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FIRST简易版虚弱评估量表评分在新诊断多发性骨髓瘤患者中的应用价值分析
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作者 姚琼 王鑫炜 +4 位作者 杨慧 李林宇 赵洁 贺少龙 田卫伟 《中国临床新医学》 2024年第2期186-191,共6页
目的分析FIRST简易版虚弱评估量表评分在新诊断多发性骨髓瘤(NDMM)患者中的应用价值。方法回顾性分析2014年7月1日至2021年12月31日山西医科大学第三医院收治的131例NDMM患者的临床资料。根据FIRST简易版虚弱评估量表评分将其分为虚弱组... 目的分析FIRST简易版虚弱评估量表评分在新诊断多发性骨髓瘤(NDMM)患者中的应用价值。方法回顾性分析2014年7月1日至2021年12月31日山西医科大学第三医院收治的131例NDMM患者的临床资料。根据FIRST简易版虚弱评估量表评分将其分为虚弱组(50例)和非虚弱组(81例)。比较两组患者疗效、累积早期≥3级感染发生率及生存预后情况。并对接受硼替佐米为基础诱导治疗方案的患者进行亚组分析。结果两组疗效为≥非常好的部分缓解(VGPR)的人数比例差异无统计学意义(45.68%vs 36.00%,P>0.05)。虚弱组和非虚弱组分别有26例(52.00%)和27例(33.33%)发生早期≥3级感染,虚弱组早期≥3级感染相关预后更差(log-rank检验:χ^(2)=4.472,P=0.020)。虚弱组中位总生存(OS)时间和中位无进展生存(PFS)时间均短于非虚弱组(36个月vs 81个月;16个月vs 34个月),非虚弱组生存预后情况显著优于虚弱组(P<0.05)。在接受硼替佐米为基础诱导方案治疗的100例患者中,虚弱组中位OS时间和中位PFS时间均短于非虚弱组(34个月vs 84个月;15个月vs 33个月),非虚弱组生存预后情况显著优于虚弱组(P<0.05)。结论FIRST简易版虚弱评估量表评分对NDMM患者有较好的应用价值。 展开更多
关键词 多发性骨髓瘤 first简易版虚弱评估量表 虚弱 感染 预后
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A Brief List of "Firsts" for Women in World Politics
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《China Today》 1994年第12期21-21,共1页
The world's first woman president was Isabel Martinez de Peron(b.1931).In July,1974,Juan Domingo Peron,the president of Argentina,died,leaving his wife Isabel Martinez de Peron,then the vice-president,to succeed h... The world's first woman president was Isabel Martinez de Peron(b.1931).In July,1974,Juan Domingo Peron,the president of Argentina,died,leaving his wife Isabel Martinez de Peron,then the vice-president,to succeed him according to the cons stitution. 展开更多
关键词 World for Women in World Politics A Brief List of firsts
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Community Knowledge and Attitude about Burns First Aid (BFA) in Jazan, Saudi Arabia
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作者 Md. Mazharul Hoque Mohamed E. Moukhyer +9 位作者 Nizar A. Khamjan Bahja Al Siddig Elsie Maguen Shane Alam Abdulrahman Ibrahim Ali Hakami Siraj Yahya Mohammed Mobarki Bandar Hassan Sulaiman Ghazwani Ayman Abdulrhman Alhathiq Lamyaa El Hassan Aziza Mukhayer 《Journal of Biosciences and Medicines》 2024年第4期135-148,共14页
Introduction and Significance: Burn injury (BI) is a considerable health issue which is responsible for around 300,000 deaths and affecting about 11 million people every year worldwide. In Saudi Arabia, the prevalence... Introduction and Significance: Burn injury (BI) is a considerable health issue which is responsible for around 300,000 deaths and affecting about 11 million people every year worldwide. In Saudi Arabia, the prevalence of BIs array from 112 to 518 per 100,000 per year. The appropriate awareness of performing first aid could facilitate to improve the outcomes of burns. Purpose and Objectives: To appraise the community that acknowledges burns, first aid, and associated factors among the community population in Jazan City, Saudi Arabia. The paper aims to identify limitations to