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Morphological and Sulfur-Isotopic Characteristics of Pyrites in the Deep Sediments from Xisha Trough,South China Sea
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作者 CHANG Jingyi LIU Yujia +4 位作者 LU Hailong LU Jing’an SU Xin YE Jianliang XIE Wenwei 《Journal of Ocean University of China》 CAS CSCD 2024年第1期138-148,共11页
Pyrite is one of the common authigenic minerals in marine sediments.Previous studies have shown that the morphological and isotopic characteristics of pyrite are closely related to the geochemical environment where it... Pyrite is one of the common authigenic minerals in marine sediments.Previous studies have shown that the morphological and isotopic characteristics of pyrite are closely related to the geochemical environment where it is formed.To better understand the for-mation mechanism of authigenic pyrite,we analyzed the isotopic composition,morphology,and distribution of pyrite in the sediment at 500m below the seafloor from Xisha Trough,South China Sea.Mineral morphologies were observed by scanning electron micros-copy and Raman spectrography.X-Ray computed tomography was applied to measure the particle size of pyrite.The size of pyrite crystals in the matrix sediment mainly ranged between 25 and 65µm(av.ca.40µm),although crystals were larger(av.ca.50μm)in the veins.The pyrites had a fine-grained truncated octahedral shape with occasionally well-developed growth steps,which implies the low growth rate and weak anaerobic oxidation of methane-sulfate reduction when pyrite was formed.Theδ^(34)S values of pyrites ranged from+20.8‰Vienna-defined Canyon Diablo Troilite(V-CDT)to+33.2‰V-CDT and from+44.8‰V-CDT to+48.9‰,which suggest two growth stages.In the first stage,with the continuous low methane flux,the pyrite possibly formed in an environment with good access to seawater.In the second stage,the pyrites mainly developed in sediment fractures and appeared in veins,probably due to the limited availability of sulfate.The less exposure of pyrite to the environment in the second stage was probably caused by sediment accumulation or perturbation.In this study,an episodic pyritization process was identified,and the paleoenvironment was reconstructed for the sediment investigated. 展开更多
关键词 PYRITE sulfur isotope AOM methane flux Xisha trough South China Sea
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Persistent Variations in the East Asian Trough from March to April and the Possible Mechanism
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作者 Shui YU Jianqi SUN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第4期737-753,I0002-I0004,共20页
The East Asian trough(EAT)profoundly influences the East Asian spring climate.In this study,the relationship of the EATs among the three spring months is investigated.Correlation analysis shows that the variation in M... The East Asian trough(EAT)profoundly influences the East Asian spring climate.In this study,the relationship of the EATs among the three spring months is investigated.Correlation analysis shows that the variation in March EAT is closely related to that of April EAT.Extended empirical orthogonal function(EEOF)analysis also confirms the co-variation of the March and April EATs.The positive/negative EEOF1 features the persistent strengthened/weakened EAT from March to April.Further investigation indicates that the variations in EEOF1 are related to a dipole sea surface temperature(SST)pattern over the North Atlantic and the SST anomaly over the tropical Indian Ocean.The dipole SST pattern over the North Atlantic,with one center east of Newfoundland Island and another east of Bermuda,could trigger a Rossby wave train to influence the EAT in March−April.The SST anomaly over the tropical Indian Ocean can change the Walker circulation and influence the atmospheric circulation over the tropical western Pacific,subsequently impacting the southern part of the EAT in March−April.Besides the SST factors,the Northeast Asian snow cover could change the regional thermal conditions and lead to persistent EAT anomalies from March to April.These three impact factors are generally independent of each other,jointly explaining large variations in the EAT EEOF1.Moreover,the signals of the three factors could be traced back to February,consequently providing a potential prediction source for the EAT variation in March and April. 展开更多
