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基于便携GC-MS和HS/SPME-GC×GC-TOF MS分析化州橘红与广西橘红成分差异
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作者 李凯旋 黄罗旭 +4 位作者 吴曼曼 徐经纬 谭国斌 罗思凡 周振 《质谱学报》 EI CAS CSCD 北大核心 2024年第5期631-639,共9页
为探究不同产地橘红挥发性成分之间的差异,本研究采用便携气相色谱-质谱(GC-MS)和顶空固相微萃取结合全二维气相色谱-飞行时间质谱(GC×GC-TOF MS)技术分析化州橘红和广西橘红的挥发性成分。结果表明,便携GC-MS只能初步区分化州橘... 为探究不同产地橘红挥发性成分之间的差异,本研究采用便携气相色谱-质谱(GC-MS)和顶空固相微萃取结合全二维气相色谱-飞行时间质谱(GC×GC-TOF MS)技术分析化州橘红和广西橘红的挥发性成分。结果表明,便携GC-MS只能初步区分化州橘红和广西橘红,不能确定化州橘红的特征标志物;利用主成分分析法(PCA)和正交偏最小二乘法(OPLS-DA)对GC×GC-TOF MS实验数据进行处理,根据|p(corr)|>9和|p|>0.06结合VIP>1.1,共筛选出10种化州橘红标志物。该研究为化州橘红药材的质量评价与鉴定提供了依据,也为其他中药质量评价提供了方法参考。 展开更多
关键词 橘红 便携气相色谱-质谱 全二维气相色谱-飞行时间质谱(GC×GC-TOF MS) 顶空固相微萃取(HS/SPME) 化学计量学分析
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电感耦合等离子体质谱法(ICP-MS)同时测定紫菜中砷、镉含量的不确定度评定 被引量:7
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作者 姜童祥 胥艳 《河南预防医学杂志》 2017年第6期423-427,共5页
目的分析电感耦合等离子体质谱法(ICP-MS)测定紫菜中砷(As)、镉(Cd)含量的不确定度来源,提高检测结果的准确性。方法主要对样品称量、样品消解、样品定容、样品溶液中元素的测定、样品均匀性等因素进行分析,确定不确定度来源,计算合成... 目的分析电感耦合等离子体质谱法(ICP-MS)测定紫菜中砷(As)、镉(Cd)含量的不确定度来源,提高检测结果的准确性。方法主要对样品称量、样品消解、样品定容、样品溶液中元素的测定、样品均匀性等因素进行分析,确定不确定度来源,计算合成不确定度。结果本方法测定紫菜中As、Cd含量的扩展不确定度分别为5.081、0.138 mg·kg^(-1),其不确定度的主要来源为元素浓度的测定过程。结论该方法适用于紫菜粉中As、Cd含量的不确定度评定。 展开更多
关键词 电感耦合等离子体质谱(ICP-MS) 紫菜 不确定度
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糠醇-己内酰胺协同改性松木理化性能
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作者 王子衡 何盛 +2 位作者 张雪峰 李万兆 冷魏祺 《林业工程学报》 CSCD 北大核心 2024年第4期40-47,共8页
糠醇改性木材拥有较多的优点,如优异的耐腐性、耐候性、硬度等,然而经过糠醇改性的木材脆性增加,抗弯性能以及抗剪切性能均有所降低。这一缺点极大限制了糠醇改性木材的应用范围,可通过加入柔性物质己内酰胺以提高糠醇改性木材的韧性。... 糠醇改性木材拥有较多的优点,如优异的耐腐性、耐候性、硬度等,然而经过糠醇改性的木材脆性增加,抗弯性能以及抗剪切性能均有所降低。这一缺点极大限制了糠醇改性木材的应用范围,可通过加入柔性物质己内酰胺以提高糠醇改性木材的韧性。己内酰胺是聚酰胺切片的原材料,韧性较强,常用来制备纤维等柔性材料。将己内酰胺与糠醇复合改性剂协同处理马尾松,通过X射线能谱仪(EDS)、抗弯性能分析、数字图像分析(DIC)以及接触角测试分析研究协同改性对松木早晚材微观构造、元素分布、力学性能和疏水性等的影响。能谱结果表明:由于早晚材结构差异,协同改性剂在早材细胞壁和细胞腔中反应程度更高,聚合物含量更丰富。晚材构造阻碍了改性剂在其内部的渗透,导致晚材反应程度低于早材。木材疏水性结果表明,协同改性大幅提高了木材的疏水性。力学性能以及数字图像分析结果表明,协同改性不仅提高了木材的静曲强度和弹性模量,而且降低了糠醇改性导致的木材脆性。 展开更多
关键词 糠醇 己内酰胺 协同改性 力学性能 元素分布 应变 耐水性
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MS-EEPO有效教育教学法在医学院校《生物化学》实验课中的探索和应用 被引量:1
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作者 赵俊龙 毕晨 +1 位作者 陈阳 晏贤春 《生命的化学》 CAS CSCD 2019年第6期1262-1266,共5页
MS-EEPO的英文全称为Meng Shi-Effective Education in Participatory Organizations,其核心理念为"有效教育是通过组织和参与来实现的"。不同于以知识灌输为主要教学手段的传统教育理念,MS-EEPO有效教育强调"以学生为主... MS-EEPO的英文全称为Meng Shi-Effective Education in Participatory Organizations,其核心理念为"有效教育是通过组织和参与来实现的"。不同于以知识灌输为主要教学手段的传统教育理念,MS-EEPO有效教育强调"以学生为主体,向课堂要效率",给传统课堂带来了较大的冲击与挑战。为医学生开展的《生物化学》实验课具有鲜明的特点和独立性,旨在锻炼学生理论联系实践的动手能力和解决临床问题的思考能力。本文基于MS-EEPO有效教育教学法的理念和主要教学手段,结合作者本人在医学生《生物化学》实验课的教学经验和成果,简单探讨了MS-EEPO有效教育教学法在医学生《生物化学》实验课中的优势和可行性,为促进生物化学教学改革提供参考。 展开更多
关键词 MS-EEPO 平台互动 要素组合 医学生 生物化学 实验课
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轨道阱边缘场效应及其补偿方法的研究
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作者 王俊恬 任熠 +2 位作者 黄正旭 陈政阁 丁力 《质谱学报》 EI CAS CSCD 北大核心 2024年第2期237-245,共9页
