检索结果-南通市图书馆

Environmental Radiation Measurement and Assessment of Natural Radioactivity in Soil, Water and Vegetation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Applied Mathematics and Physics 2018年第11期6卷 2330-2337页

作者： nandi-Esom Chariette Ereh Meng Zhang Nuclear Science and Technology Harbin Engineering University Harbin China

Environmental radioactivity is produced by radioactive materials in the human environment. While some radioisotopes, such as strontium-90 (90Sr) and technetium-99 (99Tc), are only found on Earth as a result of human activity, and some, like potassium-40 (40k), are only present due to natural processes, a few isotopes, e.g. tritium (3H), result from both natural processes and human activities. The concentration and location of some natural isotopes, particularly uranium-238 (238U), can be affected by human activity because of the constant exposure of Human beings to radiation caused by terrestrial, extra-terrestrial and anthropogenic radio nuclides, it is necessary to determine and estimate the activity of various radio nuclides in environmental media such as vegetation, soil, and water. In the present research, the activities of 226Ra, 232Th and 40k are measured in soil, vegetation and water samples, collected from Yangdong District, Yangxi County, and Yangjiang County of Guangdong Province, China using an HPGe based gamma spectrometry system. The measured mean activity of 226Ra, 232Th and 40k in soil samples was found to be 31.19 ± 1.2, 47.00 ± 2.30 and 589.31 ± 17.52 Bqkg-1, respectively. The measured mean activity of these radionuclides in all water samples was found to be below minimum detectable activity. The measured mean activity of 226Ra, 232Th and 40k in vegetation samples was 19.92 ± 3.09, 25.36 ± 8.11 and 4982.94 ± 85.68 Bqkg-1, respectively. No anthropogenic 137Cs was detected in these environmental samples. Mean radium equivalent activity (Raeq), external radiation hazard index (Hex), internal radiation hazard index (Hin) and absorbed dose rate (D) for the area under study were determined as 142.92 Bqkg-1, 0.38, 0.47 and 66.47 nGyh-1, respectively. The annual effective dose equivalent (AEDE) varied in the range from 0.03 to 0.12 mSvy-1. It is concluded that the surveyed area do not pose any significant radiological risk to the population and environment

关键词： High Purity Germanium Detector Radium Thorium Potassium Radium Equivalent Activity Radiation Hazard Indices and Environment Measure-ment

MMCC Based Electronically Tunable Allpass Filters Using Grounded Synthetic Inductor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Circuits and Systems 2014年第4期5卷 89-97页

作者： Rabindranath nandi Palaniandavar Venkateswaran Mousiki kar Department of Electronics & Communication Engineering Heritage Institute of Technology Kolkata India Department of Electronics & Telecommunication Engineering Jadavpur University Kolkata India

New circuit implementations of electronically tunable first and second order allpass filter (AP) structures using a Multiplication Mode Current Conveyor (MMCC) building block are presented. The control voltage (V) of the MMCC tunes the desired phase (θ) while the time constant (τ) is adjustable by a Differential Voltage Current Conveyor Transconductance Amplifier (DVCCTA)-based synthetic lossless grounded inductor (L). The circuits are analyzed taking into account the device imperfections which show low active sensitivity features of the designs. The effects of port transfer error (ε) and that of the parasitic capacitances of the active devices had been meticulously examined which indicated that certain deviations in nominal design equations occur;these however, could be minimized with appropriate choice of the circuit passive components. Readily available AD-844 type Current Feedback Amplifier (CFA) elements are utilized for the topology implementation. Satisfactory test results on electronic θ-tunability, upto about 300 kHz, had been verified by PSPICE simulation and with hardware experimentation.

关键词： Allpass Filter MMCC DVCCTA CFA Synthetic Inductor Electronic Phase Shifter

Selective Filters and Tunable Sinusoid Oscillator Using a CDBA

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Circuits and Systems 2013年第2期4卷 227-232页

作者： Rabindranath nandi Palaniandavar Venkateswaran Sagarika Das B. P. Poddar Institute of Management & Technology Kolkata India Department of Electronics & Telecommunication Engineering Jadavpur University Kolkata India

The realization of some new selective filters using single current differencing buffered amplifier (CDBA) and few RC components is presented. The same topology provides lowpass (LP), bandpass (BP) and highpass (HP) characteristics with appropriate choice and location of the RC components in the circuit. Incorporation of a suitable feedback loop through a voltage buffer unity-gain cell yields a tunable sinusoid oscillator. Effects of the device port mismatch errors (ε) and parasitic z-node capacitance (Cz) of the CDBA element are shown to be insignificant and corresponding sensitivities are extremely low. Satisfactory experimental verifications of the filter quality (Q) and oscillator tuning range (500 kHz ≤ fo ≤ 5 MHz) are carried out.

