期刊文献+
共找到60,989篇文章
< 1 2 250 >
每页显示 20 50 100
Characterization of Wnt genes in Argopecten scallops and their involvement in response to different temperature stresses in“Bohai Red”scallops
1
作者 Caihui WANG Shuhua LEI +5 位作者 Min CHEN Junhao NING Xia LU Jinsheng ZHANG Bo LIU Chunde WANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第3期1122-1132,共11页
As“Bohai Red”scallops were originated from the hybrids between the Peruvian scallop(Argopecten purpuratus)and the bay scallop(Argopecten irradians)northern subspecies(Argopecten irradians irradians).Twelve Wnt membe... As“Bohai Red”scallops were originated from the hybrids between the Peruvian scallop(Argopecten purpuratus)and the bay scallop(Argopecten irradians)northern subspecies(Argopecten irradians irradians).Twelve Wnt members were identified from the two subspecies of bay scallop,and 13 Wnt genes were found in the genome of the Peruvian scallop.Protein structure analyses showed that most Wnt genes poses all 5 conserved motifs except Wnt1,Wnt2,Wnt6,and Wnt9 in the bay scallops and Wnt2 and Wnt9 in the Peruvian scallop.Unexpectedly,Wnt8 gene was present while Wnt3 was absent in both the bay scallops and the Peruvian scallop.Phylogenetic analysis revealed that Wnt3 might have disappeared in the early evolution of mollusks.The expression profile of Wnt genes in the“Bohai Red”exposed to different temperatures was examined by qRT-PCR.Results show that expression of Wnt genes responded differentially to temperature changes.The Wnt genes such as Wnt1,Wnt6,Wnt7,Wnt11,and WntA that responded slowly to low and high temperature stresses may be related to the maintenance of basic homeostasis.Other Wnt genes such as Wnt4,Wnt9,Wnt5,and Wnt2 that responded rapidly to low temperature may play an important role in organismal protection against low temperature stress.And yet some Wnt genes including Wnt10,Wnt16,and Wnt8 that responded quickly to high temperature stress may play key roles in response to high temperature stress.The results provide new insights into the evolution and function of Wnt genes in bivalves and eventually benefit culture of“Bohai Red”scallops. 展开更多
关键词 Peruvian scallop bay scallop “bohai red”scallops Wnt gene temperature change QRT-PCR
下载PDF
Geophysical prediction of organic matter abundance in source rocks based on geochemical analysis:A case study of southwestern Bozhong Sag,Bohai Sea,China 被引量:1
2
作者 Xiang Wang Guang-Di Liu +5 位作者 Xiao-Lin Wang Jin-Feng Ma Zhen-Liang Wang Fei-Long Wang Ze-Zhang Song Chang-Yu Fan 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期31-53,共23页
The Bozhong Sag is the largest petroliferous sag in the Bohai Bay Basin,and the source rocks of Paleogene Dongying and Shahejie Formations were buried deeply.Most of the drillings were located at the structural high,a... The Bozhong Sag is the largest petroliferous sag in the Bohai Bay Basin,and the source rocks of Paleogene Dongying and Shahejie Formations were buried deeply.Most of the drillings were located at the structural high,and there were few wells that met good quality source rocks,so it is difficult to evaluate the source rocks in the study area precisely by geochemical analysis only.Based on the Rock-Eval pyrolysis,total organic carbon(TOC)testing,the organic matter(OM)abundance of Paleogene source rocks in the southwestern Bozhong Sag were evaluated,including the lower of second member of Dongying Formation(E_(3)d2L),the third member of Dongying Formation(E_(3)d_(3)),the first and second members of Shahejie Formation(E_(2)s_(1+2)),the third member of Shahejie Formation(E_(2)s_(3)).The results indicate that the E_(2)s_(1+2)and E_(2)s_(3)have better hydrocarbon generative potentials with the highest OM abundance,the E_(3)d_(3)are of the second good quality,and the E_(3)d2L have poor to fair hydrocarbon generative potential.Furthermore,the well logs were applied to predict TOC and residual hydrocarbon generation potential(S_(2))based on the sedimentary facies classification,usingΔlogR,generalizedΔlogR,logging multiple linear regression and BP neural network methods.The various methods were compared,and the BP neural network method have relatively better prediction accuracy.Based on the pre-stack simultaneous inversion(P-wave impedance,P-wave velocity and density inversion results)and the post-stack seismic attributes,the three-dimensional(3D)seismic prediction of TOC and S_(2)was carried out.The results show that the seismic near well prediction