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Development characteristics and controlling factors of fractures in lacustrine shale and their geological significance for evaluating shale oil sweet spots in the third member of the Shahejie Formation in the Qikou Sag, Bohai Bay Basin
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作者 Xu Zeng Tao Yang +5 位作者 Jian-Wei Feng Cong-Sheng Bian Ming Guan Wei Liu Bing-Cheng Guo Jin Dong 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期791-805,共15页
Natural fractures are critical for shale oil and gas enrichment and development. Due to the extremely high heterogeneity of shale, the factors controlling the formation of internal fractures, especially horizontal fra... Natural fractures are critical for shale oil and gas enrichment and development. Due to the extremely high heterogeneity of shale, the factors controlling the formation of internal fractures, especially horizontal fractures, remain controversial. In this study, we integrate thin section analysis and microcomputed tomography(CT) data from several lacustrine shale samples from the third member(Es3) of the Shahejie Formation, Qikou Sag, Bohai Bay Basin, to assess the fractures in detail. The goal is to reveal the development characteristics, controlling factors, and geological significance for evaluating sweet spots in a shale oil play. The fractures in the Es3contain high-angle structural and horizontal bed-parallel fractures that are mostly shear and extensional. Various factors influence fracture development,including lithofacies, mineral composition, organic matter content, and the number of laminae. Structural fractures occur predominantly in siltstone, whereas bed-parallel fractures are abundant in laminated shale and layered mudstone. A higher quartz content results in higher shale brittleness, causing fractures, whereas the transformation between clay minerals contributes to the development of bedparallel fractures. Excess pore pressure due to hydrocarbon generation and expulsion during thermal advance can cause the formation of bed-parallel fractures. The density of the bed-parallel and structural fractures increases with the lamina density, and the bed-parallel fractures are more sensitive to the number of laminae. The fractures are critical storage spaces and flow conduits and are indicative of sweet spots. The laminated shale in the Es3with a high organic matter content contains natural fractures and is an organic-rich, liquid-rich, self-sourced shale play. Conversely, the siltstone, massive mudstone, and argillaceous carbonate lithofacies contain lower amounts of organic matter and do not have bed-parallel fractures. However, good reservoirs can form in these areas when structural fractures are present and the source, and storage spaces are separated. 展开更多
关键词 FRACTURES Development characteristics controlling factors Shale oil Sweet spot
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Hybrid Multi-Infeed Interaction Factor Calculation Method Considering Voltage Regulation Control Characteristics of Voltage Source Converter
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作者 Shan Liu Chengbin Chi +3 位作者 Fengze Han Yanan Wu Lin Zhu Tuo Wang 《Energy Engineering》 EI 2024年第8期2257-2273,共17页
Voltage source converter based high voltage direct current(VSC-HVDC)can participate in voltage regulation by flexible control to help maintain the voltage stability of the power grid.In order to quantitatively evaluat... Voltage source converter based high voltage direct current(VSC-HVDC)can participate in voltage regulation by flexible control to help maintain the voltage stability of the power grid.In order to quantitatively evaluate its influence on the voltage interaction between VSC-HVDC and line commutated converter based high voltage direct current(LCC-HVDC),this paper proposes a hybrid multi-infeed interaction factor(HMIIF)calculation method considering the voltage regulation control characteristics of VSC-HVDC.Firstly,for a hybrid multi-infeed high voltage direct current system,an additional equivalent operating admittance matrix is constructed to characterize HVDC equipment characteristics under small disturbance.Secondly,based on the characteristic curve between the reactive power and the voltage of a certain VSC-HVDC project,the additional equivalent operating admittance of VSC-HVDC is derived.The additional equivalent operating admittance matrix calculation method is proposed.Thirdly,the equivalent bus impedance matrix is obtained by modifying the alternating current(AC)system admittance matrix with the additional equivalent operating admittance matrix.On this basis,the HMIIF calculation method based on the equivalent bus impedance ratio is proposed.Finally,the effectiveness of the proposed method is verified in a hybrid dual-infeed high voltage direct current system constructed in Power Systems Computer Aided Design(PSCAD),and the influence of voltage regulation control on HMIIF is analyzed. 展开更多