encourage additional research and persuade legislators to develop improved burn-injury care recommendations and training programs. Materials and Methods: An observational-based sample survey was conducted among the people who live in Jazan City aging 13 years or more, during April 5 to May 5, 2023. Data collection was done by a validated online self-administrated questionnaire sent randomly to community members in different parts of Jazan City via social media platforms. Collected data were coded and cleaned by an excel program, and finally exported on SPSS 26.0 software. The variables were analyzed using descriptive statistics like frequencies and percentages. Also, the Chi-square test was used to investigate the relation between different variables, with a significance value of P Results: This study included 243 participants (about 62%) among them were mostly male participants (151) having a university degree. The majority of participants 75% did not take any form of BFA training in the past. This study shows that 69.9% of the participants have inadequate awareness, despite 72% having a constructive attitude towards burn first aid. Previous burn-related first aid training was significantly associated with participants’ knowledge of BFA at a p-value less than 0.05. Conclusion: This study indicates a high frequency of Jazan population having inadequate knowledge of burn first aid despite the high prevalence of a favorable attitude. There is a need to develop an effective nationwide burn prevention program and early burn first aid treatment in Saudi Arabia and promote a consistent guideline for burn first aid. 展开更多
关键词 Burn Injury (BI) Burns first Aid Knowledge first Aid Training Jazan City
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Estimation of Landfill Gas and Its Renewable Energy Potential from the Polesgo Controlled Landfill Using First-Order Decay (FOD) Models
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作者 Haro Kayaba Ouarma Issoufou +4 位作者 Dabilgou Téré Compaore Abdoulaye Sanogo Oumar Bere Antoine Koulidiati Jean 《Journal of Environmental Protection》 2024年第10期975-993,共19页
Methane generation in landfills and its inadequate management represent the major avoidable source of anthropogenic methane today. This paper models methane production and the potential resources expected (electrical ... Methane generation in landfills and its inadequate management represent the major avoidable source of anthropogenic methane today. This paper models methane production and the potential resources expected (electrical energy production and potential carbon credits from avoided CH4 emissions) from its proper management in a municipal solid waste landfill located in Ouagadougou, Burkina Faso. The modeling was carried out using two first-order decay (FOD) models (LandGEM V3.02 and SWANA) using parameters evaluated on the basis of the characteristics of the waste admitted to the landfill and weather data for the site. At the same