results of TOC and S_(2)based on seismic multi-attributes analysis correspond well with the results of well logging methods,and the plane prediction results are identical with the sedimentary facies map in the study area.The TOC and S_(2)values of E_(2)s_(1+2)and E_(2)s_(3)are higher than those in E_(3)d_(3)and E_(3)d_(2)L,basically consistent with the geochemical analysis results.This method makes up the deficiency of geochemical methods,establishing the connection between geophysical information and geochemical data,and it is helpful to the 3D quantitative prediction and the evaluation of high-quality source rocks in the areas where the drillings are limited. 展开更多
关键词 Total organic carbon(TOC) Residual hydrocarbon generation potential(S_(2)) Geophysical prediction Seismic attribute Bozhong Sag bohai Bay Basin
下载PDF
Study on crustal thickness and the prediction of prolific depressions:the Bohai Basin as an example
3
作者 Mengke Cai Gongcheng Zhang +1 位作者 Wanyin Wang Dingding Wang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第4期92-104,共13页
The deep crustal structure is closely related to oil and gas reserves.Predicting the oil and gas enrichment of depressions based on the Moho depth and crustal thickness is a promising research topic with significant i... The deep crustal structure is closely related to oil and gas reserves.Predicting the oil and gas enrichment of depressions based on the Moho depth and crustal thickness is a promising research topic with significant implications for guiding exploration in petroliferous basins.In this study,seismic data were used as a constraint on the use of satellite gravity anomaly inversion to obtain the distribution of Moho depth and crustal thickness in the Bohai Basin.Stretching factors were calculated to analyze the differential distribution of deep crustal structural activity.Four indicators,including the minimum Moho depth,minimum crustal thickness,sum of Moho stretching factors,and sum of crustal stretching factors,were selected.Principal component analysis was applied to reduce the dimensionality of the multi-indicator system and obtain an oil and gas enrichment score for quantitative prediction of favorable prolific depressions.The deviation between the inverted Moho depth and seismic constraints was small;thus,the data effectively reflect the variations in the characteristics of each depression.The analysis revealed significant statistical features related to the minimum Moho depth/crustal thickness and the sum of Moho/crustal stretching factors associated with prolific depressions.Based on the oil and gas enrichment score,the depressions were classified into four categories related to their different deep crustal structural characteristics.Highly active ClassⅠ,ClassⅡ,and ClassⅢdepressions are predicted to be favorable prolific depressions.This study expands the research on quantitatively predicting favorable prolific depressions in the Bohai Basin using the deep crustal structure and can contribute to reducing production costs and improving exploration efficiency in future explorations. 展开更多
关键词 bohai Basin satellite gravity anomaly deep crustal structure Moho depth crustal thickness favorable prolific depression
下载PDF
Research on the Relationship Between Environmental and Economic Coupling Systems in Bohai Bay Area Based on a Vector Autoregression(VAR)Model 被引量:1
4
作者 CAO Huimin WANG Ping +2 位作者 ZHANG Surong XU Dongpo TIAN Weijun 《Journal of Ocean University of China》 CAS CSCD 2024年第2期557-566,共10页
This study analyzed the impact of land-based contaminants and tertiary industrial structure on economic development in the selected Bohai Bay area,China.Based on panel data spanning 2011-2020,a vector autoregressive(V... This study analyzed the impact of land-based contaminants and tertiary industrial structure on economic development in the selected Bohai Bay area,China.Based on panel data spanning 2011-2020,a vector autoregressive(VAR)model is used to analyze and forecast the short-run and long-run relationships between three industrial structures,pollutant discharge,and economic development.The results showed that the environmental index had a long-term cointegration relationship with the industrial structure economic index.Per capital chemical oxygen demand(PCOD)and per capita ammonia nitrogen(PNH_(3)N)had a positive impact on delta per capita GDP(dPGDP),while per capita solid waste(PSW),the secondary industry rate(SIR)and delta tertiary