This study, carried out in the Léo square degree (west-central Burkina Faso) in the Palaeoproterozoic domain of the Man/Léo ridge, aims to define the shapes and positions of granitic plutons and the organisa...This study, carried out in the Léo square degree (west-central Burkina Faso) in the Palaeoproterozoic domain of the Man/Léo ridge, aims to define the shapes and positions of granitic plutons and the organisation of deformation structures using aeromagnetic data. These data have shown that there are small sub-circular granitic bodies to the north of the granitic masses in this region, and a large sub-circular granitic body to the south, around which are other smaller granitic bodies. The lineament map shows that the deformation structures are organised along three main directions and largely form these sub-circular plutonic bodies. We suggest that the granitic plutons are coalescent, pending identification of the internal structures of these granites to further refine the geodynamic model.展开更多
A miniature quad-channel optically pumped atomic magnetometer(OPM) has been developed based on the spinexchange relaxation-free(SERF) mechanism. With a vapor cell of size 8 mm×8 mm×8 mm, we have incorporated...A miniature quad-channel optically pumped atomic magnetometer(OPM) has been developed based on the spinexchange relaxation-free(SERF) mechanism. With a vapor cell of size 8 mm×8 mm×8 mm, we have incorporated four SERF magnetometer channels, which provides sufficient spatial resolution for magnetoencephalography(MEG). The four channels share the same laser beam for the best cancellation of common mode noise due to laser fluctuations. With gradient measurement, the sensitivities of the four sensors are better than 6 fT/Hz^(1/2), which is also good enough for MEG measurement. The vapor cell is heated to 160℃ by a novel nonmagnetic current-heating structure. Our sensor with high spatial resolution and compact size is particularly suitable for MEG systems.展开更多
The chemical composition and microstructure of Tibetan microcrystalline magnesite were studied by means of XRF,XRD and FESEM. It is found that the microcrystalline magnesite has uniformly distributed grains,mostly in ...The chemical composition and microstructure of Tibetan microcrystalline magnesite were studied by means of XRF,XRD and FESEM. It is found that the microcrystalline magnesite has uniformly distributed grains,mostly in the range of 2-4 μm,and the MgO content is47. 80%. In fused magnesia,the druses are colorless transparent periclase megacrysts without impurity,while the crust sand is white,with a high MgO content up to97%-99%. The periclase crystals are big,appearing as faced and step-growth morphology. Massive secondary long columnar periclase is crystallized.展开更多
This paper reports that the SmCo6.8Zr0.2 nanocrystalline permanent magnets and SmCo6.8Zr0.2/a-（Fe,Co） nanocomposite permanent magnets are successfully produced by mechanical alloying and subsequently annealing at 70...This paper reports that the SmCo6.8Zr0.2 nanocrystalline permanent magnets and SmCo6.8Zr0.2/a-（Fe,Co） nanocomposite permanent magnets are successfully produced by mechanical alloying and subsequently annealing at 700℃ for 10 minutes. The x-ray diffraction results show that the phase structure of SmCo6.8Zr0.2 nanocrystalline permanent magnets is composed of SmCo7 phase and SmCo6.8Zr0.2/a-（Fe,Co） nanocomposite permanent magnets is composed of SmCo7 and a-（Fe,Co） phases. The mechanism of magnetization reversal is mainly controlled by inhomogeneous domain wall pinning in SmCo6.8Zr0.2 and SmCo6.8Zr0.2/a-（Fe,Co） magnets. The inter-grain exchange interaction at low temperature is investigated, which shows that the inter-grain exchange interaction of SmCo6.8Zr0.2/a-（Fe,Co） magnets increases greatly by the decrease of the measured temperature. According to Amirr-H/Hcj, Amrev-H/Hcj and Xirr-H/Hcj curves at room temperature and 100 K, the changes of irreversible and reversible magnetization behaviours of SmCo6.8Zr0.2 and SmCo6.8Zr0.2/a-（Fe,Co） magnets with the decreasing temperature are analysed in detail. The magnetic viscosity and the activation volume of SmCo6.8Zr0.2 and SmCo6.8Zr0.2/a-（Fe,Co） magnets at different temperatures are also studied.展开更多
