检索结果-南通市图书馆

Effect of particle size on high-pressure methane adsorption of coal

在线全文

学校读者我要写书评

暂无评论

Petroleum Research 2016年第1期1卷 53-58页

作者： Jie Zou Reza Rezaee department of Petroleum Engineering Curtin UniversityWestern AustraliaAustralia

Adsorbed gas cannot be neglected in the evaluation of coalbed methane and shale gas since a significant proportion of gas is stored in the form of adsorbed *** methane of coal and shale has been widely studied by high-pressure methane adsorption *** sample treatment of the experiment,the sample is crushed and sieved to a particular particle size ***,how particle size influence high-pressure methane adsorption is still *** this study,low-pressure nitrogen(N_(2))and high-pressure methane adsorption have been measured on coal samples with different particle *** to N2 sorption analysis,pore volume and surface area increase with particle size *** size distribution of small pores(10nm)decreases with decreasing particle *** particle size by crushing sample introduces new connectivity for closed pores to the particle *** responses of isotherms of high-pressure methane adsorption are different with different particle *** adsorption at initial pressure(145psi)increases with decreasing particle *** increase rate at high pressure(435-870psi)decreases with particle size *** can be explained that fine sample has more pore volume and higher pore volume proportion of small pores(<10nm).Sample with particle size of 150-250μm has the highest Langmuir volume.

关键词： particle size high-pressure methane adsorption coal shale gas

Consistency between Itinerant and Local-Moment Pictures for Superconductivity in Alkaline Iron Selenide Superconductors

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 Physics Letters 2014年第6期31卷 199-202页

作者：李海超向圆圆王强华 National Laboratory of Solid State Microstructure and department of Physics Nanjing University Nanjing 210093

We study the superconducting pairing in an effective one-orbital model for alkaline iron-selenide superconductors. In both itinerant and local-moment pictures, we find that the nearest-neighbor hopping t1 plays a crucial role. The pairing symmetry changes from s-wave to d-wave as t1 is enhanced. For a reasonable t1 relevant to the experiment, the pairing symmetry is s-wave in both pictures, in agreement with the angle-resolved photo-emission. The results resolve the previous theoretical inconsistency in the two pictures.

关键词： ALKALINE solutions RESEARCH SOLUTION (Chemistry) SUPERCONDUCTORS -- Magnetic properties SELENIDES -- Synthesis PHYSICAL & theoretical chemistry MATTER -- Properties

Conditioning the γ spectrometer for activity measurement at very high background

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 Physics C 2012年第11期36卷 1082-1088页

作者：闫威华张立国张钊肖志刚 department of Physics Tsinghua University Institute of Nuclear Energy and Technology Tsinghua University

The application of a high purity Germanium （HPGe） γ spectrometer in determining the fuel element burnup in a future reactor is studied. The HPGe detector is exposed by a 60Co source with varying irradiation rate from 10× 103m s-1 to 150× 103m s-1 to simulate the input counting rate in real reactor environment. A 137Cs and a 152Eu source are positioned at given distances to generate a certain event rate in the detector with the former being proposed as a labeling nuclide to measure the burnup of a fuel element. It is shown that both the energy resolution slightly increasing with the irradiation rate and the passthrough rate at high irradiation level match the requirement of the real application. The influence of the background is studied in the different parameter sets used in the specially developed procedure of background subtraction. It is demonstrated that with the typical input irradiation rate and 137Cs intensity relevant to a deep burnup situation, the precision of the 137Cs counting rate in the current experiment is consistently below 2.8%, indicating a promising feasibility of utilizing an HPGe detector in the burnup measurement in future bed-like reactors.

关键词： fuel element burnup γ ctivity HPGe γ pectrometer

Daily shoaling patterns in the zebrafish Danio rerio

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2013年第6期59卷 754-760页

作者： Timothy PACIOREK Scott McROBERT department of Biology Saint Joseph's University Philadelphia PA 19131 USA

Shoaling intensity in zebrafish Danio rerio is believed to vary throughout subjective day and night hours. This experiment examines long term variations in shoaling behavior. Adult zebrafish Dan io rerio were maintained under a 12：12 LD cycle （with dim red light serving as reduced visibility during subjective dark hours）, and their shoaling behavior was monitored every hour for a three-day period of time. Our results show that zebrafish perform shoaling behavior throughout subjective day and under reduced visibility conditions, although mean shoaling times during the light phase were significantly higher than mean shoaling times during the dark phase. However, on the 3^rd day of the experiment, mean shoaling times during the subjective night had increased and mean shoaling times during the subjective day had decreased. This shift in intensity was not seen on the first two days of the study, and may represent the influence of experience on the behavior of the test fish. We believe this study shows that shoaling behavior changes with light/dark cycles and that fish shoal even during reduced visibility conditions.