industry(dTIR)had a negative impact on dPGDP.The VAR model under this coupling system had stability and credibility.The impulse response results showed that the short-term effect of the coupling system on dPGDP was basically consistent with the Granger causality test results.In addition,variance decomposition was used in this study to predict the long-term impact of the coupling system in the next ten periods(i.e.,ten years).It was found that dTIR had a great impact on dPGDP,with a contribution rate as high as 74.35%in the tenth period,followed by the contribution rate of PCOD up to 3.94%,while the long-term contribution rates of PSW,SIR and PNH3N were all less than 1%.The results show that the government should support the development of the tertiary industry to maintain the vitality of economic development and prevent environmental deterioration. 展开更多
关键词 bohai Bay area environmental pollution industrial structure cointegration theory VAR model impulse response
下载PDF
Effect of sodium nitroprusside on the microrheological properties of red blood cells in different media 被引量:1
5
作者 Petr Ermolinskiy Matvey Maksimov +3 位作者 Andrei Lugovtsov Alexey Muravyov Irina Tikhomirova Alexander Priezzhev 《Journal of Innovative Optical Health Sciences》 SCIE EI CSCD 2024年第5期23-31,共9页
Red blood cell(RBC)aggregation as well as their deformation significantly affects blood microrheology.These processes depend on various factors,one of which is concentration of the nitric oxide,one of the main signali... Red blood cell(RBC)aggregation as well as their deformation significantly affects blood microrheology.These processes depend on various factors,one of which is concentration of the nitric oxide,one of the main signaling molecule in the bloodstream.The purpose of this study was to investigate the effect of nitric oxide on the microrheological properties of red blood cells(RBCs)in RBC samples of various media after the addition of nitric oxide donor sodium nitroprusside in vitro.Microrheological properties were measured using laser aggregometer and ektacytometer based on diffuse light scattering and diffraction of laser light on a suspension of RBCs,respectively.The study found that heparin-stabilized blood showed increased RBC aggregation and deformation with sodium nitroprusside concentrations of 100,and 200M,while EDTA-stabilized blood showed slightly decreased aggregation and unchanged deformation.With washed RBCs in dextran solution,the addition of sodium nitroprusside(in the concentrations of 100,and 200M)resulted in decreased aggregation and increased deformation.These-ndings aid in our understanding of nitric oxide's effect on RBC microrheological properties. 展开更多
关键词 Sodium nitroprusside nitric oxide red blood cells RBC aggregation diffuse light scattering laser diffractometer
下载PDF
The protective effect of cyclodextrin on the color quality and stability of Cabernet Sauvignon red wine 被引量:1
6
作者 Caiyun Liu Lulu Wu +2 位作者 Shuyue Fan Yongsheng Tao Yunkui Li 《Journal of Integrative Agriculture》 SCIE CSCD 2024年第1期310-323,共14页
The impact of cyclodextrins(CDs)on wine quality and stability remains largely unknown.This study systematically assessed the protective effect of the post-fermentation addition of CDs on color stability of red wine fr... The impact of cyclodextrins(CDs)on wine quality and stability remains largely unknown.This study systematically assessed the protective effect of the post-fermentation addition of CDs on color stability of red wine from the viewpoints of color characteristics,copigmentation and phenolic profiles.The grey relational analysis(GRA)and principal component analysis(PCA)methods were employed to dissect the key effective determinants related to color quality.The addition of CDs induced a significant hyperchromic effect of 8.19-25.40%,a significant bathochromic effect and an enhancement of the color intensity.Furthermore,the evolution of anthocyanin forms and the content of monomeric anthocyanins revealed that β-CD is a superior favorable cofactor during wine aging,but for long-term aging,2-HP-β-CD and 2-HP-γ-CD are more beneficial in promoting the formation of polymerized anthocyanins and color stability.This work provides an important reference for the use of CDs to enhance the color quality and stability of red wines. 展开更多
关键词 cyclodextrins color properties copigmentation Helan Mountain’s East Foothill red wine aging
下载PDF
外源6-BA对小苍兰‘Red Lion’生长及花期调控的影响
7
