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Unbound^(28)O,the heaviest oxygen isotope observed:a cutting-edge probe for testing nuclear models 被引量:1
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作者 jian-guo li Bai-Shan Hu +1 位作者 Shuang Zhang Fu-Rong Xu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第2期1-2,共2页
The beyond-dripline oxygen isotopes^(27,28)O were recently observed at RIKEN,and were found to be unbound decaying into^(24)O by emitting neutrons.The unbound feature of the heaviest oxygen isotope,^(28)O,provides an ... The beyond-dripline oxygen isotopes^(27,28)O were recently observed at RIKEN,and were found to be unbound decaying into^(24)O by emitting neutrons.The unbound feature of the heaviest oxygen isotope,^(28)O,provides an excellent test for stateof-the-art nuclear models.The atomic nucleus is a self-organized quantum manybody system comprising specific numbers of protons Z and neutrons N. 展开更多
关键词 TESTING QUANTUM system
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Annexin A1 Mimetic Peptide AC2-26 Inhibits Sepsis-induced Cardiomyocyte Apoptosis through LXA4/PI3K/AKT Signaling Pathway 被引量:11
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作者 li ZHANG Yan-lei ZHENG +5 位作者 Rong-hua HU li ZHU Chen-chen HU Fei CHENG Shi li jian-guo li 《Current Medical Science》 SCIE CAS 2018年第6期997-1004,共8页
The aim of the present study was to explore the effects of annexin A1(ANXA1) mimetic peptide AC2-26 on sepsis-induced cardiomyocyte apoptosis in vivo and in vitro and the underlying mechanisms.In the in vivo study,a r... The aim of the present study was to explore the effects of annexin A1(ANXA1) mimetic peptide AC2-26 on sepsis-induced cardiomyocyte apoptosis in vivo and in vitro and the underlying mechanisms.In the in vivo study,a rat septic model was established by the cecal ligation and puncture (CLP).The rats were divided into control group,sepsis group and AC2-26 group.The rats in the AC2-26 group were intraperitoneally injected with AC2-26(1mg/kg)2h before CLP,and those in the control group and sepsis group were injected with the same volume of normal saline.The myocardial tissue was examined by hematoxylin and eosin (HE)staining and transmission electron microscopy (TEM).Furthermore,myocardial apoptosis was measured by terminal dUTP nick end-labeling (TUNEL)assay.In the in vitro study,H9C2cells were cultured and divided into three groups:control group,in which cells were only given the basic culture medium;LPS group,in which cells were treated with 10μg/mL LPS;AC2-26 group,in which cells were treated with 0.5μmol/L AC2-262h before 10μg/mL LPS was given.The apoptosis of H9C2 cells was detected by flow cytometry.The levels of lipoxin A4 receptor (LXA4),phosphoinositide3-kinase (PI3K)and protein kinase B (PKB or AKT)protein were measured by Western blotting, the activity of NF-KB and the level of TNF-α by ELISA and the activities of caspase-3/8by using the caspase activity kits.The in vivo study showed that the myocardial pathological damage and myocardial ultrastructural damage were significantly alleviated and the myocardial apoptosis significantly decreased in the AC2-26 group as compared with the sepsis group (P<0.05 for all). The in vivo study revealed that the apoptosis of H9C2 cells was profoundly ameliorated in the AC2-26 group relative to the sepsis group (P<0.05).The protein expression levels of LXA4 were significantly up-regulated,and those of PI3K and AKT prominently down-regulated in the AC2-26 group when compared with those in the LPS group (P<0.05 for all).The activity of NF-κB was greatly inhibited and the level of TNF-α markedly decreased in the AC2-26 group as compared with those in the LPS group (P<0.05 for all).AC2-26 treatment also significantly suppressed the activities of caspase-3/8 in H9C2 cells.In conclusion,these findings suggest that AC2-26 may alleviate the sepsis-induced cardiomyocyte apoptosis in vivo and in vivo through the LXA4/PI3K/ AKT signaling pathway. 展开更多
关键词 SEPSIS AC2-26 H9C2 apoptosis inflammation
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Mechanism to remove oxide inclusions from molten aluminum by solid fluxes refining method 被引量:4
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作者 Cong li jian-guo li +1 位作者 Yi-zhe Mao Jia-cheng Ji 《China Foundry》 SCIE 2017年第4期233-243,共11页
A novel flux charging method and a crucible quenching method were employed to study the mechanism of solid fluxes refining method regarding the removal of oxide inclusions(Al_2O_3) from molten aluminum. Electrochemica... A novel flux charging method and a crucible quenching method were employed to study the mechanism of solid fluxes refining method regarding the removal of oxide inclusions(Al_2O_3) from molten aluminum. Electrochemical polishing method was adopted to prepare surfaces of the samples. Through experiments, the morphology of the residual solidified flux in the solidified samples as well as the wetting action of the molten flux during refining were observed for the first time. Three wetting regimes denoted by absorbing regime, engulfing regime and penetration regime correlating with the removal of oxide films(the most typical and common oxide inclusions in molten aluminum) were proposed in terms of different types and distributions of oxide films and different size ratios of the molten flux to oxide films. Particularly, from a thermodynamic point of view, for the first time, the penetration regime provided concrete evidence that the practical oxide inclusions can be wet by molten flux under ambient fluid of molten aluminum. A spreading model was proposed, according to which ingredients and size parameters of practical solid fluxes can be optimized. 展开更多
