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战时化与平时化:抗战时期大学学生自治会活动的双重取向研究 被引量:1
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作者 董柏林 《高教探索》 CSSCI 北大核心 2021年第2期109-114,共6页
抗战的爆发扰乱了国民政府管控学生自治会的正常节奏,也打破了学生自治会以校内活动为主的发展格局。如何限制学生自治会的越界活动并引导其构筑抗日救亡的第二条战线,是抗战时期国民政府制定学生团体活动规则的主要依据和核心诉求。为... 抗战的爆发扰乱了国民政府管控学生自治会的正常节奏,也打破了学生自治会以校内活动为主的发展格局。如何限制学生自治会的越界活动并引导其构筑抗日救亡的第二条战线,是抗战时期国民政府制定学生团体活动规则的主要依据和核心诉求。为适应抗战需要及维护正常教育秩序,国民政府将“战时须作平时看”的教育方针确定为学生自治会开展各项活动的指导原则,以实现学生自治会活动“战时化”与“平时化”的有机衔接与相生相成。“两化”方针作为政府巩固基层社会政治秩序建构的有效形式,在抗战初期达到了统制学生自治会的目的,促使学生自治会的发展与国家和政府的需求紧密结合。随着抗战形势的转变与民主运动的兴起,国民政府对学生自治会的强力整合逐渐失去效力,追求自由与民主的学生自治会最终走向了国民政府的对立面。 展开更多
关键词 抗战时期 大学学生自治会 活动取向 战时 平时化
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Temporal and spatial differences and imbalance of China's urbanization development during 1950-2006 被引量:7
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作者 方创琳 刘晓丽 《Journal of Geographical Sciences》 SCIE CSCD 2009年第6期719-732,共14页
A better understanding of the regional disparity and imbalance characteristics of China's urbanization development is the important premise for constituting correct policy and strategy and promoting the healthy an... A better understanding of the regional disparity and imbalance characteristics of China's urbanization development is the important premise for constituting correct policy and strategy and promoting the healthy and sustainable development of urbanization in the 21st century. The regional differences of China's urbanization level have close relations with natural conditions of landform and climate etc.,the urbanization level reduces with the eleva-tion of topography and decrease of precipitation. According to the statistical data set of ur-banization in 1950-2006,the temporal change course of inter-provincial disparity of Chinese urbanization level since the founding of New China in 1949 was studied,and then the inter-regional and intra-regional disparities of urbanization development were analyzed by the Theil index and its nested decomposition method,to grasp the dynamic change of spatial disparities of China's urbanization level on the whole. Using the imbalance index model,the imbalance status of urban population distribution relative to total population,grain output,total agricultural output value,gross output value of industry,tertiary industrial output value as well as gross regional product was discussed,to hold the balance characteristics of urbanization development relative to the regional development conditions from the macroscopic scales. 展开更多
关键词 URBANIZATION DIFFERENCE imbalance index China
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A Nucleus-encoded Topological Specificity Factor PpMinE in Physcomitrella patens has Conserved Function Similar to Its Chloroplast-encoded Ancestor
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作者 朱佳瑛 刘维仲 +2 位作者 周伟巍 胡勇 何奕昆 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第3期229-238,共10页
A nucleus-encoded MinE gene, designated PpMinE, from Physcomitrella patens was identified using RT-PCR. The presence of both N- and C-terminal extensions in PpMinE protein suggested its cyanobacterial origin. The tran... A nucleus-encoded MinE gene, designated PpMinE, from Physcomitrella patens was identified using RT-PCR. The presence of both N- and C-terminal extensions in PpMinE protein suggested its cyanobacterial origin. The transient expression of PpMinE using green fluorescent protein fusion in tobacco (Nicotiana tabacum L.) indicated that the PpMinE was a chloroplast-targeted protein. Overexpression of PpMinE in Escherichia coli caused division site misplacement and minicell formation, suggesting evolutionary functional conservation of MinE during plant phylogenesis. According to the phylogenetic tree, PpMinE protein has a close relationship with the highland plants, which suggests that the transfer events of MinE gene from plastid to nucleus might have occurred before the origin of the land plants. 展开更多
关键词 Physcomitrella patens plastid division PpMinE lateral gene transfer (LGT) evolution transient expression
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Changes in temperature extremes over China under 1.5 ℃ and 2 ℃ global warming targets 被引量:31
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作者 SHI Chen JIANG Zhi-Hong +1 位作者 CHEN Wei-Lin Laurent LI 《Advances in Climate Change Research》 SCIE CSCD 2018年第2期120-129,共10页