关键词 Hybrid multi-infeed high voltage direct current system hybrid multi-infeed interaction factor control modes equivalent node impedance ratio voltage interaction characteristics
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Baoziwan-Majiashan Area of Jiyuan Oilfield Analysis of Reservoir Characteristics and Main Control Factors in Long 4 5 Section
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作者 Zhengxi Cui Zhipeng Zhang Mingling Shen 《Open Journal of Yangtze Oil and Gas》 2024年第2期48-64,共17页
Based on the sheet, scanning electron microscope and high pressure mercury analysis method, this paper takes Jiyuan oilfield-Ma Jia mountain district 4 5 sandstone reservoir as the research object, from the reservoir ... Based on the sheet, scanning electron microscope and high pressure mercury analysis method, this paper takes Jiyuan oilfield-Ma Jia mountain district 4 5 sandstone reservoir as the research object, from the reservoir petrology, pore type and porosity, permeability, the system analyzed the reservoir characteristics and its control factors. The results show that the sandstone in the 4 5 section of Baoziwan-Majiashan area of Jiyuan oilfield is fine in size and high in filling content. The pore types were dominated by intergranular pores and dissolved pores, with a low face rate. The reservoir property is relatively poor, with mean porosity of 11.11% and mean permeability of 1.16 × 10<sup>−</sup><sup>3</sup> µm<sup>2</sup>. In the low porous, low otonic background, the development of relatively high pore hypertonic areas. Compaction and cementation should play a destructive role in reservoir properties, and dissolution should play a positive role in reservoir properties. Compaction adjusts the migration of clay minerals and miscellaneous bases in the original sediment in the study area, greatly reducing the porosity and permeability of the reservoir;the development of the cement cement, carbonate cementation and some quartz secondary compounds reduces the storage space;the dissolution effect, especially the secondary dissolution pores of the reservoir, which obviously improves the properties of the reservoir. 展开更多
关键词 Ordos Basin Jiyuan Area Reservoir characteristics Reservoir control Factor Long 4 5 Section
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Reservoir Characteristics and Main Controlling Factors of the Flow III Section of the K Oilfield in the Weixinan Depression
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作者 Shijin Tan 《Open Journal of Yangtze Oil and Gas》 2024年第2期33-47,共15页
In order to clarify the reservoir characteristics and main controlling factors of the flow three section of the K oil field in the Weixinan Depression, a study on the reservoir characteristics and main controlling fac... In order to clarify the reservoir characteristics and main controlling factors of the flow three section of the K oil field in the Weixinan Depression, a study on the reservoir characteristics and main controlling factors of the flow three section of the K oil field in the Weixinan Depression has been carried out by utilizing the data of cores, casting thin sections, physical property tests and logging wells. The results show that the lithology of the reservoir in the flow three section of the study area is dominated by coarse sandstone and medium sandstone, followed by conglomerate-bearing sandstone and sand conglomerate. The porosity is mainly distributed in the range of medium-high porosity, and the permeability is mainly medium seepage, and the overall physical properties are good. The three sections of the stream in the study area mainly include four sedimentary microphases, namely, underwater diversion channel, estuarine dam, mat sand and inter-diversion bay. The underwater diversion channel has the best physical properties, characterized by coarse grains and low mud content. The medium and coarse sand content of various lithologic reservoirs is the main factor in the formation of high-quality reservoirs. Rock-forming action is an important factor affecting the physical properties of local reservoirs, comparing the compaction, cementation and dissolution between different sedimentary microphases, the underwater diverging river has the lowest rate of compaction and pore reduction, the highest rate of pore increase by dissolution, and the best physical properties. Therefore, the weakly cemented-strongly dissolved coarse sandstone phase developed in the microphase of the underwater diversion channel in section 3 of the flow in the study area is the most favorable reservoir. 展开更多
关键词 Weinan Depression Liushagang Formation Reservoir characteristics Sedimentary Microphase DIAGENESIS