关键词 MELT quality INCLUSIONS removal MELT treatment FLUXES aluminum CASTING
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Recent progress on apparatus development and in situ observation of metal solidification processes via synchrotron radiation X-ray imaging: A review 被引量:3
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作者 Wen-quan LU Nai-fang ZHANG +2 位作者 Zong-ye DING Qiao-dan HU jian-guo li 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第8期2451-2479,共29页
The solidification process of metals plays a critical role in their final microstructure and, correspondingly, in their performance. It is therefore important to probe the solidification behavior of metals using advan... The solidification process of metals plays a critical role in their final microstructure and, correspondingly, in their performance. It is therefore important to probe the solidification behavior of metals using advanced in situ techniques. Synchrotron radiation X-ray imaging is one of the most powerful techniques to observe the solidification process of metals directly. Here, we review the development of the solidification apparatus, including the directional solidification device, resistance furnace, multi-field coupling device, semisolid forming device, aerodynamic levitation apparatus, and laser additive manufacturing apparatus. We highlight the recent research progress on the use of synchrotron radiation X-ray imaging to reveal the solidification behavior of metals in the above circumstances. The future perspectives of synchrotron radiation X-ray imaging in metal research are discussed. Further development of this technique will contribute to improve the understanding of the solidification process of metals and other types of materials at different scales. 展开更多
关键词 synchrotron radiation imaging in situ observation solidification behavior solidification apparatus METAL
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SIRT1 facilitates amyloid beta peptide degradation by upregulating lysosome number in primary astrocytes 被引量:2
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作者 Min-Zhe li liang-Jun Zheng +5 位作者 Jian Shen Xin-Ya li Qi Zhang Xue Bai Qing-Song Wang jian-guo li 《Neural Regeneration Research》 SCIE CAS CSCD 2018年第11期2005-2013,共9页
Previous studies have shown that sirtuin 1(SIRT1) reduces the production of neuronal amyloid beta(Aβ) and inhibits the inflammatory response of glial cells, thereby generating a neuroprotective effect against Aβ... Previous studies have shown that sirtuin 1(SIRT1) reduces the production of neuronal amyloid beta(Aβ) and inhibits the inflammatory response of glial cells, thereby generating a neuroprotective effect against Aβ neurotoxicity in animal models of Alzheimer's disease. However, the protective effect of SIRT1 on astrocytes is still under investigation. This study established a time point model for the clearance of Aβ in primary astrocytes. Results showed that 12 hours of culture was sufficient for endocytosis of oligomeric Aβ, and 36 hours sufficient for effective degradation. Immunofluorescence demonstrated that Aβ degradation in primary astrocytes relies on lysosome function. Enzymatic agonists or SIRT1 inhibitors were used to stimulate cells over a concentration gradient. Aβ was co-cultured for 36 hours in medium. Western blot assay results under different conditions revealed that SIRT1 relies on its deacetylase activity to promote intracellular Aβ degradation. The experiment further screened SIRT1 using quantitative proteomics to investigate downstream, differentially expressed proteins in the Aβ degradation pathway and selected the ones related to enzyme activity of SIRT1. Most of the differentially expressed proteins detected are close to the primary astrocyte lysosomal pathway. Immunofluorescence staining demonstrated that SIRT1 relies on its deacetylase activity to upregulate lysosome number in primary astrocytes. Taken together, these findings confirm that SIRT1 relies on its deacetylase activity to upregulate lysosome number, thereby facilitating oligomeric Aβ degradation in primary astrocytes. 展开更多
关键词 nerve regeneration amyloid beta peptide Alzheimer's disease NEURODEGENERATION ASTROCYTES gliocytes sirtuin 1 quantitative proteomics LYSOSOME time point model peptide degradation neural regeneration
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Intelligent Mining Technology for an Underground Metal Mine Based on Unmanned Equipment 被引量:39
