期刊文献+
共找到372,436篇文章
< 1 2 250 >
每页显示 20 50 100
基于Valued ERGMs模型的核心技术网络成长机制研究——以量子计算领域为例 被引量:2
1
作者 任海英 李真 《科技进步与对策》 CSSCI 北大核心 2024年第4期1-11,共11页
对核心技术网络及其成长机制的研究有助于梳理核心技术之间的依赖和促进关系,为研究核心技术演化提供新的理论视角和方法。以技术演化相关理论为基础,归纳核心技术网络成长的影响因素,基于量子计算领域专利数据,识别以技术概念和技术关... 对核心技术网络及其成长机制的研究有助于梳理核心技术之间的依赖和促进关系,为研究核心技术演化提供新的理论视角和方法。以技术演化相关理论为基础,归纳核心技术网络成长的影响因素,基于量子计算领域专利数据,识别以技术概念和技术关系为基础的量子计算领域核心技术网络,并基于Valued ERGMs模型构建核心技术网络成长机制模型。结果表明,技术要素中心性、专利技术研发能力、与TRIZ进化法则匹配程度以及技术要素同配性对核心技术网络成长具有正向促进作用;在技术路径方面,核心技术网络成长受到技术要素路径依赖性和技术突破的双重影响。最后,根据量子计算领域核心技术网络成长机制的实证研究结果,从技术研发层面、企业层面、政府层面为相关领域技术发展提出策略建议。 展开更多
关键词 技术演化 核心技术网络 技术网络成长机制 valued ERGMs模型 量子计算
下载PDF
弹性退休制度下谁更愿意延迟退休?——基于Option Value模型的微观模拟
2
作者 郭秀云 李悦心 《人口与发展》 CSSCI 北大核心 2024年第4期132-144,共13页
人口老龄化背景下延迟退休年龄、建立弹性退休制度是大势所趋。养老金激励是弹性退休制度的重要内容。建立期权价值模型和养老金给付及奖惩因子模型,基于中国家庭收入调查项目(CHIP2018)的数据,对不同特征人群的养老金峰值、期权价值、... 人口老龄化背景下延迟退休年龄、建立弹性退休制度是大势所趋。养老金激励是弹性退休制度的重要内容。建立期权价值模型和养老金给付及奖惩因子模型,基于中国家庭收入调查项目(CHIP2018)的数据,对不同特征人群的养老金峰值、期权价值、内部报酬率进行模拟。研究发现:养老金总财富随退休年龄“先增后减”,男性的峰值年龄早于女性;引入养老金“奖惩”机制有助于提高最优退休年龄,激励劳动者延迟退休;考虑闲暇偏好的异质性,男性参保者更倾向于早退休,而女性参保者特别是女性较高收入群体更愿意延迟退休;厌恶风险的参保者更有可能选择早退休。建议尽早建立弹性退休年龄政策体系,增加劳动者的选择权和制度灵活性;引入精算调节因子构建养老金奖惩机制,完善养老保险待遇计发办法。 展开更多
关键词 延迟退休 养老金财富 Option value模型
下载PDF
Five New MVL Current Mode Differential Absolute Value Circuits Based on Carbon Nano-tube Field Effect Transistors(CNTFETs) 被引量:2
3
作者 Mojtaba Jamalizadeh Fazel Sharifi +2 位作者 Mohammad Hossein Moaiyeri Keivan Navi Omid Hashemipour 《Nano-Micro Letters》 SCIE EI CAS 2010年第4期227-234,共8页
Carbon Nano-Tube Field Effect Transistors(CNTFETs) are being widely studied as possible successors to silicon MOSFETs.Using current mode has many advantages such as performing sum operation by means of a simple wired ... Carbon Nano-Tube Field Effect Transistors(CNTFETs) are being widely studied as possible successors to silicon MOSFETs.Using current mode has many advantages such as performing sum operation by means of a simple wired connection.Also,direction of the current can be used to exhibit the sign of digits.It is expected that the advantages of current mode approaches will become even more important with increased speed requirements and decreased supply voltage.In this paper,we present five new circuit designs for differential absolute value in current mode logic which have been simulated by CNTFET model.The considered base current for this model is 2 μA and supply voltage is 0.9 V.In all of our designs we used N-type CNTFET current mirrors which operate as truncated difference circuits.The operation of Differential Absolute Value circuit calculates the difference between two input currents and our circuit designs are operate in 8 logic levels. 展开更多
关键词 CNTFET current mode Truncated difference Differential absolute value
下载PDF
A novel method to calculate the thrust of linear induction motor based on instantaneous current value 被引量:2
4
作者 Jiaqing MA Yunpeng ZHU Jing JIANG 《Journal of Modern Transportation》 2012年第2期76-81,共6页
Because of the end effect, a linear induction motor (LIM) runs in an asymmetrical state even though the winding of each phase is symmetric. Based on the basic principle of the LIM, a new approach was proposed to cal... Because of the end effect, a linear induction motor (LIM) runs in an asymmetrical state even though the winding of each phase is symmetric. Based on the basic principle of the LIM, a new approach was proposed to calculate the thrust of the LIM using the instantaneous current value. A three-phase LIM model with 12 slots and a singlelayer winding was designed to validate this method. The experiments show that when the current is small, the calculated results basically agree with the experiments. The agreement becomes worse with the increase of the current because of the saturation of the primary iron core. The proposed formula is suitable when the iron core of the LIM primary is in an unsaturated state. 展开更多
关键词 linear induction motor (LIM) asymmetrical state instantaneous current value
下载PDF
Value of Topology Approach to Diagnose of CAD Based on Magnetocardiographic Current Distribution Maps in Difficult-to-Diagnose Patients 被引量:2
5
作者 I. Chaikovsky L. Stadnyuk +5 位作者 A. Verba Yu. Vasetskyi M. Budnyk G. Mjasnikov A. Kazmirchuk A. Lomakovskyi 《World Journal of Cardiovascular Diseases》 2016年第7期235-245,共12页