作者 李雪茹 穆红梅 +1 位作者 罗亚桃 文莹莹 《山东农业科学》 北大核心 2024年第4期66-71,共6页
本试验以小苍兰品种‘Red Lion’为材料,研究喷施不同浓度6-BA(25、50、100 mg/L和200 mg/L)对小苍兰生长、生理生化特性及花期的影响,以期为小苍兰花期调控和切花栽培提供技术支持。结果表明:喷施适当浓度的6-BA有利于延长小苍兰‘Red ... 本试验以小苍兰品种‘Red Lion’为材料,研究喷施不同浓度6-BA(25、50、100 mg/L和200 mg/L)对小苍兰生长、生理生化特性及花期的影响,以期为小苍兰花期调控和切花栽培提供技术支持。结果表明:喷施适当浓度的6-BA有利于延长小苍兰‘Red Lion’花期;6-BA浓度为200 mg/L时显著提高小苍兰的花朵直径、花葶长度、小花数、株高、叶片数,较对照花期延长11 d、花朵直径增加50.45%、小花数增加114.89%,同时叶片的丙二醛含量较CK降低34.65%,叶片抗氧化酶(POD、CAT)活性升高,分别比CK提高97.26%和393.24%。综之,喷施适当浓度的6-BA能够显著提高小苍兰‘Red Lion’花朵质量及数量,延长小苍兰花期,其中200 mg/L 6-BA处理效果最佳。 展开更多
关键词 小苍兰‘red Lion’ 6-BA 花期调控 生理生化指标
下载PDF
Red/ET同源重组介导的基因克隆载体pBACS的构建、鉴定与应用
8
作者 侯少阳 李岚芳 +5 位作者 杜丽霞 孙林慧 李典 禚惠荣 姜莉莉 张大虎 《沈阳药科大学学报》 CAS CSCD 2024年第5期590-597,共8页
目的通过Red/ET同源重组技术构建pBACS基因克隆及测序质粒载体。方法以质粒pBAC2015、pET28a为模板设计四对引物,PCR扩增得到四段彼此间有50 bp同源区域的基因片段,分别命名为bac-sop、bac-ori、bac-kan和bac-T7。利用Red/ET同源重组技... 目的通过Red/ET同源重组技术构建pBACS基因克隆及测序质粒载体。方法以质粒pBAC2015、pET28a为模板设计四对引物,PCR扩增得到四段彼此间有50 bp同源区域的基因片段,分别命名为bac-sop、bac-ori、bac-kan和bac-T7。利用Red/ET同源重组技术,将四段基因片段电转至E.coli GB05-dir感受态中进行线线重组。经酶切、测序验证阳性克隆质粒。此外,对重组质粒pBACS进行稳定性鉴定;利用pBACS分别进行细菌16S rDNA和真菌ITS基因克隆和基因测序。结果酶切和测序的验证结果显示,质粒的大小、元件方向及序列正确;pBACS具有较强的稳定性,适用于作为基因工程的克隆载体;可高效用于细菌16S rDNA和真菌ITS序列的克隆,阳性率为100%。结论成功利用Red/ET技术构建克隆载体pBACS,质粒载体具有稳定性强、重组效率高的特点,在基因克隆和基因测序等方面具有良好的应用潜力。 展开更多
关键词 pBACS 克隆 red/ET技术 同源重组
下载PDF
5G RedCap技术在电力行业应用的研究
9
作者 刘凯 王元杰 +1 位作者 邱学 李正浩 《通信世界》 2024年第12期26-30,共5页
Red Cap(5G轻量化)技术通过精简设备能力和降低复杂度,达到节约成本、降低设备功耗和缩小尺寸等目标,同时保留了5G原生能力,实现了技术和成本的平衡。本文研究了Red Cap的技术特性和相关国家政策,并结合电力行业网络需求,分析Red Cap在... Red Cap(5G轻量化)技术通过精简设备能力和降低复杂度,达到节约成本、降低设备功耗和缩小尺寸等目标,同时保留了5G原生能力,实现了技术和成本的平衡。本文研究了Red Cap的技术特性和相关国家政策,并结合电力行业网络需求,分析Red Cap在电力行业不同场景的应用和部署方案,探讨了Red Cap技术的发展潜力和运营商的部署策略。 展开更多
关键词 电力行业 网络需求 部署策略 设备功耗 发展潜力 部署方案 red 节约成本
下载PDF
5G RedCap网络规划优化和升级部署建议 被引量:2
10
作者 刁兆坤 蔡杰 陈青山 《通信世界》 2024年第5期36-38,共3页
完善5G无线体系,助力5G应用“轻装上阵”,RedCap(Reduced Capability,轻量化5G)已正式商用部署。5G符合产业应用对网络的长期需求,轻量化则符合终端大规模部署的低成本要求,因此,RedCap大规模发展和应用是必然,产业界正在积极推进RedCa... 完善5G无线体系,助力5G应用“轻装上阵”,RedCap(Reduced Capability,轻量化5G)已正式商用部署。5G符合产业应用对网络的长期需求,轻量化则符合终端大规模部署的低成本要求,因此,RedCap大规模发展和应用是必然,产业界正在积极推进RedCap规模化落地。 展开更多
关键词 长期需求 red 商用部署 部署建议 轻量化 规模化
下载PDF
The Middle and Late Holocene climate change in Bohai Bay revealed by diatom proxy
11
作者 Zhiwen SHANG Jianfen LI +1 位作者 Fu WANG Hong WANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第5期1493-1506,共14页
A total of 98 samples from two boreholes in shallow sea area and two oyster reefs in adjacent coastal plain in the northwestern coast of Bohai Bay were collected for diatom analyses and species identification.The rati... A total of 98 samples from two boreholes in shallow sea area and two oyster reefs in adjacent coastal plain in the northwestern coast of Bohai Bay were collected for diatom analyses and species identification.The ratio of the marine species Thalassionema nitzschioides to the intertidal-coastal species complex Cyclotella striata/stylorum serves as a novel proxy for assessing the strength of marine influence.Chronological data,corrected for the local residence time effect,facilitated the construction of a diatom proxy-based marine influence curve for the study area.This curve delineates the dynamics of marine influence and their correlations with paleo-climate fluctuations and the East Asian monsoon variability,as well as their role in chenier formation.Results include:(1)eight periods of intensified marine influence have been documented since 7000 a BP in the study area.The peak of each period,as determined by the diatom proxy,corresponds closely to the warm climatic phases and stronger East Asian summer monsoons,suggesting that the peaks marine influence indicate typically the periods of climatic warmth and monsoon activity intensification in the region;(2)a strong correlation exists between the development of cheniers and marine influence,and chenier formation began with the increasing marine influence and terminated at the end of warm periods as marine influence weakens.The climatic changes in the coastal area,as indicated by the diatom proxy,hold significant potential for future related research endeavors. 展开更多
关键词 bohai Bay DIATOM diatom-based marine influence curve paleo-climate HOLOCENE
下载PDF
Using Optical Tweezers to Study the Friction of the Red Blood Cells
12
作者 Edoukoua Jean Michel Konin Pavel Yale +3 位作者 Abadê Ange-Boris N’guessan Kouassi Benoit Kouakou Abaka Michel Kouacou Eugene Megnassan 《Advances in Bioscience and Biotechnology》 CAS 2024年第2期100-111,共12页