Pancreatic ductal adenocarcinoma is the most common malignant tumor of the pancreas. The remaining pancreatic tumors are a diverse group of pancreatic neoplasms that comprises cystic pancreatic neoplasms, endocrine tu...Pancreatic ductal adenocarcinoma is the most common malignant tumor of the pancreas. The remaining pancreatic tumors are a diverse group of pancreatic neoplasms that comprises cystic pancreatic neoplasms, endocrine tumors and other uncommon pancreatic tumors. Due to the excellent soft tissue contrast resolution, magnetic resonance imaging(MRI) is frequently able to readily separate cystic from noncystic tumors. Cystic tumors are often easy to diagnose with MRI; however, noncystic non-adenocarcinoma tumors may show a wide spectrum of imaging features, which can potentially mimic ductal adenocarcinoma. MRI is a reliable technique for the characterization of pancreatic lesions. The implementation of novel motionresistant pulse sequences and respiratory gating techniques, as well as the recognized benefits of MR cholangiopancreatography, make MRI a very accurate examination for the evaluation of pancreatic masses. MRI has the distinctive ability of non-invasive assessment of the pancreatic ducts, pancreatic parenchyma, neighbouring soft tissues, and vascular network in one examination. MRI can identify different characteristics of various solid pancreatic lesions, potentially allowing the differentiation of adenocarcinoma from other benign and malignant entities. In this review we describe the MRI protocols and MRI characteristics of various solid pancreatic lesions. Recognition of these characteristics may establish the right diagnosis or at least narrow the differential diagnosis, thus avoiding unnecessary tests or procedures and permitting better management.展开更多
[ Objective ] The aim was to screen out chemicals with good control effect against Mycogone peniciosa Magn in Agaricus bisporus. [ Method ] M. peniciosa ofA. b/sporus was taken as the detection bacteria, and nine kind...[ Objective ] The aim was to screen out chemicals with good control effect against Mycogone peniciosa Magn in Agaricus bisporus. [ Method ] M. peniciosa ofA. b/sporus was taken as the detection bacteria, and nine kinds of chemicals were conducted plate efficacy test in the laboratory. Mushroom house validation was carried out for the screened chemicals with strong inhibition to M. peniciosa. [ Result] Nine kinds of chemicals had obvious difference in control effects on M. peniciosa and effects on growth ofA. bisporus; 2 400 and 3 200 times dilution of 78% Boer MZ WP and 2 400 times dilution of 69% Fulishuang WP after casing material processing had good control effects on M. peniciosa and had no apparent adverse effects on mycelial growth and fruiting development of A. bisporus. [ Conclusion] The 2 400 and 3 200 times dilution of 78% Boer MZ WP and 2 400 times dilution of 69% Fulishuang WP are worth popularizing.展开更多
Magneli phase titanium sub-oxide conductive ceramic Tin O2n-1 was used as the support for Pt due to its excellent resistance to electrochemical oxidation, and Pt/Tin O2n-1 composites were prepared by the impregnation-...Magneli phase titanium sub-oxide conductive ceramic Tin O2n-1 was used as the support for Pt due to its excellent resistance to electrochemical oxidation, and Pt/Tin O2n-1 composites were prepared by the impregnation-reduction method. The electrochemical stability of Tin O2n-1 was investigated and the results show almost no change in the redox region after oxidation for 20 h at 1.2 V(vs NHE) in 0.5 mol/L H2SO4 aqueous solution. The catalytic activity and stability of the Pt/Tin O2n-1 toward the oxygen reduction reaction(ORR) in 0.5 mol/L H2SO4 solution were investigated through the accelerated aging tests(AAT), and the morphology of the catalysts before and after the AAT was observed by transmission electron microscopy. At the potential of 0.55 V(vs SCE), the specific kinetic current density of the ORR on the Pt/Tin O2n-1 is about 1.5 times that of the Pt/C. The LSV curves for the Pt/C shift negatively obviously with the half-wave potential shifting about 0.02 V after 8000 cycles AAT, while no obvious change takes place for the LSV curves for the Pt/Tin O2n-1. The Pt particles supported on the carbon aggregate obviously, while the morphology of the Pt supported on Tin O2n-1 remains almost unchanged, which contributes to the electrochemical surface area loss of Pt/C being about 2times that of the Pt/Tin O2n-1. The superior catalytic stability of Pt/Tin O2n-1 toward the ORR could be attributed to the excellent stability of the Tin O2n-1 and the electronic interaction between the metals and the support.展开更多