The long-term goal of the 2015 Paris Agreement is to limit global warming to well below 2 ℃above pre-industrial levels and to pursue efforts to limit it to 1.5 ℃. However, for climate mitigation and adaption efforts... The long-term goal of the 2015 Paris Agreement is to limit global warming to well below 2 ℃above pre-industrial levels and to pursue efforts to limit it to 1.5 ℃. However, for climate mitigation and adaption efforts, further studies are still needed to understand the regional consequences between the two global warming limits. Here we provide an assessment of changes in temperature extremes over China (relative to 1986-2005) at 1.5 ℃ and 2 ℃ warming levels (relative to 1861-1900) by using the 5th phase of the Coupled Model Intercomparison Project (CMIP5) models under three RCP scenarios (RCP2.6, RCP4.5, RCP8.5). Results show that the increases in mean temperature and temperature extremes over China are greater than that in global mean temperature. With respect to 1986-2005, the temperature of hottest day (TXx) and coldest night (TNn) are projected to increase about 1/1.6 ℃ and 1.1/1.8 ℃, whereas warm days (TX90p) and warm spell duration (WSDI) will increase about 7.5/13.8% and 15/30 d for the 1.5/2 ℃ global warming target, respectively. Under an additional 0.5 ℃ global warming, the projected increases of temperature in warmest day/night and coldest day/night are both more than 0.5 ℃ across almost the whole China. In Northwest China, Northeast China and the Tibetan Plateau, the projected changes are particularly sensitive to the additional 0.5 ℃ global warming, for example, multi-model mean increase in coldest day (TXn) and coldest night (TNn) will be about 2 times higher than a change of 0.5 ℃ global warming. Although the area-averaged changes in temperature extremes are very similar for different scenarios, spatial hotspot still exists, such as in Northwest China and North China, the increases in temperatures are apparently larger in RCP8.5 than that in RCP4.5. 展开更多
关键词 1.5 global warming 2 global warming Temperature extremes CMIP5 China
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Mean Residence Time of CO2 Molecules in Flexible ZIF-8 Cages Explored by Molecular Dynamics Simulations 被引量:2
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作者 Zhen Yang Lian Liu +2 位作者 Tian Gui Rong-fei Zhou Xiang-shu Chen 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2013年第5期553-557,I0003,共6页
The adsorption sites and diffusion mechanism of CO2 molecules in the flexible Zn(MeIM)2 (MeIM=2-methylimidazole) (ZIF-8) have been investigated by grand canonical Monte Carlo and molecular dynamics simulations. ... The adsorption sites and diffusion mechanism of CO2 molecules in the flexible Zn(MeIM)2 (MeIM=2-methylimidazole) (ZIF-8) have been investigated by grand canonical Monte Carlo and molecular dynamics simulations. A reasonable time correlation function is for the first time constructed to explore the mean residence time of CO2 molecules in the ZIF-8 cages, suggesting that C02 molecules can remain in the same cage for up to several tens of picoseconds. Furthermore, we find that the mean residence time almost linearly increases with the increasing pressure (or loading) at 273 and 298 K. 展开更多
关键词 DIFFUSION Adsorption Carbon dioxide Zeolitic imidazolate frameworks Molecular dynamics simulation
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Role of surgical intervention in managing gastrointestinal metastases from lung cancer 被引量:7
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作者 Po-Chu Lee Chiao Lo +2 位作者 Ming-Tsan Lin Jin-Tung Liang Been-Ren Lin 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第38期4314-4320,共7页
AIM:To investigate the clinicopathological characteristics of late-stage lung cancer patients with gastrointestinal(GI)-tract metastases,focusing on therapeutic options and outcomes.METHODS:Our institution(the Nationa... AIM:To investigate the clinicopathological characteristics of late-stage lung cancer patients with gastrointestinal(GI)-tract metastases,focusing on therapeutic options and outcomes.METHODS:Our institution(the National Taiwan University Hospital) diagnosed 8159 patients with lung cancer between 1987 and 2008,of which 21 developed symptomatic GI metastases.This study reviewed all of the patients' information,including survival data,pathological reports,and surgical notes.RESULTS:The most common histological type of lung cancer was adenocarcinoma,and 0.26% of patients with lung cancer developed GI metastases.The median