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A "Superpower" instead of "Unipolarity"
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作者 Li Changjiu is a Research Professor at the Center of World Studies of Xinhua News Agency. 《Contemporary International Relations》 2003年第9期16-22,共7页
The power position and influence of a country depend on its comprehensive national power based on economics. While addressing to the press in Kansas on July 6, 1971, President Nixon noted: "Comparing to our overw... The power position and influence of a country depend on its comprehensive national power based on economics. While addressing to the press in Kansas on July 6, 1971, President Nixon noted: "Comparing to our overwhelming position at the end of World War II, the United States is now facing immense challenges that we have never expected before. " He added, "In terms of economics, the United States is no longer a dominant power or an overwhelming global power. At present, there exist not only two superpowers. In consideration of eco- 展开更多
关键词 instead of IS on Superpower unipolarity that
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Using the THINC-integrated tool to compare the characteristics of cognitive dysfunction in patients with unipolar and bipolar depression
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作者 Na Zhu Qi Zhang +6 位作者 Jia Huang Jie Tong Heng-Fen Gong Ming-Huan Zhu Wei Lu Jie Zhang Xi-Rong Sun 《World Journal of Psychiatry》 2025年第3期175-185,共11页
BACKGROUND Major depressive disorder(MDD)and bipolar depression(BD-D)are both intricate,enduring,and profound psychiatric conditions characterized primarily by depressive episodes and cognitive dysfunction.However,dis... BACKGROUND Major depressive disorder(MDD)and bipolar depression(BD-D)are both intricate,enduring,and profound psychiatric conditions characterized primarily by depressive episodes and cognitive dysfunction.However,distinguishing the characteristics and influencing factors of cognitive impairment in unipolar and BD-D is crucial for identification and intervention.AIM To compare neurocognitive characteristics and investigate associations between cognitive function and clinical features in unipolar and BD-D.METHODS The THINC-integrated tool(THINC-it)as a cognitive assessment tool was applied to 295 individuals:75 patients with depressive disorders(MDD),120 individuals with BD-D,and 100 healthy controls.The Hamilton Depression Scale-17(HAMD),Hamilton Anxiety Scale-14(HAMA),and Pittsburgh Sleep Quality Index(PSQI)were employed to assess depression,anxiety,and sleep.Neurocognitive function characteristics and the relationships between cognitive impairment and general clinical attributes were analyzed.RESULTS There were no statistically significant differences in the overall THINC-it with each objective subscale.However,the subjective subscale(Perceived Deficits Questionnaire for Depression-5-item)showed significant differences between MDD and BD-D(P<0.001).Linear regression analyses were explored to determine associations.Age,years of education,age at onset,and HAMD were significantly co-associated with the overall THINC-it and each subscale in both MDD and BD-D(P<0.05).Furthermore,years of education showed a positive correlation with objective cognitive impairment(e.g.,Codebreaker,Trails)(P<0.05).There was a notable difference in that the number of depressive episodes,disease duration,hospitalizations,HAMA,and PSQI were significantly associated with the overall THINC-it with each subscale between MDD and BD-D(P<0.05).CONCLUSION Although both unipolar and BD-D showed similar objective cognitive impairments,there was a significant difference in subjective cognitive impairment.Our findings suggest that factors like age,years of education,age at onset,and depression severity might not be significantly difference in the influence of cognitive impairment.Furthermore,we found that education was a protective factor for cognitive impairment in both unipolar and BD-D.Our analysis revealed that distinct factors including disease duration,number of depressive episodes,hospitalizations,anxiety levels,and sleep quality influenced cognitive impairment between unipolar and BD-D.Therefore,it was important to investigate the specific characteristics of cognitive impairment and influencing factors to identify differentiating unipolar and BD-D. 展开更多
关键词 Unipolar and bipolar depression THINC-integrated tool Objective cognitive impairments Subjective cognitive impairment Depression Influencing factor
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Lattice strain induced by trace Pt single atoms in nickel for accelerating industrial hydrogen evolution 被引量:1