关键词 spring East Asian trough sea surface temperature snow cover
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Heat Transfer Enhancement of the Absorber Tube in a Parabolic Trough Solar Collector through the Insertion of Novel Cylindrical Turbulators
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作者 Yasser Jebbar Fadhil Fluiful Wisam Khudhayer 《Fluid Dynamics & Materials Processing》 EI 2024年第6期1279-1297,共19页
This study includes an experimental and numerical analysis of the performances of a parabolic trough collector(PTC)with and without cylindrical turbulators.The PTC is designed with dimensions of 2.00 m in length and 1... This study includes an experimental and numerical analysis of the performances of a parabolic trough collector(PTC)with and without cylindrical turbulators.The PTC is designed with dimensions of 2.00 m in length and 1.00 m in width.The related reflector is made of lined sheets of aluminum,and the tubes are made of stainless steel used for the absorption of heat.They have an outer diameter of 0.051 m and a wall thickness of 0.002 m.Water,used as a heat transfer fluid(HTF),flows through the absorber tube at a mass flow rate of 0.7 kg/s.The dimensions of cylindrical turbulators are 0.04 m in length and 0.047 m in diameter.Simulations are performed using the ANSYS Fluent 2020 R2 software.The PTC performance is evaluated by comparing the experimental and numerical outcomes,namely,the outlet temperature,useful heat,and thermal efficiency for a modified tube(MT)(tube with novel cylindrical turbulators)and a plain tube(PT)(tube without novel cylindrical turbulators).According to the results,the experimental outlet temperatures recorded 63.2°C and 50.5°C for the MT and PT,respectively.The heat gain reaches 1137.5 Win the MT and 685.8 Win the PT.Compared to the PT collector,the PTC exhibited a(1.64 times)higher efficiency. 展开更多
关键词 Parabolic trough collector turbulators absorber tube ANSYS thermal efficiency
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Elemental Compositions of Clinopyroxenes from Southern Okinawa Trough Basalt:Implications for Magmatism and Structural Environment in an Initial Back-Arc Basin
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作者 GUO Kun ZHAI Shikui +3 位作者 FAN Di ZHANG Xia ZHANG Yu ZHU Zhimin 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第3期643-653,共11页
The major and trace elemental compositions of clinopyroxene from basalt were used to characterize the nature of the primitive magma and structural environment beneath the southern Okinawa Trough(SOT),which is an initi... The major and trace elemental compositions of clinopyroxene from basalt were used to characterize the nature of the primitive magma and structural environment beneath the southern Okinawa Trough(SOT),which is an initial back-arc basin at a continental margin.The clinopyroxenes in the basalt were augite with variable Mg^(#)contents(73.37-78.22).The regular variations in major oxide contents(i.e.,CaO,FeO,TiO_(2),and Cr)with decreasing Mg#implied that the clinopyroxenes evolved from being enriched in Mg,Ca,and Cr to being enriched in Fe and Ti.The clinopyroxenes had relatively low rare earth element concentrations(7.51×10^(-6) to 12.68×10^(-6))and negative Eu anomalies(δEu=0.67-0.95).The Kd_(cpx) values of clinopyroxenes(0.2-0.26),which were used to examine whether the clinopyroxene was equilibrated with its host basalt,demonstrate that these clinopyroxene phenocrysts were not captured crystals but were instead produced by crystallization differentiation of the magma.The calculated clinopyroxene crystallization temperatures showed a narrow range of 990-1061℃,and their crystallization pressures ranged from 2.0 to 3.2 kbar.The geochemistry features of these clinopyroxenes indicated that the parent magma belonged to the subalkaline tholeiitic magma series and suggested that the magma experienced crystallization differentiation of olivine,plagioclase,and clinopyroxene,where the crystallization of plagioclase occurred earlier than that of clinopyroxene.Combined with geophysical data,this research on primitive magma and its crystallization differentiation from clinopyroxene indicates that the SOT is in the stage of‘seafloor spreading’and that basaltic rocks produced from tholeiitic magma represent the generation of oceanic crust. 展开更多