Objective: The purpose of this work is to examine the usefulness of the topological approach for analysis of current density maps during ST-T interval in detection of coronary artery disease (CAD) in patients with pro... Objective: The purpose of this work is to examine the usefulness of the topological approach for analysis of current density maps during ST-T interval in detection of coronary artery disease (CAD) in patients with proved CAD but normal results of routine tests. Materials and Methods: The patient group included 123 patients. Coronary angiography was done due to chest pain. The control group consisted of 124 healthy volunteers. The MCG test was done by 4-channels MCG system installed at unshielded setting. An integral topological index Kideal, consisting of 4 parameters, has been counted. Results and Conclusions: It is shown that Kideal was higher in patient group compared to control one. Sensitivity was 87%, and specificity was 64%. The topological analysis of MCG current density maps is a valuable tool in noninvasive detection of CAD in difficult-to-diagnose patients with uninformative results of routine tests. 展开更多
关键词 MAGNETOCARDIOGRAPHY Coronary Artery Disease current Distribution Difficult-to-Diagnose Patients Topology Parameters
下载PDF
Catalytic conversion of CO_2 to value added fuels: Current status, challenges, and future directions 被引量:3
6
作者 Jingjie Wu Xiao-Dong Zhou 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第7期999-1015,共17页
The electrochemical reduction of C02 into liquid fuels especially coupling with the intermittent renewable electricity offers a promising means of storing electricity in chemical form, which reduces the dependence on ... The electrochemical reduction of C02 into liquid fuels especially coupling with the intermittent renewable electricity offers a promising means of storing electricity in chemical form, which reduces the dependence on fossil fuels and mitigates the negative impact of anthropogenic C02 emissions on the planet. Although converting CO2 to fuels is not in itself a new concept, the field has not sub- stantially advanced in the last 30 years primarily because of the challenge of discovery of structural electrocatalysts and the development of membrane architectures for efficient collection of reactants and separation of products. This overview summarizes recent advances in catalytic conversion of CO2 and presents the challenges and future directions in producing value-added fuels. 展开更多
关键词 value added fuelsElectrocatalystsCatalytic conversionCarbon dioxideDurability
下载PDF
Temperature Stimulation of Effective Value of Density of the Current of Semiconductor Solar Cells
7
作者 Aliev Rayimjon Ikromov Rustamjon Gulomjonovich Alinazarova Mahfuza Alisherovna 《Energy and Power Engineering》 2019年第2期92-97,共6页
Influence of temperature on effective value of a current density of a semiconductor solar cell is investigated. New equations for explanation of dependence of photovoltaic characteristics of solar cell from temperatur... Influence of temperature on effective value of a current density of a semiconductor solar cell is investigated. New equations for explanation of dependence of photovoltaic characteristics of solar cell from temperature are received. 展开更多
关键词 SEMICONDUCTOR Solar Сell Effective value of a current TEMPERATURE DEPENDENCE of PHOTOVOLTAIC Parameters PHOTOVOLTAIC Characteristics
下载PDF
Complex Valued Recurrent Neural Network: From Architecture to Training 被引量:1
8
作者 Alexey Minin Alois Knoll Hans-Georg Zimmermann 《Journal of Signal and Information Processing》 2012年第2期192-197,共6页
Recurrent Neural Networks were invented a long time ago, and dozens of different architectures have been published. In this paper we generalize recurrent architectures to a state space model, and we also generalize th... Recurrent Neural Networks were invented a long time ago, and dozens of different architectures have been published. In this paper we generalize recurrent architectures to a state space model, and we also generalize the numbers the network can process to the complex domain. We show how to train the recurrent network in the complex valued case, and we present the theorems and procedures to make the training stable. We also show that the complex valued recurrent neural network is a generalization of the real valued counterpart and that it has specific advantages over the latter. We conclude the paper with a discussion of possible applications and scenarios for using these networks. 展开更多