关键词： Current Differencing Buffered Amplifier Selective Filter Sinewave Generator Tunable Oscillator

New Integrators and Differentiators Using a MMCC

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Circuits and Systems 2012年第3期3卷 288-294页

作者： Palaniandavar Venkateswaran Rabindranath nandi Sagarika Das B. P. Poddar Institute of Management & Technology Kolkata-700052 India Department of Electronics & Telecommunication Engineering Jadavpur University Kolkata-700032 India

Using the new building block Multiplication-Mode Current Conveyor (MMCC), some inverting/non-inverting type integrator and differentiator designs are presented, wherein the time constant (τ) is tuned electronically. The MMCC is implemented by a readily available chip-level configuration using a multiplier (ICL 8013) and a current feedback amplifier (AD-844 IC) CFA. Detailed analysis, taking into account the device non-idealities, had been carried out that indicates slight deviations affecting the values of the nominal time constant but the design is practically insensitive to the port mismatch errors (ε). Satisfactory response on wave conversion, for signal frequencies up to 600 khz had been verified with both hardware circuit test and PSPICE macromodel simulation.

关键词： Voltage-Controlled Oscillator Multiplication Mode Current Conveyor (MMCC) Current Feedback Opamp (CFA) Quadrature Oscillator

适应新工科特色的《食品发酵技术》线上教学模式探索与反思

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

食品与发酵工业 2022年第3期48卷 325-330页

作者：陈磊周楠迪陈鹏程江南大学生物工程学院江苏无锡214122

为适应新工科特色的专业建设,《食品发酵技术》这门知识点多、交叉性强、覆盖面广的课程在教学内容的扩展、知识体系的构建、教学方式的更新和教学资源的网络化等方面都有进一步的提升空间。基于《食品发酵技术》课程线下教学过程中存... 详细信息

为适应新工科特色的专业建设,《食品发酵技术》这门知识点多、交叉性强、覆盖面广的课程在教学内容的扩展、知识体系的构建、教学方式的更新和教学资源的网络化等方面都有进一步的提升空间。基于《食品发酵技术》课程线下教学过程中存在的问题,为贯彻"成果导向教育(Outcome Based Education,OBE)"理念,落实课程思政要求,结合课程特点和"新冠"疫情期间线上教学模式的探索,对该课程的进一步改革和完善进行了深入反思。在此基础上,对教改前后学生评价结果进行总结分析,以人为本,使课程建设更加符合新工科专业建设的要求。

关键词：新工科食品发酵技术线上教学教学模式改革

Hydrogeomorphological Study in Bamanghaty Subdivision of Mayurbhanj District, Odisha an Integrated Remote Sensing and GIS Approach

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

International Journal of Geosciences 2017年第11期8卷 1361-1373页

作者： Debabrata nandi Pramod Chandra Sahu Shreerup Goswami Department of Remote Sensing and GIS North Orissa University Odisha India Department of Geology MPC Autonomous Colleges Baripada Odisha India Department of Earth Science Sambalpur University Sambalpur Odisha India

Remote Sensing (RS) and geographic information system (GIS) are now very essential tools for efficient planning and management and handling a range of data simultaneously in a time- and cost-efficient manner for targeting of groundwater, which assists in measuring, monitoring, and conserving groundwater resources. Survey of India toposheets, LISS-III and CARTOSAT DEM satellite imageries are used to prepare various thematic layers viz., geology, slope, lineament, drainage, and geomorphology, and were transformed to raster data using feature to raster conversion tool in ArcGIS spatial analysis, then we reclassify each raster map using reclassify tools. By using weight overlay analysis, each weighted thematic layer is statistically computed to get the ground water potential zones. Then, five different groundwater potential zones were identified, namely “very good”, “good”, “moderate”, “poor”, and “very poor”. The villages under poor groundwater potential zone and the villages under very good groundwater potential zone are finding out. The above study has clearly demonstrated the capabilities of Remote Sensing and GIS in demarcation of the different groundwater potential zones in hard rock terrain.

关键词： Hydrogeomorphology Remote Sensing GIS

印度梅加拉亚晚白垩世沉积中的三突口器类花粉(英文)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

古生物学报 2002年第4期41卷 601-610页

作者： B.nandi S.Chattopadhyay 印度kalyani大学植物系印度西孟加拉Kalyani741235

作者在研究梅加拉亚盆地(Meghalaya)晚白垩世,特别是白垩-第三纪界线附近孢粉时发现大量三突口器类以及其他类型的花粉,这些花粉主要包括:Aquilapollenites indicus,***,*** ***.,以及新属Farabeipollis,该新属包括3个新种;还有Integric... 详细信息

作者在研究梅加拉亚盆地(Meghalaya)晚白垩世,特别是白垩-第三纪界线附近孢粉时发现大量三突口器类以及其他类型的花粉,这些花粉主要包括:Aquilapollenites indicus,***,*** ***.,以及新属Farabeipollis,该新属包括3个新种;还有Integricorpus brevicolpatum ***.,Integricorpus langparensis ***.,Mancicorpus albertensis,Striaticorpus pyriforme,***。孢粉地层学研究显示早马斯特里赫期孢粉植物群中正型粉类居统治地位,而三突口器类花粉的种类和数量都较少。三突口器类花粉是在晚白垩世正型粉类消失后才开始分异发育的。

