern subterranean termites tunnel geometry
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Redefinition to bilayer osmotic pump tablets as subterranean river system within mini-earth via three-dimensional structure mechanism 被引量:1
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作者 Abi Maharjan Hongyu Sun +11 位作者 Zeying Cao Ke Li Jinping Liu Jun Liu Tiqiao Xiao Guanyun Peng Junqiu Ji Peter York Balmukunda Regmi Xianzhen Yin Jiwen Zhang Li Wu 《Acta Pharmaceutica Sinica B》 SCIE CAS CSCD 2022年第5期2568-2577,共10页
Defining and visualizing the three-dimensional(3 D) structures of pharmaceuticals provides a new and important tool to elucidate the phenomenal behavior and underlying mechanisms of drug delivery systems. The mechanis... Defining and visualizing the three-dimensional(3 D) structures of pharmaceuticals provides a new and important tool to elucidate the phenomenal behavior and underlying mechanisms of drug delivery systems. The mechanism of drug release from complex structured dosage forms, such as bilayer osmotic pump tablets, has not been investigated widely for most solid 3 D structures. In this study, bilayer osmotic pump tablets undergoing dissolution, as well as after dissolution in a desiccated solid state were examined, and visualized by synchrotron radiation micro-computed tomography(SR-μCT). In situ formed 3 D structures at different in vitro drug release states were characterized comprehensively. A distinct movement pattern of NaCl crystals from the push layer to the drug layer was observed, beneath the semi-permeable coating in the desiccated tablet samples. The 3 D structures at different dissolution time revealed that the pushing upsurge in the bilayer osmotic pump tablet was directed via peripheral“roadways”. Typically, different regions of the osmotic front, infiltration region, and dormant region were classified in the push layer during the dissolution of drug from tablet samples. According to the observed3 D microstructures, a “subterranean river model” for the drug release mechanism has been defined to explain the drug release mechanism. 展开更多
关键词 Bilayer osmotic pump tablet Synchrotron radiation micro-computed tomography Three-dimensional microstructure Release kinetics Void formation Peripheral“roadways” Push-pull model subterranean river model
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密植滴灌技术对玉米根系的影响
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作者 马斐 李娜 余海兵 《安徽农学通报》 2024年第17期14-17,共4页
本试验以玉米品种郑单958、安科985和黄金粮MY73为材料,研究在滴灌和常规施肥条件下,不同种植密度(6.75万、8.25万、9.00万、9.75万和10.50万株/hm^(2))对玉米根系生长的影响。结果表明,随着玉米种植密度的增加,玉米根系干重、气生根和... 本试验以玉米品种郑单958、安科985和黄金粮MY73为材料,研究在滴灌和常规施肥条件下,不同种植密度(6.75万、8.25万、9.00万、9.75万和10.50万株/hm^(2))对玉米根系生长的影响。结果表明,随着玉米种植密度的增加,玉米根系干重、气生根和地下根数均呈降低趋势;不同施肥方式对玉米根系生长的影响有所不同,滴灌施肥技术能够促进玉米根系生长;品种黄金粮MY73的根系性状表现较好。栽植密度6.75万株/hm^(2)、滴灌施肥有助于促进玉米根系生长发育。 展开更多
关键词 滴灌施肥 常规施肥 气生根 地下根
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陕西泾阳蒋刘遗址2021年发掘简报
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作者 邵晶 裴学松 +2 位作者 袁媛(照相/执笔) 王学文(绘图) 韩飞(绘图) 《考古与文物》 CSSCI 北大核心 2024年第1期3-12,共10页