In the last two decades the study of red blood cell elasticity using optical tweezers has known a rise appearing in the scientific research with regard to the various works carried out. Despite the various work done, ... In the last two decades the study of red blood cell elasticity using optical tweezers has known a rise appearing in the scientific research with regard to the various works carried out. Despite the various work done, no study has been done so far to study the influence of friction on the red blood cell indentation response using optical tweezers. In this study, we have developed a new approach to determine the coefficient of friction as well as the frictional forces of the red blood cell. This approach therefore allowed us to simultaneously carry out the indentation and traction test, which allowed us to extract the interfacial properties of the microbead red blood cell couple, among other things, the friction coefficient. This property would be extremely important to investigate the survival and mechanical features of cells, which will be of great physiological and pathological significance. But taking into account the hypothesis of friction as defined by the isotropic Coulomb law. The experiment performed for this purpose is the Brinell Hardness Test (DB). 展开更多
关键词 FRICTION INDENTATION Optical Tweezers TRIBOLOGY red Blood Cells
下载PDF
Analysis and Assessment on the Heavy Metals in a Severely Degraded Subtropical Red Soil Region
13
作者 Fang Wang Yun Zhou +5 位作者 Xiangping Fu Yuxiao Zhao Yiyao Wen Xintao Cui Shunbao Lu Yanjie Zhang 《American Journal of Plant Sciences》 CAS 2024年第2期110-121,共12页
5 different forests of Pinus massoniana, Schima superba, Liquidambar formosana, P. massoniana × S. superba, P. massoniana × L. formosana as the research object were set up to study the Cr, Cu and Zn content ... 5 different forests of Pinus massoniana, Schima superba, Liquidambar formosana, P. massoniana × S. superba, P. massoniana × L. formosana as the research object were set up to study the Cr, Cu and Zn content of degraded red soil region in subtropics. The soil heavy metal pollution degree was evaluated by national environmental quality standard (II class). The results showed that three soil metals of P. massoniana × S. superba were the highest, and the soil metals enrichment ability was strong. The order of single factor pollution index of metal elements was Cu (1.38) > Cr (0.81) > Zn (0.42), and moderately pollution, pollution warning and no pollution, respectively. There was no significant correlation between three soil heavy metals and soil total carbon (TC), total nitrogen (TN) and total phosphorus (TP). These results suggested that the accumulation of heavy metal elements was not derived from the parent material of soil. There was a significant positive correlation between the three metal elements which indicated that the sources of the three elements were similar. The structural equation model showed that the direct and indirect effects among the influencing factors ultimately affected the activity of heavy metals by cascade effects. 展开更多
关键词 Subtropical Forest Type Degraded red Soil Heavy Metals Pollution Evaluation
下载PDF
Spatial correlations in time and frequency domains between chlorophyll-a concentration and environmental factors in the Bohai Sea
14
作者 Wan XU Di MU +1 位作者 Zhenteng YANG Dekui YUAN 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第4期1143-1156,共14页
Based on the reconstructed MODIS data and ECMWF reanalysis data from 2003 to 2021,spatial correlations between chlorophyll a(Chl a)and sea surface temperature(SST),photosynthetically available radiation(PAR),aerosol o... Based on the reconstructed MODIS data and ECMWF reanalysis data from 2003 to 2021,spatial correlations between chlorophyll a(Chl a)and sea surface temperature(SST),photosynthetically available radiation(PAR),aerosol optical thickness(AOT),and wind speed(WS)in the Bohai Sea were analyzed from the perspective of time domain and frequency domain.Results indicate that the frequency domain analysis was more conducive to revealing the correlations between Chl a and environmental factors.The spatial pattern of time-domain correlations was similar to the isobaths of the Bohai Sea,which was positive in shallow waters and negative in deep waters for SST,PAR,and AOT,and was reversed for WS.Frequency-domain correlations were obtained by performing Fourier Transform and were higher than correlations in time domain.The spatial distributions indicated that the effects of SST and PAR on Chl a were greater than AOT and WS in the Bohai Sea.Additionally,cross-spectrum analysis was applied to explore the response relationships.A depth-dependent pattern was shown in correlations and time lags,indicating that the influential mechanism of environmental factors on Chl-a concentration is related to seawater depth. 展开更多