关键词：印度梅加拉亚晚白垩世沉积三突口器类花粉

Novel Hemorrhagic Risk Score in Elderly Patients with Coronary Artery Disease and Gastrointestinal Malignant Tumor Comorbidity:A 10-year Clinical Inpatient Data Analysis from 2 Medical Centers

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Cardiology Discovery 2021年第3期1卷 163-172页

作者： nandi Bao Wanling Wang Huitao Wu Yabin Wang Hebin Che Wenwen Meng Jiaxin Miao Dong Han Fan Yin National Clinical Research Center for Geriatric Diseases The Second Medical Center of Chinese People's Liberation Army General HospitalBeijing 100853China Medical School of Chinese People's Liberation Army General Hospital Beijing 100853China National Engineering Laboratory for Medical Big Data Application Technology The First Medical Center of Chinese People's Liberation Army General HospitalBeijing 100853China Department of Oncology The Second Medical Center of Chinese People's Liberation Army General HospitalBeijing 100853China

Objective:Older patients with comorbidity,such as coronary heart disease(CHD)and malignant gastrointestinal tumors,are at a high risk of bleeding ***,risk prediction models based on risk factor assessment remain *** study aimed to establish an individualized bleeding risk assessment system based on the analysis of 10-year inpatient clinical big ***:Total clinical data of 56,819 patients with CHD and 25,988 patients with malignant digestive tract tumors(admitted from January 2008 to December 2017)were retrospectively collected at the First and Second Medical Centers of Chinese People's Liberation Army General *** them,1307 patients with CHD and malignant digestive tract tumors were screened as the derivation *** dependent variable was the occurrence of major clinical bleeding *** statistics and hypothesis tests of differences were performed for independent variables according to the occurrence of *** Tree,eXtreme Gradient Boosting(XGBoost),logistic regression,and random forest models were used for *** accuracy,sensitivity,specificity,and area under the receiver operating characteristic curve(AUC-ROC)were applied as the criteria for evaluating and verifying model *** evaluate this developed model,another cohort comprising 454 patients(admitted from January 2018 to December 2019)was prospectively enrolled as the validation cohort based on the same inclusion and exclusion ***:Among the 64 variables with<50%missing values,the recursive feature elimination method with a random forest model was used to screen the selected *** highest accuracy was obtained following the selection of 10 scalars,and the final model was constructed *** demonstrated the best performance *** AUC-ROC of this model was 0.981,with an accuracy,sensitivity,and specificity of 0.939,0.950,and 0.927,*** the validation cohort,the AUC-ROC,accurac

关键词： Coronary disease Gastrointestinal cancers Bleeding Multivariate analysis Risk factors Machine learning

Diversity of Primate Lentiviruses Rebooted

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Biosciences and Medicines 2019年第12期7卷 126-138页

作者： Jayashree S. nandi Anil k. Chhangani Shravan Singh Rathore Bajrang Raj J. Mathur Department of Microbiology & Immunology Albert Einstein College of Medicine New York USA Department of Environmental Science Maharaja Ganga Singh University Bikaner India Department of Wildlife Machiya Biological Park Jodhpur India Department of Veterinary Sciences Patanjali Products 1-B-1 Kamla Nehru Nagar Behind Konark School Jodhpur India

Highlight: The present report reveals for the first time natural lentiviral infection of wild Indian NHPs, rhesus monkeys (Macaca mulatta) and langurs (Semnopithecus entellus) by SIVs that are phylogenetically diverse from all known SIVs, including “SIVmac”, which infects captive rhesus monkeys. The novel SIVs are intriguingly homologous to HIV-1, based on serology and partial lentiviral genomic sequence analyses. Diverse lenti-viruses infect human and nonhuman primates (NHPs). There are more than 45 different “species-specific” simian immunodeficiency viruses (SIVs) that infect their cognate NHP hosts in natural habitats in Africa. Indian NHPs are not known to be infected by SIVs in the wild. Conventionally SIVs are named after their natural hosts, except for SIVmac, which infects captive rather than wild rhesus macaques. SIVmac is therefore a misnomer. It is a genetic variant of the African SIVsmm, which infects wild African sooty mangabey monkeys. SIVsmm is the progenitor of human immunodeficiency virus (HIV-2), while SIVcpz that infects wild chimpanzees is the progenitor of HIV-1. Although natural infections cannot be easily studied in wild NHP populations, we have previously reported co-infection of wild Indian NHPs by other retroviruses: simian retroviruses (SRVs) and Simian Foamy viruses (SFV). Apart from zoonosis, transmission of pathogens from humans to animals: anthroponosis, has also been reported in literature.

关键词： Lentivirus HIV-1 SIV Wild Indian Langur Rhesus Monkey Zoonosis Anthroponosis