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A Bibliometric Analysis Unveils Valuable Insights into the Past,Present,and Future Dynamics of Plant Acclimation to Temperature
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作者 Yong Cui Yongju Zhao +3 位作者 Shengnan Ouyang Changchang Shao Liangliang Li Honglang Duan 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第2期291-312,共22页
Plant temperature acclimation is closely related to maintaining a positive carbon gain under future climate change.However,no systematic summary of the field has been conducted.Based on this,we analyzed data on plant ... Plant temperature acclimation is closely related to maintaining a positive carbon gain under future climate change.However,no systematic summary of the field has been conducted.Based on this,we analyzed data on plant temperature acclimation from the Web of Science Core Collection database using bibliometric software R,RStudio and VOSviewer.Our study demonstrated that a stabilized upward trajectory was noted in publications(298 papers)from 1986 to 2011,followed by a swift growth(373 papers)from 2012 to 2022.The most impactful journals were Plant Cell and Environment,boasting the greatest count of worldwide citations and articles,the highest H-index and G-index,followed by Global Change Biology and New Phytologist,and Frontiers in Plant Science which had the highest M-index.The USA and China were identified as the most influential countries,while Atkin was the most influential author,and the Chinese Academy of Sciences was the most influential research institution.The most cited articles were published in the Annual Review of Plant Biology in 1999.“Cold acclimation”was the most prominent keyword.Future plant temperature acclimation research is expected to focus on thermal acclimation and photosynthesis,which have important significance for future agricultural production,forestry carbon sequestration,and global food security.In general,this study provides a systematic insight of the advancement,trend,and future of plant temperature acclimation research,enhancing the comprehension of how plants will deal with forthcoming climate change. 展开更多
关键词 TEMPERATURE acclimation plant responses climate change BIBLIOMETRIC
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Current optimization-based control of dual three-phase PMSM for low-frequency temperature swing reduction
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作者 Linlin Lu Xueqing Wang +3 位作者 Luhan Jin Qiong Liu Yun Zhang Yao Mao 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第4期238-246,共9页
In this paper,a control scheme based on current optimization is proposed for dual three-phase permanent-magnet synchronous motor(DTP-PMSM)drive to reduce the low-frequency temperature swing.The reduction of temperatur... In this paper,a control scheme based on current optimization is proposed for dual three-phase permanent-magnet synchronous motor(DTP-PMSM)drive to reduce the low-frequency temperature swing.The reduction of temperature swing can be equivalent to reducing maximum instantaneous phase copper loss in this paper.First,a two-level optimization aiming at minimizing maximum instantaneous phase copper loss at each electrical angle is proposed.Then,the optimization is transformed to a singlelevel optimization by introducing the auxiliary variable for easy solving.Considering that singleobjective optimization trades a great total copper loss for a small reduction of maximum phase copper loss,the optimization considering both instantaneous total copper loss and maximum phase copper loss is proposed,which has the same performance of temperature swing reduction but with lower total loss.In this way,the proposed control scheme can reduce maximum junction temperature by 11%.Both simulation and experimental results are presented to prove the effectiveness and superiority of the proposed control scheme for low-frequency temperature swing reduction. 展开更多
关键词 Dual three-phase PMSM Low-frequency temperature swing Copper loss Current optimization Connected neutral points
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Deciphering engineering principle of three-phase interface for advanced gas-involved electrochemical reactions 被引量:2
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作者 Yanzheng He Sisi Liu +3 位作者 Mengfan Wang Qiyang Cheng Tao Qian Chenglin Yan 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第5期302-323,I0008,共23页