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作者 jian-guo li Kai Zhan 《Engineering》 2018年第3期381-391,共11页
This article analyzes the current research status and development trend of intelligent technologies for underground metal mines in China, where such technologies are under development for use to develop mineral resour... This article analyzes the current research status and development trend of intelligent technologies for underground metal mines in China, where such technologies are under development for use to develop mineral resources in a safe, efficient, and environmentally friendly manner. We analyze and summarize the research status of underground metal mining technology at home and abroad, including some specific examples of equipment, technology, and applications. We introduce the latest equipment and technolo- gies with independent intellectual property rights for unmanned mining, including intelligent and unmanned control technologies for rock-drilling jumbos, down-the-hole (DTH) drills, underground scrapers, underground mining trucks, and underground charging vehicles. Three basic platforms are used for intelligent and unmanned mining: the positioning and navigation platform, information-acquisition and communication platform, and scheduling and control platform. Unmanned equipment was tested in the Fankou Lead-Zinc Mine in China, and industrial tests on the basic platforms of intelligent and unmanned mining were carried out in the mine. The experiment focused on the intelligent scraper, which can achieve autonomous intelligent driving by relying on a wireless communication system, location and navigation system, and data-acquisition system. These industrial experiments indicate that the technol- ogy is feasible. The results show that unmanned mining can promote mining technology in China to an intelligent level and can enhance the core competitive ability of China's mining industry. 展开更多
关键词 UNDERGROUND AUTONOMOUS COMMUNICATION NAVIGATION INTELLIGENT
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Abnormal breakdown of Stokes–Einstein relation in liquid aluminium
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作者 Chen-Hui li Xiu-Jun Han +1 位作者 Ying-Wei Luan jian-guo li 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第1期333-343,共11页
We present the results of systematic molecular dynamics simulations of pure aluminium melt with a well-accepted embedded atom potential. The structure and dynamics were calculated over a wide temperature range, and th... We present the results of systematic molecular dynamics simulations of pure aluminium melt with a well-accepted embedded atom potential. The structure and dynamics were calculated over a wide temperature range, and the calculated results(including the pair correlation function, self-diffusion coefficient, and viscosity) agree well with the available experimental observations. The calculated data were used to examine the Stokes–Einstein relation(SER). The results indicate that the SER begins to break down at a temperature Tx(-1090 K) which is well above the equilibrium melting point(912.5 K).This high-temperature breakdown is confirmed by the evolution of dynamics heterogeneity, which is characterised by the non-Gaussian parameter α2(t). The maximum value of α 2(t), α(2,max), increases at an accelerating rate as the temperature falls below Tx. The development of α(2,max) was found to be related to the liquid structure change evidenced by local fivefold symmetry. Accordingly, we suggest that this high-temperature breakdown of SER has a structural origin. The results of this study are expected to make researchers reconsider the applicability of SER and promote greater understanding of the relationship between dynamics and structure. 展开更多
关键词 diffusion VISCOSITY dynamics heterogeneity local five-fold symmetry
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Size distribution of inclusions in 12%Cr stainless steel with a wide range of solidification cooling rates
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作者 Han-song Yu jian-guo li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2015年第11期1157-1162,共6页
The effect of solidification cooling rate on the size and distribution of inclusions in 12%Cr stainless steel was investigated. A wide range of solidification cooling rates(from 0.05 to 106 K·s^-1) was achieved... The effect of solidification cooling rate on the size and distribution of inclusions in 12%Cr stainless steel was investigated. A wide range of solidification cooling rates(from 0.05 to 106 K·s^-1) was achieved using various solidification processes, including conventional casting, laser remelting, and melt spinning. The size and distribution of inclusions in the steel were observed and statistically collected. For comparison, mathematical models were used to calculate the sizes of inclusions at different solidification cooling rates. Both the statistical size determined from observations and that predicted from calculations tended to decrease with increasing cooling rate; however, the experimental and calculated results did not agree well with each other at excessively high or low cooling rate. The reasons for this discrepancy were theoretically analyzed. For the size distribution of inclusions, the effect of cooling rate on the number densities of large-sized(〉 2 μm) inclusions and small-sized(≤ 2 μm) inclusions were distinct. The number density of inclusions larger than 1 μm was not affected when the cooing rate was less than or equal to 6 K·s^-1 because inclusion precipitation was suppressed by the increased cooling rate. 展开更多
