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No change over three decades in the realized spatial niche of a salamander population living in a subterranean habitat
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作者 Sebastiano Salvidio Andrea Costa +2 位作者 Fabrizio Oneto Giacomo Rosa Mauro Valerio Pastorino 《Current Zoology》 2025年第5期678-681,共4页
Subterranean environments are buffered from external climatic fluctuations due to the absence of light and a delayed thermal response to surface conditions(Mammola 2019).Terrestrial salamanders are often found in subt... Subterranean environments are buffered from external climatic fluctuations due to the absence of light and a delayed thermal response to surface conditions(Mammola 2019).Terrestrial salamanders are often found in subterranean habitats,but few studies have assessed the influence of climatic effects on their long-term spatial distribution and niche breadth.In this study,we investigated the variability over 29 consecutive years of the spatial niche in a terrestrial salamander population inhabiting an artificial subterranean habitat.We hypothesized that juvenile salamanders,which are typically active near cave entrances and more exposed to climatic variability and dehydration(Peterman et al.2013),would exhibit an earlier and more variable behavioral adaptation to increasing external temperatures compared to adults. 展开更多
关键词 long-term ecological research niche breadth PLETHODONTIDAE Speleomantes subterranean habitat
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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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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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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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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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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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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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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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哈民忙哈半地穴房址的空间构建方式研究
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作者 钱耀鹏 邓悦 《考古与文物》 北大核心 2025年第9期70-77,共8页
房屋建筑的空间构建方式是微观聚落考古研究的重要内容之一。该文以哈民忙哈遗址突然废弃的半地穴房址为对象,通过穴壁立柱划分出不同类别,借鉴传统木构件特征辨析了残断炭化木构件的属性。进而以半地穴面积为据,并参考人体工程及建材... 房屋建筑的空间构建方式是微观聚落考古研究的重要内容之一。该文以哈民忙哈遗址突然废弃的半地穴房址为对象,通过穴壁立柱划分出不同类别,借鉴传统木构件特征辨析了残断炭化木构件的属性。进而以半地穴面积为据,并参考人体工程及建材长度规格,系统分析了中小型半地穴房屋的三维空间构建方式,提出哈民忙哈遗址可能存在攒尖顶和平顶(或囤顶)两种结构形式。这对于认识史前建筑形式演进具有重要启发意义。 展开更多