As an alternative to conventional energy conversion and storage reactions,gas-involved electrochemical reactions,including the carbon dioxide reduction reaction(CO_(2)RR),nitrogen reduction reaction(NRR)and hydrogen e... As an alternative to conventional energy conversion and storage reactions,gas-involved electrochemical reactions,including the carbon dioxide reduction reaction(CO_(2)RR),nitrogen reduction reaction(NRR)and hydrogen evolution reaction(HER),have become an emerging research direction and have gained increasing attention due to their advantages of environmental friendliness and sustainability.Various studies have been designed to accelerate sluggish kinetics but with limited results.Most of them promote the reaction by modulating the intrinsic properties of the catalyst,ignoring the synergistic effect of the reaction as a whole.Due to the introduction of gas,traditional liquid-solid two-phase reactions are no longer applicable to future research.Since gas-involved electrochemical reactions mostly occur at the junctions of gaseous reactants,liquid electrolytes and solid catalysts,the focus of future research on reaction kinetics should gradually shift to three-phase reaction interfaces.In this review,we briefly introduce the formation and constraints of the three-phase interface and propose three criteria to judge its merit,namely,the active site,mass diffusion and electron mass transfer.Subsequently,a series of modulation methods and relevant works are discussed in detail from the three improvement directions of‘exposing more active sites,promoting mass diffusion and accelerating electron transfer’.Definitively,we provide farsighted insights into the understanding and research of three-phase interfaces in the future and point out the possible development direction of future regulatory methods,hoping that this review can broaden the future applications of the three-phase interface,including but not limited to gas-involved electrochemical reactions. 展开更多
关键词 three-phase reaction Surface reactions Mass diffusion Electron transfer Gas-involved electrochemical reactions
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Electrical characteristics of new three-phase traction power supply system for rail transit 被引量:1
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作者 Xiaohong Huang Hanlin Wang +4 位作者 Qunzhan Li Naiqi Yang Tao Ren You Peng Haoyang Li 《Railway Engineering Science》 2023年第1期75-88,共14页
A novel three-phase traction power supply system is proposed to eliminate the adverse effects caused by electric phase separation in catenary and accomplish a unifying manner of traction power supply for rail transit.... A novel three-phase traction power supply system is proposed to eliminate the adverse effects caused by electric phase separation in catenary and accomplish a unifying manner of traction power supply for rail transit.With the application of two-stage three-phase continuous power supply structure,the electrical characteristics exhibit new features differing from the existing traction system.In this work,the principle for voltage levels determining two-stage network is dissected in accordance with the requirements of traction network and electric locomotive.The equivalent model of three-phase traction system is built for deducing the formula of current distribution and voltage losses.Based on the chain network model of the traction network,a simulation model is established to analyze the electrical characteristics such as traction current distribution,voltage losses,system equivalent impedance,voltage distribution,voltage unbalance and regenerative energy utilization.In a few words,quite a lot traction current of about 99%is undertaken by long-section cable network.The proportion of system voltage losses is small attributed to the two-stage three-phase power supply structure,and the voltage unbal-ance caused by impedance asymmetry of traction network is less than 1‰.In addition,the utilization rate of regenerative energy for locomotive achieves a significant promotion of over 97%. 展开更多
关键词 three-phase AC power supply Two-stage power supply structure Electrical characteristics Current distribution Voltage losses Regenerative energy
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Speed Regulation Method Using Genetic Algorithm for Dual Three-phase Permanent Magnet Synchronous Motors 被引量:1
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作者 Xiuhong Jiang Yuying Wang Jiarui Dong 《CES Transactions on Electrical Machines and Systems》 CSCD 2023年第2期171-178,共8页