To the Editor:More than half of the patients undergoing invasive coronary angiography for angina or signs of myocardial ischemia present with non-obstructive coronary arteries(NOCA,<50%diameter reduction or fractio...To the Editor:More than half of the patients undergoing invasive coronary angiography for angina or signs of myocardial ischemia present with non-obstructive coronary arteries(NOCA,<50%diameter reduction or fractional flow reserve>0.80).[1]Coronary microvascular dysfunction(CMD)is a significant pathophysiological factor in these patients and is linked to adverse outcomes.[2]Although coronary reactivity testing(CRT)remains the gold standard for diagnosing CMD,it is both invasive and costly.Stress cardiac magnetic resonance(CMR)is a non-invasive and promising alternative,providing essential perfusion parameters such as myocardial perfusion reserve index(MPRI)and myocardial perfusion reserve(MPR)to diagnose CMD.Thus,based on current literature,there is robust evidence supporting the effectiveness of stress CMR in diagnosing CMD in patients with NOCA,as defined by CRT.展开更多
文摘This study, carried out in the Léo square degree (west-central Burkina Faso) in the Palaeoproterozoic domain of the Man/Léo ridge, aims to define the shapes and positions of granitic plutons and the organisation of deformation structures using aeromagnetic data. These data have shown that there are small sub-circular granitic bodies to the north of the granitic masses in this region, and a large sub-circular granitic body to the south, around which are other smaller granitic bodies. The lineament map shows that the deformation structures are organised along three main directions and largely form these sub-circular plutonic bodies. We suggest that the granitic plutons are coalescent, pending identification of the internal structures of these granites to further refine the geodynamic model.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2016YFA0300600 and 2016YFA0301500)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB07030000)the National Natural Science Foundation of China(Grant No.11474347)
文摘A miniature quad-channel optically pumped atomic magnetometer(OPM) has been developed based on the spinexchange relaxation-free(SERF) mechanism. With a vapor cell of size 8 mm×8 mm×8 mm, we have incorporated four SERF magnetometer channels, which provides sufficient spatial resolution for magnetoencephalography(MEG). The four channels share the same laser beam for the best cancellation of common mode noise due to laser fluctuations. With gradient measurement, the sensitivities of the four sensors are better than 6 fT/Hz^(1/2), which is also good enough for MEG measurement. The vapor cell is heated to 160℃ by a novel nonmagnetic current-heating structure. Our sensor with high spatial resolution and compact size is particularly suitable for MEG systems.
文摘The chemical composition and microstructure of Tibetan microcrystalline magnesite were studied by means of XRF,XRD and FESEM. It is found that the microcrystalline magnesite has uniformly distributed grains,mostly in the range of 2-4 μm,and the MgO content is47. 80%. In fused magnesia,the druses are colorless transparent periclase megacrysts without impurity,while the crust sand is white,with a high MgO content up to97%-99%. The periclase crystals are big,appearing as faced and step-growth morphology. Massive secondary long columnar periclase is crystallized.
基金Project supported by the Natural Science Foundation of Zhejiang Province of China (Grant No.Y407174)Major Scientific and Technological Special Fund of Zhejiang Province of China (Grant No.2007C11046)the National Basic Research Program of China (Grant No.2010CB934601)
文摘This paper reports that the SmCo6.8Zr0.2 nanocrystalline permanent magnets and SmCo6.8Zr0.2/a-（Fe,Co） nanocomposite permanent magnets are successfully produced by mechanical alloying and subsequently annealing at 700℃ for 10 minutes. The x-ray diffraction results show that the phase structure of SmCo6.8Zr0.2 nanocrystalline permanent magnets is composed of SmCo7 phase and SmCo6.8Zr0.2/a-（Fe,Co） nanocomposite permanent magnets is composed of SmCo7 and a-（Fe,Co） phases. The mechanism of magnetization reversal is mainly controlled by inhomogeneous domain wall pinning in SmCo6.8Zr0.2 and SmCo6.8Zr0.2/a-（Fe,Co） magnets. The inter-grain exchange interaction at low temperature is investigated, which shows that the inter-grain exchange interaction of SmCo6.8Zr0.2/a-（Fe,Co） magnets increases greatly by the decrease of the measured temperature. According to Amirr-H/Hcj, Amrev-H/Hcj and Xirr-H/Hcj curves at room temperature and 100 K, the changes of irreversible and reversible magnetization behaviours of SmCo6.8Zr0.2 and SmCo6.8Zr0.2/a-（Fe,Co） magnets with the decreasing temperature are analysed in detail. The magnetic viscosity and the activation volume of SmCo6.8Zr0.2 and SmCo6.8Zr0.2/a-（Fe,Co） magnets at different temperatures are also studied.