关键词 solidification cooling rate inclusions size distribution number density stainless steels
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Effect of a disposable endoscope precleaning kit in the cleaning procedure of gastrointestinal endoscope:A multi-center observational study 被引量:1
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作者 Yi-Fan Wang Yu Wu +10 位作者 Xiao-Wei liu jian-guo li Yan-Qiong Zhan Bin liu Wen-ling Fan Zi-Heng Peng Jin-Tao Xiao Bing-Bing li Jian He Jun Yi Zhao-Xia Lu 《World Journal of Gastrointestinal Endoscopy》 2023年第12期705-714,共10页
BACKGROUND Precleaning is a key step in endoscopic reprocessing.AIM To develop an effective and economic endoscope cleaning method by using a disposable endoscope bedside precleaning kit.METHODS Altogether,228 used ga... BACKGROUND Precleaning is a key step in endoscopic reprocessing.AIM To develop an effective and economic endoscope cleaning method by using a disposable endoscope bedside precleaning kit.METHODS Altogether,228 used gastrointestinal endoscopes were selected from five high-volume endoscopy units and precleaned by a traditional precleaning bucket(group T)or a disposable endoscope bedside precleaning kit(group D).Each group was further subdivided based on the replacement frequency of the cleaning solution,which was replaced every time in subgroups T1 and D1 and every several times in subgroups Ts and Ds.The adenosine triphosphate(ATP)level and residual proteins were measured three times:Before and after precleaning and after manual cleaning.RESULTS After precleaning,the precleaning kit significantly reduced the ATP levels(P=0.034)and has a more stable ATP clearance rate than the traditional precleaning bucket.The precleaning kit also saved a quarter of the cost of enzymatic detergent used during the precleaning process.After manual cleaning,the ATP levels were also significantly lower in the precleaning kit group than in the traditional precleaning bucket group(P<0.05).Meanwhile,the number of uses of the cleaning solution(up to four times)has no significant impact on the cleaning effect(P>0.05).CONCLUSION Considering its economic cost and cleaning effect,the use of a disposable endoscope bedside precleaning kit can be an optimal option in the precleaning stage with the cleaning solution being replaced several times in the manual cleaning stage. 展开更多
关键词 Cleaning effect Economic cost ENDOSCOPE Multi-center study Precleaning
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Donor-Derived Transmission of Scedosporiosis in Kidney Transplant Recipients from a Systemic lupus erythematosus donor
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作者 Cheng ZENG Yong-sheng MA +7 位作者 Jun-ying ZHOU Cheng-biao XUE Yan XIONG Wei ZHOU li-hua ZHOU jian-guo li Shao-jun YE Qi-fa YE 《Current Medical Science》 SCIE CAS 2023年第2期417-420,共4页
Donor-derived infection(DDI)associated with Scedosporium spp is extremely rare,and results in a very poor prognosis.The present study reports a probable DDI due to Scedosporium boydii(S.boydii)from a donor with neurop... Donor-derived infection(DDI)associated with Scedosporium spp is extremely rare,and results in a very poor prognosis.The present study reports a probable DDI due to Scedosporium boydii(S.boydii)from a donor with neuropsychiatric systemic lupus erythematosus.Two recipients developed Scedosporiosis after kidney transplantation from the same donor.Recipient 1 died of central nervous system infection due to S.boydii based on the clinical presentations,and the positive metagenomic next-generation sequencing(mNGS)and culture results for the cerebrospinal fluid.The other recipient with urinary tract obstruction due to S.boydii,which was identified through the positive culture and mNGS results of the removed stents,was successfully treated by stent replacement and voriconazole administration.Undiagnosed disseminated donor infection and the transmission of S.boydii should be given attention,particularly when the donor and recipients have primary immunodeficiency disease.The screening of donors and recipients for S.boydii using mNGS may be helpful in guiding antifungal prophylaxis and treatment recipients,due to its higher sensitivity and shorter diagnostic time relative to other traditional techniques. 展开更多
关键词 kidney transplant Scedosporium boydii fungal infection donor-derived infection
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Performance of supersonic model combustors with staged injections of supercritical aviation kerosene 被引量:4