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作者 Rui Yao Yun Wu +4 位作者 Kaiyang Zhang Shuhui Fan Qiang Zhao Jinping Li Guang Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第11期503-511,共9页
Strategically designing the electrocatalytic system and cleverly inducing strain is an effective approach to balance the cost and activity of Pt-based electrocatalysts for industrial-scale hydrogen production.Herein,w... Strategically designing the electrocatalytic system and cleverly inducing strain is an effective approach to balance the cost and activity of Pt-based electrocatalysts for industrial-scale hydrogen production.Herein,we present a unipolar pulsed electrodeposition(UPED) strategy to induce strain in the Ni lattice by introducing trace amounts of Pt single atoms(SAs)(0.22 wt%).The overpotential decreased by 183 mV at 10 mA cm^(-2) in 1.0 M KOH after introducing trace amounts of Pt_(SAs).The industrial electrolyzer,assembled with Pt_(SAs)Ni cathode and a commercial NiFeO_(x) anode,requires a cell voltage of 1.90 V to attain 1 A cm^(-2) of current density and remains stable for 280 h,demonstrating significant potential for practical applications.Spherical aberration corrected scanning transmission electron microscopy(AC-STEM),X-ray absorption(XAS),and geometric phase analysis(GPA) indicate that the introduction of trace amounts of Pt SAs induces tensile strain in the Ni lattice,thereby altering the local electronic structure and coordination environment around cubic Ni for enhancing the water decomposition kinetics and fundamentally changing the reaction pathway.The doping-strain strategy showcases conformational relationships that could offer new ideas to construct efficient hydrogen evolution reaction(HER) electrocatalysts for industrial hydrogen production in the future. 展开更多
关键词 Unipolar pulsed electrodeposition Pt single atoms Ni lattice Hydrogen evolution reaction H intermediates
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On the Unipolar Generator: An Experimental and Theoretical Study 被引量:1
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作者 Konstantinos Patrinos 《Journal of Applied Mathematics and Physics》 2024年第8期2928-2958,共31页
When studying the phenomenon of the induced electromotive force, which originates from Faraday’s unipolar inductor, the contrast between Faraday’s view of the magnetic field dynamic lines and the theory of relativit... When studying the phenomenon of the induced electromotive force, which originates from Faraday’s unipolar inductor, the contrast between Faraday’s view of the magnetic field dynamic lines and the theory of relativity is revealed. In order to remove this contradiction, this phenomenon was studied in depth, theoretically and experimentally, using an experimental setup similar to Faraday’s. Calculations of the induced electromotive force, based on relativity on the one hand and on Faraday’s view on the other were made with the help of measurements of the magnetic field components. Accurate magnetic field measurements are confirmed by analytical calculations. Precise-induced electromotive force measurements confirmed Faraday’s view and contradicted the theory of relativity. 展开更多
关键词 Faraday’s Experiment Unipolar Generator Homopolar Generator Faraday’s Inductor Unipolar Induction
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Bipolar Theory of MOS Field-Effect Transistors and Experiments
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作者 薩支唐 揭斌斌 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2007年第10期1497-1502,共6页
The bipolar theory of field-effect transistor is introduced to replace the 55-year-old classic unipolar theory invented by Shockley in 1952 in order to account for the characteristics observed in recent double-gate na... The bipolar theory of field-effect transistor is introduced to replace the 55-year-old classic unipolar theory invented by Shockley in 1952 in order to account for the characteristics observed in recent double-gate nanometer silicon MOS field-effect transistors. Two electron and two hole surface channels are simultaneously present in all channel current ranges. Output and transfer characteristics are computed over practical base and gate oxide thicknesses. The bipolar theory corroborates well with experimental data reported recently for FinFETs with metal/silicon and p/n junction source/drain contacts. Single-device realization of CMOS inverter and SRAM memory circuit functions are recognized. 展开更多
关键词 unipolar FET theory bipolar FET theory simultaneous hole and electron surface channels volume channel DOUBLE-GATE pure-base
