Evaluation of the virulence of entomopathogenic fungus, Isaria fumosorosea isolates against subterranean termites Coptotermes spp.(Isoptera:Rhinotermitidae)

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.

The Utilization of Real-Time High Resolution Monitoring Techniques in Karst Carbon Sequestration:A Case Study of the Station in Banzhai Subterranean Stream Catchment

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.

RESEARCH ON THE SPATIAL STRUCTURE OF KARST MASSIF——Taking the Basin of the Houzhai Subterranean Stream in Puding Country for Example

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.

Subterranean-SAE 算法的条件立方攻击

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.

Characteristics Research of Immersed and Waterlogged Subterranean River System of Reservoir Areas of Hydroelectric Stations

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.

Electrical Performance and Effect of Frequency Electromagnetic Waves on Subterranean Termites <i>Coptotermes curvignathus</i>Holmgren

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.

Developmental environment contributes to rapid trait shifts among newly colonized subterranean habitats

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.

Microbiota of a seepage face at the mouth of a subterranean estuary:diversity,distribution and substrate dependence

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.

Molecular identification of Taenia mustelae cysts in subterranean rodent plateau zokors(Eospalax baileyi)

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.

Spatial distribution and export of nutrients and metal elements in the subterranean estuary of Daya Bay

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.

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

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。

基于开源GemPy的城市地下空间三维隐式势场建模方法研究

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。

密植滴灌技术对玉米根系的影响

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。

陕西泾阳蒋刘遗址2021年发掘简报

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。

基于PLAXIS-BP神经网络的暗挖隧道地表沉降预测

为研究浅埋暗挖隧道施工过程中多因素联合作用对地表沉降的影响,准确评估施工风险,基于离心模型试验实测数据,将有限元软件PLAXIS^(3D)与BP神经网络学习算法相结合,建立了饱和黏土地层隧道暗挖施工地表沉降预测模型。通过调节BP神经网络中的隐含层层数和节点数,得到最优神经网络结构,通过增加验证集和敏感性分析进行二次验证,并进行了特征重要性分析,量化各因素对最大地表沉降的影响程度。结果表明:通过调节BP神经网络超参数,所建模型误差小于5%,满足工程精度要求,且预测沉降变化趋势符合工程实际。

重庆岩溶地下河水文地球化学特征及环境意义

岩溶地下河系统是岩溶地区重要的地下水资源,重庆地区分布有岩溶地下河380条,是重庆市重要的地下水资源。为宏观掌握重庆地区岩溶地下河水化学特征,了解区域岩溶地下河水化学影响因素及分布规律,研究了重庆不同地区61条岩溶地下河水文地球化学特征。结果表明,重庆地区岩溶地下河的溶解组分主要来源于碳酸盐岩的溶解,水化学类型为Ca-HCO3型或Ca(Mg)-HCO3型,但部分地下河水化学受到人类活动影响变为Na+Ca-HCO3型、Na+Ca-SO4型、Na+Ca-Cl型或Ca-SO4+HCO3型,且农业活动或城市废水对地下河水化学的影响比工矿业活动普遍。地下河水温度随海拔升高而逐渐降低。在相同的地质背景下,地下河Ca2+、Mg2+、HCO3-等离子由于受不同区域岩溶作用强度差异的影响呈现出明显的区域性,SO42-、NO3-、Cl-等指标由于受不同区域人类活动强度和方式的影响也显示出明显的区域性。总体来看,岩溶地下河水质正在恶化。

在线技术在岩溶地下水示踪试验中的应用——以青木关地下河系统岩口落水洞至姜家泉段为例

在岩溶水文地质调查的基础上,采用高分辨率野外自动化荧光仪、人工取样和放置活性炭的方法,对青木关地下河系统投放的示踪剂荧光素钠接收情况进行检测。结果表明:(1)姜家泉是青木关地下河系统的主要出口,岩口落水洞投放的示踪剂在姜家泉的回收量为93.9%,初现时间为33.3h,地下水最大视流速为222.2m/h,平均视流速为176.6m/h,众数视流速为172.1m/h,说明本试验段内地下径流为典型的紊流流态,岩溶含水介质极不均匀,可能有规模较大且无岔道的岩溶管道存在;(2)岩口落水洞与大木水窝泉、纸厂泉没有直接的水力联系,出口姜家泉与纸厂泉也无直接的水力联系;(3)野外自动化荧光仪精度和自动化程度高,携带方便,大大节约了试验成本,在我国西南岩溶区的地下水示踪试验中具有较大的推广和应用价值。

降雨条件下岩溶槽谷泉水的水文地球化学特征

在示踪试验判断岩溶含水介质形态的基础上,通过观测降雨条件下姜家泉泉水的电导率、pH值、水温、泉口实时水位、降雨量以及降雨的pH值、钙离子浓度、电导率和计算出的泉水方解石饱和指数及CO2分压,分析了降雨条件下岩溶槽谷泉水文地球化学行为的动态变化。研究结果表明在以管道为主的岩溶含水介质槽谷中,泉水水位随降雨暴涨暴落,其水温、电导率、pH值、方解石饱和指数和CO2分压对降雨响应迅速,能敏锐地感应和反馈环境的变化。酸雨将可能引起泉水pH值的降低和电导率的升高,因而应重视酸雨对岩溶泉水文地球化学行为和岩溶含水介质演化过程的影响。降雨期间雨水将地表土壤带入地下河,引起泉水浊度的升高,表明此时泉水可能受到微生物的污染。

广西主要地下河水质评价及其变化趋势

采用广西境内 32条典型地下河 2 0世纪 70年代末、80年代初和 2 1世纪初两个时期所取的 6 4个水样品的分析结果 ,对地下河水质进行了评价 ,分析了地下河水中主要离子 2 0年来的变化趋势和原因。结果表明 ,地下河水中绝大部分离子和指标符合地下水质量标准 (GB/ T14 84 8- 93)规定的 、 类水质标准 ,地下水质量较好 ,但离子浓度普遍升高 ,水质有恶化倾向。升高最显著的是 SO4 2 - 、NO3- 及总溶解固体 ,HCO3- 、Ca2 + 、Mg2 + 、K+ 、总硬度和永久硬度有所升高 ,Cl- 、p H值有下降趋势。离子浓度的变化是 SO2 、CO2 等酸性气体排放量的剧增、过量施用化肥、石漠化等造成环境酸化的结果。