time, production data have been collected since 2016 in order to compare them with the model results. The results obtained from these models were compared to experimental one. For the simulation of methane production, the SWANA model showed better consistency with experimental data, with a coefficient of determination (R²) of 0.59 compared with the LandGEM model, which obtained a coefficient of 0.006. Thus, despite the low correlation values linked to the poor consistency of experimental data, the SWANA model models methane production much better than the LandGEM model. Thus, despite the low correlation values linked to the poor consistency of the experimental data, the SWANA model models methane production much better than the LandGEM V3.02 model. It was noted that the poor consistency of the experimental data justifies these low coefficients, and that they can be improved in the future thanks to ongoing in situ measurements. According to the SWANA model prediction, in 27 years of operation a biogas plant with 33% electrical efficiency using biogas from the Polesgo landfill would avoid 1,340 GgCO2e. Also, the evaluation of revenues due to electricity and carbon credit gave a total revenue derived from methane production of US$27.38 million at a cost of US$10.5/tonne CO2e. 展开更多
关键词 first-Order Decay METHANE Modeling LANDFILL Renewable Energy
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Community Knowledge about Bleeding Control in Jazan, KSA: Is There a Need for First Aid Educational Programs
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作者 Md Mazharul Hoque Hamoud Yahya Alsuriha +10 位作者 Mohamed E. Moukhyer Bahja Siddig Mohamed Mubarak Almaki Amna Moukhyer Fawaz Yahya Masswadi Mofareh Salman Harubi Elias Yosef Modabish Talal Omar Khasawi Yaser Mohammed Hantool Mohammed Awaji Mohammed Madkhali Aziza Mukhayer 《Journal of Biosciences and Medicines》 2024年第6期64-84,共21页
The current study aimed to evaluate the first aid knowledge and general awareness of bleeding control, and their relations with different variables among the population of Jazan City, Saudi Arabia, in 2023. A cross-se... The current study aimed to evaluate the first aid knowledge and general awareness of bleeding control, and their relations with different variables among the population of Jazan City, Saudi Arabia, in 2023. A cross-sectional study was conducted in Jazan City, Saudi Arabia between April 2023 and May 2023. Participants, >13 years old, living in Jazan City, were self-enrolled. Data collection was carried out by distributing a self-reported online survey questionnaire via email and social media apps. A validated, pretested online self-report questionnaire was used for data collection, with data analysis performed using (MS) Excel 2022 and SPSS version 26. A Chi-square test was used to determine the association of sociodemographic variables and Bleeding Control (BC) knowledge with, significance set at p < 0.05. A total of 250 participants completed