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Acupuncture/electroacupuncture enhances antidepressant effect of Seroxat:the Symptom Checklist-90 scores 被引量:5
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作者 Junqi Chen Weirong Lin +6 位作者 Shengxu Wang Chongqi Wang Ganlong Li Shanshan Qu Yong Huang Zhangjin Zhang Wei Xiao 《Neural Regeneration Research》 SCIE CAS CSCD 2014年第2期213-222,共10页
One hundred and five patients with primary unipolar depression were randomly divided into three groups: drug group (Seroxat administration), acupuncture group (Seroxat plus acupunc- ture), and electroacupuncture ... One hundred and five patients with primary unipolar depression were randomly divided into three groups: drug group (Seroxat administration), acupuncture group (Seroxat plus acupunc- ture), and electroacupuncture group (Seroxat plus acupuncture plus electroacupuncture). Patients' symptoms were evaluated using a psychometric questionnaire, the Symptom Check- list-90, before intervention and after 2, 4, 6 and 10 weeks of treatment. The individual factor scores and the total score from the Symptom Checldist-90 reduced in all three groups as treat- ment progressed. In the acupuncture and electroacupuncture groups, the total score and the factor scores for obsessive-compulsive symptoms, depression, and anxiety were significantly lower than those in the drug group. There was no significant difference in the factor scores or total scores between the acupuncture and electroacupuncture groups. Some factor scores in the electroacupuncture group, such as somatization, depression, hostility, and phobic anxiety, were increased at 10 weeks compared with the respective score immediately after the course of electroacupuncture at 6 weeks. Our findings indicate that administration of Seroxat alone or in combination with acupuncture/electroacupuncture can produce a significant effect in patients with primary unipolar depression. Furthermore, acupuncture/electroacupuncture has a rapid onset of therapeutic effect and produces a noticeable improvement in obsessive-compulsive, de- pressive and anxiety symptoms. 展开更多
关键词 nerve regeneration acupuncture and moxibustion ELECTROACUPUNCTURE selective sero-tonin reuptake inhibitor SEROXAT primary unipolar depression Symptom Checklist-90 anxiety NSFC grant neural regeneration
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Resistive switching characteristics of Dy_2O_3 film with a Pt nanocrystal embedding layer formed by pulsed laser deposition 被引量:3
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作者 Hong-Bin Zhao Hai-Ling Tu +3 位作者 Feng Wei Xin-Qiang Zhang Yu-Hua Xiong Jun Du 《Rare Metals》 SCIE EI CAS CSCD 2014年第1期75-79,共5页
Resistive switching (RS) behaviors of Dy2O3- based memory devices with and without Pt nanocrystals (Pt-nc) layer were investigated for nonvolatile memory applications. The Cu/Pt-nc/Dy2O3/Pt memory exhibits excelle... Resistive switching (RS) behaviors of Dy2O3- based memory devices with and without Pt nanocrystals (Pt-nc) layer were investigated for nonvolatile memory applications. The Cu/Pt-nc/Dy2O3/Pt memory exhibits excellent unipolar RS characteristics, including highly uniform switching parameters, lower switching voltage (〈1.2 V), high resistance ratio (〉1 × 104), a large number of switching cycles, as well as long retention time (〉1 × 105 s), owing to the local electric field confined and strengthened near the nanocrystals' location. 展开更多
关键词 Dy2O3 Unipolar resistive switching Pt nanocrystal layer Pulsed laser deposition
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Grey matter volume abnormalities in patients with bipolar I depressive disorder and unipolar depressive disorder:a voxelbased morphometry study 被引量:11
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作者 Yi Cai Jun Liu +10 位作者 Li Zhang Mei Liao Yan Zhang Lifeng Wang Hongjun Peng Zhong He Zexuan Li Weihui Li Shaojia Lu Yuqiang Ding Lingjiang Li 《Neuroscience Bulletin》 SCIE CAS CSCD 2015年第1期4-12,共9页
Bipolar disorder and unipolar depressive disorder(UD) may be different in brain structure. In the present study,we performed voxel-based morphometry(VBM) to quantify the grey matter volumes in 23 patients with bip... Bipolar disorder and unipolar depressive disorder(UD) may be different in brain structure. In the present study,we performed voxel-based morphometry(VBM) to quantify the grey matter volumes in 23 patients with bipolar I depressive disorder(BP1) and 23 patients with UD,and 23 age-,gender-,and educationmatched healthy controls(HCs) using magnetic resonance imaging. We found that compared with the HC and UD groups,the BP1 group showed reduced grey matter volumes in the right inferior frontal gyrus and middle cingulate gyrus,while the UD group showed reduced volume in the right inferior frontal gyrus compared to HCs. In addition,correlation analyses revealed that the grey matter volumes of these regions were negatively correlated with the Hamilton depression rating scores. Taken together,the results of our study suggest that decreased grey matter volume of the right inferior frontal gyrus is a common abnormality in BP1 and UD,and decreasedgrey matter volume in the right middle cingulate gyrus may be specifi c to BP1. 展开更多