静电轨道阱(Orbitrap)自推出以来已被证明是一款强大的离子分析器,其分辨率受电极结构中边缘场的影响。因此,亟需研究由离子入射孔和外电极间隙共同导致的畸变场对分辨率的影响,并提出边缘场效应的解决方法。本实验利用离子光学仿真软件... 静电轨道阱(Orbitrap)自推出以来已被证明是一款强大的离子分析器,其分辨率受电极结构中边缘场的影响。因此,亟需研究由离子入射孔和外电极间隙共同导致的畸变场对分辨率的影响,并提出边缘场效应的解决方法。本实验利用离子光学仿真软件(SIMION)分别建立了理想、畸变和矫正3种结构模型,以测量不同初始轴向振幅和不同轨道半径对应的轴向振动周期分散来衡量轨道阱可以达到的极限分辨率。通过对比理想模型的实验结果与理论结果,验证了仿真参数选取和离子运动计算方法的可靠性;在畸变模型实验中,探究外电极间隙和离子入射孔导致的边缘场效应引起的离子轴向运动周期分散情况,及其对分辨率产生的影响;在矫正模型实验中证明了可以通过调节2个补偿电极的电压来修正畸变场,从而克服离子入射孔和外电极间隙共同产生的边缘场效应,乃至其他缺陷所引起的场畸变问题,仿真得到轨道阱对m/z 100离子的极限质量分辨率可达2500000。 展开更多
关键词 轨道阱 边缘场 补偿电极 分辨率 仿真模拟
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Evaluation of Moving Grid Adjustment (MGA) Method in Field Variation Control
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作者 Jixiang Wu Johnie N. Jenkins Jack C. McCarty 《Open Journal of Statistics》 2024年第5期450-466,共17页
Spatial variation is often encountered when large scale field trials are conducted which can result in biased estimation or prediction of treatment (i.e. genotype) values. An effective removal of spatial variation is ... Spatial variation is often encountered when large scale field trials are conducted which can result in biased estimation or prediction of treatment (i.e. genotype) values. An effective removal of spatial variation is needed to ensure unbiased estimation or prediction and thus increase the accuracy of field data evaluation. A moving grid adjustment (MGA) method, which was proposed by Technow, was evaluated through Monte Carlo simulation for its statistical properties regarding field spatial variation control. Our simulation results showed that the MGA method can effectively account for field spatial variation if it does exist;however, this method will not change phenotype results if field spatial variation does not exist. The MGA method was applied to a large-scale cotton field trial data set with two representative agronomic traits: lint yield (strong field spatial pattern) and lint percentage (no field spatial pattern). The results suggested that the MGA method was able to effectively separate the spatial variation including blocking effects from random error variation for lint yield while the adjusted data remained almost identical to the original phenotypic data. With application of the MGA method, the estimated variance for residuals was significantly reduced (62.2% decrease) for lint yield while more genetic variation (29.7% increase) was detected compared to the original data analysis subject to the conventional randomized complete block design analysis. On the other hand, the results were almost identical for lint percentage with and without the application of the MGA method. Therefore, the MGA method can be a useful addition to enhance data analysis when field spatial pattern exists. 展开更多
关键词 Spatial Variation Linear Mixed Model Approach Experimental Design Moving Grid Adjustment Crop Trial
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Numerical Modelling of Sediment Particle Transportation on a Navigation Inlet Using the Particle Tracking Model (PTM)
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作者 Lloyd Ndlovu Zaid Mustafa 《Open Journal of Civil Engineering》 2024年第3期374-390,共17页