Dual three-phase Permanent Magnet Synchronous Motor(DTP-PMSM)is a nonlinear,strongly coupled,high-order multivariable system.In today’s application scenarios,it is difficult for traditional PI controllers to meet the... Dual three-phase Permanent Magnet Synchronous Motor(DTP-PMSM)is a nonlinear,strongly coupled,high-order multivariable system.In today’s application scenarios,it is difficult for traditional PI controllers to meet the requirements of fast response,high accuracy and good robustness.In order to improve the performance of DTP-PMSM speed regulation system,a control strategy of PI controller based on genetic algorithm is proposed.Firstly,the basic mathematical model of DTP-PMSM is established,and the PI parameters of DTP-PMSM speed regulation system are optimized by genetic algorithm,and the modeling and simulation experiments of DTP-PMSM control system are carried out by MATLAB/SIMULINK.The simulation results show that,compared with the traditional PI control,the proposed algorithm significantly improves the performance of the control system,and the speed output overshoot of the GA-PI speed control system is smaller.The anti-interference ability is stronger,and the torque and double three-phase current output fluctuations are smaller. 展开更多
关键词 Dual three-phase permanent magnet synchronous motor Genetic algorithm PI control Speed regulation
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Optimization of Control Loops and Operating Parameters for Three-Phase Separators Used in Oilfield Central Processing Facilities
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作者 Zhenfeng Li Yaqiao Li Guangjun Wei 《Fluid Dynamics & Materials Processing》 EI 2023年第3期635-649,共15页
In this study,the Stokes formula is used to analyze the separation effect of three-phase separators used in a Oilfield Central Processing Facility.The considered main influencing factors include(but are not limited to... In this study,the Stokes formula is used to analyze the separation effect of three-phase separators used in a Oilfield Central Processing Facility.The considered main influencing factors include(but are not limited to)the typical size of oil and water droplets,the residence time and temperature of fluid and the dosage of demulsifier.Using the“Specification for Oil and Gas Separators”as a basis,the control loops and operating parameters of each separator are optimized Considering the Halfaya Oilfield as a testbed,it is shown that the proposed approach can lead to good results in the production stage. 展开更多
关键词 Distributed control system(DCS) three-phase separator control loop operating parameter
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Purification of Moringa oleifera Leaves Protease by Three-Phase Partitioning and Investigation of Its Potential Antibacterial Activity
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作者 Adam Abdoulaye Agossou D. P. Noumavo +6 位作者 Durand Dah-Nouvlessounon Messan A. B. Ohin Hasan Bayraktar Farid T. Bade Honoré S. Bankole Lamine Baba-Moussa Farid Baba-Moussa 《American Journal of Plant Sciences》 CAS 2023年第1期64-76,共13页
One of plant-based products for dental care is plant-based proteolytic enzymes which are principally proteases. In order not to damage the protein and bioactive content, an efficient method should be employed for thei... One of plant-based products for dental care is plant-based proteolytic enzymes which are principally proteases. In order not to damage the protein and bioactive content, an efficient method should be employed for their purifications. As such, three-phase partitioning (TPP) was used to purify protease from moringa (Moringa oleifera). TPP is an emerging, promising, non-chromatographic and economical technology which is simple, quick, efficient and often one-step process for the separation and purification of bioactive molecules from natural sources. It involves the addition of salt (ammonium sulphate) to the crude extract followed by the addition of an organic solvent (butanol). The protein appears as an interfacial precipitate between upper organic solvent and lower aqueous phases. The various conditions such as ammonium sulphate, ratio of crude extract to t-butanol and pH which are required for attaining efficient purification of the protease fractions were optimized. Under optimized conditions, it was seen that, 35% of ammonium sulphate saturation with 1:0.75 ratio of crude extract to t-butanol at pH 7 gave 4.94-fold purification with 96.20% activity yield of protease in the middle phase of the TPP system. The purified enzyme from Moringa oleifera has no antimicrobial effect on the pathogenic bacteria tested. However, this purified enzyme, can be considered as a promising agent, cheap, and safe source which is suitable for using in various industries. 展开更多
关键词 three-phase Partitioning Moringa oleifera PROTEASE Protein Purification ANTIMICROBIAL
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Vibration characteristics of sandwich plates with an auxetic honeycomb core and laminated three-phase skin layers under blast load
