检索结果-南通市图书馆

Journal of Environmental Sciences 2007年第5期19卷 572-577页

作者： cheng yan-li bai yu-hua li jin-long liu zhao-rong College of Environmental Sciences Peking University Beijing 100871 China

A modified two-dimensional Eulerian air quality model was used to simulate both the gaseous and particulate pollutant concentrations during October 21-24, 2004 in the Pearl River Delta （PRD） region, China. The most significant improvement to the model is the added capability to predict the secondary organic aerosols （SOA） concentrations because of the inclusion of the SOA formation chemistry. The meteorological input data were prepared using the CALMET meteorological model. The concentrations of aerosol-bound species such as NO3^-, NH4^＋, SO4^2-, and SOA were calculated in the fine particle size range （〈2.5 μm）. The results of the two-dimensional model were compared to the measurements at the ground level during the PRD Intensive Monitoring Campaign （IMC）. Overall, there were good agreements between the measured and modeled concentrations of inorganic aerosol components and O3. Both the measured and the modeled results indicated that the maximum hourly O3 concentrations exceeded the China National Air Quality Standard. The predicted 24-h average SOA concentrations were in reasonable agreement with those predicted by the method of minimum OC/EC ratio.

关键词： air quality model numerical simulation secondary organic aerosol inorganic aerosol

First Oligocene mummified plant Lagerst?tte at the low latitudes of East Asia

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2016年第3期59卷 445-448页

作者： QUAN cheng FU Qiong Yao SHI Gong Le liu yu Sheng li long liu Xiao yan jin Jian hua Research Center of Paleontology and Stratigraphy Jilin University State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources School of Life SciencesSun Yat-sen University Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Office of Research and Graduate Studies Prairie View A & M University

Mummified fossils are extraordinarily important for understanding both biotic evolution and ecology in the geological time,by uniquely providing a far more detailed source of information in comparison to impression ***,mummified fossils are extremely rare because of the inevitable requirement of unusual preservation conditions during fossilization,including the lithological features and deposition rate of surrounding rocks,and moisture and temperature conditions（Taylor et al.,2009）.To date,only a few Cenozoic sites have been reported to yield mummified plant fossils around the world,

关键词： fossilization preservation inevitable Cenozoic uniquely ecology extremely moisture providing Miocene

Calculation model of mass action concentrations for CaO-MgO-SiO_2-Al_2O_3-Cr_2O_3 penta-slag

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2010年第2期21卷 229-233页

作者： Guo, hua Hu, yu Ting Cang, Da Qiang jin, Yi Wang, li Xin cheng, Xiang li bai, Hao Zong, yan Bing Univ Sci & Technol Beijing Sch Met & Ecol Engn Beijing 100083 Peoples R China Taiyuan Iron & Steel Co Ltd Taiyuan 030003 Peoples R China

Two calculation models of mass action concentrations for CaO-MgO-SiO_2-Al_2O_3-Cr_2O_3 penta-slag was presented whether 3CaO·Cr_2O_3·3SiO_2 was existence or *** mass action concentration of each element structure was *** the models results were compared with experimental *** final results illustrated the model without 3CaO·Cr_2O_33SiO_2 was suit for *** model could response the element structure of slag as well.

关键词： Slag Cr_2O_3 Co-existence theory Thermodynamic calculation model

Programmable time-domain digital-coding metasurface for non-linear harmonic manipulation and new wireless communication systems

在线全文

学校读者我要写书评

暂无评论

National Science Review 2019年第2期6卷 231-238页

作者： Jie zhao Xi yang Jun yan Dai Qiang cheng Xiang li Ning hua Qi Jun Chen Ke Guo Dong bai Shuo liu Shi jin Andrea Alù Tie Jun Cui State Key Laboratory of Millimeter Waves Southeast University Jiangsu Cyber-Space Science & Technology Co. Ltd Physics Program The Graduate Center City University of New York National Mobile Communication Research Laboratory Southeast University Synergetic Innovation Center of Wireless Communication Technology Southeast University Department of Electrical Engineering City College of New York Photonics Initiative Advanced Science Research Center City University of New York