the questionnaire, predominantly aged between 16 - 25 years, with 152 (60.8%) being male, and about 90% being Saudi citizens. Only 53 (21.2%) participated in previous first aid training concentrating on bleeding control. Only 76 (30.4%) of participants had good knowledge, while 131 (52.4%) exhibited positive attitude towards BC first aid. There were no statistically significant associations between BC knowledge and age, gender, occupation, nationality, and education. However, a significant association was observed between previous BC training and knowledge (Chi-test = 40.373, d.f = 1, p = 0.000) at p < 0.05. Conclusion: The prevalence of poor knowledge of bleeding control among community members in Jazan City was high. The findings of this study should be carefully considered by various healthcare organizations to implement educational first-aid programs and activities aimed at enhancing community awareness and knowledge of bleeding control. 展开更多
关键词 INJURY Uncontrolled Bleeding first Aid Knowledge ATTITUDE Jazan City
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第一性原理对M@B_(12)N_(12)(M=Sc-Zn)团簇结构和性质的研究
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作者 张颂 程露 吴学科 《原子与分子物理学报》 CAS 北大核心 2025年第4期93-99,共7页
利用基于密度泛函理论的第一性原理对M@B_(12)N_(12)(M=Sc-Zn)团簇的几何、电子结构,电偶极性和红外吸收光谱进行详细的研究.结果显示:当B_(12)N_(12)团簇内嵌过渡金属原子后,虽然结构稳定性稍稍降低,但其化学活性得到提高,摩尔体积明... 利用基于密度泛函理论的第一性原理对M@B_(12)N_(12)(M=Sc-Zn)团簇的几何、电子结构,电偶极性和红外吸收光谱进行详细的研究.结果显示:当B_(12)N_(12)团簇内嵌过渡金属原子后,虽然结构稳定性稍稍降低,但其化学活性得到提高,摩尔体积明显增大.过渡金属原子与B_(12)N_(12)结合的过程中,除Cu和B原子外,剩余金属与N原子的Mulliken电荷出现负值.另外,金属原子的加入,不仅增加电偶极矩和极化率的值,还促使其红外吸收光谱发生红移. 展开更多
关键词 团簇 结构 性质 第一性原理
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First-Principles Investigation of Charge Transfer Mechanism of B-Doped 3C-SiC Semiconductor Material
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作者 Abdullahi Alkali Dauda Muhammad Yusuf Onimisi +7 位作者 Adeyemi Joshua Owolabi Hameed Adeneyi Lawal Hassan Muhammad Gambo Bashir Mohammed Aliyu Surajo Bala Muhammad Lamido Madugu Muhammad Abdurrahman Nainna Johnson Akinade Bamikole 《World Journal of Condensed Matter Physics》 CAS 2024年第2期35-44,共10页
This study delves into the charge transfer mechanism of boron (B)-doped 3C-SiC through first-principles investigations. We explore the effects of B doping on the electronic properties of 3C-SiC, focusing on a 12.5% im... This study delves into the charge transfer mechanism of boron (B)-doped 3C-SiC through first-principles investigations. We explore the effects of B doping on the electronic properties of 3C-SiC, focusing on a 12.5% impurity concentration. Our comprehensive analysis encompasses structural properties, electronic band structures, and charge density distributions. The optimized lattice constant and band gap energy of 3C-SiC were found to be 4.373 Å and 1.36 eV respectively, which is in agreement with previous research (Bui, 2012;Muchiri et al., 2018). Our results show that B doping narrows the band gap, enhances electrical conductivity, and influences charge transfer interactions. The charge density analysis reveals substantial interactions between B dopants and surrounding carbon atoms. This work not only enhances our understanding of the material’s electronic properties, but also highlights the importance of charge density analysis for characterizing charge transfer mechanisms and their implications in the 3C-SiC semiconductors. 展开更多