This paper investigates particle transportation using a numerical model application approach to understand the final fate of suspended sediment particle masses due to a dredging operation in a navigational harbor inle... This paper investigates particle transportation using a numerical model application approach to understand the final fate of suspended sediment particle masses due to a dredging operation in a navigational harbor inlet using PTM (Particle Tracking Model). The investigation applied PTM and simulated particle transportation at a navigational harbor called St Jerome Creek Inlet in Chesapeake Bay in Maryland. The United States Army Corps of Engineers (USACE), Maryland District, designed jetties for the inlet, which, when constructed, would minimize dredging requirements from once in a two-year period to once in a ten-year period. In the meantime, due to the frequent dredging requirements of the inlet, there exists a need to understand the fate of the suspended sediments from the dredging operations to assess the environmental impact on the aquatic environment and the coastal community. This study used PTM to simulate the transportation of sediments in a 30-day period during a dredging operation. Ten sediment source locations were selected as possible sites from which dredged materials could be introduced into the flow system. The model output was analyzed to draw conclusions. Results showed that most suspended sediment particle masses moved from their initial site locations and settled along the shoreline, whilst the sediments that found their way out of the inlet system towards the ocean migrated southward and settled approximately 6 miles at the tip of the mainland. The objective of the study is to track sediment particles from a dredging operation. This would be significant in tracking possible contaminants in an aquatic environment for future environmental management decisions. 展开更多
关键词 PTM Suspended Sediments DREDGING Particle Tracking
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Phytoremediation Strategies for Heavy Metal Contamination: A Review on Sustainable Approach for Environmental Restoration
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作者 Mariam Salifu Matthew Abu John +3 位作者 Murtala Abubakar Ibukunoluwa Abimbola Bankole Nneka Damola Ajayi Olawumi Amusan 《Journal of Environmental Protection》 2024年第4期450-474,共25页
Current globalization trends and important breakthroughs globally need a complete study of heavy metal contamination, its causes, its impacts on human and environmental health, and different remediation strategies. He... Current globalization trends and important breakthroughs globally need a complete study of heavy metal contamination, its causes, its impacts on human and environmental health, and different remediation strategies. Heavy metal pollution is mostly produced by urbanization and industry, which threatens ecosystems and human health. Herein, we discuss a sustainable environmental restoration strategy employing phytoremediation for heavy metal pollution, the carcinogenic, mutagenic, and cytotoxic effects of heavy metals such as cadmium, copper, mercury, selenium, zinc, arsenic, chromium, lead, nickel, and silver, which may be fatal. Phytoremediation, which was prioritized, uses plants to remove, accumulate, and depollute pollutants. This eco-friendly method may safely collect, accumulate, and detoxify toxins using plants, making it popular. This study covers