关键词 chlorophyll a(Chl a) frequency domain spatial correlation bohai Sea
下载PDF
Reproductive biology of Hemitripterus villosus in the Bohai Strait,China
15
作者 Ping SUN Song QIN +1 位作者 Zhengyi LIU Longchuan ZHUANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第3期881-892,共12页
To understand the reproductive biology of Hemitripterus villosus in the Bohai Strait,and fill the key knowledge gap in verifying reproductive seasonality and documenting gonadotropin dependent reproductive cycle of th... To understand the reproductive biology of Hemitripterus villosus in the Bohai Strait,and fill the key knowledge gap in verifying reproductive seasonality and documenting gonadotropin dependent reproductive cycle of this species,a year-round detail study was conducted for the first time.In total,263 individuals were randomly sampled off the coasts of the Bohai Strait.Results show that and the overall female-to-male ratio(1.35:1)did not differ significantly from the 1:1 sex ratio.The length and weight relationship for females and males were regressed,depicting an isometric growth for both sexes.Four reproductive phases of the complete gonadotropin dependent reproductive cycle in both sexes were identified.The monthly variations in the gonadosomatic and hepatosomatic indexes for both sexes further indicated that this species spawns a single batch of eggs per year and the peak spawning period is from October to December.The average diameter of eggs ranged from 2.10 to 3.57 mm.The length at first sexual maturity was 224.87 mm for females and 241.26 mm for males.Significant positive relationships between absolute fecundity and fish size,and also gonadal weight were observed.H.villosus from the Bohai Strait exhibited smaller body size,smaller egg diameter,lower gonadosomatic index,lower absolute fecundity,and higher population extinction risk than the other populations’studied previously.Our findings contribute to understanding the status of this isolated westernmost population,and we emphasize that more efficient protection measures for the species and control measures are urgently required to improve the coastal environment in the Bohai Strait. 展开更多
关键词 Hemitripterus villosus bohai Strait FECUNDITY length at first maturity reproductive seasonality
下载PDF
Paleoenvironmental reconstruction and organic matter accumulation of the paleogene shahejie oil shale in the Zhanhua Sag, Bohai Bay Basin, Eastern China
16
作者 Xiao-Lin Wang Xiao-Min Zhu +5 位作者 Jin Lai Xing-Yue Lin Xiang Wang Yu-Shan Du Chao Huang Yu-Rui Zhu 《Petroleum Science》 SCIE EI CAS CSCD 2024年第3期1552-1568,共17页
The controlling factors of organic-rich shale accumulation is essential for the exploration and development of shale oil and gas resources.The sedimentary environment plays a vital role in the formation of organic-ric... The controlling factors of organic-rich shale accumulation is essential for the exploration and development of shale oil and gas resources.The sedimentary environment plays a vital role in the formation of organic-rich sediments in lacustrine facies.This article unravels the mineralogy,geochemistry,and paleoenvironmental evolution during the deposition of the Paleogene Shahejie Formation(Es_(3)^(L)).It discusses the effects of paleoclimate,paleosalinity,paleoredox conditions,paleowater depth,and paleoproductivity on organic matter(OM)enrichment.Finally,the OM enrichment model was established.The results show that the mineralogical compositions are mainly composed of calcite(avg.40.13%),quartz(avg.21.64%)and clay minerals(avg.24.07%),accompanied by dolomite(avg.7.07%),feldspar(avg.6.36%)and pyrite(avg.2.95%).The Es_(3)^(L) shale has a high abundance of OM,with total organic carbon(TOC)ranging from 1.07%to 5.12%.The organic matter type is mainly composed of type I-II_(1) kerogen,which is generally considered a good-quality source rock.The source of OM is a mixture of lower bacteria,algae,and plants.During the early sedimentary period,the paleoclimate was dry and cold,with high salinity,intense reducibility,and relatively low productivity.During the late