关键词 COMPLEX valueD NEURAL NETWORKS COMPLEX valueD System Identification REcurrent NEURAL NETWORKS COMPLEX valueD REcurrent NEURAL NETWORKS
下载PDF
Current Situation and Reasonable Construction of Consumption Value of Rural Residents in Kongpo
9
作者 Shuang QI Xuelin YAO Lianjiu SONG 《Asian Agricultural Research》 2014年第12期79-81,84,共4页
On the basis of analyzing the consumption status of rural residents in Kongpo,it can be seen that the concept of consumption value of rural residents in Kongpo tends to be cautious in daily consumption. There also exi... On the basis of analyzing the consumption status of rural residents in Kongpo,it can be seen that the concept of consumption value of rural residents in Kongpo tends to be cautious in daily consumption. There also exist premature consumption and excessive consumption that are centralized,seasonal and religious. This paper aims to put forward countermeasures and suggestions for guiding the rural residents in Kongpo to develop a scientific concept of consumption value in the light of the factors that restrict the formation of scientific consumption value among rural residents. 展开更多
关键词 Kongpo RURAL RESIDENTS CONSUMPTION value
下载PDF
On the functions of astrocyte-mediated neuronal slow inward currents 被引量:2
10
作者 Balázs Pál 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第12期2602-2612,共11页
Slow inward currents are known as neuronal excitatory currents mediated by glutamate release and activation of neuronal extra synaptic N-met hyl-D-aspartate receptors with the contribution of astrocytes.These events a... Slow inward currents are known as neuronal excitatory currents mediated by glutamate release and activation of neuronal extra synaptic N-met hyl-D-aspartate receptors with the contribution of astrocytes.These events are significantly slower than the excitatory postsynaptic currents.Parameters of slow inward currents are determined by seve ral factors including the mechanisms of astrocytic activation and glutamate release,as well as the diffusion pathways from the release site towards the extra synaptic recepto rs.Astrocytes are stimulated by neuronal network activity,which in turn excite neurons,forming an astrocyte-neuron feedback loop.Mostly as a consequence of brain edema,astrocytic swelling can also induce slow inward currents under pathological conditions.There is a growing body of evidence on the roles of slow inward currents on a single neuron or local network level.These events often occur in synchro ny on neurons located in the same astrocytic domain.Besides synchronization of neuronal excitability,slow inward currents also set synaptic strength via eliciting timing-dependent synaptic plasticity.In addition,slow inward currents are also subject to non-synaptic plasticity triggered by long-la sting stimulation of the excitatory inputs.Of note,there might be important regionspecific differences in the roles and actions triggering slow inward currents.In greater networks,the pathophysiological roles of slow inward currents can be better understood than physiological ones.Slow inward currents are identified in the pathophysiological background of autism,as slow inward currents drive early hypersynchrony of the neural networks.Slow inward currents are significant contributors to paroxysmal depolarizational shifts/interictal spikes.These events are related to epilepsy,but also found in Alzheimer's disease,Parkinson's disease,and stroke,leading to the decline of cognitive functions.Events with features overlapping with slow inward currents(excitatory,N-methyl-Daspartate-receptor mediated currents with astrocytic contribution) as ischemic currents and spreading depolarization also have a well-known pathophysiological role in worsening consequences of stroke,traumatic brain injury,or epilepsy.One might assume that slow inward currents occurring with low frequency under physiological conditions might contribute to synaptic plasticity and memory formation.However,to state this,more experimental evidence from greater neuronal networks or the level of the individual is needed.In this review,I aimed to summarize findings on slow inward currents and to speculate on the potential functions of it. 展开更多