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Cross-section distortion and springback characteristics of double-cavity aluminum profile in force controlled stretch-bending
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作者 Zhi-wen LIU Zi-xuan DONG +2 位作者 Cong-chang XU Jie YI Luo-xing LI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第8期2476-2490,共15页
3D elastic-plastic FE model for simulating the force controlled stretch-bending process of double-cavity aluminum profile was established using hybrid explicit−implicit solvent method.Considering the computational acc... 3D elastic-plastic FE model for simulating the force controlled stretch-bending process of double-cavity aluminum profile was established using hybrid explicit−implicit solvent method.Considering the computational accuracy and efficiency,the optimal choices of numerical parameters and algorithms in FE modelling were determined.The formation mechanisms of cross-section distortion and springback were revealed.The effects of pre-stretching,post-stretching,friction,and the addition of internal fillers on forming quality were investigated.The results show that the stress state of profile in stretch-bending is uniaxial with only a circumferential stress.The stress distribution along the length direction of profile is non-uniform and the maximum tensile stress is located at a certain distance away from the center of profile.As aluminum profile is gradually attached to bending die,the distribution characteristic of cross-section distortion along the length direction of profile changes from V-shape to W-shape.After unloading the forming tools,cross-section distortion decreases obviously due to the stress relaxation,with a maximum distortion difference of 13%before and after unloading.As pre-stretching and post-stretching forces increase,cross-section distortion increases gradually,while springback first decreases and then remains unchanged.With increasing friction between bending die and profile,cross-section distortion slightly decreases,while springback increases.Cross-section distortion decreases by 83%with adding PVC fillers into the cavities of profile,while springback increases by 192.2%. 展开更多
关键词 hollow aluminum profile force controlled stretch-bending numerical parameters springback analysis approach cross-section distortion SPRINGBACK process parameters
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Near-infrared brain functional characteristics of mild cognitive impairment with sleep disorders
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作者 Heng Liao Sha Liao +5 位作者 Yu-Jiao Gao Xi Wang Li-Hong Guo Su Zheng Wu Yang Yi-Nan Dai 《World Journal of Psychiatry》 SCIE 2025年第1期106-116,共11页
BACKGROUND Mild cognitive impairment(MCI)has a high risk of progression to Alzheimer’s disease.The disease is often accompanied by sleep disorders,and whether sleep disorders have an effect on brain function in patie... BACKGROUND Mild cognitive impairment(MCI)has a high risk of progression to Alzheimer’s disease.The disease is often accompanied by sleep disorders,and whether sleep disorders have an effect on brain function in patients with MCI is unclear.AIM To explore the near-infrared brain function characteristics of MCI with sleep disorders.METHODS A total of 120 patients with MCI(MCI group)and 50 healthy subjects(control group)were selected.All subjects underwent the functional near-infrared spec-troscopy test.Collect baseline data,Mini-Mental State Examination,Montreal Cognitive Assessment scale,fatigue severity scale(FSS)score,sleep parameter,and oxyhemoglobin(Oxy-Hb)concentration and peak time of functional near-infrared spectroscopy test during the task period.The relationship between Oxy-RESULTS Compared with the control group,the FSS score of the MCI group was higher(t=11.310),and the scores of Pittsburgh sleep quality index,sleep time,sleep efficiency,nocturnal sleep disturbance,and daytime dysfunction were higher(Z=-10.518,-10.368,-9.035,-10.661,-10.088).Subjective sleep quality and total sleep time scores were lower(Z=-11.592,-9.924).The sleep efficiency of the MCI group was lower,and the awakening frequency,rem sleep latency period,total sleep time,and oxygen desaturation index were higher(t=5.969,5.829,2.887,3.003,5.937).The Oxy-Hb concentration at T0,T1,and T2 in the MCI group was lower(t=14.940,11.280,5.721),and the peak time was higher(t=18.800,13.350,9.827).In MCI patients,the concentration of Oxy-Hb during T0 was negatively correlated with the scores of Pittsburgh sleep quality index,sleep time,total sleep time,and sleep efficiency(r=-0.611,-0.388,-0.563,-0.356).It was positively correlated with sleep efficiency and total sleep time(r=0.754,0.650),and negatively correlated with oxygen desaturation index(r=-0.561)and FSS score(r=-0.526).All comparisons were P<0.05.CONCLUSION Patients with MCI and sleep disorders have lower near-infrared brain function than normal people,which is related to sleep quality.Clinically,a comprehensive assessment of the near-infrared brain function of patients should be carried out to guide targeted treatment and improve curative effect. 展开更多