duration from lung cancer diagnosis to GI metastases was three months(range,0-108 mo),and the average time from diagnosis of GI metastasis to death was 2.8 mo.Most patients with symptomatic gastric and/or duodenal metastases exhibited GI bleeding and were diagnosed by panendoscopy.In contrast,small bowel metastases typically presented as an acute abdomen and were not diagnosed until laparotomy.All patients with small bowel or colonic metastases underwent surgical intervention,and their perioperative mortality was 22%.Our data revealed a therapeutic effect in patients with solitary GI metastasis and a favorable palliative effect on survival when metastases were diagnosed preoperatively.In patients with multiple GI metastases,the presentation varied according to the locations of the metastases.CONCLUSION:Surgical treatment is worthwhile in a select group of patients with bowel perforation or obstruction.Physicians should be more alert to symptoms or signs indicating GI metastases. 展开更多
关键词 Gastrointestinal metastasis Lung cancer Palliative effect Prognosis Surgical intervention
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Straight line feature based image distortion correction 被引量:1
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作者 Zhang Haofeng Zhao Chunxia Lu Jianfeng Tang Zhenmin Yang Jingyu 《Engineering Sciences》 EI 2008年第2期83-86,96,共5页
An image distortion correction method is proposed, which uses the straight line features. Many parallel lines of different direction from different images were extracted, and then were used to optimize the distortion ... An image distortion correction method is proposed, which uses the straight line features. Many parallel lines of different direction from different images were extracted, and then were used to optimize the distortion parameters by nonlinear least square. The thought of step by step was added when the optimization method working. 3D world coordination is not need to know, and the method is easy to implement. The experiment result shows its high accuracy. 展开更多
关键词 distortion correction straight line feature nonlinear least square multi-step optimization
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Prognosis of HER2 over-expressing gastric cancer patients with liver metastasis 被引量:17
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作者 Hai-Zhen Dang Yang Yu Shun-Chang Jiao 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第19期2402-2407,共6页
AIM:To study the risk factors for liver metastasis and the prognosis in patients with human epidermal growth factor receptor 2(HER2) over-expressing gastric cancer(GC).METHODS:A total of 84 GC patients recruited from ... AIM:To study the risk factors for liver metastasis and the prognosis in patients with human epidermal growth factor receptor 2(HER2) over-expressing gastric cancer(GC).METHODS:A total of 84 GC patients recruited from the General Hospital of the People's Liberation Army(PLA) between 2003 and 2010 were randomly enrolled in this study.HER2 expression was detected by immunohistochemistry in 84 GC patients with liver metastases.The study group consisted of 66 men and 18 women,with an average age of 54 years(range:19-74 years).Liver metastasis was diagnosed by magnetic resonance imaging or computed tomography.Patients were followed-up and predictive factors of liver metastasis were evaluated.RESULTS:The median follow-up period was 47 mo(range:6-85 mo).The characteristics of 35(25.7%) patients with HER2 over-expression of liver metastatic GC are presented.HER2 over-expression was detected in 23 out of 49(46.9%) patients with intestinal GC,and 9 out of 35(25.7%) patients with diffuse GC.29 out of 59(49.2%) patients aged < 60 years were HER2positive,while 8 out of 25(32%) patients aged ≥ 60 were HER2-positive;a significant difference(P < 0.05).Univariate analysis(log-rank test) showed that HER2 over-expression,sex,Lauren classification,differentiation and disease-free interval were correlated with poor survival(P < 0.05).Survival analysis with a survival curve showed that HER2 over-expression was significantly relevant,with a reduced survival time in GC patients with liver metastases(P < 0.01).2-year survival was not associated with the patient's age.A diseasefree survival longer than 12 mo has a significant association with extended overall survival(OS) in GC patients with liver metastases.The median survival time after the diagnosis of liver metastases was 18 mo [95% confidence interval(CI):9.07-26.94] among HER2 positive GC patients with liver metastases.In comparison,for 49(69.4%) out of 84 HER2 negative patients with liver metastatic GC,the median survival time was 47 mo(95% CI:19.37-74.63).In patients with HER2 positive liver metastatic GC,the median OS was significantly shorter than in HER2 negative patients(median,20.32 mo;95% CI:16.51-24.13 vs median,50.14 mo;95% CI:37.83-62.45;P < 0.01).CONCLUSION:HER2 over-expressing GC patients with liver metastases have a poor prognosis.Overall survival was significantly lower in HER2 positive patients.HER2overexpression is correlated with a lower survival rate. 展开更多