关键词 ASTROCYTE cortical spreading depolarization gliotransmission GLUTAMATE neural synchronization NMDA receptor paroxysmal depolarizational shift slow inward current
下载PDF
Evaluation of the value of combined detection of tumor markers CA724,carcinoembryonic antigen,CA242,and CA19-9 in gastric cancer 被引量:1
11
作者 Chong-Mei Zhou Shao-Hua Zhao 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第5期1737-1744,共8页
BACKGROUND Gastric cancer is a global health concern that poses a significant threat to human well-being.AIM To detecting serum changes in carcinoembryonic antigen(CEA),carbohydrate antigens(CA)724,CA242,and CA19-9 ex... BACKGROUND Gastric cancer is a global health concern that poses a significant threat to human well-being.AIM To detecting serum changes in carcinoembryonic antigen(CEA),carbohydrate antigens(CA)724,CA242,and CA19-9 expression among patients with gastric cancer.METHODS Eighty patients diagnosed with gastric cancer between January 2020 and January 2023 were included in the observation group,while 80 patients with benign gastric diseases were included in the control group.Both groups were tested for tumor markers(CA724,CEA,CA242,and CA19-9].Tumor marker indicators(CA724,CEA,CA242,and CA19-9)were compared between the two groups,assessing positive rates of tumor markers across various stages in the observation group.Additionally,single and combined detection of various tumor markers were examined.RESULTS The sensitivity,specificity,accuracy,positive predictive value,and negative predictive value observed for the combined detection of CA724,CEA,CA242,and CA19-9 were higher than those of CA724,CEA,CA242,and CA19-9 individually.Therefore,the combined detection of CA724,CEA,CA242,and CA19-9 has a high diagnostic accuracy and could reduce the occurrence of missed or misdiagnosed cases,facilitating the early diagnosis and treatment of patients.CONCLUSION CA724,CEA,CA242,and CA19-9 serum levels in gastric cancer patients significantly surpassed those in non-gastric cancer patients(P<0.05).Their combined detection can improve the diagnostic accuracy for gastric cancer,warranting clinical promotion. 展开更多
关键词 Biomarkers SERUM Gastric cancer Diagnostic value
下载PDF
Improving the nutritional values of yellow mealworm Tenebrio molitor(Coleoptera: Tenebrionidae) larvae as an animal feed ingredient: a review 被引量:1
12
作者 Linggawastu Syahrulawal Magnhild Oust Torske +2 位作者 Rumakanta Sapkota Geir Næss Prabhat Khanal 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第1期35-52,共18页
Yellow mealworm larvae(YML;Tenebrio molitor) are considered as a valuable insect species for animal feed due to their high nutritional values and ability to grow under different substrates and rearing conditions. Adva... Yellow mealworm larvae(YML;Tenebrio molitor) are considered as a valuable insect species for animal feed due to their high nutritional values and ability to grow under different substrates and rearing conditions. Advances in the understanding of entomophagy and animal nutrition over the past decades have propelled research areas toward testing multiple aspects of YML to exploit them better as animal feed sources. This review aims to summarize various approaches that could be exploited to maximize the nutritional values of YML as an animal feed ingredient. In addition, YML has the potential to be used as an antimicrobial or bioactive agent to improve animal health and immune function in production animals. The dynamics of the nutritional profile of YML can be influenced by multiple factors and should be taken into account when attempting to optimize the nutrient contents of YML as an animal feed ingredient. Specifically, the use of novel land-based and aquatic feeding resources, probiotics, and the exploitation of larval gut microbiomes as novel strategies can assist to maximize the nutritional potential of YML. Selection of relevant feed supplies, optimization of ambient conditions, the introduction of novel genetic selection procedures, and implementation of effective post-harvest processing may be required in the future to commercialize mealworm production. Furthermore, the use of appropriate agricultural practices and technological improvements within the mealworm production sector should be aimed at achieving both economic and environmental sustainability. The issues highlighted in this review could pave the way for future approaches to improve the nutritional value of YML. 展开更多