文摘Pancreatic ductal adenocarcinoma is the most common malignant tumor of the pancreas. The remaining pancreatic tumors are a diverse group of pancreatic neoplasms that comprises cystic pancreatic neoplasms, endocrine tumors and other uncommon pancreatic tumors. Due to the excellent soft tissue contrast resolution, magnetic resonance imaging(MRI) is frequently able to readily separate cystic from noncystic tumors. Cystic tumors are often easy to diagnose with MRI; however, noncystic non-adenocarcinoma tumors may show a wide spectrum of imaging features, which can potentially mimic ductal adenocarcinoma. MRI is a reliable technique for the characterization of pancreatic lesions. The implementation of novel motionresistant pulse sequences and respiratory gating techniques, as well as the recognized benefits of MR cholangiopancreatography, make MRI a very accurate examination for the evaluation of pancreatic masses. MRI has the distinctive ability of non-invasive assessment of the pancreatic ducts, pancreatic parenchyma, neighbouring soft tissues, and vascular network in one examination. MRI can identify different characteristics of various solid pancreatic lesions, potentially allowing the differentiation of adenocarcinoma from other benign and malignant entities. In this review we describe the MRI protocols and MRI characteristics of various solid pancreatic lesions. Recognition of these characteristics may establish the right diagnosis or at least narrow the differential diagnosis, thus avoiding unnecessary tests or procedures and permitting better management.
基金Supported by Science and Technology Project of Jiaxing Science and Technology Bureau (2010AY1014)
文摘[ Objective ] The aim was to screen out chemicals with good control effect against Mycogone peniciosa Magn in Agaricus bisporus. [ Method ] M. peniciosa ofA. b/sporus was taken as the detection bacteria, and nine kinds of chemicals were conducted plate efficacy test in the laboratory. Mushroom house validation was carried out for the screened chemicals with strong inhibition to M. peniciosa. [ Result] Nine kinds of chemicals had obvious difference in control effects on M. peniciosa and effects on growth ofA. bisporus; 2 400 and 3 200 times dilution of 78% Boer MZ WP and 2 400 times dilution of 69% Fulishuang WP after casing material processing had good control effects on M. peniciosa and had no apparent adverse effects on mycelial growth and fruiting development of A. bisporus. [ Conclusion] The 2 400 and 3 200 times dilution of 78% Boer MZ WP and 2 400 times dilution of 69% Fulishuang WP are worth popularizing.
基金Project(21406273)supported by the National Natural Science Foundation of China
文摘Magneli phase titanium sub-oxide conductive ceramic Tin O2n-1 was used as the support for Pt due to its excellent resistance to electrochemical oxidation, and Pt/Tin O2n-1 composites were prepared by the impregnation-reduction method. The electrochemical stability of Tin O2n-1 was investigated and the results show almost no change in the redox region after oxidation for 20 h at 1.2 V(vs NHE) in 0.5 mol/L H2SO4 aqueous solution. The catalytic activity and stability of the Pt/Tin O2n-1 toward the oxygen reduction reaction(ORR) in 0.5 mol/L H2SO4 solution were investigated through the accelerated aging tests(AAT), and the morphology of the catalysts before and after the AAT was observed by transmission electron microscopy. At the potential of 0.55 V(vs SCE), the specific kinetic current density of the ORR on the Pt/Tin O2n-1 is about 1.5 times that of the Pt/C. The LSV curves for the Pt/C shift negatively obviously with the half-wave potential shifting about 0.02 V after 8000 cycles AAT, while no obvious change takes place for the LSV curves for the Pt/Tin O2n-1. The Pt particles supported on the carbon aggregate obviously, while the morphology of the Pt supported on Tin O2n-1 remains almost unchanged, which contributes to the electrochemical surface area loss of Pt/C being about 2times that of the Pt/Tin O2n-1. The superior catalytic stability of Pt/Tin O2n-1 toward the ORR could be attributed to the excellent stability of the Tin O2n-1 and the electronic interaction between the metals and the support.
基金supported by the National Key R&D Program of China(Nos.2021YFF0501400 and 2021YFF0501404)the Key Project of National Natural Science Foundation of China(No.81930044).
文摘To the Editor:More than half of the patients undergoing invasive coronary angiography for angina or signs of myocardial ischemia present with non-obstructive coronary arteries(NOCA,<50%diameter reduction or fractional flow reserve>0.80).[1]Coronary microvascular dysfunction(CMD)is a significant pathophysiological factor in these patients and is linked to adverse outcomes.[2]Although coronary reactivity testing(CRT)remains the gold standard for diagnosing CMD,it is both invasive and costly.Stress cardiac magnetic resonance(CMR)is a non-invasive and promising alternative,providing essential perfusion parameters such as myocardial perfusion reserve index(MPRI)and myocardial perfusion reserve(MPR)to diagnose CMD.Thus,based on current literature,there is robust evidence supporting the effectiveness of stress CMR in diagnosing CMD in patients with NOCA,as defined by CRT.