关键词 Human epidermal growth factor receptor 2 OVEREXPRESSION Gastric cancer Liver metastasis Over-all survival PROGNOSIS
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Impact of Meteorological Drought on Streamflow Drought in Jinghe River Basin of China 被引量:5
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作者 ZHAO Lin LYU Aifeng +5 位作者 WU Jianjun Michael HAYES TANG Zhenghong HE Bin LIU Jinghui LIU Ming 《Chinese Geographical Science》 SCIE CSCD 2014年第6期694-705,共12页
Under global climate change, drought has become one of the most serious natural hazards, affecting the ecological environment and human life. Drought can be categorized as meteorological, agricultural, hydrological or... Under global climate change, drought has become one of the most serious natural hazards, affecting the ecological environment and human life. Drought can be categorized as meteorological, agricultural, hydrological or socio-economic drought. Among the different categories of drought, hydrological drought, especially streamflow drought, has been given more attention by local governments, researchers and the public in recent years. Identifying the occurrence of streamflow drought and issuing early warning can provide timely information for effective water resources management. In this study, streamflow drought is detected by using the Standardized Runoff Index, whereas meteorological drought is detected by the Standardized Precipitation Index. Comparative analyses of frequency, magnitude, onset and duration are conducted to identify the impact of meteorological drought on streamflow drought. This study focuses on the Jinghe River Basin in Northwest China, mainly providing the following findings. 1) Eleven meteorological droughts and six streamflow droughts were indicated during 1970 and 1990 after pooling using Inter-event time and volume Criterion method. 2) Streamflow drought in the Jinghe River Basin lagged meteorological drought for about 127 days. 3) The frequency of streamflow drought in Jinghe River Basin was less than meteorological drought. However, the average duration of streamflow drought is longer. 4) The magnitude of streamflow drought is greater than meteorological drought. These results not only play an important theoretical role in understanding relationships between different drought categories, but also have practical implications for streamflow drought mitigation and regional water resources management. 展开更多
关键词 streamflow drought meteorological drought Standardized Precipitation Index (SPI) Standardized Runoff Index (SRI) timelag Jinghe River Basin
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Accurate Calculation of Equilibrium Reduced Density Matrix for the System-Bath Model:a Multilayer Multiconfiguration Time-Dependent Hartree Approach and its Comparison to a Multi-Electronic-State Path Integral Molecular Dynamics Approach
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作者 Haobin Wang Xinzijian Liu Jian Liu 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2018年第4期446-456,614,共12页
An efficient and accurate method for computing the equilibriurn reduced density matrix is presented for treating open quantum systems characterized by the systern-bath model. The method employs the rnultilayer nmltico... An efficient and accurate method for computing the equilibriurn reduced density matrix is presented for treating open quantum systems characterized by the systern-bath model. The method employs the rnultilayer nmlticonfiguration tirne-dependent Hartree theory for imag- inary time propagation and an importance sampling procedure for calculating the quantum mechanical trace. The method is applied to the spin-boson Harniltonian, which leads to ac- curate results in agreement with those produced by the rnulti-electronic-state path integral molecular dynamics method. 展开更多