关键词 Alternative protein source Feed application Nutritional value Yellow mealworm
下载PDF
Altered synaptic currents,mitophagy,mitochondrial dynamics in Alzheimer's disease models and therapeutic potential of Dengzhan Shengmai capsules intervention 被引量:1
13
作者 Binbin Zhao Dongfeng Wei +12 位作者 Qinghua Long Qingjie Chen Fushun Wang Linlin Chen Zefei Li Tong Li Tao Ma Wei Liu Linshuang Wang Caishui Yang Xiaxia Zhang Ping Wang Zhanjun Zhang 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2024年第3期348-370,共23页
Emerging research suggests a potential association of progression of Alzheimer's disease(AD)with alterations in synaptic currents and mitochondrial dynamics.However,the specific associations between these patholog... Emerging research suggests a potential association of progression of Alzheimer's disease(AD)with alterations in synaptic currents and mitochondrial dynamics.However,the specific associations between these pathological changes remain unclear.In this study,we utilized Aβ42-induced AD rats and primary neural cells as in vivo and in vitro models.The investigations included behavioural tests,brain magnetic resonance imaging(MRI),liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)analysis,Nissl staining,thioflavin-S staining,enzyme-linked immunosorbent assay,Golgi-Cox staining,transmission electron microscopy(TEM),immunofluorescence staining,proteomics,adenosine triphosphate(ATP)detection,mitochondrial membrane potential(MMP)and reactive oxygen species(ROS)assessment,mitochondrial morphology analysis,electrophysiological studies,Western blotting,and molecular docking.The results revealed changes in synaptic currents,mitophagy,and mitochondrial dynamics in the AD models.Remarkably,intervention with Dengzhan Shengmai(DZSM)capsules emerged as a pivotal element in this investigation.Aβ42-induced synaptic dysfunction was significantly mitigated by DZSM intervention,which notably amplified the frequency and amplitude of synaptic transmission.The cognitive impairment observed in AD rats was ameliorated and accompanied by robust protection against structural damage in key brain regions,including the hippocampal CA3,primary cingular cortex,prelimbic system,and dysgranular insular cortex.DZSM intervention led to increased IDE levels,augmented long-term potential(LTP)amplitude,and enhanced dendritic spine density and length.Moreover,DZSM intervention led to favourable changes in mitochondrial parameters,including ROS expression,MMP and ATP contents,and mitochondrial morphology.In conclusion,our findings delved into the realm of altered synaptic currents,mitophagy,and mitochondrial dynamics in AD,concurrently highlighting the therapeutic potential of DZSM intervention. 展开更多
关键词 Alzheimer's disease Synaptic currents MITOPHAGY Mitochondrial fusion and fission Dengzhan Shengmai capsules
下载PDF
Diagnostic value of serum vascular endothelial growth factor and interleukin-17 in primary hepatocellular carcinoma 被引量:1
14
作者 Qi Tian Hui Zeng +2 位作者 Qi-Quan Lu Hai-Ying Xie Yong Li 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第9期2934-2941,共8页
BACKGROUND Despite significant advancements in the medical treatment of primary hepato-cellular carcinoma(PHC)in recent years,enhancing therapeutic effects and im-proving prognosis remain substantial challenges worldw... BACKGROUND Despite significant advancements in the medical treatment of primary hepato-cellular carcinoma(PHC)in recent years,enhancing therapeutic effects and im-proving prognosis remain substantial challenges worldwide.AIM To investigate the expression levels of serum vascular endothelial growth factor(VEGF)and interleukin(IL)-17 in patients with PHC and evaluate their diagnostic value while exploring their relationship with patients’clinical characteristics.METHODS The study