关键词： Shoaling behavior Zebrafish Danio rerio Variation

Effects of periodical application of bioactive peptides derived from cottonseed on performance,immunity,total antioxidant activity of serum and intestinal development of broilers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Animal Nutrition 2021年第1期7卷 134-141页

作者： Nasir Landy Farshid Kheiri Mostafa Faghani department of Animal Science Shahrekord BranchIslamic Azad UniversityShahrekord***Iran

This experiment aimed to examine the effect of periodical application of bioactive peptides derived from cottonseed(BPC)in comparison with using sub-therapeutic doses of lincomycin and the excessive in-clusion of vitamin E on performance,immunity,total antioxidant capacity of serum and intestinal morphology of broiler chickens.A total of 240 one-d-old male broiler chicks with similar initial weight(Ross strain)were randomly assigned to 6 groups(8 chicks/pen):non-treated group(basal diet),basal diet supplemented with 2 mg/kg lincomycin,basal diet supplemented with 50 IU vitamin E,basal diet supplemented with 6 g BPC/kg in starter period,basal diet supplemented with 6 g BPC/kg in starter and grower periods and basal diet supplemented with 6 g BPC/kg throughout the whole *** highest final body weight was obtained in the group supplemented with BPC in starter and grower *** the finisher phase,broilers fed the diet containing BPC in the starter period and in the whole trial had significantly(P0.05).Broilers supplemented with BPC in starter and grower,and in the whole trial had significantly(P<0.05)higher antibody titers against sheep red blood cells(SRBC).The highest total antioxidant capacity was obtained in broilers supplemented with the excessive level of vitamin E,furthermore it tended to improve in broilers fed the diet containing BPC in the whole *** summary,the results of the study indicated that addition of BPC in broiler diets in the

关键词： Antibiotic Bioactive peptide Broiler Immunity Lincomycin Vitamin E

Optimization of the resonant frequency servo loop technique in the resonator micro optic gyro

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第11期12卷 942-950页

作者： Yang REN Zhong-he JIN Yan CHEN Hui-lian MA department of Information Science ＆ Electronic Engineering Zhejiang University Hangzhou 310027 China

Proportional integrator (PI) is always adopted in the resonant frequency servo loop in a resonator micro optic gyro (RMOG). The oscillation phenomenon is observed when adjusting the loop gain surpassing a threshold. This phenomenon limits system performance on step response speed and residual error. Based on the experiment system, a simulation model was set up. Further analysis shows that the threshold gain is related to the system loop filter setting and the loop delay. The traditional PI frequency servo loop technique in the RMOG system cannot keep up with the environment's disturbance quickly enough, which leads to a large residual error. A compensating method is proposed to optimize the tracking performance, solve the oscillation problem, and speed up the system response. Simulation and experiment results show that the compensated system is superior in performance. It has less residual error in the stable state and is 10 times quicker than the uncompensated system on the step response.

关键词： Resonator micro optic gyro (RMOG) Resonance frequency servo loop Phase compensating method

Geometric precision evaluation methodology of multiple reference station network algorithms

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2013年第1期20卷 134-141页

作者：李显吴美平张开东黄杨明 department of Automatic Control College of Mechatronics and AutomationNational University of Defense Technology

To evaluate the performance of real time kinematic (RTK) network algorithms without applying actual measurements, a new method called geometric precision evaluation methodology (GPEM) based on covariance analysis was presented. Three types of multiple reference station interpolation algorithms, including partial derivation algorithm (PDA), linear interpolation algorithms (LIA) and least squares condition (LSC) were discussed and analyzed. The geometric dilution of precision (GDOP) was defined to describe the influence of the network geometry on the interpolation precision, and the different GDOP expressions of above-mentioned algorithms were deduced. In order to compare geometric precision characteristics among different multiple reference station network algorithms, a simulation was conducted, and the GDOP contours of these algorithms were enumerated. Finally, to confirm the validation of GPEM, an experiment was conducted using data from Unite State Continuously Operating Reference Stations (US-CORS), and the precision performances were calculated according to the real test data and GPEM, respectively. The results show that GPEM generates very accurate estimation of the performance compared to the real data test.