关键词 MILD Cognitive impairment Sleep disorders NEAR-INFRARED Brain functional characteristicS
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Advanced Functional Electromagnetic Shielding Materials:A Review Based on Micro‑Nano Structure Interface Control of Biomass Cell Walls
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作者 Yang Shi Mingjun Wu +14 位作者 Shengbo Ge Jianzhang Li Anoud Saud Alshammari Jing Luo Mohammed A.Amin Hua Qiu Jinxuan Jiang Yazeed M.Asiri Runzhou Huang Hua Hou Zeinhom M.El‑Bahy Zhanhu Guo Chong Jia Kaimeng Xu Xiangmeng Chen 《Nano-Micro Letters》 SCIE EI CAS 2025年第1期98-134,共37页
Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and... Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and hierarchical.Due to their porous nature,interfacial compatibility,and electrical conductivity,biomass materials hold significant potential as EMI shielding materials.Despite concerted efforts on the EMI shielding of biomass materials have been reported,this research area is still relatively new compared to traditional EMI shielding materials.In particular,a more comprehensive study and summary of the factors influencing biomass EMI shielding materials including the pore structure adjustment,preparation process,and micro-control would be valuable.The preparation methods and characteristics of wood,bamboo,cellulose and lignin in EMI shielding field are critically discussed in this paper,and similar biomass EMI materials are summarized and analyzed.The composite methods and fillers of various biomass materials were reviewed.this paper also highlights the mechanism of EMI shielding as well as existing prospects and challenges for development trends in this field. 展开更多
关键词 Biomass materials Electromagnetic interference shielding Micro-nano structure interface control CONDUCTIVITY
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Association of the glycemic background patterns and the diabetes management efficacy in poorly controlled type 2 diabetes
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作者 Ayşe N Erbakan Müzeyyen Arslan Bahadır +6 位作者 FatoşN Kaya Büşra Güleç MiraçVural Keskinler Ümmügülsüm AktemurÇelik Özge Faydalıel Banu Mesçi Aytekin Oğuz 《World Journal of Diabetes》 SCIE 2025年第1期74-90,共17页
BACKGROUND Inadequate glycemic control in patients with type 2 diabetes(T2DM)is a major public health problem and a significant risk factor for the progression of diabetic complications.AIM To evaluate the effects of ... BACKGROUND Inadequate glycemic control in patients with type 2 diabetes(T2DM)is a major public health problem and a significant risk factor for the progression of diabetic complications.AIM To evaluate the effects of intensive and supportive glycemic management strategies over a 12-month period in individuals with T2DM with glycated hemoglobin(HbA1c)≥10%and varying backgrounds of glycemic control.METHODS This prospective observational study investigated glycemic control in patients with poorly controlled T2DM over 12 months.Participants were categorized into four groups based on prior glycemic history:Newly diagnosed,previously well controlled with recent worsening,previously off-target but now worsening,and HbA1c consistently above 10%.HbA1c levels were monitored quarterly,and patients received medical,educational,and dietary support as needed.The analysis focused on the success rates of good glycemic control and the associated factors within each group.RESULTS The study showed significant improvements in HbA1c levels in all participants.The most significant improvement was observed in individuals newly diagnosed with diabetes:65%achieved an HbA1c target of≤7%.The results varied between participants with different glycemic control histories,followed by decreasing success rates:39%in participants with previously good glycemic control,21%in participants whose glycemic control had deteriorated compared to before,and only 10%in participants with persistently poor control,with mean HbA1c levels of 6.3%,7.7%,8.2%,and 9.7%,respectively.After one year,65.2%of the“newly diagnosed patients”,39.3%in the“previously controlled group”,21.9%in the“previously off-target but now worsened'”group and 10%in the“poorly controlled from the start”group had achieved HbA1c levels of 7 and below.CONCLUSION In poorly controlled diabetes,the rate at which treatment goals are achieved is associated with the glycemic background characteristics,emphasizing the need for tailored strategies.Therefore,different and comprehensive treatment approaches are needed for patients with persistent uncontrolled diabetes. 展开更多