included 50 patients with confirmed PHC who visited Wuhan Han-yang Hospital from January 2021 to January 2022,and 50 healthy individuals from the same period served as the control group.Serum VEGF and IL-17 levels in both groups were measured by Enzyme-Linked Immunosorbent Assay,and their diagnostic value was assessed using receiver operating characteristic(ROC)curves.Pearson correlation analysis was performed to examine the relationship between serum VEGF and IL-17 levels.Pathological data of the PHC patients were analyzed to determine the relationship between serum VEGF and IL-17 levels and pathological characteristics.RESULTS Serum VEGF and IL-17 levels were significantly higher in the study group com-pared to the control group(P<0.05).No significant association was observed between serum VEGF and IL-17 levels and gender,age,combined cirrhosis,tumor diameter,or degree of differentiation(P>0.05).However,there was a significant relationship between clinical TNM stage,tumor metastasis,and serum VEGF and IL-17 levels(P<0.05).Correlation analysis revealed a positive correlation between serum VEGF and IL-17(P<0.05).ROC analysis demonstrated that both serum VEGF and IL-17 had good diagnostic efficacy for PHC.CONCLUSION Serum VEGF and IL-17 levels were significantly higher in PHC patients compared to healthy individuals.Their levels were closely related to pathological features such as tumor metastasis and clinical TNM stage,and there was a significant positive correlation between VEGF and IL-17.These biomarkers may serve as valuable reference in-dicators for the early diagnosis and treatment guidance of PHC. 展开更多
关键词 Primary liver cancer Vascular endothelial growth factor INTERLEUKIN-17 Serum level Diagnostic value Cor-relation
下载PDF
Comprehensive Evaluation of Flower Border Application Value of New and Superior Plants in Hefei Area 被引量:1
15
作者 MENG Yi ZHAO Zhiyan +1 位作者 LIANG Tingwu LU Zhaoliang 《Journal of Landscape Research》 2024年第2期69-71,76,共4页
An analytic hierarchy process(AHP)was employed to assess the applicability of 18 new and superior varieties of flowers in Hefei City flower border applications.A total of 12 indicators were selected from three distinc... An analytic hierarchy process(AHP)was employed to assess the applicability of 18 new and superior varieties of flowers in Hefei City flower border applications.A total of 12 indicators were selected from three distinct aspects of adaptability,ornamental characteristics and use traits,in order to establish a comprehensive evaluation model.The results demonstrate that grade I(J≥2.685)exhibits excellent application value,encompassing six species of plants,such asHydrangeamacrophylla‘Endless Summer’;grade II(2.684≤J≤2.420)is also of notable application value,encompassing five species of plants,such asCallistemonrigidus;grade III(2.419≤J≤2.615)is of average application value,including five species of plants,such asCrocosmiacrocosmiflora;grade IV(J≤2.16)is of relatively poor application value.The evaluation results may be utilized as a theoretical reference for the promotion of new and superior varieties in the flower border of Hefei. 展开更多
关键词 Analytic hierarchy process(AHP) New and superior variety Application value Comprehensive evaluation
下载PDF
Low-power high-speed interconnection networks in NOC using multi-valued current-mode techniques
16
作者 Hatami Aziz Navt Ketvan Dargahi Akbar 《通讯和计算机(中英文版)》 2009年第8期23-30,共8页
关键词 互连网络 电流模式 低功耗 超大规模集成电路 技术 多值 电子应用 增长速度
下载PDF
Predictive value of diaphragm ultrasound for mechanical ventilation outcome in patients with acute exacerbation of chronic obstructive pulmonary disease 被引量:1
17
作者 Lei-Lei Qu Wen-Ping Zhao +1 位作者 Ji-Ping Li Wei Zhang 《World Journal of Clinical Cases》 SCIE 2024年第26期5893-5900,共8页
