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Insect Science 2009年第5期16卷 381-386页

作者： Brian David shaw john Tane Christeller The New Zealand Institute of Plant and Food Research Palmerston North New Zealand

The protein digestive capability of the larvae of the longhorn beetle （Oemona hirta, Coleoptera： Cerambycidae, Fabricius, 1775） was investigated. This species feeds only on wood where there is a high proportion of vascular tissue. The pH of the midgut, the major digestive organ, was alkaline and protein hydrolysis was maximal at alkaline pH. Use of specific synthetic peptide substrates showed that the major protease activities were the endopeptidases, trypsin and chymotrypsin-like activity, and the exopeptidase, leucine aminopeptidase and the pH curves corresponded to that with protein substrate. Studies using a range ofserine protease inhibitors as well as specific inhibitors ofmetalloproteases, cysteine proteases and aspartate proteases confirmed a serine protease-based digestive system similar to earlier reports of sapwood-feeding Cerambycids. Control of these insect pests using protease inhibitors is discussed.

关键词： chymotrypsin digestion Oemona hirta trypsin xylophagy

Analysis on variety and characteristics of maghemite

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Science China Earth Sciences 2010年第8期53卷 1153-1162页

作者： shaw john BLOEMENDAL Jan HESSE Paul ROLPH Tim Department of Earth Sciences University of Liverpool Department of Geography University of Liverpool Department of Environment and Geography Macquarie University Department of Geology University of Newcastle

Maghemite (γ-Fe2O3) is a very common mineral at the earth’s surface and also an important material for making music and video tapes. Maghemite is usually synthesized from magnetite under oxidizing conditions after a few hours or a few days below a temperature of 300°C. The magnetic property of thermal instability and the chemical action after heating is an important character for maghemite. That is, it will become hematite in certain proportion after being heated above 250°C. Maghemite is therefore actually unable to have its Curie temperature measured. But late using synthetic sample, maghemite was further found partially thermal stable with a measurable Curie temperature ~645°C. During our thermally magnetic experiments for a set of synthetic magnetite, we found that extra fined grain size (pseudo single domain (PSD) and small multi-domain (MD), mainly 1-10 μm) magnetite was formed to a completely thermally stable maghemite. This maghemite can also be produced by heating the same powder up to 700°C in an oven and keeping this temperature for 10 min, then cooling it down. When the generated maghemite by these two ways is heated from room temperature to 700°C, it shows almost fully reversible, or thermally stable. We used X-ray powder diffraction and Mssbauer spectroscopy to confirm the identity of this maghemite and compared its magnetic hysteresis, high temperature magnetization, low temperature thermal demagnetization, and low temperature susceptibility with those of the original preheated magnetite. Such quickly oxidized maghemite by heating to high temperature implies some types of maghemite formed in certain natural condition can carry a thermal remnant magnetization (TRM). Four types of maghemite were characterized and discussed according to their thermal stability. Among them, partially stable and fully thermally stable maghemite after heating should possess capability of carrying TRM. There is possibly a compensation of synthetizing maghemite between heatin

关键词： maghemite paleomagnetism environmental magnetism magnetic mineral thermal stability TRM

Magnetic polarity ages of the fossil-bearing strata at the Sihetun section,West Liaoning:A preliminary result

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Chinese Science Bulletin 2001年第17期46卷 1473-1476页

作者： PAN Yongxin ZHU Rixiang john shaw ZHOU Yaoxiu Institute of Geology and Geophysics Chinese Academy of SciencesBeijing 100101China Geomagnetism Laboratory University of LiverpoolLiverpool L69 7ZEUK The Aviatic Remote Sensing Center Ministry of Land and ResourcesBeijing 100083China

Rock-magnetic and palaeomagnetic studies have been carried out on the interval of famous fossil-bearing sedimentary rocks and its overlying basalts and underlying basalts at the Sihetun section, West Liaoning Province. Normal polarity was obtained for the sedimentary interval and the underlying basalts, while reversed polarity was found in the overlying basalts. Taking account of the new 40Ar/39Ar ages (Swisher et al., 1999), we classified the fossil-bearing sedimentary interval into the Barremian M3n zone (Early Cretaceous age). Several abnormal horizons on magnetic properties, probably corresponding to the tuffs, were observed in the fossil-bearing sedimentary interval. This implies that the massive bio-extinction may link to dramatic environmental changes that were caused by volcanic eruptions.