关键词 trace elements CLINOPYROXENES southern Okinawa trough seafloor spreading back-arc basin
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Design and Development of a Parabolic Trough Solar Air Heater for a Greenhouse Dryer
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作者 Eric King’ori Isaac N. Simate 《Journal of Power and Energy Engineering》 2024年第9期1-18,共18页
Design and Development of a Parabolic Trough Solar Air Heater (PTSAH) for a Greenhouse Dryer (GD) was done to improve the dryer’s performance. The materials used for the fabrication of the PTSAH included galvanized s... Design and Development of a Parabolic Trough Solar Air Heater (PTSAH) for a Greenhouse Dryer (GD) was done to improve the dryer’s performance. The materials used for the fabrication of the PTSAH included galvanized sheets covered with aluminium foil, an absorber tube made of GI pipe painted matt black to increase heat absorbance at the focal line, mild steel square tubes, shutter plywood, and an axial fan to push air through the absorber tube. Key geometrical parameters used for the design of the PTSAH were a rim angle of 98 degrees, focal length of 0.2608 m, height of 0.3451 m, length of 2 m, and an aperture width of 1.2 m. The PTSAH’s total aperture surface area was 2.4 m2, while its absorber tube surface area was 0.1587 m2. The PTSAH was experimentally tested to establish its thermal performance. It was found that the ambient air recorded an average value of 31.1˚C and that the air heater could increase the air temperature by 45.6˚C above ambient with a thermal efficiency of 5.3%. It can, therefore, be concluded that the PTSAH can significantly improve the performance of a GD by supplying the GD with air at a higher temperature than ambient. 展开更多
关键词 Solar Air Heater Greenhouse Dryer Parabolic trough Thermal Performance
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Improving Heat Transfer in Parabolic Trough Solar Collectors by Magnetic Nanofluids
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作者 Ritesh Singh Abhishek Gupta +2 位作者 Akshoy Ranjan Paul Bireswar Paul Suvash C.Saha 《Energy Engineering》 EI 2024年第4期835-848,共14页
A parabolic trough solar collector(PTSC)converts solar radiation into thermal energy.However,low thermal efficiency of PTSC poses a hindrance to the deployment of solar thermal power plants.Thermal performance of PTSC... A parabolic trough solar collector(PTSC)converts solar radiation into thermal energy.However,low thermal efficiency of PTSC poses a hindrance to the deployment of solar thermal power plants.Thermal performance of PTSC is enhanced in this study by incorporating magnetic nanoparticles into the working fluid.The circular receiver pipe,with dimensions of 66 mm diameter,2 mm thickness,and 24 m length,is exposed to uniform temperature and velocity conditions.The working fluid,Therminol-66,is supplemented with Fe3O4 magnetic nanoparticles at concentrations ranging from 1%to 4%.The findings demonstrate that the inclusion of nanoparticles increases the convective heat transfer coefficient(HTC)of the PTSC,with higher nanoparticle volume fractions leading to greater heat transfer but increased pressure drop.The thermal enhancement factor(TEF)of the PTSC is positively affected by the volume fraction of nanoparticles,both with and without a magnetic field.Notably,the scenario with a 4%nanoparticle volume fraction and a magnetic field strength of 250 G exhibits the highest TEF,indicating superior thermal performance.These findings offer potential avenues for improving the efficiency of PTSCs in solar thermal plants by introducing magnetic nanoparticles into the working fluid. 展开更多