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作者 Feng-Quan Zhong Xue-Jun Fan +2 位作者 Gong Yu jian-guo li Chih-Jen Sung 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2010年第5期661-668,共8页
Supersonic model combustors using two-stage injections of supercritical kerosene were experimentally investigated in both Mach 2.5 and 3.0 model combustors with stagnation temperatures of approximately 1,750 K. Superc... Supersonic model combustors using two-stage injections of supercritical kerosene were experimentally investigated in both Mach 2.5 and 3.0 model combustors with stagnation temperatures of approximately 1,750 K. Supercritical kerosene of approximately 760 K was prepared and injected in the overall equivalence ratio range of 0.5-1.46. Two pairs of integrated injector/flameholder cavity modules in tandem were used to facilitate fuel-air mixing and stable combustion. For single-stage fuel injection at an upstream location, it was found that the boundary layer separation could propagate into the isolator with increasing fuel equivalence ratio due to excessive local heat release, which in turns changed the entry airflow conditions. Moving the fuel injection to a further downstream location could alleviate the problem, while it would result in a decrease in combustion efficiency due to shorter fuel residence time. With two-stage fuel injections the overall combustor performance was shown to be improved and kerosene injections at fuel rich conditions could be reached without the upstream propagation of the boundary layer separation into the isolator. Furthermore, effects of the entry Mach number and pilot hydrogen on combustion performance were also studied. 展开更多
关键词 Supersonic combustion Staged injection Combustion efficiency Supercritical kerosene
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Distributions of Sr and Fe and their influence on modification of hypoeutectic Al-Si alloy 被引量:3
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作者 Tu Lan jian-guo li 《China Foundry》 SCIE 2016年第2期85-92,共8页
The influence of cooling rate and Fe-containing phases on Sr-modification of Si phases in hypoeutectic Al-Si alloys, a problem with great industrial importance, was investigated. The microstructures of samples were ex... The influence of cooling rate and Fe-containing phases on Sr-modification of Si phases in hypoeutectic Al-Si alloys, a problem with great industrial importance, was investigated. The microstructures of samples were examined using scanning electron microscopy(SEM) with energy-dispersive X-ray spectroscopy(EDX). A new method of electron probe microanalysis(EPMA) map scanning was used to analyze the Sr distribution, which gave quantitative results covering more Si particles. EPMA map scanning, together with SEM with EDX, was also used in analyzing the distribution of Fe phases. Results show that Fe-containing phase was related to the unmodified Si particles in samples with partial modification failure and the plate-like Si phases in samples without modification failure. Such a relationship was further confirmed by the microstructure observation.In conclusion, a partial failure of Sr-modification can be caused by both slow cooling rate and Fe-containing phases. 展开更多
关键词 Al-Si Alloys cooling rate modification theory Sr segregation Fe-contained phases
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Impact of Admission Hyperglycemia on Stroke-Associated Pneumoniain Acute Cerebral Hemorrhage: A Retrospective Observational Study 被引量:7
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作者 Tian-Hua Ren Biao Yuan +8 位作者 Tie-Cheng Yang jian-guo li Niu Chi Qian-Wei Ren Hong-Mei Shi Dong-Ming Yu Kai Shan li-Xia li Xiao-Yan Dong 《Open Journal of Emergency Medicine》 2015年第1期1-8,共8页
Background: Hyperglycemia is always seen amongst acute intra-cerebral hemorrhage (ICH) and usually has been reported in literature and studied in relation to mortality and poor recovery. However, literature specific t... Background: Hyperglycemia is always seen amongst acute intra-cerebral hemorrhage (ICH) and usually has been reported in literature and studied in relation to mortality and poor recovery. However, literature specific to stroke-associated pneumonia (SAP) on this topic is very small. Further, how to differentiate the predictive value of hyperglycemia with and without abnormal HbA1C in such patients is still a matter of debate and no universal consensus. We evaluated hyperglycemia as a marker for SAP in patients with ICH to assess its usefulness as a potential predictor. Materials and methods: Clinical characteristics for a sample of 551 patients with acute ICH were collected from the Beijing Tiantan Hospital of Capital Medical University, Beijing, China. Possible associated risk factors of SAP were reviewed. Hyperglycemia and HbA1C on admission were the main hypothetic predictor, SAP occurring within the first 7 days is the primary outcome. Results: The cohort study includes 551 hospitalized patients. The prevalence of hyperglycemia was 52.5% and SAP occurred in 147 (26.7%). The incidence of SAP was higher in the group with hyperglycemia than those without hyperglycemia (37.7% versus 14.5%, p 6.5) (OR, 1.57;95%CI, 0.81 - 3.23) had not been shown to be associated with SAP. Conclusions: In this hospital-based cohort of patients presenting with acute intra-hemorrhage, hyperglycemia on admission was associated significantly with SAP. The association was stronger for hyperglycemia with normal HgbA1C than for hyperglycemia with high HgbA1C. Hyperglycemia with normal HgbA1C might be a more sensitive predictor of early acute complication, such as SAP. 展开更多