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作者 Quoc-Hoa Pham Van Ke Tran Trung Thanh Tran 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第6期148-163,共16页
In this article,vibration characteristics of sandwich plates with an auxetic honeycomb core and laminated three-phase skin layers subjected to blast load are studied.Higher-order ES-MITC3 element based on higher-order... In this article,vibration characteristics of sandwich plates with an auxetic honeycomb core and laminated three-phase skin layers subjected to blast load are studied.Higher-order ES-MITC3 element based on higher-order shear deformation theory(HSDT)to achieve the governing equations.The sandwich plates with the ultra-light feature of the auxetic honeycomb core layer(negative Poisson’s ratio)and reinforced by two laminated three-phase skin layers.The obtained results in our work are compared with other previously published to confirm accuracy and reliability.In addition,the effects of parameters such as geometrical and material parameters on the vibration characteristics of sandwich plates with an auxetic honeycomb core and laminated three-phase skin layers are fully investigated. 展开更多
关键词 Laminated three-phase Sandwich plate Auxetic honeycomb ES-MITC3 element High-order shear deformation theory
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Enhancing ammonia production rates from electrochemical nitrogen reduction by engineering three-phase boundary with phosphorus-activated Cu catalysts
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作者 Jeehye Kim Cho Hee Lee +5 位作者 Yong Hyun Moon Min Hee Lee Eun Hyup Kim Sun Hee Choi Youn Jeong Jang Jae Sung Lee 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第9期394-401,共8页
Electrochemical N_(2) reduction reaction(eNRR) over Cu-based catalysts suffers from an intrinsically low activity of Cu for activation of stable N_(2) molecules and the limited supply of N_(2) to the catalyst due to i... Electrochemical N_(2) reduction reaction(eNRR) over Cu-based catalysts suffers from an intrinsically low activity of Cu for activation of stable N_(2) molecules and the limited supply of N_(2) to the catalyst due to its low solubility in aqueous electrolytes.Herein,we propose phosphorus-activated Cu electrocatalysts to generate electron-deficient Cu sites on the catalyst surface to promote the adsorption of N_(2) molecules.The eNRR system is further modified using a gas diffusion electrode(GDE) coated with polytetrafluoroethylene(PTFE) to form an effective three-phase boundary of liquid water-gas N_(2)-solid catalyst to facilitate easy access of N_(2) to the catalytic sites.As a result,the new catalyst in the flow-type cell records a Faradaic efficiency of 13.15% and an NH_(3) production rate of 7.69 μg h^(-1) cm^(-2) at-0.2 V_(RHE),which represent 3.56 and 59.2 times increases from those obtained with a pristine Cu electrode in a typical electrolytic cell.This work represents a successful demonstration of dual modification strategies;catalyst modification and N_(2) supplying system engineering,and the results would provide a useful platform for further developments of electrocatalysts and reaction systems. 展开更多
关键词 Electrochemical nitrogen reduction reaction Ammonia production Phosphorous modified copper electrodes Gas diffusion electrodes three-phase boundary PTFE coating
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Automatic measurement of three-phase contact angles in pore throats based on digital images
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作者 ZANG Chuanzhen WANG Lida +3 位作者 ZHOU Kaihu YU Fuwei JIANG Hanqiao LI Junjian 《Petroleum Exploration and Development》 SCIE 2023年第2期442-449,共8页
With the help of digital image processing technology, an automatic measurement method for the three-phase contact angles in the pore throats of the microfluidic model was established using the microfluidic water flood... With the help of digital image processing technology, an automatic measurement method for the three-phase contact angles in the pore throats of the microfluidic model was established using the microfluidic water flooding experiment videos as the data source. The results of the new method were verified through comparing with the manual measurement data.On this basis, the dynamic changes of the three-phase contact angles under flow conditions were clarified by the contact angles probability density curve and mean value change curve. The results show that, for water-wetting rocks, the mean value of the contact angles is acute angle during the early stage of the water flooding process, and it increases