关键词 Parabolic trough solar collector(PTSC) magnetic nanofluid(MNF) heat transfer convective heat transfer coefficient(HTC) thermal enhancement factor(TEF)
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Clinical Evaluation of a Vancomycin Dosage Strategy Based on a Serum Trough Concentration Model in Elderly Patients with Severe Pneumonia 被引量:2
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作者 YAN Wei SUN Xiao Yan +2 位作者 WANG Meng ZHAO Fei Fan ZHOU Qing Tao 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2023年第5期397-405,共9页
Objective This study aimed to evaluate the clinical benefits of a vancomycin dosage strategy based on a serum trough concentration model in elderly patients.Methods This prospective single-center, open-label, randomiz... Objective This study aimed to evaluate the clinical benefits of a vancomycin dosage strategy based on a serum trough concentration model in elderly patients.Methods This prospective single-center, open-label, randomized controlled trial categorized 66 elderly patients with severe pneumonia into study and control groups. The control group received vancomycin using a regimen decided by the attending physician. Meanwhile, the study group received individualized vancomycin therapy with a dosing strategy based on a serum trough concentration model. The primary endpoint was the proportion of patients with serum trough concentrations reaching the target values.The secondary endpoints were clinical response, vancomycin treatment duration, and vancomycinassociated acute kidney injury(VA-AKI) occurrence.Results All patients were at least 60 years old(median age = 81 years). The proportion of patients with target trough concentration achievement(≥ 15 mg/L) with the initial vancomycin regimen was significantly higher in the study group compared to the control group(75.8% vs. 42.4%, P = 0.006).Forty-five patients(68.2%) achieved clinical success, the median duration of vancomycin therapy was10.0 days, and VA-AKI occurred in eight patients(12.1%). However, there were no significant differences in these parameters between the two groups. The model for predicting vancomycin trough concentrations was upgraded to: serum trough concentration(mg/L) = 17.194-0.104 × creatinine clearance rate(mL/min) + 0.313 × vancomycin daily dose [mg/(kg·d)].Conclusion A vancomycin dosage strategy based on a serum trough concentration model can improve the proportion of patients achieving target trough concentrations in elderly patients with severe pneumonia. 展开更多
关键词 PNEUMONIA Clinical trials VANCOMYCIN trough concentration Elderly patients
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Geological characteristics of the southern segment of the Late Sinian–Early Cambrian Deyang-Anyue rift trough in Sichuan Basin, SW China 被引量:3
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作者 LI Rong WANG Yongxiao +4 位作者 WANG Zecheng XIE Wuren LI Wenzheng GU Mingfeng LIANG Zirui 《Petroleum Exploration and Development》 SCIE 2023年第2期321-333,共13页
Based on the latest drilling, seismic and field outcrop data, the geological characteristics(e.g. strata, development and sedimentary evolution) of the southern segment of the Late Sinian–Early Cambrian Deyang–Anyue... Based on the latest drilling, seismic and field outcrop data, the geological characteristics(e.g. strata, development and sedimentary evolution) of the southern segment of the Late Sinian–Early Cambrian Deyang–Anyue rift trough in the Sichuan Basin are analyzed. First, the strata in the southern segment are complete. The first to second members of Dengying Formation(Deng 1 + Deng 2) are found with relatively stable thickness(400–550 m), and the third to fourth members(Deng 3+ Deng 4) show great thickness difference between the marginal trough and the inner trough, which is up to 250 m. The Cambrian Maidiping Formation and Qiongzhusi Formation in southern Sichuan Basin are relatively thin, with the thickness changing greatly and frequently. Second, the Deyang–Anyue rift trough extended southward during the Deng 4 period, affecting southern Sichuan Basin. Compared to the middle