关键词 Type 2 diabetes mellitus Glycated hemoglobin Glycemic control Patient-centered care Diabetes management glycemic background
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Passive activity enhances residual control ability in patients with complete spinal cord injury
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作者 Yanqing Xiao Mingming Gao +6 位作者 Zejia He Jia Zheng Hongming Bai Jia-Sheng Rao Guiyun Song Wei Song Xiaoguang Li 《Neural Regeneration Research》 SCIE CAS 2025年第8期2337-2347,共11页
Patients with complete spinal cord injury retain the potential for volitional muscle activity in muscles located below the spinal injury level.However,because of prolonged inactivity,initial attempts to activate these... Patients with complete spinal cord injury retain the potential for volitional muscle activity in muscles located below the spinal injury level.However,because of prolonged inactivity,initial attempts to activate these muscles may not effectively engage any of the remaining neurons in the descending pathway.A previous study unexpectedly found that a brief clinical round of passive activity significantly increased volitional muscle activation,as measured by surface electromyography.In this study,we further explored the effect of passive activity on surface electromyographic signals during volitional control tasks among individuals with complete spinal cord injury.Eleven patients with chronic complete thoracic spinal cord injury were recruited.Surface electromyography data from eight major leg muscles were acquired and compared before and after the passive activity protocol.The results indicated that the passive activity led to an increased number of activated volitional muscles and an increased frequency of activation.Although the cumulative root mean square of surface electromyography amplitude for volitional control of movement showed a slight increase after passive activity,the difference was not statistically significant.These findings suggest that brief passive activity may enhance the ability to initiate volitional muscle activity during surface electromyography tasks and underscore the potential of passive activity for improving residual motor control among patients with motor complete spinal cord injury. 展开更多
关键词 complete spinal cord injury cycle training epidural electrical stimulation motor training passive activity physiological state spinal cord circuit surface electromyography volitional control task
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A matrix metalloproteinase-responsive hydrogel system controls angiogenic peptide release for repair of cerebral ischemia/reperfusion injury
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作者 Qi Liu Jianye Xie +5 位作者 Runxue Zhou Jin Deng Weihong Nie Shuwei Sun Haiping Wang Chunying Shi 《Neural Regeneration Research》 SCIE CAS 2025年第2期503-517,共15页
Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug deliv... Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug delivery often results in a burst release of the drug,leading to transient retention(inefficacy)and undesirable diffusion(toxicity)in vivo.Therefore,a drug delivery system that responds to changes in the microenvironment of tissue regeneration and controls vascular endothelial growth factor release is crucial to improve the treatment of ischemic stroke.Matrix metalloproteinase-2(MMP-2)is gradually upregulated after cerebral ischemia.Herein,vascular endothelial growth factor mimic peptide QK was self-assembled with MMP-2-cleaved peptide PLGLAG(TIMP)and customizable peptide amphiphilic(PA)molecules to construct nanofiber hydrogel PA-TIMP-QK.PA-TIMP-QK was found to control the delivery of QK by MMP-2 upregulation after cerebral ischemia/reperfusion and had a similar biological activity with vascular endothelial growth factor in vitro.The results indicated that PA-TIMP-QK promoted neuronal survival,restored local blood circulation,reduced blood-brain barrier permeability,and restored motor function.These findings suggest that the self-assembling nanofiber hydrogel PA-TIMP-QK may provide an intelligent drug delivery system that responds to the microenvironment and promotes regeneration and repair after cerebral ischemia/reperfusion injury. 展开更多
关键词 angiogenesis biomaterial blood-brain barrier cerebral ischemia/reperfusion injury control release drug delivery inflammation QK peptides matrix metalloproteinase-2 NEUROPROTECTION self-assembling nanofiber hydrogel
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Construction controlling and strength increasing characteristics of locally developed epoxy asphalt mixture 被引量:7
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作者 陈春 钱振东 陈磊磊 《Journal of Southeast University(English Edition)》 EI CAS 2011年第1期61-64,共4页