关键词 Multilayer multiconfiguration time-dependent Hartree Path integral riurn reduced density matrix Imaginary time propagation
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Variations of Terrestrial Water Storage in the Yangtze River Basin under Climate Change Scenarios 被引量:1
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作者 MA Qian XIE Zheng-Hui ZHAO Lin-Na 《Atmospheric and Oceanic Science Letters》 2010年第6期293-298,共6页
In this study, the water balance-based Precipitation-Evapotranspiration-Runoff (PER) method combined with the land surface model Variable Infiltration Capacity (VIC) was used to estimate the spatiotemporal variations ... In this study, the water balance-based Precipitation-Evapotranspiration-Runoff (PER) method combined with the land surface model Variable Infiltration Capacity (VIC) was used to estimate the spatiotemporal variations of terrestrial water storage (TWS) for two periods, 1982-2005 (baseline) and 2071-2100, under future climate scenarios A2 and B2 in the Yangtze River basin. The results show that the estimated TWS during the baseline period and under the two future climate scenarios have similar seasonal amplitudes of 60-70 mm. The higher values of TWS appear in June during the baseline period and under the B2 scenario, whereas the TWS under A2 shows two peaks in response to the related precipitation pattern. It also shows that the TWS is recharged from February to June during the baseline period, but it is replenished from March to June under the A2 and B2 scenarios. An analysis of the standard derivation of seasonal and interannual TWS time series under the three scenarios demonstrates that the seasonal TWS of the southeastern part of the Yangtze River basin varies remarkably and that the southeastern and central parts of the basin have higher variations in interannual TWS. With respect to the first mode of the Empirical Orthogonal Function (EOF), the inverse-phase change in seasonal TWS mainly appears across the Guizhou-Sichuan-Shaanxi belt, and the entire basin generally represents a synchronous change in interannual TWS. As a whole, the TWS under A2 presents a larger seasonal variation whereas that under B2 displays a greater interannual variation. These results imply that climate change could trigger severe disasters in the southeastern and central parts of the basin. 展开更多
关键词 terrestrial water storage the Yangtze River basin climate change VARIATIONS
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Multi-domain High-Resolution Platform for Integrated Spectroscopy and Microscopy Characterizations 被引量:1
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作者 Li Wang Shen-long Jiang +1 位作者 Qun Zhang Yi Luo 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2020年第6期680-685,I0002,共7页
In recent decades,materials science has experienced rapid development and posed increasingly high requirements for the characterizations of structures,properties,and performances.Herein,we report on our recent establi... In recent decades,materials science has experienced rapid development and posed increasingly high requirements for the characterizations of structures,properties,and performances.Herein,we report on our recent establishment of a multi-domain(energy,space,time)highresolution platform for integrated spectroscopy and microscopy characterizations,offering an unprecedented way to analyze materials in terms of spectral(energy)and spatial mapping as well as temporal evolution.We present several proof-of-principle results collected on this platform,including in-situ Raman imaging(high-resolution Raman,polarization Raman,low-wavenumber Raman),time-resolved photoluminescence imaging,and photoelectrical performance imaging.It can be envisioned that our newly established platform would be very powerful and effective in the multi-domain high-resolution characterizations of various materials of photoelectrochemical importance in the near future. 展开更多
关键词 Multi-domain platform Spectral/spatial/temporal resolution Integrated characterizations SPECTROSCOPY MICROSCOPY Imaging
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Sorafenib in hepatocellular carcinoma:efficacy and predictive factors
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作者 Li Jing Huang Liang Yan Jianjun Zhou Feiguo Liu Caifeng Yan Yiqu 《Journal of Medical Colleges of PLA(China)》 CAS 2011年第6期324-334,共11页