and northern segments of the rift trough, the southern segment is generally wide, gentle and shallow, with multiple steps, and alternating uplifts and sags, which are distributed in finger shape. Third, the Deng 1 + Deng 2 in southern Sichuan Basin records the dominance of carbonate platform and unobvious sedimentary differentiation, and the Deng 4 exhibits obvious sedimentary differentiation, namely, basin–slope–secondary slope–slope–secondary slope–platform margin–restricted platform, from the inner trough to the marginal trough. Fourth, the rift trough in southern Sichuan Basin has evolved in four stages: stabilization of Deng 1–Deng 2, initialization of Deng 3–Deng 4, filling of Maidiping–Qiongzhusi, and extinction of Canglangpu Formation. 展开更多
关键词 Deyang-Anyue rift trough geological characteristics secondary slope development and evolution Cambrian Maidiping Formation Cambrian Qiongzhusi Formation Sinian Dengying Formation Sichuan Basin
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Effect of Different Silica Fumes on Properties of Al_(2)O_(3)-SiC-C Castables for Iron Trough 被引量:1
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作者 CAO Zhuang JIA Qingwei +6 位作者 ZHANG Jun ZHOU Huijun LI Jinfeng HUN Xianlei YAN Leixin QIN Hongbin ZHANG Sanhua 《China's Refractories》 CAS 2023年第2期31-36,共6页
In order to improve the performance of Al_(2)O_(3)-SiC-C castables for iron trough,samples were prepared using brown corundum,dense corundum,activated alumina micropowder,ball pitch,and silicon as main raw materials,c... In order to improve the performance of Al_(2)O_(3)-SiC-C castables for iron trough,samples were prepared using brown corundum,dense corundum,activated alumina micropowder,ball pitch,and silicon as main raw materials,calcium aluminate cement as the binder.Several kinds of silica fumes(93SiO_(2),96SiO_(2),and 99SiO_(2))with different particle size distributions and chemical composition were added to research the effects on the properties of castables.The results show that the sample with 99SiO_(2) fume has high water requirement for molding,but the bulk density is the lowest,the apparent porosity is the highest,the oxidation resistance is the worst,and the permanent linear change on heating is low after firing at 1 450 ℃ for 3 h.The bulk density and the apparent porosity of the sample with 93SiO_(2) fume or 96SiO_(2) fume are equivalent,the hot modulus of rupture of the sample with 93SiO_(2) fume is the lowest,and the slag resistance of the sample with 96SiO_(2) fume is the best.The comprehensive performance of the sample with 96SiO_(2) fume is the best. 展开更多
关键词 alumina-silicon carbide-carbon iron trough castables silica fume STRENGTH oxidation resistance slag resistance
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The Mamfe Basin in the southern Benue trough extension between Cameroon and Nigeria:Gem origin and problem of lithostratigraphic nomenclature and marine transgression
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作者 Milan Stafford Tchouatcha Primus Tamfuh Azinwi +4 位作者 Christel Sobdjou Kemteu Augustin Desire Balla Ondoa Leopold Darlus Ngantchu Basil Azeh Anong Courage Gabvourta 《Acta Geochimica》 EI CAS CSCD 2023年第3期495-516,共22页
The Mamfe Basin has been the subject of many studies,but some debates persist,especially concerning the stratigraphic nomenclature,corundum origin,and marine transgression.The aims of this work are(1)to propose a new ... The Mamfe Basin has been the subject of many studies,but some debates persist,especially concerning the stratigraphic nomenclature,corundum origin,and marine transgression.The aims of this work are(1)to propose a new lithostratigraphic nomenclature of the Mamfe Basin formation based on new field observations,(2)to determine the source rock distribution and the origin of gem deposits and(3)to correlate the Cameroon section of the Mamfe Basin with the Nigerian deposits.The main results show that the name Manyu River Group is more appropriate as the Manyu River crosses all the facies in the Mamfe sedimentary Basin belonging to the Manyu Division.According to the facies analysis,the age of