The construction controlling elements,including construction performance at low ambient temperatures,reserved time ranges,and the strength increasing rule,for locally developed epoxy asphalt mixture(LDEAM) are studi... The construction controlling elements,including construction performance at low ambient temperatures,reserved time ranges,and the strength increasing rule,for locally developed epoxy asphalt mixture(LDEAM) are studied through laboratory tests.Air void and Marshall stability are chosen as the performance measures for evaluating the construction quality.The wheel rolling test is used to simulate the actual construction situations,while the Marshall test and the Brookfield viscosity test are adopted to study the strength increasing rule.The experimental results reveal that the LDEAM can be constructed under a low ambient temperature condition of 10℃,and its longest reserved time is 70 min at a reserved temperature of 120℃.Test also shows that the strength of the LDEAM increases with time and temperature before cured.Finally,the theoretical reason for the strength increasing rule is analyzed on the basis of the organic chemistry theory. 展开更多
关键词 construction characteristics locally developed epoxy asphalt strength increasing characteristics
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Development Characteristics and Control Measures for Semiothisa cineraria Bremer & Grey 被引量:1
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作者 唐浩 李军民 +2 位作者 吴家全 高华清 张松光 《Agricultural Science & Technology》 CAS 2014年第6期933-936,共4页
The development characteristics of Semiothisa cinerearia Bremer & Grey was summarized, and we also put forward the control measures of well completing insect surveys to provide scientific basis for the control and ac... The development characteristics of Semiothisa cinerearia Bremer & Grey was summarized, and we also put forward the control measures of well completing insect surveys to provide scientific basis for the control and actively carrying out comprehensive management to control the pests damage in the economic permissible level. 展开更多
关键词 Semiothisa cinerearia Bremer Grey Development characteristics control measures
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Effects of Gel-based Controlled Release Fertilizers on Agronomic Characteristics and Physiological Indices of Corn 被引量:1
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作者 丁洪 张玉树 +3 位作者 陈静蕊 秦胜金 郑祥洲 李世清 《Agricultural Science & Technology》 CAS 2013年第6期820-824,846,共6页
[Objective] This study aimed to investigate the effects of gel-based controlled release fertilizers (CRFs) on agronomic characteristics and physiological indices of corn. [Method] Pot experiment was carried out to i... [Objective] This study aimed to investigate the effects of gel-based controlled release fertilizers (CRFs) on agronomic characteristics and physiological indices of corn. [Method] Pot experiment was carried out to investigate the agronomic characteristics and physiological indices of corn fertilized with controlled release fertilizers compared with conventional fertilizer (CF). [Result] Plant height, stem girth, leaf area and root volume of corn were significantly increased under the CRF treatments; photosynthetic rate and soluble protein content were also improved. Dry matter accumulations under the two CRF treatments were increased by 21.3% and 17.0% compared with CF application at one time (CF1), and 19.6% and 15.4% with CF application at two times (CF2), respectively. Accumulation amounts of N, P and K in whole plant under the two CRF treatments were increased by 44.0% -24.7% , 40.0%-25.9% and 20.1% -13.9% ; and the nutrient use efficiencies of N, P and K were improved by 22.9% -13.4% , 11.2% -9.6% and 17.5% -12.1% , respectively. [Conclusion] The results implied that the CRFs could significantly improve nutrient use efficiency and plant yield. 展开更多
关键词 Gel-based controlled release fertilizer Conventional fertilizer Agronomic characteristics Physiological index Nutrient use efficiency Dry matter accumulation
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COUPLED DYNAMIC CHARACTERISTICS AND CONTROL OF ROTOR-CONICAL MAGNETIC BEARING SYSTEM 被引量:1
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作者 杨静 虞烈 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2004年第3期189-194,共6页
The coupled dynamic characteristics of the conical electromagnetic bearing are presented and their definitions are given. On the basis of the analyses of the characteristics, the dynamic model of five degrees of freed... The coupled dynamic characteristics of the conical electromagnetic bearing are presented and their definitions are given. On the basis of the analyses of the characteristics, the dynamic model of five degrees of freedom (five-DOF) rotor-conical electromagnetic bearing system is made, and the influence of the coupled characteristics on the system optimal controller is analyzed. 展开更多