Objective:To evaluate the efficacy and safety in patients with hepatocellular carcinoma treated with sorafenib and determine the predictive factors for survival.Methods:From April 2009 to December 2010,all patients wi... Objective:To evaluate the efficacy and safety in patients with hepatocellular carcinoma treated with sorafenib and determine the predictive factors for survival.Methods:From April 2009 to December 2010,all patients with hepatocellular carcinoma treated with sorafenib were included in the study.Clinical data and survival time were collected.Survival analysis was conducted using the Kaplan-Meier method,and predictive factors for survival were analysed using the Cox's model.Results:A total of 51 patients were included in the study,the median time of follow-up was 10 months(range 1-22).All the 51 patients had one or more adverse events,of which 2 patients died of upper gastrointestinal bleeding and 6 patients discontinued treatment.The mean survival time was 11 months and 1-year survival was 60.8%.On univariate analysis,the median survival time of patients with tumors of BCLC A,B and C were 17,12.5 and 8.5 months,and 1-year survival were 71.4%,61.1%,and 23.1%, respectively(P=0.006).Compared with those with mild and poor arterial supply tumors,patients with good arterial supply tumors had longer median survival time(12 months vs 8 months and 9 months) and higher 1-year survival(52.0%vs 30.8%and 38.5%)(P=0.037).Patients with portal invasion had shorter median survival time and lower 1-year survival(8.5 months vs 13 months and 57.6%vs 16.7%,respectively) than those without(P=0.012).Patients with prealbumin≥170 mg/L had longer median survival time and higher 1-year survival(13.5 months vs 9 months and 55.6%vs 36.4%,respectively) than those with prealbumin<170 mg/L(P=0.016).Early tumor BCLC staging and high level of prealbumin were independent predictive factors for survival on multivariate analysis using Cox's regression model,the hazard ratio were 3.69(95%CI:1.30-10.53,P=0.015) and 3.53(95%CI:1.40-8.91,P=0.008) respectively.Conclusion:Upper gastrointestinal bleeding was a severe event need to be concerned in patients with hepatocellular carcinoma treated with sorafenib.Patients with high level of prealbumin could benefit more from sorafenib treatment,and prealbumin could be a predictor for survival in HCC patients treated with sorafenib. 展开更多
关键词 Hepatocellular carcinoma SORAFENIB Adverse events PREALBUMIN
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In Vitro Study of Photodynamic Therapy for Treatment of Bacteremia in Whole Blood
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作者 Jennifer Machado Soaxes Thaila Quatrini Correa +2 位作者 Natalia Mayumi Inada Vanderlei Salvador Bagnato Kate Cristina Blanco 《Journal of Pharmacy and Pharmacology》 2018年第9期863-869,共7页
Antibiotic resistance has been compromised hospitalized patients with serious infections. The main cases of bacteremia can be caused by antibiotic resistant pathogens. Photodynamic therapy (PDT) has been shown as an... Antibiotic resistance has been compromised hospitalized patients with serious infections. The main cases of bacteremia can be caused by antibiotic resistant pathogens. Photodynamic therapy (PDT) has been shown as an alternative for inactivation of microorganisms in blood. In this therapy photochemical mechanisms occur that may prevent the development of bacteria. This study aims optimization of PDT parameters for blood decontamination. Concentration ofphotosensitizer (PS), light dose (LD) and incubation time (IT) were studied for hemolysis and cell toxic effects. It was observed that PDT can be used for microbial inactivation in total blood reducing 0.85 log10 CFU/mL ofS. aureus at 15 J/cm^2 and 50μg/mL of Photogem . 展开更多
关键词 Staphylococcus aureus photodynamic therapy BACTEREMIA BLOOD
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Heat center of the western Pacific warm pool 被引量:4
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作者 HU Shijian Hu Dunxin 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第1期169-176,共8页