关键词 bipolar depressive disorder unipolar depressive disorder prefrontal cortex cingulate gyrus voxel-based morphometry
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Coexistence of unipolar and bipolar modes in Ag/ZnO/Pt resistive switching memory with oxygen-vacancy and metal-Ag filaments 被引量:1
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作者 马寒露 王中强 +5 位作者 徐海阳 张磊 赵晓宁 韩曼舒 马剑钢 刘益春 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第12期418-423,共6页
In this study, the unipolar resistive switching (URS) and bipolar resistive switching (BRS) are demonstrated to be coexistent in the Ag/ZnO/Pt memory device, and both modes are observed to strongly depend on the p... In this study, the unipolar resistive switching (URS) and bipolar resistive switching (BRS) are demonstrated to be coexistent in the Ag/ZnO/Pt memory device, and both modes are observed to strongly depend on the polarity of forming voltage. The mechanisms of the URS and BRS behaviors could be attributed to the electric-field-induced migration of oxygen vacancies (Vo) and metal-Ag conducting filaments (CFs) respectively, which are confirmed by investigating the temperature dependences of low resistance states in both modes. Furthermore, we compare the resistive switching (RS) characteristics (e.g., forming and switching voltages, reset current and resistance states) between these two modes based on Vo- and Ag-CFs. The BRS mode shows better switching uniformity and lower power than the URS mode. Both of these modes exhibit good RS performances, including good retention, reliable cycling and high-speed switching. The result indicates that the coexistence of URS and BRS behaviors in a single device has great potential applications in future nonvolatile multi-level memory. 展开更多
关键词 resistive switching UNIPOLAR BIPOLAR oxygen vacancy METAL conductive filament
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Differences in Non-suicidal Self-injury Behaviors between Unipolar Depression and Bipolar Depression in Adolescent Outpatients 被引量:1
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作者 Ting-wei WANG Jian GONG +9 位作者 Yang WANG Zhen LIANG Ke-liang PANG Jie-si WANG Zhi-guo ZHANG Chun-yan ZHANG Yue ZHOU Jun-chang LI Yan-ni WANG Yong-jie ZHOU 《Current Medical Science》 SCIE CAS 2023年第5期998-1004,共7页
Objective Non-suicidal self-injury(NSSI)has a higher prevalence in adolescents with depressive disorders than in community adolescents.This study examined the differences in NSSI behaviors between adolescents with uni... Objective Non-suicidal self-injury(NSSI)has a higher prevalence in adolescents with depressive disorders than in community adolescents.This study examined the differences in NSSI behaviors between adolescents with unipolar depression(UD)and those with bipolar depression(BD).Methods Adolescents with UD or BD were recruited from 20 general or psychiatric hospitals across China.The methods,frequency,and function of NSSI were assessed by Functional Assessment of Self-Mutilation.The Beck Suicide Ideation Scale was used to evaluate adolescents’suicidal ideation,and the 10-item Kessler Psychological Distress Scale to estimate the anxiety and depression symptoms.Results The UD group had higher levels of depression(19.16 vs.17.37,F=15.23,P<0.001)and anxiety symptoms(17.73 vs.16.70,F=5.00,P=0.026)than the BD group.Adolescents with BD had a longer course of NSSI than those with UD(2.00 vs.1.00 year,Z=−3.39,P=0.001).There were no statistical differences in the frequency and the number of methods of NSSI between the UD and BD groups.Depression(r=0.408,P<0.01)and anxiety(r=0.391,P<0.01)were significantly and positively related to NSSI frequency.Conclusion Adolescents with BD had a longer course of NSSI than those with UD.More importantly,NSSI frequency were positively and strongly correlated with depression and anxiety symptoms,indicating the importance of adequate treatment of depression and anxiety in preventing and intervening adolescents’NSSI behaviors. 展开更多
关键词 non-suicidal self-injury unipolar depression bipolar depression DEPRESSION ANXIETY ADOLESCENT