关键词 Acute INTRACEREBRAL HEMORRHAGE (ICH) Stroke-Associated Pneumonia (SAP) HYPERGLYCEMIA HEMOGLOBIN (Hb)A1C
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Management of procedural pain in the intensive care unit 被引量:3
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作者 Na-Na Guo Hong-liang Wang +7 位作者 Ming-Yan Zhao jian-guo li Hai-Tao liu Ting-Xin Zhang Xin-Yu Zhang Yi-Jun Chu Kai-Jiang Yu Chang-Song Wang 《World Journal of Clinical Cases》 SCIE 2022年第5期1473-1484,共12页
Pain is a common experience for inpatients,and intensive care unit(ICU)patients undergo more pain than other departmental patients,with an incidence of 50%at rest and up to 80%during common care procedures.At present,... Pain is a common experience for inpatients,and intensive care unit(ICU)patients undergo more pain than other departmental patients,with an incidence of 50%at rest and up to 80%during common care procedures.At present,the management of persistent pain in ICU patients has attracted considerable attention,and there are many related clinical studies and guidelines.However,the management of transient pain caused by certain ICU procedures has not received sufficient attention.We reviewed the different management strategies for procedural pain in the ICU and reached a conclusion.Pain management is a process of continuous quality improvement that requires multidisciplinary team cooperation,painrelated training of all relevant personnel,effective relief of all kinds of pain,and improvement of patients'quality of life.In clinical work,which involves complex and diverse patients,we should pay attention to the following points for procedural pain:(1)Consider not only the patient's persistent pain but also his or her procedural pain;(2)Conduct multimodal pain management;(3)Provide combined sedation on the basis of pain management;and(4)Perform individualized pain management.Until now,the pain management of procedural pain in the ICU has not attracted extensive attention.Therefore,we expect additional studies to solve the existing problems of procedural pain management in the ICU. 展开更多
关键词 Procedural pain Persistent pain Transient pain Pain management Topical anesthesia Intensive care unit
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Determination of formation age(0.14 Ma)of the Pengyang sandstone-type uranium deposit in the Ordos Basin,China:Using pitchblende in situ femtosecond LA-MC-ICP-MS method 被引量:5
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作者 Hua-lei Zhao jian-guo li +5 位作者 Zhi-bin Xiao Pei-sen Miao Qing-hong Si Lu-lu Chen Reng-anYu Yin Chen 《China Geology》 2021年第4期747-748,共2页
1.Objective Because of the characteristics of multistage mineralization,long duration,relatively new age,and complicated occurrence of ore minerals,dating of sandstone-type uranium deposits has been a challenging prob... 1.Objective Because of the characteristics of multistage mineralization,long duration,relatively new age,and complicated occurrence of ore minerals,dating of sandstone-type uranium deposits has been a challenging problem.For a long time,the whole-rock U-Pb isochronal method has been used in the dating of sandstone-type uranium deposits,but its accuracy has been questioned by experts. 展开更多
关键词 SANDSTONE DATING DEPOSIT
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Characteristics of compressible flow of supercritical kerosene 被引量:2
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作者 Feng-Quan Zhong Xue-Jun Fan +2 位作者 Jing Wang Gong Yu jian-guo li 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第1期8-13,共6页
In this paper, compressible flow of aviation kerosene at supercritical conditions has been studied both numerically and experimentally. The thermophysical properties of supercritical kerosene are calculated using a 10... In this paper, compressible flow of aviation kerosene at supercritical conditions has been studied both numerically and experimentally. The thermophysical properties of supercritical kerosene are calculated using a 10- species surrogate based on the principle of extended corresponding states (ECS). Isentropic acceleration of supercritical kerosene to subsonic and supersonic speeds has been analyzed numerically. It has been found that the isentropic relationships of supercritical kerosene are significantly dif- ferent from those of ideal gases, A two-stage fuel heating and delivery system is used to heat the kerosene up to a tem- perature of 820 K and pressure of 5.5 MPa with a maximum mass flow rate of 100 g/s. The characteristics of supercritical kerosene flows in a converging-diverging nozzle (Laval nozzle) have been studied experimentally. The results show that stable supersonic flows of kerosene could be established in the temperature range of 730 K-820 K and the measurements in the wall pressure agree with the numerical calculation. 展开更多