A heat center (HC) of the western Pacific warm pool (WPWP) is defined, its variability is examined, and a possible mechanism is discussed. Analysis and calculation of a temperature dataset from 1945-2006 show that... A heat center (HC) of the western Pacific warm pool (WPWP) is defined, its variability is examined, and a possible mechanism is discussed. Analysis and calculation of a temperature dataset from 1945-2006 show that the mean position of the HC during this period was near 0.4°S/169.0°E, at 38.0 m depth. From a time series of the HC, remarkable seasonal variability was found, mainly in the meridional and vertical directions. Interannual variabilities were dominant in the zonal and vertical directions. In addition, semiannual variation in the HC depth was discovered. The longitude of the HC varies with ENSO events, and its latitude is weakly related to ENSO on time scales shorter than a decade. The variation of the HC longitude leads the Nifio-3 index by about 3-4 months, and its depth lags the index for approximately 3 months. It is concluded that the HC depth results from a combination of its longitudinal and latitudinal variations. Low-pass-filtered time series reveal that the HC has moved eastward since the mid 1980s. 展开更多
关键词 western Pacific warm pool heat center VARIABILITY
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FPGA-Based Real-Time Simulation of Modular Multilevel Converter HVDC Systems
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作者 Luc-André Grégoire Jean Bélanger Wei Li 《Journal of Energy and Power Engineering》 2012年第7期1119-1125,共7页
AC-HVDC-AC energy conversion systems using MMC (modular multilevel converters) are becoming popular to integrate distributed energy systems to the main grid. Such multilevel converters pose a serious problems for H... AC-HVDC-AC energy conversion systems using MMC (modular multilevel converters) are becoming popular to integrate distributed energy systems to the main grid. Such multilevel converters pose a serious problems for HIL (hardware in the loop) simulators required for control, protection design and testing due to the large number of cells that must be simulated individually using very small time steps. This paper demonstrates the advantages of using a very small time step to simulate a MMC topology. The MMC is implemented on FPGA (fiel-programmable gate array) to simulate fast transient with a time step of 250 ns. The AC network and HVDC bus is simulated on the PC, with a slower time step of 10 μs to 20 μs. The simulator architecture and the components simulated on the FPGA and on the PC will be discussed, as well as the method allowing the interconnection of this slow and fast system. 展开更多
关键词 FPGA simulation modular multi-level voltage source converters (MMC) MMC converter real-time simulation HIL(hardware-in-the-loop).
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The multi-motion-overlap algorithms for minimizing the time between successive scans of wafer stage
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作者 潘海鸿 Chen Lin +1 位作者 Li Xiaoqing Zhou Yunfei 《High Technology Letters》 EI CAS 2008年第3期282-288,共7页
In order to optimize the transitional time during the successive exposure scans for a step-and-scan lithography and improve the productivity in a wafer production process, an investigation of the motion trajectory pla... In order to optimize the transitional time during the successive exposure scans for a step-and-scan lithography and improve the productivity in a wafer production process, an investigation of the motion trajectory planning along the scanning direction for wafer stage was carried out. The motions of wafer stage were divided into two respective logical moves (i. e. step-move and scan-move) and the multi-motionoverlap algorithms (MMOA) were presented for optimizing the transitional time between the successive exposure scans. The conventional motion planning method, the Hazelton method and the MMOA were analyzed theoretically and simulated using MATLAB under four different exposure field sizes. The results show that the total time between two successive scans consumed by MMOA is reduced by 4.82%, 2.62%, 3.06% and 3.96%, compared with those of the conventional motion planning method; and reduced by 2.58%, 0.76%, 1.63% and 2.92%, compared with those of the Hazehon method respectively. The theoretical analyses and simulation results illuminate that the MMOA can effectively minimize the transitional step time between successive exposure scans and therefore increase the wafer fabricating productivity. 展开更多
关键词 multi-motion-overlap algorithm minimizing time successive exposure scans wafer stage step-and-scan lithography
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Time-Dependent Nonlinear Forcing Singular Vector-Type Tendency Error of the Zebiak-Cane Model 被引量:1
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作者 ZHAO Peng DUAN Wan-Suo 《Atmospheric and Oceanic Science Letters》 CSCD 2014年第5期395-399,共5页