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Enhanced unipolar electrical fatigue resistance and related mechanism in grain-oriented Pb(Mg_(1/3)Nb_(2/3))O_(3)-Pb(Zr,Ti)O_(3)piezoceramics 被引量:1
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作者 Linjing Liu Bin Yang +7 位作者 Rui Lv Qiangwei Kou Shuai Yang Hang Xie Yuan Sun Yunfei Chang Shan-Tao Zhang Fei Li 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第14期40-47,共8页
Piezoceramics with high and fatigue-resisted piezoelectric properties are strongly desired for actuator ap-plications.In this work,textured Pb(Mg_(1/3)Nb_(2/3))O_(3)-Pb(Zr,Ti)O_(3)ceramics with Lotgering factor F_(001... Piezoceramics with high and fatigue-resisted piezoelectric properties are strongly desired for actuator ap-plications.In this work,textured Pb(Mg_(1/3)Nb_(2/3))O_(3)-Pb(Zr,Ti)O_(3)ceramics with Lotgering factor F_(001)∼98%were fabricated by templated grain growth technique.Strong[001]c-grain orientation(f∼90%and r∼0.22)of the textured ceramics effectively produced about 230%enhanced piezoelectric coefficient d_(33)^(∗)(i.e.,S_(max)/E_(max))and substantially improved unipolar electrical fatigue resistance.Unipolar polarization P max and d_(33)^(∗)of the textured ceramics were nearly maintained up to 106 unipolar cycles,while 19%and 14%degradations were respectively observed from randomly oriented counterparts.Especially,normal-ized d_(33)^(∗)of the textured ceramics shows better unipolar fatigue resistance than those of piezoceramics reported previously.Much lower bipolar strain asymmetryγs(∼4%)was observed from the textured samples fatigued after 106 unipolar cycles as compared toγs∼23%for randomly oriented counterparts.While charged defect accumulation model described the serious fatigue deteriorations in randomly ori-ented ceramics,the current work revealed that substantially enhanced unipolar fatigue resistance of the textured ceramics is mainly associated with the inherent fatigue anisotropy,weakened local bias fields owing to both enhanced domain mobility and lower defect density near grain boundaries/interfaces,and increased intrinsic contribution due to more tetragonal content.These superior characteristics suggest the great potential of textured ceramics for high-performance and robust actuator applications. 展开更多
关键词 CERAMICS Grain orientation Piezoelectric strain Unipolar fatigue Defect accumulation
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Bipolar spectrum: Relevant psychological and biological factors 被引量:1
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作者 Takeshi Terao 《World Journal of Psychiatry》 SCIE 2012年第5期71-73,共3页
The bipolar spectrum is a concept which bridges bipolar Ⅰ disorder and unipolar depression. As Kraepelin described, there may be continuity across mood disorders. If this is the case, why should we discriminate for d... The bipolar spectrum is a concept which bridges bipolar Ⅰ disorder and unipolar depression. As Kraepelin described, there may be continuity across mood disorders. If this is the case, why should we discriminate for drug choice? For example, it is generally accepted that mood stabilizers should be used for the bipolar spectrum, whereas antidepressants are for unipolar depression. If these disorders are diagnostically continuous, it is possible that the same drug could be effective in treating both bipolar Ⅰ disorder/spectrum and unipolar depression. To resolve this question, I would like to propose my hypothesis that there is an inflexion point which constitutes the boundary between the bipolar spectrum and unipolar depression. It is likely that this inflexion point consists of temperaments as, reportedly, there are many significant differences in the presence of various temperaments between the bipolar spectrum(bipolar Ⅱ, Ⅱ1/2 and Ⅳ) and unipolar depression. These findings suggest that temperaments could draw a boundary between the bipolar spectrum and unipolar depression. Moreover, it has been shown that certain temperaments may be associated with several biological factors and may be associated with drug response. As such, whilst the concept of the bipolar spectrum emphasizes continuity, it is the proposed inflexion point that discriminates drug responses between the bipolar spectrum and unipolar depression. At the moment, although hypothetical, I consider this idea worthy of further research. 展开更多
关键词 BIPOLAR DISORDER UNIPOLAR depression BIPOLAR spectrum TEMPERAMENT SEROTONIN Light
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Mood Spectrum Model:Evidence reconsidered in the light of DSM-5 被引量:1
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作者 Antonella Benvenuti Mario Miniati +3 位作者 Antonio Callari Michela Giorgi Mariani Mauro Mauri Liliana Dell’Osso 《World Journal of Psychiatry》 SCIE 2015年第1期126-137,共12页