关键词 first-Principles Calculations DFT Boron (B)-Doped 3C-SiC Charge Transfer
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A Survey on the Current Situation of Prehospital First Aid about Knowledge, Belief and Behavior among University Students in Jingzhou
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作者 Tianyue Zhang Hong Zhou +1 位作者 Chenyang Xu Juan Zhou 《Open Journal of Applied Sciences》 2024年第5期1251-1261,共11页
Objective: To understand the current situation of prehospital first aid knowledge, attitude and behavior of university students in Jingzhou City. Methods: A prehospital first aid knowledge questionnaire and the conven... Objective: To understand the current situation of prehospital first aid knowledge, attitude and behavior of university students in Jingzhou City. Methods: A prehospital first aid knowledge questionnaire and the convenience sampling method were used to survey 307 university students in Jingzhou City. Results: The mean score of prehospital first aid knowledge of university students in Jingzhou City was 12.85 ± 2.643, the mean score of attitude was 50.73 ± 4.114, and the mean score of behavior was 39.05 ± 8.898;There was a statistically significant difference in the scores of prehospital first aid knowledge, attitude, and behavior of university students depending on whether or not they had received prehospital first aid training (P P Conclusion: Jingzhou University students have a positive attitude toward pre-hospital first aid, but the knowledge level and behavior are low, which suggests that the government, society and the school should create good conditions to promote the improvement of pre-hospital first aid knowledge and ability. 展开更多
关键词 Prehospital first Aid University Student KNOWLEDGE ATTITUDE BEHAVIORS
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甲烷在钠基蒙脱土吸附的第一性原理研究
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作者 方志杰 李博 +4 位作者 宋昌辉 刘美玲 何秋芝 刘翔 莫曼 《原子与分子物理学报》 CAS 北大核心 2025年第2期8-14,共7页
随着经济的发展,能源需求日益增加,为了弥补国内少油缺气短板,页岩气的开发成为近期新能源的热点,探索页岩气储存规律是页岩气能源开发的关键所在.本文采用密度泛函理论的第一性原理方法,计算甲烷(CH_(4))在钠基蒙脱土表面和层间的吸附... 随着经济的发展,能源需求日益增加,为了弥补国内少油缺气短板,页岩气的开发成为近期新能源的热点,探索页岩气储存规律是页岩气能源开发的关键所在.本文采用密度泛函理论的第一性原理方法,计算甲烷(CH_(4))在钠基蒙脱土表面和层间的吸附能,对比吸附前后的态密度和物理结构以及差分电荷密度.结果表明:钠基蒙脱土表面吸附中,甲烷最佳选择是桥位,吸附能为-0.08eV,被吸附后甲烷的键长和键角变化率均小于0.96%.层间吸附中,伴随着甲烷吸附量增加,纳基蒙脱土体积向c轴方向线性增加,a、b轴方向则变化不大.总态密度随着吸附量的增加,总能级数量也增加,甲烷分子的分波态密度峰向低能级移动.本文的研究成果,从原子角度分析了甲烷在蒙脱石表面以及层间的吸附能力,为解释页岩气在页岩储存规律提供理论依据. 展开更多
关键词 钠基蒙脱土 第一性原理 甲烷 吸附 态密度
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Research Progress of Radical Treatment of Helicobacter Pylori Based on Drug Sensitivity Test as First-Line Treatment