关键词： magnetic polarity age Jehol fauna Sihetun section.

Mineral magnetic variation of the Jingbian loess/paleosol sequence in the northern Loess Plateau of China:Implications for Quaternary development of Asian aridification and cooling

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Mineral magnetic variation of the Jingbian loess/paleosol se...

中国科学院地质与地球物理研究所2006学术年会

作者： john shaw Geomagnetism Laboratory Department of Earth and Ocean SciencesUniversity of LiverpoolLiverpool L69 7ZEUK

A high-resolution mineral magnetic investigation has been carried out on the Jingbian loess/paleosol sequence at the northern extremity of the Chinese Loess *** show that the magnetic assemblage is dominated by large pseudo-single domain and multidomain-like magnetite with associated maghemite and *** in the ratios of SIRMT/SIRM, SIRM/SIRM and SIRM/SIRM(SIRM is the saturation isothermal remanent magnetization;SIRM represents the residual SIRM after an n mT alternating field demagnetization) have been used to document regional paieoclimate change in the Asian interior by correlating the mineral magnetic record with the compositeδO record in deep-sea sediments. The long-term up-section decreasing trend in those ratios in both loess and paleosol units has been attributed to a long-term decrease in the relative contributions of eolian hematite during glacial extrema and of pedogenic hematite during interglacial extrema,respectively,which reveals a long-term decreasing trend in chemical weathering intensity in both glacial-stage source region (the Gobi and deserts in northwestern China) and interglacial-stage depositional area(the Loess Plateau region).We further relate this long-timescale variation to long-term increasing aridification and cooling,during both glacial extrema in the dust source region and interglacial extrema in the depositional area,over the Quaternary *** in those ratios are most likely due to Quaternary aridification and cooling driven by ongoing global cooling,expansion of the Arctic ice-sheet,and progressive uplift of the Himalayan-Tibetan complex during this period.

关键词： Chinese Loess Plateau loess paleosol mineral magnetism magnetoclimatology Asian aridification and cooling

Further evidence for low intensity of the geomagnetic field during the early Cretaceous time:using the modified shaw method and microwave technique

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Further evidence for low intensity of the geomagnetic field ...

中国科学院地质与地球物理研究所2004学术年会

作者： Mimi.J.Hill john shaw Geomagnetism Laboratory Department of Earth and Ocean ScienceUniversity of Liverpool.Liverpool L69 7ZE.UK Geomagnetism Laboratory Department of Earth and Ocean ScienceUniversity of LiverpoolLiverpool L69 7ZEUK

We report new absolute palaeointensity estimates using basalts from northeastern China(K/Ar age,125-120 Ma) using the modified shaw method in conjunction with the microwave technique. Samples for the palaeointensity experiments were selected mainly based on their good reversibility of thermomagnetic curves and single primary magnetization *** the modified shaw method,28 out of 45 measured samples from 10 cooling units give a virtual dipole moment of(3.1±1.0)×10 Am,and the microwave technique using 14 acceptable determinations(out of 20 measured) give an average value of(2.9±0.9)×10 Am. Results using both the modified shaw method and the microwave technique demonstrate that the geomagnetic field strength recorded by these lavas was *** is in agreement with previous results of the same time interval obtained by the Thellier method with partial thermal remanence(p-TRM) *** fact that different techniques give qualitatively compatible low palaeointensity results provides greater confidence that the weak field features seen just prior to the Cretaceous normal superchron(CNS) are the result of the actual field recorded by the basalts as opposed to artefacts of the method/*** study also demonstrates that the microwave technique can be used for very old basalts.

关键词： absolute palaeointensity basalt China microwave palaeointensity technique modified shaw method

Reply to comment by *** on“Experimental reassessment of the shaw paleointensity method using laboratory-induced thermal remanent magnetization”

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Reply to comment by *** on“Experimental reassessment of the...

中国科学院地质与地球物理研究所2003学术年会

作者： john shaw Mimi J.Hill Geomagnetism Laboratory University of LiverpoolLiverpoolUK.