sedimentary period,the climate became warmer and more humid.As a result,the salinity decreased to a level that was suitable for biological reproduction,and productivity increased gradually due to the input of terrigenous plants.Paleosalinity and paleoclimate determined the environment of the sedimentary period,in addition,paleoproductivity and paleoredox condition indicated the formation and preservation conditions of OM.The warm and humid climate,brackish water,suitable reduction conditions and high productivity are the favorable conditions for the generation and preservation of organic matter.The research results may have implications for the genetic mechanisms of organic matter accumulation.They will provide theoretical and technical insights into the exploration and development of shale oil. 展开更多
关键词 Elemental geochemical PALEOENVIRONMENT Organic matter accumulation Paleogene shahejie formation Zhanhua Sag bohai Bay Basin
下载PDF
Evaluating the biosignature potential of ammonium in Proterozoic red beds and implications for the search for life on Mars
17
作者 Eva E.Stüeken Philip Fralick +1 位作者 Stephen Hillier Anthony R.Prave 《Earth and Planetary Physics》 EI CAS CSCD 2024年第6期836-853,共18页
Over the past two decades,it has become increasingly apparent that early Mars may once have been warmer,wetter and more habitable for microbial life than it is today,which has spurred discussions about potential biosi... Over the past two decades,it has become increasingly apparent that early Mars may once have been warmer,wetter and more habitable for microbial life than it is today,which has spurred discussions about potential biosignatures that may be preserved in Martian sediments.An impediment to this line of research is the pervasive oxidation of Mars’surface due to photochemical oxidants that have likely destroyed remnants of organic matter.Here,we investigate whether nitrogen(N)transferred from biomass to phyllosilicate minerals during diagenesis can be preserved in oxidized mudrocks.We investigate two sequences of terrestrial Proterozoic red beds,namely the Sibley Group(1.4 Ga)in Canada and the Stoer Group(1.2 Ga)in Scotland,and we find enrichments in authigenic N in the range of several tens of ppm in both units.The highest concentrations(ca.100 ppm on average)are found in the most desiccated red beds of the Stoer Group,concurrent with enrichments in potassium(K).We discuss similarities and differences between the two sets of rocks with regards to salinity,pH,biological productivity and K-metasomatism,and we conclude that the ideal mechanism for the preservation of biogenic N in red beds may be in-situ release of ammonium from microbial mats into the clay substrate,possibly facilitated by early diagenetic,biologically induced illitization.Illite and smectite have been observed on Mars,and experiments suggest that Martian waters contained moderate amounts of dissolved K.Hence,it is conceivable that a similar K and N enrichment process could have occurred as to what we document for the Proterozoic,preserving evidence of life that may have survived to the modern day. 展开更多
关键词 red beds BIOSIGNATURE MARS NITROGEN AMMONIUM clay minerals
下载PDF
Solidification/Stabilization of Chromium in Red Mud-based Geopolymer
18
作者 田崇霏 LUO Zhongtao +4 位作者 LIU Lei LIU Xiaohai 张美香 陈萌 HAI Ran 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第4期819-830,共12页
Up to 1.5wt%of Cr(Ⅲ)salts(CrCl_(3),and Cr_(2)O_(3))and Cr(Ⅵ)salts(Na_(2)CrO_(4),and CaCr_(2)O_(7))were incorporated into red mud-based geopolymers,respectively.The solidification/stabilization,compressive strength,a... Up to 1.5wt%of Cr(Ⅲ)salts(CrCl_(3),and Cr_(2)O_(3))and Cr(Ⅵ)salts(Na_(2)CrO_(4),and CaCr_(2)O_(7))were incorporated into red mud-based geopolymers,respectively.The solidification/stabilization,compressive strength,and durability of the Cr-containing geopolymers were investigated.The experimental results indicate that the red mud-based geopolymer could effectively solidify/stabilize different types of Cr salts with solidification/stabilization rates of above 99.61%.Geopolymers are environmentally safe when the dosage of CaCr_(2)O_(7)is≤1.0wt%,or the dosage of CrCl_(3),Cr_(2)O_(3),and Na_(2)CrO_(4)is≤1.5wt%,respectively.The effects of Cr salts on the compressive strength varies with the type and content of Cr salts.The freeze-thaw cycle is more destructive to geopolymer properties than sulfate attack or acid rain erosion.The solidification/stabilization of Cr is mainly attributed to the following reasons:a)The chemical binding of Cr is related to the formation of Cr-containing hydrates(eg,magnesiochromite((Mg,Fe)(Cr,Al)_(2)O_(4)))and doping into N-A-S-H gel and C-A-S-H gel framework;b)The physical effect is related to the encapsulation by the hydration products(e g,N-A-S-H gel and C-A-S-H gel).This study provides a reference for the treatment of hazardous Cr-containing wastes by solid waste-based geopolymers. 展开更多