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作者 Dong Luo Haidong Zhou +8 位作者 Changtai Luo Wei Wang Luchang Chen Wujia Yang Xianqi Qin Song Huang Wenzhao Zhang Jiahou Xu Jihua Wei 《Journal of Biosciences and Medicines》 2024年第8期30-39,共10页
Helicobacter pylori (HP) infection is a global problem that affects about half of the world’s population and requires sufficient attention in clinical and scientific work. Due to differences in economic and medical c... Helicobacter pylori (HP) infection is a global problem that affects about half of the world’s population and requires sufficient attention in clinical and scientific work. Due to differences in economic and medical conditions among countries around the world, there is currently no unified treatment plan for anti-HP. In China, empirical quadruple therapy is mainly used. With the abuse of antibiotics, many patients face the problem of secondary eradication after failure, and the resistance rate of HP is gradually increasing. After eradication failure, drug sensitivity cultivation is carried out to choose sensitive antibiotics for treatment. A new strategy is currently needed to address how to improve the eradication rate of HP during the first eradication. This article aims to discuss the first-line treatment plans and research progress for eradicating HP based on drug sensitivity testing before eradication. Compared with traditional empirical therapies, treatment based on drug sensitivity results can effectively improve the eradication rate of HP, and reduce drug resistance rates, and adverse reactions, among other benefits. . 展开更多
关键词 Drug Susceptibility Test Helicobacter Pylori (HP) Infection first-Line Treatment HP Culture
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金属卤素钙钛矿CsPbBr3的电声耦合输运特性研究
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作者 杨帆 周贤中 《原子与分子物理学报》 CAS 北大核心 2025年第2期169-174,共6页
金属卤素钙钛矿CsPbBr_(3)在发光方面(Light emitter)的优良表现吸引了许多人把它作为下一代发光、显示与量子信息的可选材料,但其关键的漂移迁移率会受到声子限制.本文将以第一性原理计算得到CsPbBr_(3)的包括极性光学声子(Polar optic... 金属卤素钙钛矿CsPbBr_(3)在发光方面(Light emitter)的优良表现吸引了许多人把它作为下一代发光、显示与量子信息的可选材料,但其关键的漂移迁移率会受到声子限制.本文将以第一性原理计算得到CsPbBr_(3)的包括极性光学声子(Polar optical phonon)在内的电声耦合特性,然后使用线性玻尔兹曼方程给出在电场下的解,从而得出漂移迁移率.在论文详述中会给出CsPbBr_(3)的各向异性载流子输运特性的研究,为金属卤素钙钛矿的应用提供一些必要信息. 展开更多
关键词 第一性原理计算 电子-声子耦合 漂移迁移率
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Comparative Studies between Picard’s and Taylor’s Methods of Numerical Solutions of First Ordinary Order Differential Equations Arising from Real-Life Problems
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作者 Khalid Abd Elrazig Awad Alla Elnour 《Journal of Applied Mathematics and Physics》 2024年第3期877-896,共20页