INDEX TERMS:1521 Geomagnetism and Paleomagnetism:Paleointensity;,1540 Geomagnetism and Paleomagnetism:Rock and mineral magnetism;1594 Geomagnetism and Paleomagnetism:Instruments and techniques;*** [1]Pan et al.’s[2002]aim was to investigate the reliability of the shaw paleointensity method[shaw,1974;Kono,1978;Rolph and shaw,1985]using basalt samples containing laboratory-induced thermal remanent magnetization as the natural remanent magnetization(NRM).The shaw method usesalternating field(AF) demagnetization of

关键词： paleointensity shaw method anhysteretic remanent magnetization alteration P value

Experimental reassessment of the shaw paleointensity method using laboratory-induced thermal remanent magnetization

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Experimental reassessment of the Shaw paleointensity method ...

中国科学院地质与地球物理研究所2002学术年会

作者： john shaw Mimi J.Hill Geomagnetism Laboratory University of LiverpoolLiverpoolUK

Artificial thermoremanent magnetization imposed on natural basalt samples was used to check the reliability of shaw’s palaeointensity method[shaw,1974;Kono,1978;Rolph and shaw,1985] and to give an indication of the accuracy of ***,thermal remanence was induced in all samples(50 in total) in a known field(50±0.1 mT).This remanence was regarded as the"original"natural remanent magnetization("NRM").The samples were divided in to three subsets(A, B,and C) and intensity experiments were *** subset of samples used different thermal remanent magnetization(TRM) acquisition ***-magnetic properties on 14 representative subsamples were also measured both before and after the TRM acquisition steps to monitor possible magnetochemical *** has been demonstrated that intensity estimates by the shaw method give values close to the expected value(50±5mT) in all three sets of basalt *** modified method with Rolph and shaw[1985]correction,i.e.,using ratios of anhysteretic remanent magnetization given before the TRM step(ARM1) and after(ARM2),is proved to be a powerful approach to correct the TRM capacity changes that result from agnetochemical *** is especially so for sample set C, where the samples were heated up to 700 and then were held at this temperature for 40 min during TRM *** correction,45%of set C samples gave acceptable ***,some samples with strong magnetochemical alteration sometimes invalidated the ARM1/ARM2 ratio correction and gave wrong intensity *** rock magnetic properties is therefore very important when applying the shaw method.

关键词： paleointensity thermal remanent magnetization shaw method rock magnetic checks

Magnetostratigraphy and palaeoclimate of Red Clay sequences from Chinese Loess Plateau

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Science China Earth Sciences 1997年第4期40卷 337-343页

作者：孙东怀刘东生陈明扬安芷生 john shaw Xi'an Laboratory of Loess and Quaternary Geology Chinese Academy of Sciences Xi'an 710054 China Geomagnetism Laboratory University of Liverpool Liverpool L69 7ZE UK

Two Red Clay profiles near Xi' an and Xifeng were investigated in an attempt to determine magne-tostratigraphic and palaeoclimatic records. The results show that aeolian dust accumulation and the related East Asia palaeomonsoon system had begun by 6.5 Ma, and it is deduced that the Tibetan Plateau had reached a significant elevation at that time. The late Tertiary palaeoclimatic history of the Red Clay as reflected by magnetic susceptibility is reconstructed during the period of 6.5-2.5 Ma. Stepwise increase in susceptibility of aeolian dust accumulation appears to have a close correlation to the uplift processes of the Tibetan Plateau. The remarkable increase of aeolian dust accumulation at 3.2 Ma appears to be due to the influence of global ice volume on the East Asia monsoon. Palaeomonsoon variation during the late Tertiary as recorded in the Red Clay sequences from the Chinese Loess Plateau can be regarded as the product of a number of interacting factors, such as uplift of the Tibetan Plateau, solar radiation, global ice volume, etc.

关键词： magnetostratigraphy of Red Clay aeolian dust accumulation monsoon variation uplift of Tibetan Plateau

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中国黄土磁性矿物特征及其古气候意义

第四纪研究 1993年第3期13卷 281-287页

作者：刘秀铭刘东生 john shaw 中国科学院地质研究所英国利物浦大学地磁实验室

最直观、最直接的古气候记录莫过于陆相黄土地层,它由许多黄土和古土壤层叠覆而成,详细地记录了第四纪以来的古气候变化。黄土高原中部黄土和古土壤的风化和发育程度可以用磁学参数,如磁化率等来描述。本文作者对甘肃西峰剖面约13万年... 详细信息