关键词 Supercritical kerosene - Compressible flow Laval nozzle Isentropic process
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Hot deformation characteristics of as-cast high-Cr ultra-super-critical rotor steel with columnar grains 被引量:4
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作者 Zong-ye Ding Qiao-dan Hu +1 位作者 Long Zeng jian-guo li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2016年第11期1275-1285,共11页
Isothermal hot compression tests of as-cast high-Cr ultra-super-critical(USC) rotor steel with columnar grains perpendicular to the compression direction were carried out in the temperature range from 950 to 1250... Isothermal hot compression tests of as-cast high-Cr ultra-super-critical(USC) rotor steel with columnar grains perpendicular to the compression direction were carried out in the temperature range from 950 to 1250°C at strain rates ranging from 0.001 to 1 s^(-1). The softening mechanism was dynamic recovery(DRV) at 950°C and the strain rate of 1 s^(-1), whereas it was dynamic recrystallization(DRX) under the other conditions. A modified constitutive equation based on the Arrhenius model with strain compensation reasonably predicted the flow stress under various deformation conditions, and the activation energy was calculated to be 643.92 kJ ×mol^(-1). The critical stresses of dynamic recrystallization under different conditions were determined from the work-hardening rate(θ)–flow stress(σ) and-θ/σ–σ curves. The optimum processing parameters via analysis of the processing map and the softening mechanism were determined to be a deformation temperature range from 1100 to 1200°C and a strain-rate range from 0.001 to 0.08 s^(-1), with a power dissipation efficiency η greater than 31%. 展开更多
关键词 rotor steel columnar grains dynamic recrystallization constitutive models critical conditions processing maps
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Nucleation interface of Al-Sb alloys on single crystal Al_2O_3 substrate 被引量:1
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作者 Lu WANG lin YANG +3 位作者 Di ZHANG Ming-xu XIA Bin CHEN jian-guo li 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第9期2104-2111,共8页
Lattice structure information of heterogeneous nucleation at nucleation interface was present.The crystal orientation,and interfacial structure characteristic of liquid Al alloys nucleated on the basal surface(0001)Al... Lattice structure information of heterogeneous nucleation at nucleation interface was present.The crystal orientation,and interfacial structure characteristic of liquid Al alloys nucleated on the basal surface(0001)Al2O3single crystal substrate were identified by X-ray diffraction(XRD),scanning electron microscopy(SEM)and high resolution transmission electron microscopy(HRTEM)analysis.The preferred crystal orientations of pure Al and Al-1%Sb(mass fraction)alloy adjacent to the nucleation interface were examined as(200)and(220)planes of Al,respectively,and two corresponding orientation relationships were obtained.An improved nucleation efficiency and refined grains were attributed to both the reduced interplanar spacing of preferred orientation and the decrease of lattice misfit from16.4%to7.0%in Al-1%Sb/Al2O3nucleation group. 展开更多
关键词 aluminium alloy NUCLEATION interfacial structure orientation relationship
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Aerosolized Amikacin as Adjunctive Therapy of Ventilator-associated Pneumonia Caused by Multidrug-resistant Gram-negative Bacteria: A Single-center Randomized Controlled Trial 被引量:21
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作者 Chang liu Yu-Ting Zhang +4 位作者 Zhi-Yong Peng Qing Zhou Bo Hu Hui Zhou jian-guo li 《Chinese Medical Journal》 SCIE CAS CSCD 2017年第10期1196-1201,共6页
Background: Aerosolized amikacin (AA) is a current option for the management of ventilator-associated pneumonia (VAP) caused by multidrug-resistant Gram-negative bacteria (MDR-GNB), as it is reported that AA co... Background: Aerosolized amikacin (AA) is a current option for the management of ventilator-associated pneumonia (VAP) caused by multidrug-resistant Gram-negative bacteria (MDR-GNB), as it is reported that AA could increase the alveolar level of the drug without increasing systemic toxicity. This study aimed to evaluate the efficacy and safety of AA as an adjunctive therapy for VAP caused by MDR-GNB. Methods: In this single-center, double-blind study conducted in a 36-bed general Intensive Care Unit (ICU) in a tertiary hospital from June 2014 to June 2016, 52 ICU patients with confirmed MDR-GNB VAP were randomized to two groups (AA group, n - 27 and placebo group, n = 25). Amikacin (400 rag, q8h) or saline placebo (4 ml, q8h) was aerosolized for 7 days. The attending physician determined the administration of systemic antibiotics for VAP. Patients were tbllowed up for 28 days. Bacteriological eradication, clinical pulmonary infection score (CP1S), and serum creatinine were assessed on day 7 of therapy. New resistance to amikacin, cure rate of VAP, weaning rate, and mortality were assessed on day 28. Results: The baseline characteristics of patients in both groups were similar. At the end of the treatment, 13 of the 32 initially detected bacterial isolates were eradicated in AA group, compared to 4 of 28 in placebo group (41% vs. 14%, P - 0.024). As for patients, 11 of 27 patients treated with AA and 4 of 25 patients treated with placebo have eradication (41% vs. 16%, P = 0.049). The adjunction of AA reduced CPIS (4.2 ± 1.6 vs. 5.8 ± 2.1, P = 0.007). New drug resistance to amikacin and the change in serum creatinine were not detected in AA group. No significant differences in the clinical cure rate in survivors (48% vs. 35%, P = 0.444), weaning rate (48% vs. 32%, P = 0.236), and mortality (22% vs. 32%, P = 0.427) were detected between the two groups on day 28. Conclusions: As an adjunctive therapy of MDR-GNB VAP, AA successfully eradicated existing MDR organisms without inducing new resistance to amikacin or change in serum creatinine. However, the improvement of mortality was not found. 展开更多
关键词 Aerosol Drug Therapy AMIKACIN Gram-negative Bacteria Multidrug Resistance Pnet monia Ventilator-associated
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A National Multicenter Survey on Management of Pain, Agitation, and Delirium in Intensive Care Units in China 被引量:8
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作者 Jing Wang Zhi-Yong Peng +3 位作者 Wen-Hal Zhou Bo Hu Xin Rao jian-guo li 《Chinese Medical Journal》 SCIE CAS CSCD 2017年第10期1182-1188,共7页
Background: The management of pain, agitation, and deliriunl (PAD) in Intensive Care Unit (ICU) is beneficial for patients and makes it widely applied in clinical practice. Previous studies showed that the clinic... Background: The management of pain, agitation, and deliriunl (PAD) in Intensive Care Unit (ICU) is beneficial for patients and makes it widely applied in clinical practice. Previous studies showed that the clinical practice of PAD in ICU was improving: yet relatively little intbrmation is available in China. This study aimed to investigate the practice of PAD in ICUs in China. Methods: A multicenter, nationwide survey was conducted using a clinician-directed questionnaire from September 19 to December 18, 2016. The questionnaire focused on the assessment and naanagement of PAD by the clinicians in ICUs. The practice of PAD was compared among the lbur regions of China (North, Southeast, Northwest, and Southwest). The data were expressed as percentage and fi'equency. The Chi-square test, Fisher's exact test, and line-row Chi-square test were used. Results: Of the 1011 valid questionnaire lbrms, the response rtite was 80.37%. The clinicians came from 704 hospitals across 158 cities of China. The rate of PAD assessment was 75.77%, 90.21%, and 66.77%, respectively. The rates of PAD scores were 45.8%, 68.94%, and 34.03%, respectively. The visual analog scale, Richmond agitation-sedation scale, and conlktsion assessment method lbr the ICU were the first choices of scales for PAl) assessment. Fentanyl, midazolam, and dexmedetomidine were the first choices of agents for analgesic, sedation, and delirium treatment. While choosing analgesics and sedatives, the clinicians put the pharmacological characteristics of drugs in the first place (66.07% and 76.36%). Daily interruption for sedation was carried out by 67.26% clinicians. Most of the clinicians (87.24%) used analgesics while using sedatives. Of the 738 (73%) clinicians titrating the sedatives oil the basis of the proposed target sedation level, 268 (26.61%) clinicians just depended on their clinical experience. Totally, 519 (51.34%) clinicians never used other nondrug strategies tbr PAD. The working time of clinicians was an important thctor in the management of analgesia and sedation rather than their titles and educational background. The ratios of pain score and sedation score in the Southwest China were the highest and the North China were the lowest. The ratios of delirium assessment and score were the same in the four regions of China. Moreover, the first choices of scales for PAD in the four regions were the same. However, the top three choices of agents in PAD treatment in the four regions were not the same. Conclusions: The practice of PAD in China lbllows the international guidelines; however, the pain assessment should be improved. The PAD practice is a little different across the four regions of China: however, the trend is consistent. Trial Registration: The study is registered at http://www.clinicaltrials.gov (No. ChiCTR-OOC-16000014, www.chictr, org.cn/index.aspx.). 展开更多
关键词 Agitation Delirium: Intensive Care Unit Pain Sedation
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