To solve the first-order differential equation derived from the problem of a free-falling object and the problem arising from Newton’s law of cooling, the study compares the numerical solutions obtained from Picard’... To solve the first-order differential equation derived from the problem of a free-falling object and the problem arising from Newton’s law of cooling, the study compares the numerical solutions obtained from Picard’s and Taylor’s series methods. We have carried out a descriptive analysis using the MATLAB software. Picard’s and Taylor’s techniques for deriving numerical solutions are both strong mathematical instruments that behave similarly. All first-order differential equations in standard form that have a constant function on the right-hand side share this similarity. As a result, we can conclude that Taylor’s approach is simpler to use, more effective, and more accurate. We will contrast Rung Kutta and Taylor’s methods in more detail in the following section. 展开更多
关键词 first-Order Differential Equations Picard Method Taylor Series Method Numerical Solutions Numerical Examples MATLAB Software
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单轴应变对本征和N掺杂4H-SiC电子结构的影响
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作者 秦彦军 张建强 +5 位作者 杨慧雅 方峥 范晓珍 邝富丽 叶慧群 方允樟 《原子与分子物理学报》 CAS 北大核心 2025年第3期173-179,共7页
采用基于密度泛函理论的第一性原理方法,研究了单轴应变对本征和N掺杂4H-SiC电子结构的影响.研究表明应变可以有效调控本征和N掺杂4H-SiC的带隙,在拉应变作用下,带隙单调减小;而在压应变作用下,带隙先增大后减小,当压应变为-1%时,带隙... 采用基于密度泛函理论的第一性原理方法,研究了单轴应变对本征和N掺杂4H-SiC电子结构的影响.研究表明应变可以有效调控本征和N掺杂4H-SiC的带隙,在拉应变作用下,带隙单调减小;而在压应变作用下,带隙先增大后减小,当压应变为-1%时,带隙达到最大值.对态密度的分析可知本征和N掺杂4H-SiC的价带顶主要来自Si 3p和C 2p态电子,导带底主要来自Si 3p态电子,C 2p态和Si 3p态通过影响价带顶和导带底从而导致应变结构中带隙发生变化.通过Mulliken布局和差分电荷密度分析可知,随着晶格常数的增加Si原子向C原子和N原子转移的电荷减少,同时Si-C原子和Si-N原子之间的共价性减弱. 展开更多
关键词 4H-SIC 单轴应变 电子结构 第一性原理
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锯齿形氮化铝纳米带负阻器件电子输运性质研究
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作者 黄绛雪 黄启俊 +2 位作者 何进 王豪 常胜 《原子与分子物理学报》 CAS 北大核心 2025年第2期85-90,共6页
低维纳米带材料因为其结构的特异性而呈现出新奇的物理性质.修饰纳米带的边缘能够调制其电子性质.本文运用基于密度泛函理论(DFT)的第一性原理计算方法,探究了锯齿形氮化铝纳米带(ZAlNNR)单边氟化、单边氯化以及单边氢化的电子结构和输... 低维纳米带材料因为其结构的特异性而呈现出新奇的物理性质.修饰纳米带的边缘能够调制其电子性质.本文运用基于密度泛函理论(DFT)的第一性原理计算方法,探究了锯齿形氮化铝纳米带(ZAlNNR)单边氟化、单边氯化以及单边氢化的电子结构和输运特性.研究表明:锯齿型氮化铝纳米带可以通过以上手段实现能带结构的半导体-金属转换.计算电子输运特性,我们发现三种边缘修饰的器件均呈现出负微分电阻效应,其中AlN-F器件有最大峰谷电流比(PVCR),达到了1.78×10^(7),是硅烯纳米器件以及黑磷纳米器件的10^(6)倍.值得一提的是,相比于H-AlN-Cove纳米器件,AlN-F器件能够在更小的偏压范围内实现高PVCR.该结果为锯齿形氮化铝纳米带在低功耗纳米器件中的应用提供了广泛的前景. 展开更多
关键词 锯齿形氮化铝纳米带 电子输运 负微分电阻效应 第一性原理
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VA族元素修饰对二维AlN电磁性质调控的理论研究
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作者 莫秋燕 陈广萍 +2 位作者 张颂 荆涛 吴家隐 《原子与分子物理学报》 CAS 北大核心 2025年第6期159-166,共8页
采用基于密度泛函理论的第一性原理计算方法,研究了VA族元素(N、P、As、Sb、Bi)对二维AlN电磁性质的影响.研究发现,VA族元素修饰后,二维AlN的能带结构发生显著劈裂,表明体系转变为磁性材料.同时,导带底部向低能量区域移动,使得二维AlN... 采用基于密度泛函理论的第一性原理计算方法,研究了VA族元素(N、P、As、Sb、Bi)对二维AlN电磁性质的影响.研究发现,VA族元素修饰后,二维AlN的能带结构发生显著劈裂,表明体系转变为磁性材料.同时,导带底部向低能量区域移动,使得二维AlN的吸收阈值从紫外线区域扩展至可见光区域.因此,VA族元素的修饰显著调控了二维AlN的电子结构和磁性,为实现可见光响应的光电子和自旋电子器件提供了新思路和可能性. 展开更多
关键词 二维AlN 第一性原理 修饰 电子结构
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数据分布型sort-first并行图形绘制系统的研究与实现 被引量:11
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作者 金哲凡 林海 石教英 《计算机研究与发展》 EI CSCD 北大核心 2004年第2期376-382,共7页