with the displacement time and becomes obtuse angle in the middle-late stage of displacement as the dominant force of oil phase gradually changes from viscous force to capillary force. The droplet flow in the remaining oil occurs in the central part of the pore throats, without three-phase contact angle. The contact angles for the porous flow and the columnar flow change slightly during the displacement and present as obtuse angles in view of mean values, which makes the remaining oil poorly movable and thus hard to be recovered. The mean value of the contact angle for the cluster flow tends to increase in the flooding process, which makes the remaining oil more difficult to be recovered. The contact angles for the membrane flow are mainly obtuse angles and reach the highest mean value in the late stage of displacement, which makes the remaining oil most difficult to be recovered. After displacement, the remaining oils under different flow regimes are just subjected to capillary force, with obtuse contact angles, and the wettability of the pore throat walls in the microfluidic model tends to be oil-wet under the action of crude oil. 展开更多
关键词 microfluidic model water flooding experiment digital image processing three-phase contact angle measure-ment method flow regime of the remaining oil
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Application of CD34 expression combined with three-phase dynamic contrast-enhanced computed tomography scanning in preoperative staging of gastric cancer
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作者 Hua Liu Kang-Yan Zhao 《World Journal of Gastrointestinal Surgery》 SCIE 2023年第11期2513-2524,共12页
BACKGROUND Accurate preoperative staging of gastric cancer(GC),a common malignant tumor worldwide,is critical for appropriate treatment plans and prognosis.Dynamic three-phase enhanced computed tomography(CT)scanning ... BACKGROUND Accurate preoperative staging of gastric cancer(GC),a common malignant tumor worldwide,is critical for appropriate treatment plans and prognosis.Dynamic three-phase enhanced computed tomography(CT)scanning for preoperative staging of GC has limitations in evaluating tumor angiogenesis.CD34,a marker on vascular endothelial cell surfaces,is promising in evaluating tumor angiogenesis.We explored the value of their combination for preoperative staging of GC to improve the efficacy and prognosis of patients with GC.Medical records of 106 patients with GC treated at the First People's Hospital of Lianyungang between February 2021 and January 2023 were retrospectively studied.All patients underwent three-phase dynamic contrast-enhanced CT scanning before surgery,and CD34 was detected in gastroscopic biopsy specimens.Using surgical and pathological results as the gold standard,the diagnostic results of three-phase dynamic contrast-enhanced CT scanning at different T and N stages were analyzed,and the expression of CD34-marked microvessel density(MVD)at different T and N stages was determined.The specificity and sensitivity of three-phase dynamic contrast-enhanced CT and CD34 in T and N staging were calculated;those of the combined diagnosis of the two were evaluated in parallel.Independent factors affecting lymph node metastasis were analyzed using multiple logistic regression.RESULTS The accuracy of three-phase dynamic contrast-enhanced CT scanning in diagnosing stages T1,T2,T3 and T4 were 68.00%,75.00%,79.41%,and 73.68%,respectively,and for diagnosing stages N0,N1,N2,and N3 were 75.68%,74.07%,85.00%,and 77.27%,respectively.CD34-marked MVD expression increased with increasing T and N stages.Specificity and sensitivity of three-phase dynamic contrast-enhanced CT in T staging were 86.79%and 88.68%;for N staging,89.06%and 92.86%;for CD34 in T staging,64.15%and 88.68%;and for CD34 in N staging,84.38%and 78.57%,respectively.Specificity and sensitivity of joint diagnosis in T staging were 55.68%and 98.72%,and N staging were 75.15%and 98.47%,respectively,with the area under the curve for diagnosis improving accordingly.According to multivariate analysis,a longer tumor diameter,higher pathological T stage,lower differ-entiation degree,and higher expression of CD34-marked MVD were independent risk factors for lymph node metastasis in patients with GC.CONCLUSION With high accuracy in preoperatively determining the invasion depth and lymph node metastasis of GC,CD34 expression and three-phase dynamic contrast-enhanced CT can provide a reliable basis for surgical resection. 展开更多
关键词 CD34 three-phase dynamic contrast-enhanced computed tomography scanning Gastric cancer Preoperative staging INVASION Lymph node metastasis