deposition,the mineralogic and geochemical data such as the V vs.Al2O3andΣREE vs.Al_(2)O_(3),TiO_(2)MgO,Na_(2)O,P_(2)O_(5),and CaO diagrams,this Group is composed of at least five Formations,including four Cretaceous Formations,from bottom to top:the Etoko Formation(alluvial and fluvial channel to fluvio-lacustrine deposits),the Nfaitok Formation(lagoonal deposits),the Bachuo Ntai Formation(fluvial braided channels or fluvio-deltaic environment)and the Eyumojock/NsanaragatiFormation(fluvio-lacustrine deposits)and the new Cenozoic Formation named Bakebe Formation(fluvio-lacustrine deposits).The gem minerals such as corundum,rutile,or tourmaline in the Cretaceous deposits of the Mamfe Basin are mainly detrital as indicated by the presence of worn shapes and fragments of these minerals.The presence of sapphire in the AlboCenomanian deposits indicates a Precambrian age of the felsic source rock,likely the plutonic rocks such as granite or pegmatite as indicated by the abundance of tourmaline and high LREE/HREE ratios(14.81–34.29)and slightly negative and positive Eu anomalies(0.85–1.15).This marine incursion in the Mamfe Basin was probably from West Nigeria,according to the geographic location of the Mamfe Basin and the general palaeogeographic evolution of the Benue Trough. 展开更多
关键词 LITHOSTRATIGRAPHY Marine transgression Heavy minerals SAPPHIRES Mamfe Basin Benue trough
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Evaluating Vancomycin Clinical Outcomes Using Area under the Curve versus Trough Based Dosing Strategies
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作者 Chelsea A. Schneider William Rodriguez +1 位作者 Jenny Martinez William R. Wolowich 《Advances in Infectious Diseases》 2023年第3期442-451,共10页
Background: The 2020 consensus guidelines recommend AUC guided dosing as the preferred monitoring method for vancomycin. AUC based dosing has shown to reduce incidence of acute kidney injury (AKI), utilize lower daily... Background: The 2020 consensus guidelines recommend AUC guided dosing as the preferred monitoring method for vancomycin. AUC based dosing has shown to reduce incidence of acute kidney injury (AKI), utilize lower daily doses in obese patients, and maintain efficacy. Several institutions have adjusted their protocols to utilize AUC guided dosing. However, there are limited studies comparing the clinical outcomes of AUC versus trough monitoring. Methods: This was a retrospective, observational, single centered study. The primary outcome was to evaluate the clinical success of AUC dosing versus trough based dosing of vancomycin for MRSA infections using a composite outcome of afebrile post treatment ( Results: Forty-seven patients were included in this study, 17 in the AUC group and 30 in the trough group. The primary composite outcome showed a significant benefit of AUC dosing (p = 0.04). The composite component culture clearance showed the largest improvement for the AUC group when compared with the trough group (p = 0.03). More patients achieved therapeutic target attainment and reached the target sooner (3 days versus 4 days, p = 0.2) in the AUC group. Over the study course, 94.1% of patients in the AUC group were considered therapeutic compared to 63.8% in the trough group (p = 0.03). Vancomycin levels were collected less frequently in the AUC group (3 versus 4, p = 0.2). Conclusion: The outcomes of this study may suggest AUC guided dosing as a beneficial alternative to trough based dosing. AUC based dosing may improve clinical success which can be further explored in larger prospective clinical trials. 展开更多
关键词 AUC MRSA PHARMACOKINETICS trough Based Dosing VANCOMYCIN
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Investigation and simulation of parabolic trough collector with the presence of hybrid nanofluid in the finned receiver tube
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作者 M.Javidan M.Gorji-Bandpy A.Al-Araji 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2023年第6期484-493,共10页