关键词 CHROMIUM SOLIDIFICATION/STABILIZATION GEOPOLYMER red mud DURABILITY
下载PDF
Analysis of Tidal Current Energy Potential in the Major Channels of the Bohai Strait Based on Delft3D
19
作者 MA Pengcheng SHI Hongyuan +2 位作者 XUE Huaiyuan LI Pingping SUN Yongkang 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第4期859-870,共12页
The utilization and development of tidal current energy can help alleviate the current energy shortage,improve the global ecological environment,and maintain sustainable development.In this study,numerical simulation ... The utilization and development of tidal current energy can help alleviate the current energy shortage,improve the global ecological environment,and maintain sustainable development.In this study,numerical simulation is carried out on a rectangular grid using Delft3D.The tidal current energy potential of the major channels in the Bohai Strait is further simulated and estimated by comparing the simulated and measured data.Results show that the flow module in Delft3D has good modeling ability for the assessment of tidal current energy potential.The average flow velocity,maximum flow velocity,and energy flow density are consistent.The Laotieshan Channel,located in the northern part of the Bohai Strait,shows a large tidal current energy potential.The maximum flow velocity of this channel can reach 2 m s-1,and the maximum energy flow density can exceed 500 W m-2.The tidal current energy in the Laotieshan Channel is more than 10 times that in other channels.Therefore,this study advocates for the continued exploration and exploitation of the tidal current energy resources in the Laotieshan Channel. 展开更多
关键词 Delft3D bohai Strait tidal current energy numerical simulation power density
下载PDF
Evolution model and failure mechanisms of rainfall-induced cracked red clay slopes:insights from Xinshao County,China
20
作者 JIAO Weizhi ZHANG Ming +4 位作者 LI Peng XIE Junjin PANG Haisong LIU Fuxing YANG Long 《Journal of Mountain Science》 SCIE CSCD 2024年第3期867-881,共15页
Red clay landslides are widely distributed worldwide,resulting in severe loss of life and property.Although rainfall-induced red clay slopes have received extensive attention,the role of cracks in the evolutionary pro... Red clay landslides are widely distributed worldwide,resulting in severe loss of life and property.Although rainfall-induced red clay slopes have received extensive attention,the role of cracks in the evolutionary process of red clay slopes and their connection to failure mechanisms is still poorly understood.A comprehensive approach integrating field investigation,laboratory tests,and numerical simulations was conducted to study the 168 red clay landslides in Xinshao County,China.The results show that red clay is prone to forming cracks at high moisture content due to its low swelling and high shrinkage properties.The failure mode of red clay slopes can be summarized in three stages:crack generation,slope excavation,and slope failure.Furthermore,the retrospective analysis and numerical simulations of the typical landslide in Guanchong indicated that intense rainfall primarily impacts the shallow layer of soil within approximately 0.5 m on the intact slope.However,cracks change the pattern of rainfall infiltration in the slope.Rainwater infiltrates rapidly through the preferential channels induced by the cracks rather than uniformly and slowly from the slope surface.This results in a significant increase in both the depth of infiltration and the saturated zone area of the cracked slope,reaching 3.8 m and 36.2 m^(2),respectively.Consequently,the factor of safety of the slope decreases by 13.4%compared to the intact slope,ultimately triggering landslides.This study can provide valuable insights into understanding the failure mechanisms of red clay slopes in China and other regions with similar geological settings. 展开更多
关键词 red clay slopes Cracks Preferential flow Failure mechanism
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部