关键词 conical electromagnetic bearing current coupling geometry coupling optimal controller
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Biological Characteristics of Sugarcane Rust in Beihai and Its Control Methods
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作者 韦金菊 邓展云 +3 位作者 黄伟华 潘雪红 王伯辉 刘晓静 《Plant Diseases and Pests》 CAS 2010年第4期16-19,共4页
The sugarcane rust was the main disease causing damage on sugarcane leaves. The biological characteristics of the sugarcane rust pathogens found in Beihai were studied. The research results showed that the germination... The sugarcane rust was the main disease causing damage on sugarcane leaves. The biological characteristics of the sugarcane rust pathogens found in Beihai were studied. The research results showed that the germination of uredospores would be promoted under the dark condition or with the glucose concentration of 1.5%. The suitable temperature range for the germination of uredospore was 20 -25 ℃, 25 ℃3 was the optimum temperature. The range of relative humidity (RH) for the germination of uredospore was over 80%, the optimum relative humidity for the germination of uredospore was 100% +water drops with the germination rate of 28.3%. Urediospore could germinate in the pH value range of 4.1 - 11.1, the most suitable pH value was 7.0. At routine conditions, the longest survival period of uredospore was 120 days. Selection of resistant varieties and cultivation management was the key of control measures. 展开更多
关键词 Sugarcane rust Biological charactedstics control measures
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Transient characteristics analysis of linear flux-switching permanent magnet machines for precision control
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作者 周士贵 余海涛 +2 位作者 胡敏强 黄磊 袁榜 《Journal of Southeast University(English Edition)》 EI CAS 2011年第1期31-35,共5页
A dynamical dq model is proposed for a linear flux-switching permanent magnet(LFSPM) machine which is suitable for high-precision control applications.The operation principle of the prototype machine is analyzed usi... A dynamical dq model is proposed for a linear flux-switching permanent magnet(LFSPM) machine which is suitable for high-precision control applications.The operation principle of the prototype machine is analyzed using the finite element method(FEM),and the parameters,such as the back electromotive force(EMF) and the phase flux linkage,are calculated.The calculated and measured results reveal that the back EMF and the flux linkage are essentially sinusoidal,and the variation of the phase flux linkage profile of the LFSPM machine is similar to that of the linear surface permanent magnet(LSPM) machine.Based on this,a dynamical dq model and a simulation control model are proposed.The simulation results are compared with the test results obtained from a DSP-based control platform,which verifies that the model is correct and effective.Moreover,the model can be used for design optimization and control development. 展开更多
关键词 precision control FLUX-SWITCHING permanent magnet machine dq model vector control
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Development Characteristics and Controlling Countermeasures of Rice Stem Borer, Chilo suppressalis(Walker) 被引量:3
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作者 唐浩 李军民 +2 位作者 吴家全 高华清 张松光 《Agricultural Science & Technology》 CAS 2014年第5期843-845,849,共4页
The development characteristics of rice stem border, Chilo suppressalis (Walker) was introduced, and the corresponding control ing measures were put forward, including agricultural control, physical control, biologi... The development characteristics of rice stem border, Chilo suppressalis (Walker) was introduced, and the corresponding control ing measures were put forward, including agricultural control, physical control, biological control, chemical control. 展开更多
关键词 RICE Development characteristics control-ling countermeasures
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Theoretical Analysis and Numerical Simulation of the Static and Dynamic Characteristics of Hydrostatic Guides Based on Progressive Mengen Flow Controller 被引量:13
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作者 GAO Dianrong ZHENG Dan ZHANG Zuochao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2010年第6期709-716,共8页