phytostabilization, phytodegradation, rhizodegradation, phytoextraction, phytovolatilization, and rhizofiltration. A phytoremediation process’s efficiency in varied environmental circumstances depends on these components’ complex interplay. This paper also introduces developing phytoremediation approaches including microbe-assisted, chemical-assisted, and organic or bio-char use. These advancements attempt to overcome conventional phytoremediation’s limitations, such as limited suitable plant species, location problems, and sluggish remediation. Current research includes machine learning techniques and computer modeling, biostimulation, genetic engineering, bioaugmentation, and hybrid remediation. These front-line solutions show that phytoremediation research is developing towards transdisciplinary efficiency enhancement. We acknowledge phytoremediation’s promise but also its drawbacks, such as site-specific variables, biomass buildup, and sluggish remediation, as well as ongoing research to address them. In conclusion, heavy metal pollution threatens the ecology and public health and must be reduced. Phytoremediation treats heavy metal pollution in different ways. Over time, phytoremediation systems have developed unique ways that improve efficiency. Despite difficulties like site-specificity, sluggish remediation, and biomass buildup potential, phytoremediation is still a vital tool for environmental sustainability. 展开更多
关键词 PHYTOREMEDIATION HEAVY-METAL CONTAMINATION SUSTAINABILITY RESTORATION
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Epidemiology and Clinical Features of Mycobacterium avium Complex Pulmonary Disease in a Brazilian Amazon Cohort
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作者 Jose Tadeu Colares Monteiro Adriana Rodrigues Barretto +9 位作者 Ruan Seguin Azevedo Quaresma Bianca Miranda Gouveia Ismari Perini Furlaneto Victória Menezes da Costa Yan Corrêa Rodrigues Layana Rufino Ribeiro Ricardo J. de Paula Souza e Guimarães Alex Brito Souza Ana Roberta Fusco da Costa Karla Valéria Batista Lima 《Advances in Microbiology》 CAS 2024年第6期287-302,共16页
The incidence of Mycobacterium avium complex pulmonary disease (MACPD) has been globally increasing. The present study aims to provide a comprehensive analysis of clinical characteristics and treatment response among ... The incidence of Mycobacterium avium complex pulmonary disease (MACPD) has been globally increasing. The present study aims to provide a comprehensive analysis of clinical characteristics and treatment response among patients in the Amazon region of Brazil and conduct a retrospective cohort study at a prominent referral hospital in the State of Par, Brazil, from 2012 to 2020. The M. avium group represented 58.9% of cases, followed by M. intracellulare (35.7%), M. colombiense (3.6%), and M. chimaera (1.8%). The majority of patients (73.2%) were female and with an average age of 63 years. Primary clinical manifestations included persistent cough and sputum production. The Charlson comorbidity index (CCI) averaged 2.47, with 36.3% of patients having a CCI score equal to higher than 3. Notably, over 70% of patients had received treatment for pulmonary tuberculosis before initiating treatment for MAC infection. The