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Role of CaCl_(2) in Cold Acclimation-Induced Freezing Resistance of Populus tomentosa Cuttings 被引量:2
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作者 林善枝 林元震 +2 位作者 张志毅 雍军 张谦 《Forestry Studies in China》 CAS 2002年第2期38-42,共5页
Populus tomentosa cuttings were treated with 1mmol·L -1 , 5mmol·L -1 , 10mmol·L -1 or 15mmol·L -1 of CaCl 2 for 1\|7 d, respectively, for studying the effects of different conc... Populus tomentosa cuttings were treated with 1mmol·L -1 , 5mmol·L -1 , 10mmol·L -1 or 15mmol·L -1 of CaCl 2 for 1\|7 d, respectively, for studying the effects of different concentrations of CaCl 2 on freezing resistance. Results indicated that 10?mmol·L -1 of CaCl 2 has greater effect than other concentrations on the enhancement of freezing resistance, and the optimum time of pretreatment was 5?d. In addition, cuttings used for cold acclimation at -3℃ were pretreated with or without 10?mmol·L -1 of CaCl 2, 3?mmol·L -1 of Ca 2+ chelator EGTA, 0 05?mmol·L -1 of CaM antagonist CPZ or 0 1?mmol·L -1 of Ca 2+ channel inhibitor LaCl 3 The changes in CaM and freezing resistance of all cuttings were investigated. The results showed that cold acclimation at -3℃ increased CaM content and decreased the minimum temperature for 100% survival. The CaCl 2 pretreatment enhanced the effect of cold acclimation and obviously increased CaM content and decreased the minimum temperature for 100% survival, but this effect was strongly inhibited by the EGTA, CPZ or LaCl 3 It is concluded that the effect of CaCl 2 on freezing resistance is associated with its concentration and time of pretreatment, Ca 2+ CaM may be involved in the induction of freezing resistance of the cuttings. 展开更多
关键词 Populus tomentosa cuttings cold acclimation CaCl 2 CAM freezing resistance
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Effects of Cold Acclimation and CaCl_2 on Total Soluble Protein, CaM and Freezing Resistance of Populus tomentosa Seedlings 被引量:6
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作者 林善枝 张志毅 《Forestry Studies in China》 CAS 2002年第1期5-12,共8页
Populus tomentosa seedlings used for cold acclimation at -3℃ were pretreated with or without 10?mmol·L -1 CaCl 2, 3?mmol·L -1 of Ca 2+ chelator EGTA, 0 1?mmol·L -1 of Ca 2+ ... Populus tomentosa seedlings used for cold acclimation at -3℃ were pretreated with or without 10?mmol·L -1 CaCl 2, 3?mmol·L -1 of Ca 2+ chelator EGTA, 0 1?mmol·L -1 of Ca 2+ channel inhibitor LaCl 3,and 0 05?mmol·L -1 of CaM antagonist CPZ. The changes in the contents of total soluble protein and CaM, and freezing resistance in all pretreated seedlings in various periods ( viz: following cold acclimation, chilling stress and recovery) were investigated. Results showed that cold acclimation increased the contents of total soluble protein and CaM, and freezing resistance of seedlings, which could be strongly reduced by the pretreatments of EGTA CPZ and LaCl 3 Cold acclimation combined with CaCl 2 pretreatment enhanced the effect of cold acclimation on freezing resistance, and obviously increased the contents of total soluble protein and CaM, reduced the declining degree of the contents of total soluble protein and CaM caused by chilling stress as compared with cold acclimation, augmented the increase in the level of total soluble protein and CaM during the recovery periods. Further analysis found that an increase in total soluble protein content during cold acclimation with or without CaCl 2 pretreatment mainly resulted from the increase in content of heat stable protein in total soluble protein. It is suggested that Ca 2+ calmodulin may be involved in the synthesis of total soluble protein, and the induction of freezing resistance of seedlings. 展开更多
关键词 Populus tomentosa cold acclimation CaCl 2 total soluble protein CAM freezing resistance
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Cold Acclimation-Induced Changes in Total Soluble Protein, RNA, DNA, RNase and Freezing Resistance in Populus tomentosa Cuttings 被引量:3
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作者 林善枝 张志毅 《Forestry Studies in China》 CAS 2002年第2期9-15,共7页