Based on the Zebiak-Cane model, the timedependent nonlinear forcing singular vector (NFSV)-type tendency errors with components of 4 and 12 (denoted by NFSV-4 and NFSV-12) are calculated for predetermined El Nifio... Based on the Zebiak-Cane model, the timedependent nonlinear forcing singular vector (NFSV)-type tendency errors with components of 4 and 12 (denoted by NFSV-4 and NFSV-12) are calculated for predetermined El Nifio events and compared with the constant NFSV (denoted by NFSV-1) from their patterns and resultant prediction errors. Specifically, NFSV-1 has a zonal dipolar sea surface temperature anomaly (SSTA) pattern with negative anomalies in the equatorial eastern Pacific and positive anomalies in the equatorial central-western Pa- cific. Although the first few components in NFSV-4 and NFSV-12 present patterns similar to NFSV-1, they tend to extend their dipoles farther westward; meanwhile, the positive anomalies gradually cover much smaller regions with the lag times. In addition, the authors calculate the predic- tion errors caused by the three kinds of NFSVs, and the results indicate that the prediction error induced by NFSV-12 is the largest, followed by the NFSV-4. However, when compared with the prediction errors caused by random tendency errors, the NFSVs generate significantly larger prediction errors. It is therefore shown that the spatial structure of tendency errors is important for producing large prediction errors. Furthermore, in exploring the tendency errors that cause the largest prediction error for E1 Nifio events, the timedependent NFSV should be evaluated. 展开更多
关键词 PREDICTABILITY model error optimal perturbation
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Long Work Hours and Work-Life Balance in Korea and Japan
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作者 Jik-Soo Kim 《Sociology Study》 2014年第10期844-858,共15页
This study examines long work hours and work-life balance in relation to wage level, workaholism, and consumerism in both Korea and Japan. Findings of this study can be summarized as follows. First, the hypothesis tha... This study examines long work hours and work-life balance in relation to wage level, workaholism, and consumerism in both Korea and Japan. Findings of this study can be summarized as follows. First, the hypothesis that the wages and working hours have positive but differential effects depending on wage level categories are supported. Second, effects of cultural factors, such as workaholism and consumerism, on long work hours, however, are not significant in both countries. Third, for Korean manual workers, the probability of working long hours is high, but the level of time scarcity is low; but the effect of union membership on long work hours is not significant in both Korea and Japan. Fourth, the hypothesis that negative effects of long work hours and time scarcity on satisfaction with work-life balance are supported. These findings suggest that an increase in wage for non-regular workers and a minimum wage are required to reduce working hours. In addition, they also suggest that reducing working hours, overtime work in particular, and wage gap are crucial to raising the level of satisfaction with work-life balance in both Korea and Japan. 展开更多
关键词 Working hours WAGE workaholism CONSUMERISM work-life balance
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Some Discussions on Parallel Bounded Batch Scheduling to Minimize the Sum of Squared Machine Loads
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作者 Zengxia Cai Xianzhao Zhang 《Journal of Mathematics and System Science》 2016年第2期60-65,共6页
We sttidy the problem of scheduling n jobs on m parallel bounded batch machines to minimize the sum of squared machine loads. Each batch contains at most B jobs, and the processing time of a batch is equal to the long... We sttidy the problem of scheduling n jobs on m parallel bounded batch machines to minimize the sum of squared machine loads. Each batch contains at most B jobs, and the processing time of a batch is equal to the longest processing time of the jobs in this batch. We prove this problem to be NP-hard. Furthermore, we present a polynomial time approximation scheme (PTAS) and a fully polynomial time approximation scheme (FPTAS) for this problem. 展开更多
关键词 SCHEDULING Parallel batch Polynomial time approximation scheme FPTAS
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