关键词 哈民忙哈遗址 半地穴房址 空间构建 屋顶结构
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河北阳原姜家梁遗址早期遗存发掘简报
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作者 李君 徐永江(绘图) +5 位作者 马楠(绘图) 安婧(摄影) 兰智雄(摄影) 张乃馨 李云飞 张文瑞 《考古与文物》 北大核心 2025年第3期3-15,共13页
姜家梁遗址位于河北省张家口市阳原县东城镇西水地村。1995、1998年,在发掘姜家梁遗址时清理了被墓葬打破的14座半地穴式房址,其中9座房址位于I区,5座房址位于Ⅱ区,房址间无叠压打破关系。根据出土遗物、测年数据以及与姜家梁墓葬的叠... 姜家梁遗址位于河北省张家口市阳原县东城镇西水地村。1995、1998年,在发掘姜家梁遗址时清理了被墓葬打破的14座半地穴式房址,其中9座房址位于I区,5座房址位于Ⅱ区,房址间无叠压打破关系。根据出土遗物、测年数据以及与姜家梁墓葬的叠压打破关系可知,房址年代为新石器时代中期,远远早于墓葬,二者文化内涵区别较大,分属于不同的考古学文化。该批房址的发现,填补了前仰韶时代桑干河流域古人类居址的空白,也为研究该区域的古人类生存模式、文化互动与交流提供了新的材料。 展开更多
关键词 河北阳原县 姜家梁遗址 半地穴式房址 新石器时代中期
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Three new species of Dentisphaera from Southern China(Gastropoda:Stylommatophora:Hypselostomatidae)
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作者 Zheyu Chen Liwen Lin +2 位作者 Yutong Ding Jozef Grego Barna Pall-Gergely 《Zoological Systematics》 2025年第2期150-158,共9页
Dentisphaera Páll-Gergely&Jochum,2017 is a troglobitic land snails genus known to harbour only one species found in a single cave in North Vietnam.Based on recently collected specimens from China,three specie... Dentisphaera Páll-Gergely&Jochum,2017 is a troglobitic land snails genus known to harbour only one species found in a single cave in North Vietnam.Based on recently collected specimens from China,three species,Dentisphaera lagredeae Chen,Grego&Páll-Gergely,sp.nov.,Dentisphaera shzha Chen,Grego&Páll-Gergely,sp.nov.and Dentisphaera zhoui Chen,Lin&Páll-Gergely,sp.nov.are introduced as new to science.The distribution range of Dentisphaera is extended based on the collecting records of these new species. 展开更多
关键词 China microsnails new taxa subterranean biodiversity taxonomy
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密实细砂层地铁暗挖隧道新型超前加固材料性能及注浆参数研究 被引量:1
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作者 陈铖 来弘鹏 +1 位作者 刘禹阳 朱新健 《岩土工程学报》 北大核心 2025年第7期1432-1442,共11页
为降低超前注浆加固对地铁暗挖隧道地层环境影响,注浆要求低压缓注。密实细砂层结构紧密、黏粒含量高,导致现有注浆材料在低注浆压力下扩散半径小,无法有效加固隧道掌子面。基于组分活性激发及颗粒尺寸优化理念,以矿渣微粉、超细粉煤灰... 为降低超前注浆加固对地铁暗挖隧道地层环境影响,注浆要求低压缓注。密实细砂层结构紧密、黏粒含量高,导致现有注浆材料在低注浆压力下扩散半径小,无法有效加固隧道掌子面。基于组分活性激发及颗粒尺寸优化理念,以矿渣微粉、超细粉煤灰为主体,掺入适量超细水泥及复合激活凝聚剂,制备了新型注浆材料。通过室内试验,探究了不同配合比、复合激活凝聚剂掺量影响下新型注浆材料浆液流动度、凝结时间及结石体强度变化特性。采用自主研制的小导管注浆足尺试验装置,对比分析了普通水泥、超细水泥及新型注浆材料加固效果,揭示了上覆荷载与含水率影响下新型材料浆液扩散特性及注浆终压变化规律。研究结果表明:水固比为1∶1、矿渣微粉、超细粉煤灰及超细水泥质量比为4∶2∶4,复合激活凝聚剂掺量4%时,新型注浆材料浆液流动性最优、凝结时间可控、结石体强度较高;采用小导管注浆加固时,普通水泥浆液在密实细砂层以压密扩散为主、超细水泥浆液以压密-劈裂为主,新型材料则以渗透-劈裂方式进行扩散。新型注浆材料扩散性能及加固效果最优,超细水泥次之,普通水泥最差;注浆前期,新型材料应保持低压注浆,防止注浆量过大,引起砂土局部劈裂,造成加固失效的问题;新型材料注浆终压随上覆荷载及含水率的增加呈线性增长,上覆荷载增加50 kPa,注浆压力增大50 kPa左右。含水率增加2%,注浆压力增加量约为40 kPa。研究结果对注浆加固工程理论研究及工程应用有一定指导意义。 展开更多