Optical non-linear phenomena are typically observed in natural materials interacting with light at high intensities, and they benefit a diverse range of applications from communication to sensing. However,controlling harmonic conversion with high efficiency and flexibility remains a major issue in modern optical and radio-frequency systems. Here, we introduce a dynamic time-domain digital-coding metasurface that enables efficient manipulation of spectral harmonic distribution. By dynamically modulating the local phase of the surface reflectivity, we achieve accurate control of different harmonics in a highly programmable and dynamic fashion, enabling unusual responses, such as velocity illusion. As a relevant application, we propose and realize a novel architecture for wireless communication systems based on the time-domain digital-coding metasurface, which largely simplifies the architecture of modern communication systems, at the same time yielding excellent performance for real-time signal transmission. The presented work, from new concept to new system, opens new pathways in the application of metamaterials to practical technology.

关键词： metasurface time-domain digital coding non-linear harmonics control new architecture of communication

Feasibility of hyperspectral analysis for discrimination of rabbit liver VX2 tumor

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2019年第1期11卷 1-8页

作者： Feng Duan jing yuan Xuan liu li Cui yan-hua bai Xiao-Hui li huang-rong Xu Chen-yang liu Wei-Xing yu Department of Interventional Radiology the General Hospital of Chinese People's Liberation Army Department of Pathology the General Hospital of Chinese People's Liberation Army Key Laboratory of Spectral Imaging Technology of Chinese Academy of Sciences Xi'an Institute of Optics and Precision Mechanics Chinese Academy of Sciences

BACKGROUND Hepatocellular carcinoma is one of the most common malignant tumors worldwide. Currently, the most accurate diagnosis imaging modality for hepatocellular carcinoma is enhanced magnetic resonance imaging. However, it is still difficult to distinguish cirrhosis lesions, and novel diagnosis modalities are still *** To investigate the feasibility of hyperspectral analysis for discrimination of rabbit liver VX2 *** In this study, a rabbit liver VX2 tumor model was established. After laparotomy,under direct view, VX2 tumor tissue and normal liver tissue were subjected to hyperspectral *** The spectral signature of the liver tumor was clearly distinguishable from that of the normal tissue, simply from the original spectral curves. Specifically, two absorption peaks at 600-900 nm wavelength in normal tissue disappeared but a new reflection peak appeared in the tumor. The average optical reflection at the whole waveband of 400-1800 nm in liver tumor was higher than that of the normal *** Hyperspectral analysis can differentiate rabbit VX2 tumors. Further research will continue to perform hyperspectral imaging to obtain more information for differentiation of liver cancer from normal tissue.

关键词： Hyperspectral analysis VX2 tumor liver cancer Diagnosis Animal experiment

Association between Selenium in Soil and Diabetes in Chinese Residents Aged 35–74 Years:Results from the 2010 National Survey of Chronic Diseases and Behavioral Risk Factors Surveillance

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2020年第4期33卷 260-268页

作者： WANG Qi Qi yu Shi cheng XU cheng Dong liu Jian Jun li yuan Qiu ZHANG Man Hui long Xiao Juan liu yun Ning BI yu Fang zhao Wen hua YAO Hong yan Chinese Center for Disease Control and Prevention Beijing 102206China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Peking University Third Hospital Beijing 100191China National Center for Chronic and Non communicable Disease Control and Prevention Chinese Center for Disease Control and PreventionBeijing 100050China Shanghai National Clinical Research Center for Endocrine and Metabolic Diseases Shanghai Institute of Endocrine and Metabolic DiseasesRuijin HospitalShanghai Jiao Tong University School of MedicineShanghai 200025China National Institute for Nutrition and Health Chinese Center for Disease Control and PreventionBeijing 100050China