AIM: to investigate studies conducted with the Mood Spectrum Structured Interviews and Self-Report versions(SCI-MOODS and MOODS-SR).METHODS: We conducted a review of studies published between 1997 and August 2014. The... AIM: to investigate studies conducted with the Mood Spectrum Structured Interviews and Self-Report versions(SCI-MOODS and MOODS-SR).METHODS: We conducted a review of studies published between 1997 and August 2014. The search was performed using Pubmed and Psyc INFO databases. Analysis of the papers followed the inclusion and exclusion criteria recommended by the PRISMA Guidelines, namely:(1) articles that presented a combination of at least two terms, "SCI-MOODS" [all fields] or "MOODS-SR" [all fields] or "mood spectrum" [all fields];(2) manuscript in English;(3) original articles; and(4) prospective or retrospective original studies(analytical or descriptive), experimental or quasi-experimental studies. Exclusion criteria were:(1) other study designs(case reports, case series, and reviews);(2) non-original studies including editorials, book reviews and letters to the editor; and(3) studies not specifically designed and focused on SCI-MOODS or MOODS-SR.RESULTS: The search retrieved 43 papers, including 5 reviews of literature or methodological papers, and 1 case report. After analyzing their titles and abstracts, according to the eligibility criteria, 6 were excluded and 37 were chosen and included. The SCI-MOODS and the MOODS-SR have been tested in published studies involving 52 different samples across 4 countries(Italy, United States, Spain and Japan). The proposed mood spectrum approach has demonstrated its usefulness mainly in 3 different areas:(1) Patients with the socalled "pure" unipolar depression that might manifest hypomanic atypical and/or sub-threshold aspects systematically detectable with the mood questionnaire;(2) Spectrum features not detected by other instruments are clinically relevant, because they might manifest in waves during the lifespan, sometimes together, sometimes alone, sometimes reaching the severity for a full-blown disorder, sometimes interfering withother mental disorders or complicating the course of somatic diseases; and(3) Higher scores on the MOODSSR factors assessing "psychomotor disturbances","mixed instability" and "suicidality" delineate subtypes of patients characterized by the more severe forms of mood disorders, the higher risk for psychotic symptoms,and the lower quality of life after the remission of the full-blown-episode.CONCLUSION: The mood spectrum model help researchers and clinicians in the systematic assessment of those areas of psychopathology that are still neglected by the Diagnostic and Statistical Manual of Mental Disorders 5classification. 展开更多
关键词 MOOD DISORDERS Dimensional CATEGORICAL UNIPOLAR SPECTRUM Bipolar Diagnostic and Statistical Manual of MENTAL DISORDERS 5
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Reduction of Unipolar Leakage Flux and Torque Ripple in Consequent-pole PM Vernier Machine 被引量:1
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作者 Liang Xu Yang Li +1 位作者 Wenxiang Zhao Guohai Liu 《CES Transactions on Electrical Machines and Systems》 CSCD 2023年第1期35-44,共10页
This paper proposes a new consequent-pole permanent magnet vernier machine(CPMVM),which can be regarded as a combination of two conventional CPMVM with opposite polarities.Based on the simplified axial magnetic circui... This paper proposes a new consequent-pole permanent magnet vernier machine(CPMVM),which can be regarded as a combination of two conventional CPMVM with opposite polarities.Based on the simplified axial magnetic circuit model,it is verified that the proposed CPMVM can reduce the unipolar leakage flux.In order to reduce the torque ripple of machine and improve the output torque of machine,the flux barrier is placed on the rotor of the proposed machine.Then,the parameters of the proposed CPMVM are optimized and determined.Moreover,the electromagnetic performance,including no-load air-gap flux density,average torque and torque ripple,flux linkage,back-electromotive force,cogging torque,average torque,torque ripple,power factor and loss,is compared with conventional surface-mounted permanent magnet vernier machine(SPMVM)and CPMVM.Finally,it is demonstrated that proposed CPMVM with flux barrier can effectively reduce the unipolar leakage flux and greatly reduce the torque ripple of machine.Also,compared with the SPMVM,the proposed CPMVM with flux barrier saves more than 45%of the permanent magnet material without reducing output torque. 展开更多