fibrocavitary radiologic form was the most prevalent (55.4%), frequently exhibiting a bilateral distribution (53.6%). Antimicrobial susceptibility revealed a significant prevalence of MAC resistance to drugs in the therapeutic regimen. Despite this, most of the patients experienced clinical improvement (50%). In conclusion, this study highlights a higher prevalence of MAC infections among middle-aged women, with a history of pulmonary tuberculosis treatment and presenting the fibrocavitary radiological form was predominant. 展开更多
关键词 MACDP Nontuberculous Mycobacteria Mycobacterium avium Lung Disease
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基于光谱映射和细节注入的Pansharpening 被引量:1
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作者 刘红毅 赵肖飞 +3 位作者 韩海波 Jenny Qian Du 吴泽彬 韦志辉 《电子学报》 EI CAS CSCD 北大核心 2023年第6期1527-1540,共14页
Pansharpening通过在多光谱图像中注入全色图像的空间细节,从而获得高分辨率的多光谱图像.但细节注入的同时,可能会引起光谱失真.为了提高融合图像的光谱保真,本文提出了一种空谱结合的Pansharpening方法.充分利用全色和多光谱图像之间... Pansharpening通过在多光谱图像中注入全色图像的空间细节,从而获得高分辨率的多光谱图像.但细节注入的同时,可能会引起光谱失真.为了提高融合图像的光谱保真,本文提出了一种空谱结合的Pansharpening方法.充分利用全色和多光谱图像之间潜在的光谱关系,对全色图像的光谱信息进行增强,继而将增强后的全色图像细节注入多光谱图像中,并建立了统一的变分Pansharpening模型,同时实现了融合图像的光谱信息保持和空间结构细节增强.在不同数据集上进行的数值实验表明,相比现有的Pansharpening方法,本文所提方法具有比较好的融合效果,尤其在光谱保真方面,更具有一定的优势. 展开更多
关键词 Pansharpening 多光谱图像 全色图像 光谱映射 细节注入
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强相互作用自旋-轨道耦合与夸克-胶子等离子体整体极化 被引量:8
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作者 高建华 黄旭光 +2 位作者 梁作堂 王群 王新年 《物理学报》 SCIE EI CAS CSCD 北大核心 2023年第7期109-126,共18页
在非对心相对论重离子碰撞中,参与反应的原子核物质系统具有巨大的初始轨道角动量,经过强相互作用的自旋-轨道耦合,这一巨大的轨道角动量可以转化为产生的夸克-胶子等离子体的整体极化.整体极化效应在理论上提出后,首先被美国布鲁克海... 在非对心相对论重离子碰撞中,参与反应的原子核物质系统具有巨大的初始轨道角动量,经过强相互作用的自旋-轨道耦合,这一巨大的轨道角动量可以转化为产生的夸克-胶子等离子体的整体极化.整体极化效应在理论上提出后,首先被美国布鲁克海文国家实验室的相对论重离子对撞机上的STAR实验所证实,激发了人们对相关问题的研究,成为重离子碰撞物理研究的一个新方向——重离子碰撞自旋物理.本文简单回顾了整体极化原始基本思想、理论计算体系与主要结果以及近几年的理论进展. 展开更多
关键词 自旋-轨道耦合 整体极化 自旋效应 相对论重离子碰撞
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生命起源前手性对映体富集与放大的数学规律与实验
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作者 朱华结 李志伟 +2 位作者 贾云静 朱玉俊 Charles U.Pittman,Jr 《河北科技大学学报》 CAS 北大核心 2023年第6期589-602,共14页
生命起源前的原始海洋(池)中,由于没有手性源,手性化合物在合成过程中可能受到其他不对称因素(如手性对称性破缺)等影响,它们几乎都是以极小%ee值的非外消旋体(non-racemic enantiomers)存在。从数学理论出发,结合化学反应原理,推导出... 生命起源前的原始海洋(池)中,由于没有手性源,手性化合物在合成过程中可能受到其他不对称因素(如手性对称性破缺)等影响,它们几乎都是以极小%ee值的非外消旋体(non-racemic enantiomers)存在。从数学理论出发,结合化学反应原理,推导出这些非外消旋体在通过某种反应后,其较小的%ee值(%ee 1)可以富集到较大的%ee值(%ee 2),尤其在很低%ee值的情况下,理论上其放大倍数(%ee 2/%ee 1)可以是指数级别的增加,而这是生命起源前得到高含量对映体(如L-氨基酸)所需要的。进一步使用约1%ee值的L-色氨酸甲酯(L-TME),通过与双功能基团物质(如乙二醛)发生反应,在0℃~室温条件下,将其放大富集到3.4%(%ee 2)。系列实验表明:最大放大倍数(%ee 2/%ee 1)可达1.9(从6.1%的%ee 1提高到11.7%的%ee 2);单次最大增量(Δ%ee=%ee 2-%ee 1)达到12.3%(从44.2%(%ee 1)提高到56.5%(%ee 2))。 展开更多
关键词 计算化学 手性富集/放大 对映体 史前时代 L-氨基酸
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对抗性自动编码网络在高光谱异常检测中的应用
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作者 杜谦 谢卫莹 《测绘学报》 EI CSCD 北大核心 2023年第7期1105-1114,共10页
自动编码器(autoencoder,AE)是一种典型的生成模型。由于它具有简单的学习过程、良好的收敛能力和无监督的特性而得到了广泛的应用。AE的目标函数仅是输入输出之间的重构误差。为了提高其性能,提出了对抗性自动编码器(adversarial autoe... 自动编码器(autoencoder,AE)是一种典型的生成模型。由于它具有简单的学习过程、良好的收敛能力和无监督的特性而得到了广泛的应用。AE的目标函数仅是输入输出之间的重构误差。为了提高其性能,提出了对抗性自动编码器(adversarial autoencoder,AAE),可以为原始的AE网络提供变分推理输出。本文回顾有关无监督和半监督的AAE模型在高光谱异常检测(hyperspectral anomaly detection,HAD)中的应用。除了在隐层空间中使用对抗性学习外,还可以通过在编码器的输入和解码器的输出之间添加对抗性学习来提高AAE的性能;通过这种方式,改进后的AAE网络可以更专注于学习数据分布而不仅是点对点的数值重建。试验结果表明,利用这些深度学习模型完成HAD任务的想法超越了传统HAD方法的概念,显著提高了检测性能。 展开更多