BACKGROUND Acute exacerbation of chronic obstructive pulmonary disease(AECOPD)is often combined with respiratory failure,which increases the patient's morbidity and mortality.Diaphragm ultrasound(DUS)has developed... BACKGROUND Acute exacerbation of chronic obstructive pulmonary disease(AECOPD)is often combined with respiratory failure,which increases the patient's morbidity and mortality.Diaphragm ultrasound(DUS)has developed rapidly in the field of critical care in recent years.Studies with DUS monitoring diaphragm-related rapid shallow breathing index have demonstrated important results in guiding intensive care unit patients out of the ventilator.Early prediction of the indications for withdrawal of non-invasive ventilator and early evaluation of patients to avoid or reduce disease progression are very important.AIM To explore the predictive value of DUS indexes for non-invasive ventilation outcome in patients with AECOPD.METHODS Ninety-four patients with AECOPD who received mechanical ventilation in our hospital from January 2022 to December 2023 were retrospectively analyzed,and they were divided into a successful ventilation group(68 cases)and a failed ventilation group(26 cases)according to the outcome of ventilation.The clinical data of patients with successful and failed noninvasive ventilation were compared,and the independent predictors of noninvasive ventilation outcomes in AECOPD patients were identified by multivariate logistic regression analysis.RESULTS There were no significant differences in gender,age,body mass index,complications,systolic pressure,heart rate,mean arterial pressure,respiratory rate,oxygen saturation,partial pressure of oxygen,oxygenation index,or time of inspiration between patients with successful and failed mechanical ventilation(P>0.05).The patients with successful noninvasive ventilation had shorter hospital stays and lower partial pressure of carbon dioxide(PaCO_(2))than those with failed treatment,while potential of hydrogen(pH),diaphragm thickening fraction(DTF),diaphragm activity,and diaphragm movement time were significantly higher than those with failed treatment(P<0.05).pH[odds ratio(OR)=0.005,P<0.05],PaCO_(2)(OR=0.430,P<0.05),and DTF(OR=0.570,P<0.05)were identified to be independent factors influencing the outcome of mechanical ventilation in AECOPD patients.CONCLUSION The DUS index DTF can better predict the outcome of non-invasive ventilation in AECOPD patients. 展开更多
关键词 Diaphragm ultrasound Mechanical ventilation Acute exacerbation of chronic obstructive pulmonary disease Predictive value Diaphragm thickening fraction Diaphragm activity
下载PDF
Research on Present Situation and Countermeasure of Identity Recognition among Current College Students towards Socialist Core Value System
18
作者 Xue Lei 《International English Education Research》 2015年第1期69-71,共3页
The value identity emphasizes the harmony and consistency between the different value concepts. In general, it includes three stages, namely cognition, internalization and externalization. By the investigation on the ... The value identity emphasizes the harmony and consistency between the different value concepts. In general, it includes three stages, namely cognition, internalization and externalization. By the investigation on the present situation of college students' socialist core value system identity, it can be found that, at present, there is a good development momentum of our country's higher vocational school students' thoughts in general. But it also exists some problems that can't be ignored. Therefore, the top priority should be focused on the students' physical and mental characteristics. We should reform the current education methods gradually, steadily enhance the college students' identity, emotion and behavior cognition of socialist core value system, and gradually strengthen the ideological construction of college students, so as to make them better serve the socialist modernization. 展开更多
关键词 College Students Socialist Core values IDENTITY PRACTICE
下载PDF
An Inquiry into Two Intriguing Values of the Critical Current Density of Bi-2212
19
作者 Gulshan Prakash Malik Vijaya Shankar Varma 《World Journal of Condensed Matter Physics》 CAS 2021年第3期53-64,共12页