关键词 Consequent-pole Permanent magnet vernier machine Unipolar leakage flux Torque ripple Flux barrier Output torque
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PHOTOACOUSTIC GENERATION OF FOCUSED QUASI-UNIPOLAR PRESSURE PULSES
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作者 KONSTANTIN MASLOV HAO F.ZHANG LIHONG V.WANG 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2010年第4期247-253,共7页
The photoacoustic effect was employed to generate short-duration quasi-unipolar acoustic pressure pulses in both planar and spherically focused geometries.In the focal region,the temporal profile of a pressure pulse c... The photoacoustic effect was employed to generate short-duration quasi-unipolar acoustic pressure pulses in both planar and spherically focused geometries.In the focal region,the temporal profile of a pressure pulse can be approximated by the first derivative of the temporal profile near the front transducer surface,with a time-averaged value equal to zero.This approximation agreed with experimental results acquired from photoacoustic transducers with both rigid and free boundaries.For a free boundary,the acoustic pressure in the focal region is equal to the sum of a positive pressure that follows the spatial profile of the optical energy deposition in the medium and a negative pressure that follows the temporal profile of the laser pulse. 展开更多
关键词 PHOTOACOUSTICS optoacoustics ultrasound generation unipolar pulse
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Coexistence of Bipolar and Unipolar Resistive Switching Behavior in Ag/ZnMn_2O_4/p^+-Si Device
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作者 ZHANG Yupei WANG Hua 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第6期1433-1436,共4页
ZnMn_2O_4 thin films were deposited by a sol-gel technique onto a p+-Si substrate, and a RRAM device with the Ag/ZnMn_2O_4/p^+-Si structure was fabricated. The microstructure of ZnMn_2O_4 films and the resistive switc... ZnMn_2O_4 thin films were deposited by a sol-gel technique onto a p+-Si substrate, and a RRAM device with the Ag/ZnMn_2O_4/p^+-Si structure was fabricated. The microstructure of ZnMn_2O_4 films and the resistive switching behavior of Ag/ZnMn_2O_4/p^+-Si device were investigated. ZnMn_2O_4 thin films had a spinel structure after annealing at 650 °C for 1 h. The Ag/ZnMn_2O_4/p^+-Si device showed unipolar and/or bipolar resistive switching behavior, exhibiting different ION/IOFF ratio and switching endurance properties. In bipolar resistive switching, high-resistance-state(HRS) conduction was dominated by the space-charge-limited conduction mechanism, whereas the filament conduction mechanism dictated the low resistance state(LRS). For unipolar resistive switching, HRS and LRS were controlled by the filament conduction mechanism. For bipolar resistive switching, the conduction process can be explained by the space-charge region of the p-n junction. 展开更多
关键词 ZnMn2O4 resistive switching behavior BIPOLAR UNIPOLAR
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SPICE modeling of flux-controlled unipolar memristive devices
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作者 方旭东 唐玉华 +3 位作者 吴俊杰 朱玄 周静 黄达 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第7期596-601,共6页
Unipolar memristive devices are an important kind of resistive switching devices. However, few circuit models of them have been proposed. In this paper, we propose the SPICE modeling of flux-controlled unipolar memris... Unipolar memristive devices are an important kind of resistive switching devices. However, few circuit models of them have been proposed. In this paper, we propose the SPICE modeling of flux-controlled unipolar memristive devices based on the memristance versus state map. Using our model, the flux thresholds, ON and OFF resistance, and compliance current can easily be set as model parameters. We simulate the model in HSPICE using model parameters abstracted from real devices, and the simulation results show that the proposed model caters to the real device data very well, thus demonstrating that the model is correct. Using the same modeling methodology, the SPICE model of charge-controlled unipolar memristive devices could also be developed. The proposed model could be used to model resistive memory cells, logical gates as well as synapses in artificial neural networks. 展开更多
关键词 unipolar memristive devices memristive SPICE model
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Comparison of performance between bipolar and unipolar double-frequency sinusoidal pulse width modulation in a digitally controlled H-bridge inverter system
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作者 雷博 肖国春 吴旋律 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第6期277-284,共8页