The present study discusses the thermal performance of the receiver tube,which contains a wall with various fin shapes in the parabolic trough collector.Inserted fins and bulge surfaces of the inner wall of the receiv... The present study discusses the thermal performance of the receiver tube,which contains a wall with various fin shapes in the parabolic trough collector.Inserted fins and bulge surfaces of the inner wall of the receiver tube increase the turbulent fluid flow.In pursuance of uniform distribution of heat transfer,various fin shapes such as square-shape,circle-shape,triangle-shape,and combined square-circle shapes were inserted,examined,and compared.A study of the temperature differences and fluid flow is meaningful for this project therefore finite volume method was used to investigate heat transfer.Also,hybrid Nano-Fluid AL_(2)O_(3-)CuO,TiO_(2-)Cu,and AgMgO were applied to increase thermal diffusivity.When the combined square-circle-shaped fin was inserted,the thermal peak of fluid flow in the receiver tube was lower than the other studied fin shapes by almost 1%.Besides,the hybrid nano-fluid Ag-MgO Syltherm-oil-800 has lower thermal waste in comparison to others by more than 3%. 展开更多
关键词 Parabolic trough collectors Hybrid nano-fluid Syltherm oil-800 Ag-MgO Thermal performance
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Modified Circumpolar Deep Water inflow to the Dotson-Getz Trough in the summers of 2020 and 2022
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作者 XIE Chunhu SHI Jiuxin +7 位作者 SUN Yongming JIANG Jindong Guy DWILLIAMS SHUAI Hongtao LIN Lijin XIAO Changhao CAO Yong WANG Kun 《Advances in Polar Science》 CSCD 2023年第2期80-90,共11页
The melting of the West Antarctic Ice Shelf has increased since the 1990s,driven by the relatively warm Circumpolar Deep Water(CDW)that penetrates into the West Antarctic Ice Shelf cavities through submarine glacial t... The melting of the West Antarctic Ice Shelf has increased since the 1990s,driven by the relatively warm Circumpolar Deep Water(CDW)that penetrates into the West Antarctic Ice Shelf cavities through submarine glacial troughs across the continental shelf.In this study,temperature,salinity,and current velocity data obtained by the Chinese National Antarctic Research Expedition in the Dotson-Getz Trough(DGT)shows clear differences in distribution of modified Circumpolar Deep Water(mCDW)in the summers of 2020 and 2022.Combined with contemporaneous wind data and additional temperature and salinity data from instrumented seals,the processes and mechanisms responsible for this variation are discussed.Compared with 2020,there is a significant increase in mCDW thickness in 2022,with a doubling of total heat content as the mCDW inflow path across the DGT shifts towards the eastern bank.We propose that a southward shift in the westerly winds in the summer of 2022 moved the upper oceanic divergence zone southward towards the continental slope,promoting the upwelling of mCDW above 500 m.Concurrently,stronger westerly winds over the continental slope strengthened the eastward undercurrent,increasing the transport of this mCDW and its associated heat content to the DGT through Ekman dynamics.These observations show there is strong interannual variability in the strength,path and extent of mCDW inflows to the DGT and that care must be taken when planning observation programs for long-term monitoring of the oceanic heat input to the ice shelves of this globally significant region. 展开更多
关键词 modified Circumpolar Deep Water WIND Dotson-Getz trough Amundsen Sea ANTARCTICA
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计及AA-CAES与PTC集成的综合能源系统运行优化与性能分析 被引量:1
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作者 吴迪 刘奥 +4 位作者 龚弟鑫 马帆帆 马立 韩中合 刘树华 《动力工程学报》 CAS CSCD 北大核心 2024年第1期138-147,156,共11页
为进一步发挥综合能源系统的多能互补优势,提出一种计及先进绝热压缩空气储能(AA-CAES)与槽式太阳能集热器(PTC)集成的综合能源系统(IES-PTC-CAES)优化运行策略。首先,对AA-CAES、PTC以及系统中其他设备进行分析并建立相应模型;进而以... 为进一步发挥综合能源系统的多能互补优势,提出一种计及先进绝热压缩空气储能(AA-CAES)与槽式太阳能集热器(PTC)集成的综合能源系统(IES-PTC-CAES)优化运行策略。首先,对AA-CAES、PTC以及系统中其他设备进行分析并建立相应模型;进而以经济性、环保性和能效性为优化目标,以设备运行的关键参数为优化变量,基于分时电价建立了协同优化策略,并通过K-means算法将模拟出的典型年负荷聚类为典型日负荷;最终,使用并行式的遗传算法对系统进行寻优,得到不同目标下IES-PTC-CAES的最优运行策略。结果表明:与参考系统相比,IES-PTC-CAES系统经济目标下总成本降低了14.61万元,环保目标下二氧化碳排放量减少了6194.38 kg。 展开更多