The empirically reported values of the critical current density (<i>j<sub>c</sub></i>) of Bi-2212 as 2.4 × 10<sup>5</sup> (<i>j<sub>c</sub></i><sub&g... The empirically reported values of the critical current density (<i>j<sub>c</sub></i>) of Bi-2212 as 2.4 × 10<sup>5</sup> (<i>j<sub>c</sub></i><sub>1</sub>;Sample 1) and 1.0 × 10<sup>6</sup> A/cm<sup>2</sup> (<i>j<sub>c</sub></i><sub>2</sub>;Sample 2) are intriguing because both of them correspond to the <i>same</i> values of the temperature <i>T</i> = 4.2 K and the applied magnetic field <i>H</i> = 12 × 10<sup>4</sup> G. This difference is conventionally attributed to such factors—not all of which are quantifiable—as the geometry, dimensions and the nature of dopants and the manners of preparation of the samples which cause their granular structures, grain boundaries, alignment of the grains and so on to differ. Based on the premise that the chemical potential <i>μ</i> subsumes most of these features, given herein is a novel explanation of the said results in terms of the values of <i>μ</i> of the two samples. This paper revisits the problem that was originally addressed in [Malik G.P., Varma V.S. (2020) WJCMP, 10, 53-70] in the more accurate framework of a subsequent paper [Malik G.P., Varma V.S. (2021) JSNM, 34, 1551-1561]. Besides, it distinguishes between the contributions of the electro-electron (<i>e-e</i>) and the hole-hole (<i>h-h</i>) pairs to <i>j<sub>c</sub></i>—a feature to which no heed was paid earlier. The essence of our findings is that the <i>j<sub>c</sub></i>s of the two samples differ because they are characterized by different values of the <i>primary</i> variables <i>μ<sub>i</sub></i><sub> </sub>and <img src="Edit_e1b831e9-dc51-4c3b-bd84-fa905e3e62b5.png" alt="" />, where <img src="Edit_1f775a80-30ab-447d-861f-afb4ba8fba6a.png" alt="" /> is the effective mass of a charge-carrier and <i>m<sub>e</sub></i><sub> </sub>is the free-electron mass and <i>i</i> = 1 and 2 denote Sample 1 and Sample 2, respectively. In the scenario of the charge-carriers being <i>predominantly h-h</i> pairs, the values of these parameters are estimated to be: <i>μ</i><sub>1</sub> ≈ 12.3 meV, <i>η</i><sub>1</sub> ≈ 0.58;<i>μ</i><sub>2</sub> ≈ 22.7 meV, <i>η</i><sub>2</sub> ≈ 0.94. Following from these and similar estimates when the charge-carriers are <i>e-e</i> pairs, given below for each sample are the detailed results for the values of the <i>secondary</i> variables viz. the number density of the charge-carriers and their critical velocity, the number of occupied Landau levels and the magnetic interaction parameter. 展开更多
关键词 Chemical Potential- Temperature- and Applied Magnetic Field-Dependent Critical current Density of Superconductors Number Density Landau Quantization Law of Equipartition of Energy BI-2212
下载PDF
The Economics of Competing Water Uses under a FERC Licensing Agreement: Estimation of Property Value, Recreation, and Hydroelectric Impacts
20
作者 Matthew Bingham Jason Kinnell 《Journal of Water Resource and Protection》 CAS 2024年第6期414-428,共15页
Reservoirs provide a variety of services with economic values across multiple sectors. As demands for reservoir services continue to grow and precipitation patterns evolve, it becomes ever more important to consider t... Reservoirs provide a variety of services with economic values across multiple sectors. As demands for reservoir services continue to grow and precipitation patterns evolve, it becomes ever more important to consider the integrated suite of values and tradeoffs that attend changes in water uses and availability. Section 316 (b) of the Clean Water Act requires that owners of certain water cooled power plants evaluate technologies and operational measures that can reduce their impacts to aquatic organisms. The studies must discuss the social costs and benefits of alternative technologies including cooling towers (79 Fed. Reg. 158, 48300 - 48439). Cooling towers achieve their effect through evaporation. This manuscript estimates the property value, recreation, and hydroelectric generation impacts that could result from the evaporative water loss associated with installing cooling towers at the McGuire Nuclear Generating Station (McGuire) located on Lake Norman, North Carolina. Although this study specifically evaluates the effects of evaporative water loss from cooling towers, its methods are applicable to estimating the economic benefits and costs of a new water user or reduced water input in any complex reservoir system that supports steam electric generation, hydroelectric generation, residential properties, recreation, irrigation, and municipal water use. 展开更多
关键词 Property value FERC Hydroelectric RECREATION Water Levels
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部