sort first体系结构常用来构建高性能并行图形绘制系统 基于immediate mode的数据集中型sort first系统 ,对网络带宽高度依赖 ,网络带宽和归属计算易成为系统瓶颈 提出了一个基于retain mode的数据分布型并行绘制系统 ,工作原理是将... sort first体系结构常用来构建高性能并行图形绘制系统 基于immediate mode的数据集中型sort first系统 ,对网络带宽高度依赖 ,网络带宽和归属计算易成为系统瓶颈 提出了一个基于retain mode的数据分布型并行绘制系统 ,工作原理是将几何数据分布于绘制结点 ,并利用帧间相似性动态调整绘制结点上的数据分布以适应视角的改变 ,有效地降低了数据分布所需的传输开销 系统利用Cell结构来控制并行粒度 展开更多
关键词 SORT-first 并行绘制 数据分布 粒度 帧间相似性
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FIRST和FOLLOW集合的并行算法设计 被引量:1
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作者 孙玉强 刘三阳 +1 位作者 张英丽 马正华 《计算机工程》 EI CAS CSCD 北大核心 2004年第21期71-73,125,共4页
描述了多处理机环境中 FIRST 和 FOLLOW 集合求解的一种并行处理方法,并讨论了 FIRST 和 FOLLOW 集合的并行算法设计思想和它的实现策略,在构造文法 G 的 LL(1)分析表以及判定文法 G 是否 LL(1)文法时,求解 FIRST 和 FOLLOW 集合是很重... 描述了多处理机环境中 FIRST 和 FOLLOW 集合求解的一种并行处理方法,并讨论了 FIRST 和 FOLLOW 集合的并行算法设计思想和它的实现策略,在构造文法 G 的 LL(1)分析表以及判定文法 G 是否 LL(1)文法时,求解 FIRST 和 FOLLOW 集合是很重要的内容,由于文法中终结符和非终结符个数很多,考虑 FIRST 和 FOLLOW 集合的并行处理方法,对并行编译处理和提高效率有其理论和现实意义。 展开更多
关键词 first集合 FOLLOW集合 关系矩阵 并行算法
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基于第一性原理和热力学计算的TiAl-Nb金属间化合物稳定性和相关系研究
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作者 汪文洋 徐勇 +4 位作者 田彬 甘信柱 王志刚 梁永锋 林均品 《原子与分子物理学报》 CAS 北大核心 2025年第5期151-162,共12页
采用基于广义梯度近似密度泛函理论的第一性原理计算和相图计算方法,研究了TiAl-Nb合金中γ、α_(2)、O_(2)和ωo相的热力学和力学性质以及相转变关系.研究表明,第一性原理计算得到的化合物相的参数是准确的,且分析结果与相图计算结果... 采用基于广义梯度近似密度泛函理论的第一性原理计算和相图计算方法,研究了TiAl-Nb合金中γ、α_(2)、O_(2)和ωo相的热力学和力学性质以及相转变关系.研究表明,第一性原理计算得到的化合物相的参数是准确的,且分析结果与相图计算结果相一致.四个化合物相都是能够稳定存在的相.通过热力学和力学性质的分析,发现α_(2)相更容易转变为O_(2)相,并且在一定条件下可以通过相变反应生成ωo相.而γ相更容易转变为ωo相,但无法生成O_(2)相. 展开更多
关键词 TIAL合金 第一性原理 相图 声子谱及态密度 热力学性质
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FeCoRE磁交换常数第一性原理计算和居里温度提高机制研究
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作者 李志伟 朱颖丽 +2 位作者 罗港涛 陈平安 李享成 《原子与分子物理学报》 CAS 北大核心 2025年第4期156-162,共7页
信息通讯和军事电子技术发展对磁性材料的高温磁性提出了越来越高的要求,研究高温环境下高效稳定工作的磁性材料具有重要意义.本文结合第一性原理和蒙特卡洛方法,研究了Fe、Co比例和稀土元素(Gd、Tb、Dy)掺杂对合金FeCo晶体结构、磁交... 信息通讯和军事电子技术发展对磁性材料的高温磁性提出了越来越高的要求,研究高温环境下高效稳定工作的磁性材料具有重要意义.本文结合第一性原理和蒙特卡洛方法,研究了Fe、Co比例和稀土元素(Gd、Tb、Dy)掺杂对合金FeCo晶体结构、磁交换常数和高温磁性的影响.结果表明随着Co含量增加,合金晶体结构从体心立方向简单和面心立方转变,当Co含量为50%时,Fe-Co键长最短,最近邻磁交换常数从18.05 meV增加到30.03 meV,使FeCo的居里温度提高到1580 K,相比于Fe的居里温度增幅达到60%.将稀土元素掺入FeCo体系后,发现3.125%含量Er、Dy、Tb的掺杂对合金FeCo居里温度分别有60K、45K和20K的提高,电子构型重构导致强的稀土元素与Fe和Co之间的交换作用是居里温度提升的主要原因. 展开更多
关键词 高温磁性 第一性原理 蒙特卡洛 磁交换常数
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稀土元素Er、Yb和Y掺杂ZrO_(2)的第一性原理研究 被引量:2
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作者 熊威 任浩 《原子与分子物理学报》 CAS 北大核心 2025年第1期156-162,共7页
氧化锆具有声子能量低,介电常数高和带隙较宽等优良特性,并且立方相的氧化锆(cZrO_(2))透光率高,适合作为上转换发光材料的基质.采用基于密度泛函理论(DFT)的第一性原理平面波赝势法研究了稀土元素Er、Yb和Y掺杂cZrO_(2)的电子结构和光... 氧化锆具有声子能量低,介电常数高和带隙较宽等优良特性,并且立方相的氧化锆(cZrO_(2))透光率高,适合作为上转换发光材料的基质.采用基于密度泛函理论(DFT)的第一性原理平面波赝势法研究了稀土元素Er、Yb和Y掺杂cZrO_(2)的电子结构和光学性质.计算结果显示,掺入Y元素后,cZrO_(2)转变为直接带隙材料,继续掺入Er和Yb原子后,费米能级移动到价带内,带隙显著减小.Y和Er混掺后,增强了cZrO_(2)在近红外波段的吸收能力.继续掺入Yb后,cZrO_(2)对近红外波段的吸收能力有了进一步地增加. 展开更多
关键词 氧化锆 第一性原理 电子结构 光学性质
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