The oil film thickness of oil hydrostatic guide with constant pressure supply based on capillary restrictor is greatly affected by load, and this kind of hydrostatic guide is usually applied to the machine tools with ... The oil film thickness of oil hydrostatic guide with constant pressure supply based on capillary restrictor is greatly affected by load, and this kind of hydrostatic guide is usually applied to the machine tools with moderate load. The static and dynamic characteristics of the guide have been studied by using some theoretical, numerical and experimental approaches, and some methods and measures have been proposed to improve its performances. The hydrostatic guide based on progressive mengen(PM) flow controller is especially suitable for the heavy numerical control(NC) machine tools. However, few literatures about the research on the static and dynamic characteristics of the hydrostatic guides based on PM flow controller are reported. In this paper, the formulae are derived for analyzing the static and dynamic characteristics of hydrostatic guides with rectangle pockets and PM flow controller according to the theory of hydrostatic bearing. On the basis of the analysis of hydrostatic bearing with circular pocket, some equations are derived for solving the static pressure, volume pressure and squeezing pressure which influence the dynamic characteristics of hydrostatic guides with rectangle pocket. The function and the influencing factors of three pressures are clarified. The formulae of amplitude-frequency characteristics and dynamic stiffness of the hydrostatic guide system are derived. With the help of software MATLAB, programs are coded with C++ language to simulate numerically the static and dynamic characteristics of the hydrostatic guide based on PM flow controller. The simulation results indicate that the sensitive oil volume between the outlet of the PM flow controller and the guide pocket has the greatest influence on the characteristics of the guide, and it should be reduced as small as possible when the field working condition is met. Choosing the oil with a greater viscosity is also helpful in improving the dynamic performance of hydrostatic guides. The research work has instructing significance for analyzing and designing the guide with PM flow controller. 展开更多
关键词 PM flow controller rectangle pocket static characteristics dynamic characteristics hydrostatic guides
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Experimental Study on Characteristics of NiMnGa Magnetically Controlled Shape Memory Alloy 被引量:8
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作者 Fengxiang WANG Wenjun LI Qingxin ZHANG Chenxi LI Xinjie WU 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2006年第1期55-58,共4页
The static and dynamic magnetic controlling characteristics of NiMnGa magnetically controlled shape memory alloy (MSMA) were experimentally studied. The results show that the characteristics of induced strain with r... The static and dynamic magnetic controlling characteristics of NiMnGa magnetically controlled shape memory alloy (MSMA) were experimentally studied. The results show that the characteristics of induced strain with respect to the magnetic field are nonlinear with saturation nature, and dependent on the temperature as well as the load applied to the MSMA. The magnetic shape memory effect can be observed only in complete martensite phase at room temperature. The magnetic permeability of MSMA is not constant and reduces with the increment of magnetic field. The relative saturation magnetic permeability of MSMA is about 1.5. 展开更多
关键词 NIMNGA Magnetically controlled shape memory alloy characteristicS Experimental study
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BASIC CHARACTERISTICS AND CONTROLLING FACTORS OF ANASTOMSING FLUVIAL SYSTEMS 被引量:3
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作者 Sui-ji Wang Jin-song Li Shou-peng Yin 《Chinese Geographical Science》 SCIE CSCD 2000年第1期31-38,共8页
Although anastomosing fluvial rivers are given much attention recently by some research workers because the result channel sandstone of which is one typical primary reservoirs of petroleum and natural gas, of which th... Although anastomosing fluvial rivers are given much attention recently by some research workers because the result channel sandstone of which is one typical primary reservoirs of petroleum and natural gas, of which the flood plains and the interchannel wetlands are pay zones where coals had formed, the comprehension of anastomosing river is some extent limited at present. Some researchers regard that the anastomosing river river and the anabranched river are the same kind of rivers. In this paper, the sedimentary, geomorphic and hydraulic characteristics and the main controlling factors of anastomosing fluvial system are summarized systematically. Some of the characteristics are compared with others fluvial rivers. Humid climate is suitable to form anastomosing channel systems, in arid semiarid regions anastomosing river maybe develop if many befitting factors combine together. The authors of the paper think that anastomosing river is one typical channel pattern and is dissimilar to anabranched channel pattern. 展开更多
关键词 anastomosing RIVERS geomorphic characteristicS SEDIMENTARY characteristicS controlling FACTORS
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