关键词 地铁隧道 浅埋暗挖法 密实细砂层 小导管注浆加固 浆液扩散特性 注浆参数
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土栖白蚁巢穴被动声波探测技术的室内试验研究
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作者 程森浩 邓刚 +3 位作者 侯伟亚 张延亿 张茵琪 李维朝 《中国水利水电科学研究院学报(中英文)》 北大核心 2025年第2期106-111,120,共7页
土栖白蚁在堤坝上挖穴筑巢严重危害堤坝安全,准确找到巢穴位置是处置的前提和关键,接收并分析蚁穴发出的声波是一条可能的巢穴探测定位技术路线。实验室中采集黄翅大白蚁和黑翅土白蚁巢穴周边的声波脉冲信号,幅值分别为0.075 m/s~2和0.0... 土栖白蚁在堤坝上挖穴筑巢严重危害堤坝安全,准确找到巢穴位置是处置的前提和关键,接收并分析蚁穴发出的声波是一条可能的巢穴探测定位技术路线。实验室中采集黄翅大白蚁和黑翅土白蚁巢穴周边的声波脉冲信号,幅值分别为0.075 m/s~2和0.015 m/s~2,脉冲之间有明显的间隔,单个脉冲持续时间约0.01 s,可以利用程序进行识别。在距离巢穴一定位置非共线布置4支传感器,提取各传感器采集到的100 Hz~1000 Hz之间的声波脉冲信号,标记不同传感器采集信号中的相同峰值,利用各信号到达传感器的时间差可定位蚁穴位置,误差小于蚁穴直径。按照室内试验思路,在堤坝现场巢穴附近布置多支传感器,通过量测到的白蚁巢穴声波信号,预期可以较好实现巢穴的定位。 展开更多
关键词 土栖白蚁 蚁穴 声波脉冲 探测定位 室内试验
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黄土高原地下啮齿类动物挖掘对土壤侵蚀的贡献
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作者 白晓亮 耿豪鹏 +2 位作者 刘茹 程维明 潘保田 《地理学报》 北大核心 2025年第5期1327-1338,共12页
地下啮齿类动物挖掘活动是影响坡面土壤再分配和土壤侵蚀的因素之一,对其进行深入研究有助于理解土壤侵蚀的复杂机制。为探究黄土高原地下啮齿类动物挖掘活动的空间分布特征及对土壤侵蚀的影响,本文对位于黄土高原中部的庆阳市环县平顶... 地下啮齿类动物挖掘活动是影响坡面土壤再分配和土壤侵蚀的因素之一,对其进行深入研究有助于理解土壤侵蚀的复杂机制。为探究黄土高原地下啮齿类动物挖掘活动的空间分布特征及对土壤侵蚀的影响,本文对位于黄土高原中部的庆阳市环县平顶山一处典型坡面(665 m^(2))进行了为期6个月的定点重复监测,采用无人机航测结合野外调查,追踪了地下啮齿类动物挖掘活动的空间分布,分析了挖掘活动对土壤性质的影响,并量化了研究坡面内挖掘活动引起的土壤侵蚀量。结果显示:(1)地下啮齿类动物采食活动和掘穴活动均偏好于分布在坡度较缓、流水分散区和凸形坡区域。(2)与未扰动土壤相比,挖掘活动产生的土丘容重降低了14%(P<0.05),孔隙度和饱和导水率均增加了11%(P<0.05)。(3)观测期内地下啮齿类动物的挖掘活动将0.13 t的土壤翻覆至地表,土壤再分配对应的坡面搬运通量约为2.18 cm^(3)/(cm·a)。如果全部转化为土壤侵蚀,其侵蚀模数约为397 t/(km^(2)·a)。上述结果表明挖掘活动是黄土高原坡面土壤再分配的重要营力之一,大约贡献了土壤侵蚀总量的10.1%,需要在今后的水土流失评估与模型计算中予以关注。 展开更多
关键词 地下啮齿类动物 挖掘活动 土壤侵蚀 黄土高原
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地下封闭水体内多无人艇协同的视觉定位方法
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作者 车文博 王建华 +3 位作者 郑翔 吴恭兴 张舜 王浩铸 《计算机应用》 北大核心 2025年第1期325-336,共12页
针对无人艇(USV)在地下封闭水体中卫星定位信号缺失、通信受限、环境光线弱等问题,提出一种地下封闭水体内多USV协同的视觉定位方法。首先,设计一种艇载光源合作标志物,并根据艇身结构与应用场景对标志物结构进行优化;其次,采用单目视... 针对无人艇(USV)在地下封闭水体中卫星定位信号缺失、通信受限、环境光线弱等问题,提出一种地下封闭水体内多USV协同的视觉定位方法。首先,设计一种艇载光源合作标志物,并根据艇身结构与应用场景对标志物结构进行优化;其次,采用单目视觉采集标志物图像,并求取特征点的图像坐标;再次,根据摄像机成像模型,基于合作标志物特征点的空间坐标及其对应的图像坐标之间的关系,通过改进直接线性变换方法求解相邻艇间的相对位置;然后,利用前后艇的摄像机进行艇间对视,并通过最小方差算法,融合根据前后艇摄像机图像求解所得的相对位置,以提高相对定位精度;最后,利用场景中已知的绝对坐标,获得各无人艇的绝对位置。仿真实验对影响定位误差的因素进行分析,并把所提方法与传统直接线性变换方法进行对比。结果表明,随着距离的增加,所提方法求解优势更趋明显,在距离15 m时求解的位置方差稳定在0.2 m~2以内,验证了所提方法的准确性。静态实验结果表明,所提方法能将相对误差稳定在10.0%以内;地下河道内的动态实验结果表明,所提方法求解的绝对定位的航行轨迹达到与卫星定位相当的精度,验证了所提方法的可行性。 展开更多
关键词 水面无人艇 协同定位 单目视觉 合作标志物 地下封闭水体
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