Objective To explore the association between soil selenium levels and the risk of diabetes in Chinese adults aged 35–74 *** Data for this study were derived from the China Chronic Diseases and Behavioral Risk Factors Surveillance 2010 *** concentrations in soil were obtained from the Atlas of Soil Environmental Background Values in China.A two-level binary logistic regression model was used to determine the association between soil selenium concentrations and the risk of diabetes,with participants nested within districts/*** A total of 69,332 participants aged 35–74 years,from 158 districts/counties were included in the *** of selenium in soil varied greatly across the 158 districts/counties,with a median concentration of 0.219 mg/kg(IQR:0.185–0.248).The results showed that both Quartile 1(0.119–0.185 mg/kg)and Quartile 4(0.249–0.344 mg/kg)groups were positively associated with diabetes compared to a soil selenium concentration of 0.186–0.219 mg/kg(Quartile 2),crude odds ratios(ORs)(95%CI)were 1.227(1.003–1.502)and 1.280(1.048–1.563).The P values were 0.045 and 0.013,for Quartile 1 and Quartile 4 groups,*** adjusting for all confounding factors of interest,the Quartile 1 group became non-significant,and the Quartile 4 group had an adjusted OR(95%CI)of 1.203(1.018–1.421)relative to the reference group(Quartile 2),the P values was *** significant results were seen for the Quartile 3 group(0.220–0.248 mg/kg)compared to the reference *** Excessive selenium concentrations in soil could increase the risk of diabetes among Chinese adults aged 35–74 years.

关键词： Selenium Diabetes Odds ratio Behavioral risk factors Survey

Identification of active compound combination contributing to anti-inflammatory activity of Xiao-cheng-Qi Decoction via human intestinal bacterial metabolism

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Natural Medicines 2018年第7期16卷 513-524页

作者： liu Xing-yan li li li Xue-Qing yu Bo-yang liu Ji-hua Jiangsu Key Laboratory of TCM Evaluation and Translational Research China Pharmaceutical University State Key Laboratory of Natural Medicines China Pharmaceutical University

Human intestinal bacteria play an important role in the metabolism of herbal medicines, leading to the variations in their pharmacological profile. The present study aimed to investigate the metabolism of Xiao-cheng-Qi decoction(XCQD) by human intestinal bacteria and to discover active component combination(ACC) contributing to the anti-inflammatory activity of XCQD. The water extract of XCQD was anaerobically incubated with human intestinal bacteria suspensions for 48 h at 37 °C. A liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry(LC-Q-TOF/MS) method was performed for identification of the metabolites. In addition, the anti-inflammatory effects of XCQD and biotransformed XCQD(XCQD-BT) were evaluated in vitro with cytokines in RAW264.7 cells induced by lipopolysaccharide(LPS). A total of 51 compounds were identified in XCQD and XCQD-BT. Among them, 20 metabolites were proven to be transformed by human intestinal bacteria. Significantly, a combination of 14 compounds was identified as ACC from XCQD-BT, which was as effective as XCQD in cell models of inflammation. In conclusion, this study provided an applicable method, based on intestinal bacterial metabolism, for identifying combinatory compounds responsible for a certain pharmacological activity of herbal medicines.

关键词： Xiao-cheng-Qi decoction Human intestinal bacteria Metabolism Anti-inflammatory LC-Q-TOF/MS

Estimation Study of New Cancer Cases and Deaths in Wuwei, Hexi Corridor Region, China, 2018

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2017年第11期30卷 829-833页

作者： CAO Bo yu li cheng yun XU Feng Lan liu Xiao Qin yanG yan Xu li jing GAO Cai yun rong You Ming li rong cheng li Ya li ZHENG Shan bai Ya Na YE yan cheng Institute of Epidemiology and Statistics School of Public Health Center for Cancer Prevent and Treatment Lanzhou University Department of Cancer Epidemiology Wuwei Cancer Registry Gansu Wuwei Tumor Hospital

Population-based cancer registration data were collected to estimate the cancer incidence and mortality in Wuwei, Hexi Corridor Region, China in 2018. We used the 2011-2013 data to predict the number of new cases and deaths in 2018 and the 2003-2013 data to analyze trends in cancer incidence and mortality. The goal is to enable cancer prevention and control directions. Our results indicated that stomach cancer is the most common cancer. For all cancers combined, the incidence and mortality rates showed significantly increasing trends（＋2.63% per year; P 〈 0.05 and ＋1.9% per year; P 〈 0.05）. This study revealed a significant cancer burden among the population of this area. Cancer screening and prevention should be performed after an epidemiological study of the cause of the cancer is completed.