蒋刘遗址位于陕西省咸阳市泾阳县蒋刘乡蒋刘村东北侧,为一处仰韶晚期大型环壕聚落。2021年,陕西省考古研究院对该遗址进行了发掘,发现大量窖穴、陶窑、瓮棺葬等遗迹,出土了年代集中、数量丰富的仰韶晚期遗物。通过此次发掘,明确了遗址... 蒋刘遗址位于陕西省咸阳市泾阳县蒋刘乡蒋刘村东北侧,为一处仰韶晚期大型环壕聚落。2021年,陕西省考古研究院对该遗址进行了发掘,发现大量窖穴、陶窑、瓮棺葬等遗迹,出土了年代集中、数量丰富的仰韶晚期遗物。通过此次发掘,明确了遗址的南部边界,初步确定了遗址的储藏区和陶器生产区,为探讨泾河流域仰韶文化分期、仰韶文化中晚期过渡、聚落布局和形态特征、社会发展进程等问题提供了新的资料。 展开更多
关键词 蒋刘遗址 仰韶晚期 窖穴 陶窑 瓮棺葬
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Seasonal metal fluxes derived by the interaction of surface water and groundwater in an aquaculture estuary
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作者 Xiaoxiong Wang Jordi Garcia-Orellana +5 位作者 Xiaogang Chen Jianan Liu Fenfen Zhang Jianguo Qu Zhuoyi Zhu Jinzhou Du 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第8期113-124,共12页
Submarine groundwater discharge(SGD)plays a major role as a conveyor of metals to coastal waters.However,the seasonal change of metal fluxes derived through SGD is unclear.Here,we evaluated the behaviours and fluxes o... Submarine groundwater discharge(SGD)plays a major role as a conveyor of metals to coastal waters.However,the seasonal change of metal fluxes derived through SGD is unclear.Here,we evaluated the behaviours and fluxes of trace metals(Mn,Fe,Ba,Pb,U,Cr,Zn,Cu)in an estuary under different seasonal conditions.The behaviours of trace metals revealed that SGD was the source of Mn(3.51 mmol/(m^(2)·d)),Fe(0.174 mmol/(m^(2)·d))and Ba(0.024 mmol/(m^(2)·d)),but the Cu sink(−0.55μmol/(m^(2)·d))and other metals exhibited a seasonal source‒sink conversion.The seasonal variation of dissolved organic matter and the fresh groundwater proportion in subterranean estuaries may have an important effect on metals fluxes especially for the Fe,Mn and Ba.Our result shows that the single seasonal metal fluxes estimation applied to the annual scale will cause a large deviation,up to 3.6 times for Fe,5.5 times for Mn,and 15 times for Ba.Therefore,the influence of seasonal fluctuations on SGDderived metal fluxes cannot be ignored,and our findings will be important for comprehending the metal budget and cycle in nearshore environment. 展开更多
关键词 subterranean estuary seawater intrusion heavy metals seasonal changes coastal management
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MODFLOW岩溶暗河及出口的概化与模拟效果
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作者 张子琦 许模 +2 位作者 曹聪 张强 夏强 《地质科技通报》 CAS CSCD 北大核心 2023年第4期250-258,共9页
在MODFLOW的三维渗流模拟程序集中,Conduit Flow Process(CFP)模块已被广泛用于模拟岩溶含水层中的管道流,是岩溶地下水流模拟的重要工具。使用CFP模块概化暗河管道时,暗河出口的概化有2种方案:将暗河出口设置在管道模型中(FH方案)或等... 在MODFLOW的三维渗流模拟程序集中,Conduit Flow Process(CFP)模块已被广泛用于模拟岩溶含水层中的管道流,是岩溶地下水流模拟的重要工具。使用CFP模块概化暗河管道时,暗河出口的概化有2种方案:将暗河出口设置在管道模型中(FH方案)或等效多孔介质中(Dr方案),其模拟效果有待评价。以重庆缙云山姜家龙洞暗河为例,建立了考虑管道流的地下水流数值模型,分别使用2种方案概化了暗河出口,对比分析了稳定流和非稳定流的模拟结果。结果表明:以排水沟(Drain)模块概化暗河出口的Dr方案,暗河管道的上游段排泄地下水,下游段反而补给含水层,最终在排水沟单元排泄,而定水头(Fix Head)概化的FH方案则准确模拟了暗河全段汇集地下水并在出口排泄出含水层的实际情况。进一步的水均衡分析揭示了模拟差异产生的原理。在模拟岩溶区地下水向暗河管道汇集的水文过程时,如果使用CFP概化管道,则宜配合使用CFP中的定水头边界概化暗河出口。 展开更多
关键词 岩溶管道 管道-等效多孔介质耦合模型 MODFLOW-CFP 暗河
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