The changes in the contents of total soluble protein and RNA, the activity of RNase in leaves and branches of Populus tomentosa cuttings at various periods (viz: cold acclimation, deacclimation, chilling stress an... The changes in the contents of total soluble protein and RNA, the activity of RNase in leaves and branches of Populus tomentosa cuttings at various periods (viz: cold acclimation, deacclimation, chilling stress and the recovery after chilling stress), and the survival rate and the freezing resistance of cuttings during cold acclimation at -3℃ were investigated. Results showed that cold acclimation not only increased the contents of total soluble protein and RNA, the survival rates and the freezing resistance of cuttings, decreased the activity of RNase, but also reduced the declining degree of total soluble protein and RNA contents, and the increasing level of RNase caused by chilling stress as compared with the controls. In addition, cold acclimation augmented the increase in the level of total soluble protein and RNA, and facilitated the decrease of RNase during the recovery periods. Further analysis found that the DNA content of all treatments kept relative stability at various periods. The changes in total soluble protein, RNA and RNase were closely related to the freezing resistance of cuttings. It appears that the increase of RNA content caused by cold acclimation induced decrease of RNase activity may be involved in the accumulation of total soluble protein and the induction of freezing resistance of cuttings. 展开更多
关键词 Populus tomentosa cold acclimation freezing resistance total soluble protein nucleic acid
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Analysis of rock physics response of gas-bearing volcanic reservoir based on three-phase poroelastic theory 被引量:3
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作者 吴清岭 赵海波 +1 位作者 李来林 范兴才 《Applied Geophysics》 SCIE CSCD 2008年第4期277-283,共7页
Unlike previous theories with velocity and/or elastic modulus averaging, we use a three-phase porous rock physics model developed by Santos for analyzing the seismic response of two immiscible fluids in saturated poro... Unlike previous theories with velocity and/or elastic modulus averaging, we use a three-phase porous rock physics model developed by Santos for analyzing the seismic response of two immiscible fluids in saturated porous media. Considering reservoir reference pressure and coupling drag of two fluids in pores, the effects of frequency, porosity, and gas saturation on the phase velocities of the P-and S-waves are discussed in detail under field conditions. The effects of porosity and gas saturation on Vp/Vs are also provided. The data for our numerical experiments are from a sample of deep volcanic rock from Daqing. The numerical results show that the frequency dispersion effect can be ignored for deep volcanic rocks with low porosity and low permeability. It is concluded that for deep volcanic rocks the effect of gas content in pores on Vp/Vs is negligible but the effect of porosity is significant when there is a certain amount of water contained in the pores. The accurate estimate of lithology and porosity in this case is relatively more important. 展开更多
关键词 rock physics three-phase porous media seismic response and volcanic rock
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Dynamics of Essential Metal Elements Contents in Winter Oilseed Rape during Cold Acclimation 被引量:4
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作者 张树杰 王琼 +1 位作者 李光明 张春雷 《Agricultural Science & Technology》 CAS 2011年第8期1156-1160,1165,共6页
[Objective]The paper was to investigate the dynamics of essential metal elements(Ca,Mg,Fe,Mn,Zn and Cu)contents in winter oilseed rape(Brassica napus L.)during cold acclimation,and to reveal the effects and mechan... [Objective]The paper was to investigate the dynamics of essential metal elements(Ca,Mg,Fe,Mn,Zn and Cu)contents in winter oilseed rape(Brassica napus L.)during cold acclimation,and to reveal the effects and mechanisms of essential elements in cold resistance of oilseed rape.[Method]Three varieties with different cold resistance including Zhongshuang No.11(ZS,freezing sensitive variety),Ganyouza No.1(GY)and Jinyuyou No.1(JYY,freezing tolerant varieties)were used in the study,and the changes of necessary metal elements in these oilseed rapes during cold acclimation were studied.[Result]The concentration of metal elements in oilseed rape had significant changes during cold acclimation,and the difference between varieties was significant.In plant roots,the concentrations of Ca,Mg,Fe,Mn,Zn and Cu were significantly increased,this might because that low temperature made the transpiration decreased,thus blocking the upward transport of elements.In plant shoots,the concentrations of Ca,Mg and Zn were significantly decreased,while the concentrations of Fe and Mn were significantly increased;the change extent of various elements in ZS variety was the largest.[Conclusion]Maintaining the stability of Ca,Mg and Zn concentrations and increasing Fe,Mn and Cu concentrations in plant shoots might be benefit for increasing the cold tolerance of winter oilseed rape. 展开更多