最直观、最直接的古气候记录莫过于陆相黄土地层,它由许多黄土和古土壤层叠覆而成,详细地记录了第四纪以来的古气候变化。黄土高原中部黄土和古土壤的风化和发育程度可以用磁学参数,如磁化率等来描述。本文作者对甘肃西峰剖面约13万年以来的黄土地层做了详细采样,测量其磁滞回线各参数,频率磁化率、低场和高场磁化率、温度磁化率、磁组构等参数。研究表明,黄土与古土壤中的磁性矿物组分相似而且稳定。磁铁矿、赤铁矿和磁赤铁矿(主要是磁铁矿)的含量及其颗粒大小决定了它们的磁学特征。黄土和古土壤的磁学性质差别主要受成土过程中形成细小磁铁矿的影响。

关键词：黄土古气候岩石磁学磁性矿物

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磁赤铁矿的几种类型与特点分析

中国科学：地球科学 2010年第5期40卷 592-602页

作者：刘秀铭 john shaw 蒋建中 Jan BLOEMENDAL Paul HESSE Tim ROLPH 毛学刚兰州大学西部环境与气候变化研究院兰州730000 Department of Environment and Geography Macquarie University Department of Earth and Ocean Sciences University of Liverpool 浙江大学材料与化学工程学院杭州310001 Department of Geography University of Liverpool Department of Geology University of Newcastle

随着环境磁学的广泛开展和应用,最近20年来磁赤铁矿(γ-Fe2O3)被人们所日益熟悉.现在它已经被发现是一种地表十分常见的矿物,与磁铁矿常常相伴随,是氧化透水通气环境的很好指示矿物.它也是制造音乐和录像磁带的重要磁性材料,在工业有很... 详细信息

随着环境磁学的广泛开展和应用,最近20年来磁赤铁矿(γ-Fe2O3)被人们所日益熟悉.现在它已经被发现是一种地表十分常见的矿物,与磁铁矿常常相伴随,是氧化透水通气环境的很好指示矿物.它也是制造音乐和录像磁带的重要磁性材料,在工业有很广泛的用途.磁赤铁矿的人工合成一般由磁铁矿通过在低于300℃的氧化环境中加热几个小时甚至几天时间来形成.它受热不稳定而产生化学变化的磁学性质是其重要特点,即加热到250℃之后该矿物一般就会被不同程度转变成为赤铁矿.因此实际上无法测量其居里点.后来对人工合成磁赤铁矿样品研究进一步发现,该矿物受热可以部分热稳定,居里温度约为645℃.本文通过不同粒度人工磁铁矿系列样品进行热磁测量实验时发现,超细粒级(假单畴(PSD)和多畴(MD)细粒)磁铁矿在快速加热过程中,形成了完全热稳定的磁赤铁矿.而且,用同样的样品在另外加热炉中快速加热到700℃高温,并且在该温度停留10min,然后冷却下来,也可以达到相同的效果.即由此两个过程形成的磁赤铁矿,再从室温加到700℃的居里温度测量过程几乎达到百分之百可逆,即完全对热稳定性特点.我们用X衍射和穆斯堡尔谱技术来鉴定和确认加热前的磁铁矿和快速加热形成的磁赤铁矿(和赤铁矿),并且比较其磁铁矿的磁滞迴线、高温磁化强度、低温热退磁和低温磁化率特性,结果表明,这种过程通过超细磁铁矿加热快速氧化形成完全可逆具有热稳定性质的磁赤铁矿,可能暗示着在某些加热环境形成的磁赤铁矿也可能携带热剩磁.根据磁赤铁矿是否受热不稳定及其表现形式,将它详细分成4种类型探讨分析.受热后部分稳定和完全稳定的磁赤铁矿应当具备携带热剩磁的能力.人工合成磁赤铁矿的温度与其反应时间可能有个互补关系.磁赤铁受热后稳定与否可能与多种因素有关,如受纯度大小、受热温度高低和时间长短等影响,粒度大小可能也是重要因素之一.磁赤铁矿可能如同磁铁矿,也有不同粒级超顺磁(SP)、单畴(SD)和MD对应着不同的磁学特点.细粒PSD氧化的人工磁铁矿在低温磁学测量显示为Verwey转换被"抑制"的现象,其根本原因可能是,氧化后磁铁矿的内核直径实际上已经达到或者接近该矿物的SD粒径,所以它的Verwey转换显得被"抑制".

关键词：磁性矿物磁赤铁矿古地磁环境磁学热稳定性携带热剩磁