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Potassium isotopic signatures of modern offshore detrital sediments from different climatic regimes and the implications

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Science China Earth Sciences 2024年第2期67卷 405-419页

作者： jun mu Tianyu CHEN Qian YU Shichao AN Jianfang CHEN Xuefa SHI Weiqiang LI State Key Laboratory for Mineral Deposits Research School of Earth Sciences and EngineeringNanjing UniversityNanjing210023China Ministry of Education Key Laboratory for Coast and Island Development School of Geography and Ocean ScienceNanjing UniversityNanjing210023China State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou310012China Key Laboratory of Marine Geology and Metallogeny First Institute of OceanographyMinistry of Natural ResourcesQingdao266061China

Potassium isotopes are a novel tracer for continental *** K isotope studies on chemical weathering generally targeted weathering profiles under a particular climate region,yet the effects of chemical weathering on K isotopes under different climatic backgrounds remain ***,little is known about the K isotope signatures of modern unconsolidated detrital ***,we report K isotopic data of surficial seafloor sediments from continental shelves along the east coast of China(ECC),as well as those around the tropical Hainan island in the northern South China *** ECC sediments have a relatively narrow distribution ofδ^(41)K(with reference to NIST3141a)values,which range from(-0.40±0.01)‰to(-0.57±0.04)‰,with an average of(-0.51±0.09)‰.By contrast,δ^(41)K values of Hainan offshore sediments display a larger variation,ranging from(-0.28±0.07)‰to(-0.67±0.02)‰.Theδ^(41)K values of Hainan offshore sediments exhibit negative correlations with the chemical index of alteration(CIA),Al/K,Ti/K,and total iron(FeT),which underlines the control of chemical weathering on K isotopic signatures of detritus inputs into *** also measured Mg isotope compositions for the same samples;interestingly,the variability inδ^(26)Mg of the samples is small(~0.24‰)for all ECC and Hainan offshore sediments,andδ^(26)Mg values do not show clear correlations with indexes of chemical *** study demonstrates the link between K isotopic variability of detrital sediments and climatic conditions including rainfall intensity,which indicates that K isotopes of the detrital component of marine sediments could be applied to study Earth’s climate in deep ***δ^(41)K values of the offshore detrital sediments are significantly less variable than those of pelagic marine sediments,highlighting the importance of distinguishing the effects of diagenesis and neoformation of clay minerals from continental weathering in attempts to study deep-time climate-weathering

关键词： Potassium isotopes Magnesium isotopes Chemical weathering Detrital sediments Climatic regimes Mean annual precipitation

Optimization of submerged entry nozzle parameters for ultra-high casting speed continuous casting mold of billet

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Journal of Iron and Steel Research International 2022年第1期29卷 44-52页

作者： Pei Xu Yong-zhi Zhou Deng-fu Chen mu-jun Long Hua-mei Duan Laboratory of Metallurgy and Materials College of Materials Science and EngineeringChongqing UniversityChongqing 400044China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing UniversityChongqing 400044China

Controlling the flow behavior in the mold in an appropriate way is the basis for realizing the billet ultra-high speed continuous *** on the new proposed physical water modeling experiment considering the effects of solidified shell and hydrostatic pressure,the flow behavior in the mold with cross section of 160 mm 9160 mm during continuous casting of billet is regulated by optimizing the inner diameters and immersion depths of submerged entry nozzle at the ultra-high casting speeds of 5.0–6.5 m/*** results show that under the premise of no slag entrainment,as well as uniform coverage and keeping good fluidity of liquid slag layer on the top free surface of the fluid in the mold,the appropriate parameters of submerged entry nozzle under the ultra-high casting speed of billet are 50 mm in inner diameter,95 mm in outer diameter and 180 mm in immersion *** on the basis of the obtained parameters of submerged entry nozzle,it can be known that the reasonable ranges of level fluctuation and impacting depth of the stream in the mold are about 0.82-1.11 and 593-617 mm,respectively.

关键词： Ultra-high casting speed Billet continuous casting Submerged entry nozzle Physical water modeling Flow behavior

Combined optical fiber interferometric sensors for the detection of acoustic emission

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Optoelectronics Letters 2008年第3期4卷 184-187页

作者： LIANG Yi-jun mu Lin-lin LIU jun-feng YU Xiao-tao College of science Harbin Engineering University Harbin 150001 China

A type of combined optical fiber interferometric acoustic emission sensor is proposed. The sensor can be independent on the laser source and make light interference by matching the lengths of two arms,so it can be used to monitor the health of large structure. Theoretical analyses indicate that the system can be equivalent to the Michelson interferometer with two optical fiber loop reflectors,and its sensitivity has been remarkably increased because of the decrease of the losses of light energy. PZT is powered by DC regulator to control the operating point of the system,so the system can accurately detect feeble vibration which is generated by ultrasonic waves propagating on the surface of solid. The amplitude and the frequency of feeble vibration signal are obtained by detecting the output light intensity of interferometer and using Fourier transform technique. The results indicate that the system can be used to detect the acoustic emission signals by the frequency characteristics.