关键词： network DGPS algorithms geometric precision evaluation covariance analysis partial derivation algorithm linearinterpolation algorithm least squares collocation

experimental study on drying kinetics of anchovy using centrifugal fluidized bed technique

在线全文

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2015年第5期8卷 132-141页

作者： Watcharin Dongbang Worachest Pirompugd department of Mechanical Engineering Faculty of EngineeringBurapha UniversityChonburi 20131Thailand

The present study investigated the drying kinetics of anchovy experimentally using centrifugal fluidized bed *** main purpose was to experimentally investigate the effect of the inlet air temperature on the drying kinetics of anchovy in a centrifugal fluidized bed dryer,to fit the experimental data to the widely used mathematical models of ***,the effective moisture diffusivity and activation energy in anchovy drying were investigated in the current *** drying experiment was conducted at drying air temperatures ranging over 70-120°*** air velocity and rotating speed of the air-distributor were fixed at 1.5 m/s and 150 r/min,*** drop across bed was approximately 390 Pa,while the layer height was fixed at approximately 2 *** anchovies were dried starting from 412%db down to 16%db;drying time ranged from 64 min to 172 *** was found that the drying temperature was a significant factor in decreasing the moisture content,moisture diffusivity and drying *** moisture diffusivity and activation energy were investigated at 0.11×10-9-0.25×10-9 m2/s and 20.32 kJ/mol,*** compared to existing models,the Midilli model proved to be in good agreement with change in moisture ratio.

关键词： centrifugal fluidized bed drying kinetics anchovy moisture diffusivity activation energy

New-onset diabetes in COVID-19 and clinical outcomes: A systematic review and meta-analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Virology 2021年第5期10卷 275-287页

作者： Dhan Bahadur Shrestha Pravash Budhathoki Sumit Raut Sugat Adhikari Prinska Ghimire Sabin Thapaliya Ali A Rabaan Bibodh Jung Karki department of Internal Medicine Mount Sinai HospitalChicagoIL 60608United States department of Internal Medicine BronxCare Health SystemBronxNY 10457United States department of Emergency Medicine Kathmandu Medical CollegeKathmandu 44600Nepal department of Internal Medicine Nishtar Medical UniversityMultan 59330Pakistan department of Internal Medicine Tribhuvan UniversityKathmandu 44600Nepal department of Internal Medicine Tribhuvan University Teaching HospitalKathmandu 44600Nepal Molecular Diagnostic Laboratory Johns Hopkins Aramco HealthcareDhahran 34465Saudi Arabia department of Public Health&Nutrition The University of HaripurHaripur 22620Pakistan Division of Infectious Diseases University of LouisvilleLouisvilleKY 40292United States

BACKGROUND Diabetes mellitus(DM)is associated with adverse clinical outcomes and high mortality in patients with coronavirus disease 2019(COVID-19).The relationship between diabetes and COVID-19 is known to be *** To analyze the rate of new-onset diabetes in COVID-19 patients and compare the clinical outcomes of new-onset diabetes,pre-existing diabetes,hyperglycemic,and non-diabetes among COVID-19 *** We used the Meta-analysis of Observational Studies in Epidemiology statement for the present *** databases were searched for all peerreviewed articles published until November 6,*** were screened using Covidence and data *** analysis was done using comprehensive *** the 128 studies detected after thorough database searching,seven were included in the quantitative *** proportion was reported with 95%confidence interval(CI)and heterogeneity was assessed using *** Analysis showed that 19.70%(CI:10.93-32.91)of COVID-19 patients had associated DM,and 25.23%(CI:19.07-32.58)had associated *** overall mortality rate was 15.36%(CI:12.57-18.68)of all COVID-19 cases,irrespective of their DM *** mortality rate was 9.26%among non-diabetic patients,10.59%among patients with COVID-19 associated hyperglycemia,16.03%among known DM patients,and 24.96%among COVID-19 associated DM *** overall occurrence of adverse events was 20.52%(CI:14.21-28.70)among COVID-19 patients in the included studies,15.29%among non-diabetic patients,20.41%among patients with COVID-19 associated hyperglycemia,20.69%among known DM patients,and 45.85%among new-onset *** showed an increasing rate of mortality among new hyperglycemic patients,known diabetics,and new-onset DM patients in comparison to those without *** A significantly higher rate of new onset DM and hyperglycemia was *** mortality rates and adverse events were seen in patients with

关键词： Acute respiratory distress syndrome COVID-19 Diabetes mellitus Hyperglycemia Mortality