关键词： Estimation Study of New Cancer Hexi Corridor Region

Improving Blood Monocyte Energy Metabolism Enhances Its Ability to Phagocytose Amyloid-βand Prevents Alzheimer’s Disease-Type Pathology and Cognitive Deficits

在线全文

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2023年第12期39卷 1775-1788页

作者： Zhi-Hao liu yu-Di bai Zhong-yuan yu Hui-yun li Jie liu cheng-rong Tan Gui-hua Zeng yun-Feng Tu Pu-yang Sun yu-Juan Jia jin-Cai He yan-Jiang Wang Xian-Le Bu Department of Neurology The First Affiliated Hospital of Wenzhou Medical UniversityWenzhou325000China Department of Neurology and Centre for Clinical Neuroscience Daping HospitalThird Military Medical UniversityChongqing400042China Chongqing Key Laboratory of Ageing and Brain Diseases Chongqing400042China Institute of Brain and Intelligence Third Military Medical UniversityChongqing400042China State Key Laboratory of Trauma Burns and Combined InjuryThird Military Medical UniversityChongqing400042China Center for Excellence in Brain Science and Intelligence Technology Chinese Academy of SciencesShanghai201200China

Deficiencies in the clearance of peripheral amyloidβ(Aβ)play a crucial role in the progression of Alzheimer’s disease(AD).Previous studies have shown that the ability of blood monocytes to phagocytose Aβis decreased in ***,the exact mechanism of Aβclearance dysfunction in AD monocytes remains *** the present study,we found that blood monocytes in AD mice exhibited decreases in energy metabolism,which was accompanied by cellular senescence,a senescence-associated secretory phenotype,and dysfunctional phagocytosis of Aβ.Improving energy metabolism rejuvenated monocytes and enhanced their ability to phagocytose Aβin vivo and in ***,enhancing blood monocyte Aβphagocytosis by improving energy metabolism alleviated brain Aβdeposition and neuroinflammation and eventually improved cognitive function in AD *** study reveals a new mechanism of impaired Aβphagocytosis in monocytes and provides evidence that restoring their energy metabolism may be a novel therapeutic strategy for AD.

关键词： Alzheimer's disease Aβclearance Monocyte Phagocytosis Energy metabolism

Metal-free phthalocyanine single crystal： Solvothermal synthesis and near-infrared electroluminescence

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2016年第5期27卷 764-768页

作者： Qing-long bai Chun-hua Zhang Juan-Juan Song jing-Hai liu yan-Chun Feng li-Mei Duan Chuan-Hui cheng Inner Mongolia Key Lab of Chemistry of Natural Products and Synthesis of Functional Molecules College of Chemistry and Chemical Engineering Inner Mongolia University for Nationalities Tongliao 028000 China School of Physics and Optoelectronics Technology Dalian University of Technology Dalian 116024 China

A metal-flee purple H2Pc single crystal was synthesized by a facile solvothermal method, and its solubility and near-infrared （NIR） optical properties were also investigated due to its potential applications as a light-emitting layer for OLEDs. The H2Pc single crystal is insoluble in 1-chlorine naphthalene and other organic solvents. It gives a wide absorption in the range from 620 nm to 679 nm and a wide emission in near 922 nm. As an active light-emitting layer, H2Pc was employed to fabricate electroluminescent （EL） devices with a structure of ITO/NPB （30 nm）/Alq3：H2Pc （30 nm）/BCP （20 nm）/ Alq3 （20 nm）/Al. The emission center is at 936 nm when the H2Pc doping concentration is 20 wt%. The doping concentration strongly governs the emission intensity. When doping concentration decreases from 10 wt% to 1 wt%, the emission intensity remarkably fades, and simultaneously the emission center undergoes a blue shift.

关键词： Solvothermal synthesis H2Pc single crystal Optical properties Near-infrared Electroluminescence