关键词 Cold acclimation Cold resistance Essential elements Winter oilseed rape
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Effect of Sugar on the Process of Cold-Acclimation-Induced Freezing Tolerance of Populus tomentosa 被引量:1
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作者 林善枝 张志毅 《Forestry Studies in China》 CAS 2001年第1期1-6,共6页
Populus tomentosa seedlings for cold-acclimating were pretreated wit h or without 20% saccharose. Changes in the concentrations of total soluble sugar , the survival rates, and freezing tolerance of seedlings during ... Populus tomentosa seedlings for cold-acclimating were pretreated wit h or without 20% saccharose. Changes in the concentrations of total soluble sugar , the survival rates, and freezing tolerance of seedlings during cold acclimatio n were investigated. The results showed that cold acclimation increased the conc entrations of total soluble sugar, the survival rates and freezing tolerance. Co ld acclimation, combined with the saccharose-pretreatment, enhanced the above- ment ioned effect of cold acclimation, and obviously increased the concentrations of total soluble sugar, the survival rates and freezing tolerance of seedlings. Fur ther analysis found that the concentrations of total soluble sugar in branches i ncreased greater than that in leaves during both cold acclimation with or withou t the pretreatment of saccharose. Moreover, an increase of the concentrations of total soluble sugar in branches and leaves was closely related to the freezing tolerance of seedlings. The results indicate the accumulation of soluble sugar i n seedlings induced by cold acclimation may be involved in the induction of free zing tolerance . 展开更多
关键词 Populus tomentosa cold acclimation freezing tolerance survival rat es soluble sugar
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建议“Acclimation”译作“习服” 被引量:2
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作者 顾宪红 张子仪 《科技术语研究》 2003年第2期34-34,共1页
关键词 acclimation 英语 翻译 汉语 “习服” 生物热生理学
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COMPARISON AND EVALUATION OF CURRENT REFERENCE GENERATION STRATEGIES FOR ACTIVE POWER FILTERS IN THREE-PHASE FOUR-WIRE SYSTEMS
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作者 陈东华 郭涛 +1 位作者 谢少军 周波 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2005年第4期298-306,共9页
For three phase four-wire active power filters (APFs), several typical power theories and corresponding current reference generation strategies are induced, p-q, d-q, unify power factor (UPF) and instantaneous act... For three phase four-wire active power filters (APFs), several typical power theories and corresponding current reference generation strategies are induced, p-q, d-q, unify power factor (UPF) and instantaneous active current (IAC) methods are analyzed and compared with each other. The interpretation of active and reactive currents in non-sinusoidal and unbalanced three-phase four-wire systems is given based on the generalized instantaneous reactive power theory. The performance and the characteristic are evaluated, and the application conditions of current reference generation strategies are concluded. Simulation results under different source voltages and loads verify the evaluation result. 展开更多
关键词 active power filters instantaneous reactive power current reference three-phase four wire power
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THREE-PHASE BRIDGE INVERTER FOR 9kW DOUBLY SALIENT PERMANENT MAGNET MOTOR
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作者 黄伟君 秦海鸿 +1 位作者 王慧贞 严仰光 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2006年第1期27-33,共7页
The three-phase bridge inverter is used as the converter topology in the power controller for a 9 kW doubly salient permanent magnet (DSPM) motor. Compared with common three-phase bridge inverters, the proposed inve... The three-phase bridge inverter is used as the converter topology in the power controller for a 9 kW doubly salient permanent magnet (DSPM) motor. Compared with common three-phase bridge inverters, the proposed inverter works under more complicated conditions with different principles for special winding back EMFs, position signals of hall sensors, and the given mode of switches. The ideal steady driving principles of the inverter for the motor are given. The working state with asymmetric winding back EMFs, inaccurate position signals of hall sensors, and the changing input voltage is analyzed. Finally, experimental results vertify that the given anal ysis is correct. 展开更多
关键词 doubly salient permanent magnet motor three-phase bridge inverter winding back EMF position signal of hall sensor input voltage
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