关键词： Acoustic emissions Acoustics Electric network analysis Fiber optics Fibers Fourier transforms Geodetic satellites Interferometers Interferometry Lattice vibrations Light sources Michelson interferometers Optical fibers Optical in Acoustic emission sensors Acoustic Emission signals Fiber loop reflectors Fourier Frequency characteristics Interferometric sensors Laser sources Light energy Light intensities Operating points Optical Vibration signals

Biological and chemical diversity of cytotoxin-producing symbiotic marine fungi in intertidal zone of Dalian

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Chinese Science Bulletin 2013年第19期58卷 2290-2297页

作者： ZHANG Yi mu jun FENG Yan LI HeNan DONG XueWei School of Life Science and Biotechnology Dalian University of Technology School of Environmental and Chemical Engineering Dalian Jiaotong University Key Laboratory of Experimental Marine Biology Institute of OceanologyChinese Academy of Sciences

In this study, the biological and chemical diversity of 8 symbiotic marine fungal strains, with strong cytotoxicity against brine shrimp larvae, were investigated by nucleotide sequencing, morphology and cluster analysis of HPTLC fingerprint. These strains were identified by ITS rDNA sequencing, phylogenic analysis, and morphology to be Hypocrea lixii, Chaetomium globosum, Aspergillus fumigatus, Asp. clavatus and Alternaria sp. Their differences in secondary metabolites were shown by cluster analysis of digitalized colors of HPTLC spots, a newly developed method, which produced a similar dendrogram with that of ITS cluster analysis. Furthermore, this method can fully display intraspecific differences and even the remarkable difference in Aspergillus strains which goes beyond the boundary between genera. Their biological-chemical diversity may be the basis of their potent cytotoxicity and implies their potential in producing diversified antitumor or pesticidal constituents.

关键词：生物化学海洋真菌多样性共生潮间带 rDNA序列分析聚类分析大连

Study on the Application of multiple auto-correlation in Rapid tuning of Overhauser Magnetometer 32

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Study on the Application of multiple auto-correlation in Rap...

Attenuation characteristics of electromagnetic waves in plasma generated by coating radionuclide on surface structures

第32届中国控制与决策会议

作者： XIE mu-jun FU Bao-cai JIANG Chang-hong College of Electrical and Electronic Engineering Changchun University of Technology

ISBN: (纸本)9781728158549

In order to solve the problem of slow tuning speed and easy misalignment of peak scan matching method of Overhauser magnetometer,a fast tuning method based on multiple self-correlation algorithm is proposed in this ***,according to the characteristic that the Free Induction Decay（FID） signal has an exponential attenuation and constant frequency,the signal is subjected to multiple self-correlation de-noising processing,and the frequency of the FID signal is obtained by using the *** the simulation of MATLAB is carried out,and the result shows that the multiple self-correlation algorithm has better processing effect on the FID signal detection in the strong noise background,so the FID signal frequency is accurately ***,tuning circuit structure and tuning work-flow is *** tuning capacitance value is obtained according to the FID signal frequency and the resonance *** capacitance is selected by multi-channel switch to realize fast tuning.

关键词： Magnetometer FID signal Fast tuning multiple auto-correlation

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Nuclear Science and Techniques 2020年第8期31卷 43-52页

作者： Sheng Lai Xiao-Bin Tang jun-Xu mu Zhao-Peng Feng Yun-Peng Liu Department of Nuclear Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China Key Laboratory of Nuclear Technology Application and Radiation Protection in Astronautics Ministry of Industry and Information TechnologyNanjing 210016China

Stealth technology plays an important role in modern military conflicts, especially when used in fighter jets. Since airfoil structures have a leading edge, inlet, and surface bulge that are easily detected by radar, it is necessary to study the stealth of these structures. In this study,we investigate structures coated with radionuclides to generate plasma. Using simulation and calculation methods, the attenuation of 0.1–10 GHz electromagnetic waves propagating in plasma was studied. The results showed that the attenuation of low-frequency electromagnetic waves is greater than that of high-frequency electromagnetic *** attenuation of 0.1–1 GHz electromagnetic waves is found to be less than-2.7 d B,-3.0 d B, and-15.6 d B at the airfoil leading edge, inlet, and surface bulge structures, respectively. We also found that the attenuation of electromagnetic waves with 0°-incidence is greater than that of waves with 10°, 20°, and 30° incidence ***, the attenuation of electromagnetic waves decreases gradually as the incident angle increases.