关键词 先进绝热压缩空气储能 槽式太阳能集热器 综合能源系统 遗传算法 协同优化
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连续电磁剖面法在塔里木盆地麦盖提斜坡裂陷槽深部构造研究中的应用
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作者 屈洋 杨钰菡 +4 位作者 黎立 唐强强 孙迪 罗强 葛大壮 《成都理工大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第1期152-163,共12页
随着对塔里木盆地深层油气勘探认识不断深入,认为震旦—南华系裂陷槽对烃源岩的发育保存有着重要的控制作用,因此对该区域的裂陷槽探测是油气勘探的重要探索方向。前人研究认为对塔西南地区麦盖提斜坡处存在震旦—南华系裂陷槽,但受限... 随着对塔里木盆地深层油气勘探认识不断深入,认为震旦—南华系裂陷槽对烃源岩的发育保存有着重要的控制作用,因此对该区域的裂陷槽探测是油气勘探的重要探索方向。前人研究认为对塔西南地区麦盖提斜坡处存在震旦—南华系裂陷槽,但受限于该区域地震资料品质,对该区域深层结构尤其是对基底和裂陷槽分布形态和范围认知不清。因此,通过一条跨过麦盖提斜坡与叶城凹陷的连续电磁剖面法剖面,结合研究区地质情况与井资料,构建了区域电阻率的物性分层结构,完成了对实际数据的二维反演,获取了该区域的深部电性结构与CEMP剖面的综合地质解释结果。为该区域新元古代裂陷槽发育情况的判断提供了新的电磁证据,也进一步刻画了基底、裂陷槽的电性特征与结构。探测结果认为裂陷主要由正断层控制,呈现裂陷群特点,裂陷多呈半地堑、不对称地堑及堑—垒相间的构造样式,在麦盖提斜坡、叶城凹陷处中部、南部的区域发育两个裂陷群,有利于区域内的烃源岩沉积,其中裂陷内震旦—南华系地层沉积较厚的区域具有较好的深层油气勘探潜力。 展开更多
关键词 麦盖提斜坡 连续电磁剖面法 震旦—南华系 裂陷槽 烃源岩
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牛马不同槽——嘉峪关魏晋墓两幅壁画的现实表达与文化意涵 被引量:1
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作者 魏文斌 黄婷婷 《敦煌研究》 北大核心 2024年第1期53-64,共12页
嘉峪关魏晋墓葬壁画描绘了“牛马不同槽”的现象。结合礼仪艺术与世俗绘卷中的同类图像,揭示了此类现象的现实原因,并指出其进入文化层面后的意涵。先秦哲学从牛马习性出发,抽象出了其间的对立统一关系,很多情境中牛马间的对立还可转化... 嘉峪关魏晋墓葬壁画描绘了“牛马不同槽”的现象。结合礼仪艺术与世俗绘卷中的同类图像,揭示了此类现象的现实原因,并指出其进入文化层面后的意涵。先秦哲学从牛马习性出发,抽象出了其间的对立统一关系,很多情境中牛马间的对立还可转化为对应,例如祭祀中的牛马,图像中的牛马合犋犁耕、牧马牧牛、牛车鞍马,宗教语境下的牛头马面等。“牛马不同槽”从民间俗语到文献与图像的表达,反映了古代艺术与生活的密切关系。 展开更多
关键词 牛马不同槽 嘉峪关墓葬壁画 牛车鞍马 牛头马面
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四川盆地德阳-安岳凹槽形成机理及灯影组沉积新格局
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作者 周刚 罗冰 +9 位作者 张新 徐少立 张本健 马奎 梁艺苇 严威 钟原 张自力 兰才俊 李堃宇 《天然气工业》 EI CAS CSCD 北大核心 2024年第8期13-28,共16页
四川盆地德阳—安岳凹槽两侧陡坎带震旦系灯影组天然气勘探不断取得新突破,是盆地内天然气增储上产的重要领域。为了明确该凹槽的形成机理、形成期次及沉积新格局,进一步指导灯影组气藏的深化勘探,采用最新大连片三维地震成果、结合钻... 四川盆地德阳—安岳凹槽两侧陡坎带震旦系灯影组天然气勘探不断取得新突破,是盆地内天然气增储上产的重要领域。为了明确该凹槽的形成机理、形成期次及沉积新格局,进一步指导灯影组气藏的深化勘探,采用最新大连片三维地震成果、结合钻井等资料,分析了各期陡坎之间、陡坎与台缘带之间的空间展布关系,探索了陡坎的演化规律,进一步明确了天然气的勘探方向。研究结果表明:①德阳—安岳凹槽陡坎总体表现为侵蚀谷特征,同沉积小断层的作用不明显;②灯影组二段(以下简称灯二段)发育Ⅰ、Ⅱ两个陡坎,灯影组四段(以下简称灯四段)发育一个陡坎,分别在桐湾Ⅰ和Ⅱ、Ⅲ幕侵蚀作用形成,这些陡坎与灯二段、灯四段台缘带无关;③灯二段沉积时期,受控于基底垒堑格局,发育由南向北进积的4~5排台缘带,呈北东向展布,其中蓬莱地区发育两个大型台缘带,台缘带丘滩体被陡坎Ⅱ截断,叠加岩溶作用形成优质储层。结论认为:①高石梯—磨溪地区灯四段与灯二段的陡坎叠合区发育灯四段陡坎型台缘带,而在灯四段槽上带,丘滩体仍呈北东向发育,表明该地区受陡坎Ⅱ与北东向古地貌双重因素控制;②蓬莱地区陡坎Ⅱ坡度变小,对灯四段台缘带控制作用减弱直至消失,主要发育2排北东向展布的缓坡型台缘带,即蓬莱①、②台缘带,蓬莱地区可作为今后天然气勘探重点关注目标区。 展开更多
关键词 四川盆地 德阳—安岳凹槽 震旦系灯影组 台缘带 侵蚀谷 阶地 沉积
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质量技术在土槽试验车液压系统故障排除中的应用
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作者 李国林 余涛 +5 位作者 蔡晓华 吴泽全 陶继哲 叶岩 侯云涛 东忠阁 《农机使用与维修》 2024年第8期101-105,共5页
土槽试验车是土壤耕作试验研究的主要设备。该文以土槽试验车液压系统故障排除为导向,根据排列图法、因果分析图法和措施计划表法等多种现代质量技术的应用原理,探索拓展质量技术适用范围,有机地将上述方法联合应用到生产实际中,提出解... 土槽试验车是土壤耕作试验研究的主要设备。该文以土槽试验车液压系统故障排除为导向,根据排列图法、因果分析图法和措施计划表法等多种现代质量技术的应用原理,探索拓展质量技术适用范围,有机地将上述方法联合应用到生产实际中,提出解决土槽试验车液压系统故障的具体措施,从而实现效率和效果的不断提升。 展开更多
关键词 质量技术 土槽试验车液压系统 故障排除
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槽式太阳能阵列挡风增速效果数值模拟
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作者 张立栋 李佩 +4 位作者 姜铁骝 李钦伟 张磊 徐峰 孟欣 《综合智慧能源》 CAS 2024年第6期1-7,共7页
采用开源计算流体力学软件OpenFOAM中的Simple求解器对流场进行数值模拟,研究5.00 m/s风速下槽式太阳能阵列挡风墙挡风效果。对由槽式太阳能阵列组成的6个不同高度的挡风墙对整体流场速度的影响以及不同高度挡风墙背风侧30,60,90 m处的... 采用开源计算流体力学软件OpenFOAM中的Simple求解器对流场进行数值模拟,研究5.00 m/s风速下槽式太阳能阵列挡风墙挡风效果。对由槽式太阳能阵列组成的6个不同高度的挡风墙对整体流场速度的影响以及不同高度挡风墙背风侧30,60,90 m处的速度进行了分析。研究发现,当气流通过挡风墙时,低于墙高的位置速度大幅衰减,而高于墙高的位置开始加速,存在明显的分区作用。当气流流过挡风墙后,会在其后形成明显的速度衰减区,其面积和延伸与挡风墙的高度正相关。在挡风墙背风侧较远处,高于墙高的气流开始减速,低于墙高的气流开始加速,并随着距离的增加风速逐渐趋于平稳。 展开更多
关键词 槽式太阳能 挡风墙 挡风效果 速度衰减区 OPENFOAM 数值模拟
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太原盆地交城断裂带北段工程避让范围研究
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作者 曾金艳 李宏伟 +1 位作者 陈文 李自红 《大地测量与地球动力学》 CSCD 北大核心 2024年第9期919-925,共7页
在系统分析和整理交城断裂带北段探测成果的基础上,采用地质探槽剖面法、经验统计法及数值模拟法,预测评估交城断裂带北段在发生最大潜在震级M_(S)7.2地震时的同震地表破裂带宽度,探讨不同方法结果的精度和可靠性,并提出采用综合加权方... 在系统分析和整理交城断裂带北段探测成果的基础上,采用地质探槽剖面法、经验统计法及数值模拟法,预测评估交城断裂带北段在发生最大潜在震级M_(S)7.2地震时的同震地表破裂带宽度,探讨不同方法结果的精度和可靠性,并提出采用综合加权方法确定交城断裂带北段地表破裂带宽度。在此基础上综合考虑探测方法精度、断层上下盘效应等影响因素,确定交城断裂带北段工程避让区为F_(1)^(1)迹线西侧外延15.0m至F_(1)^(2)迹线东侧外延86.9m范围。该结果对交城断裂带沿线的国土规划利用、建(构)筑抗震设计具有一定的指导意义,该方法可为同类研究提供借鉴。 展开更多
关键词 交城断裂带北段 地质探槽剖面法 经验公式法 数值模拟法 地表破裂带
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