By deriving the discrete-time models of a digitally controlled H-bridge inverter system modulated by bipolar sinu- soidal pulse width modulation (BSPWM) and unipolar double-frequency sinusoidal pulse width modulati... By deriving the discrete-time models of a digitally controlled H-bridge inverter system modulated by bipolar sinu- soidal pulse width modulation (BSPWM) and unipolar double-frequency sinusoidal pulse width modulation (UDFSPWM) respectively, the performances of the two modulation strategies are analyzed in detail. The circuit parameters, used in this paper, are fixed. When the systems, modulated by BSPWM and UDFSPWM, have the same switching frequency, the stabil- ity boundaries of the two systems are the same. However, when the equivalent switching frequencies of the two systems are the same, the BSPWM modulated system is more stable than the UDFSPWM modulated system. In addition, a convenient method of establishing the discrete-time model of piecewise smooth system is presented. Finally, the analytical results are confirmed by circuit simulations and experimental measurements. 展开更多
关键词 bipolar sinusoidal pulse width modulation (SPWM) unipolar double-frequency SPWM H-bridgeinverter discrete-time model
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Numerical Study of Pulsed Dielectric Barrier Discharge at Atmospheric Pressure Under the Needle-Plate Electrode Configuration
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作者 王艳辉 叶换换 +3 位作者 张佼 王奇 张杰 王德真 《Plasma Science and Technology》 SCIE EI CAS CSCD 2016年第5期478-484,共7页
In this paper, we study the characteristics of atmospheric-pressure pulsed dielectric barrier discharge (DBD) under the needle-plate electrode configuration using a one-dimensional self-consistent fluid model. The r... In this paper, we study the characteristics of atmospheric-pressure pulsed dielectric barrier discharge (DBD) under the needle-plate electrode configuration using a one-dimensional self-consistent fluid model. The results show that, the DBDs driven by positive pulse, negative pulse and bipolar pulse possess different behaviors. Moreover, the two discharges appearing at the rising and the falling phases of per voltage pulse also have different discharge regimes. For the case of the positive pulse, the breakdown field is much lower than that of the negative pulse, and its propagation characteristic is different from the negative pulse DBD. When the DBD is driven by a bipolar pulse voltage, there exists the interaction between the positive and negative pulses, resulting in the decrease of the breakdown field of the negative pulse DBD and causing the change of the discharge behaviors. In addition, the effects of the discharge parameters on the behaviors of pulsed DBD in the needle-plate electrode configuration are also studied. 展开更多
关键词 dielectric barrier discharge unipolar pulsed voltage bipolar pulsed voltage needle-plate electrode numerical modeling GLOW-DISCHARGE
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Bias polarity-dependent unipolar switching behavior in NiO/SrTiO_3 stacked layer
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作者 Xian-Wen Sun Cai-Hong Jia +2 位作者 Xian-Sheng Liu Guo-Qiang Li Wei-Feng Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第4期420-425,共6页
The identification of the switching location has been a key technology to tune the physical properties of unipolar resistive switching(RS) cells.Here we report the RS properties of Au/Ni O/Sr Ti O3(STO)/Pt memory ... The identification of the switching location has been a key technology to tune the physical properties of unipolar resistive switching(RS) cells.Here we report the RS properties of Au/Ni O/Sr Ti O3(STO)/Pt memory cells.The switching repeatability is closely related to the applied bias polarity,which is different from the scenario of the Au/STO/Pt cells reported in our previous researches.The high resistance in positive bias is greater than that in negative bias.The R(T)–R0I^2 R(T) plot of the on-state I–V curve shows a regular shape only with a slight bend and an abnormal shape with an abrupt increase and decrease under negative and positive bias,respectively.These comparative experimental results reveal that the conductance filament consisting of oxygen vacancies grows from the cathode to the anode.The spatial RS location is identified with the weaker part along the conductance filament length direction,which should be near the Ni O/STO interface and STO/Pt interface under positive and negative bias,respectively. 展开更多
关键词 SrTiO3 thin film unipolar resistive switching oxygen vacancies
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