关键词： Plasma stealth Radionuclide coating Electromagnetic waves Numerical simulation

Silicon acquisition and accumulation in plant and its significance for agriculture

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Journal of Integrative Agriculture 2018年第10期17卷 2138-2150页

作者： YAN Guo-chao Miroslav Nikolic YE mu-jun XIAO Zhuo-xi LIANG Yong-chao Key Laboratory of Environment Remediation and Ecological Health Ministry of Education/College of Environmental & Resource Sciences Zhejiang University Institute for multidisciplinary Research University of Belgrade

Although silicon（Si） is ubiquitous in soil and plant, evidence is still lacking that Si is essential for higher plants. However, it has been well documented that Si is beneficial for healthy growth of many plant species. Si can promote plant mechanical strength, light interception, as well as resistance to various forms of abiotic and biotic stress, thus improving both yield and quality. Indeed, application of Si fertilizer is a rather common agricultural practice in many countries and regions. As the beneficial effects provided by Si are closely correlated with Si accumulation level in plant, elucidating the possible mechanisms of Si uptake and transport in plants is extremely important to utilize the Si-induced beneficial effects in plants. Recently, rapid progress has been made in unveiling molecular mechanisms of Si uptake and transport in plants. Based on the cooperation of Si influx channels and efflux transporters, a model to decipher Si uptake, transport and distribution system in higher plants has been developed, which involves uptake and radial transport in root, xylem and inter-vascular transport and xylem unloading and deposition in leaf. In this paper, we overviewed the updated knowledge concerning Si uptake, transport and accumulation and its significance for the major crops of agricultural importance and highlighted the further research needs as well.

关键词： silicon uptake transport Si-based fertilizer agriculture

Bioactivity and constituents of several common seaweeds

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Chinese Science Bulletin 2013年第19期58卷 2282-2289页

作者： ZHANG Yi HAN JinYuan mu jun FENG Yan GU XiaoJie JI YuanXi School of Environmental and Chemical Engineering Dalian Jiaotong University School of Life Science and Biotechnology Dalian University of Technology

Bioactivity and constituents of 8 common seaweeds from Dalian intertidal zone of northern Yellow Sea were investigated. In the anti-methicillin-resistant Staphylococcus aureus (MRSA) test, Symphyocladia latiuscula and Enteromorpha intestinalis showed obvious activities with MICs much lower than 1.0 mg·mL-1 . In the DNA damage repair test (DDRT), Chondrus ocellatu showed selective inhibitory activity against the DNA repair-defective E. coli strain vs. the wild-type E. coli strain; while Sym. latiuscula, Enteromorpha intestinalis and Sar. kjellmanianum showed significant anti-E. coli activity with MICs of 64-128 g·mL-1 . In the anti-Pyricularia oryzae test, Sym. latiuscula and Rh. confervoides strongly inhibited the germination of the spores of P. oryzae on agar plate. In the brine shrimp larvicidal test, Sym. latiuscula, Rh. confervoides and Sar. kjellmanianum exhibited potent toxicity against brine shrimp larvae, with LC50 much lower than 1 mg·mL-1 . The HPTLC analysis revealed their diversified secondary metabolites. The HPLC-DAD-MS analysis of the strongest species Sym. latiuscula and database searching showed that it can produce quite diversified metabolites, including halogenated ones, some of which may be new natural products. The results demonstrated the potentials of these seaweeds in the development of new antibiotics, antitumor drugs, agricultural fungicides and pesticides.

关键词：生物活性成分海藻次生代谢产物金黄色葡萄球菌 DNA损伤修复大肠杆菌 DNA修复黄海北部

Structural motion of water-resisting key strata lying on overburden

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Journal of China University of Mining and Technology 2008年第3期18卷 353-357页

作者： PU Hai MIAO Xie-xing YAO Bang-hua TIAN mu-jun School of Sciences China University of Mining ＆ Technology Xuzhou Jiangsu 221116 China State Key Laboratory for Geomechanics ＆ Deep Underground Engineering China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China

Water-preserved mining is one of the important parts of the ‘Green Mining’ technological system. The purpose of wa-ter-preserved mining is to prevent water from bursting out in coal mines and thus to protect water resources. The principle of wa-ter-resisting key strata (WKS) is proposed to establish a model capable of guiding and developing water-preserved mining technol-ogy. The experimental model of the WKS is constructed following requirements of the Data Image Correlative Method (DICM). Five experimental schemes are designed according to different combined patterns of the WKS. The water-resisting performance of the WKS is analyzed from observation of structural stability. All of them provide referential value for water-preserved mining.

关键词： water-preserved mining water-resisting key strata (WKS) digital image correlative method (DICM) water-inrush in coal mine