关键词 高光谱影像 异常检测 自动编码器 对抗性自动编码器 对抗学习
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Antifungal Activity of Poncirus trifoliata Roots against Colletotrichum Species
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作者 Kumudini M. Meepagala Tamang Prabin 《Agricultural Sciences》 CAS 2023年第3期346-355,共10页
Fruits and vegetables are an essential part of a healthy diet, providing humans with vitamins, phytonutrients, and minerals. They are significantly vulnerable, however, to post-harvest diseases caused by numerous fung... Fruits and vegetables are an essential part of a healthy diet, providing humans with vitamins, phytonutrients, and minerals. They are significantly vulnerable, however, to post-harvest diseases caused by numerous fungal and bacterial pathogens. These pathogens can cause significant quantitative and qualitative losses from harvest to consumption during the handling and storage processes. Chemical fungicides are commonly used but are likely to leave residues on the produce, rendering short shelf-life produce, such as berries, unsuitable for human consumption. Identifying eco-friendly methods to control post-harvest disease is, therefore, of utmost importance. The presence of antifungal constituents in the roots of Poncirus trifoliata extracts was detected by thin layer chromatography-based bioautography. The active constituents were isolated and identified by bioautography assay-guided fractionation using flash chromatography followed by spectroscopic techniques. In this study, xanthoxyletin, demethylsuberosin, dentatin, nordentatin, ponfolin, and clausarin were isolated from the root extracts. The antifungal activity of these compounds was moderate to weak compared to the commercial fungicide captan. This study reports the isolation and identification of natural compounds from Poncirus trifoliata that exhibited antifungal activity against Colletotrichum fragariae and Botrytis cinerea, two major post-harvest pathogens. 展开更多
关键词 Poncirus trifoliata BIOAUTOGRAPHY Colletotrichum fragariae FUNGICIDE
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Nonstandard Unitary Transformations of Quantum States
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作者 Gombojav O. Ariunbold 《Journal of Applied Mathematics and Physics》 2023年第9期2568-2575,共8页
In quantum optics, unitary transformations of arbitrary states are evaluated by using the Taylor series expansion. However, this traditional approach can become cumbersome for the transformations involving non-commuti... In quantum optics, unitary transformations of arbitrary states are evaluated by using the Taylor series expansion. However, this traditional approach can become cumbersome for the transformations involving non-commuting operators. Addressing this issue, a nonstandard unitary transformation technique is highlighted here with new perspective. In a spirit of “quantum” series expansions, the transition probabilities between initial and final states, such as displaced, squeezed and other nonlinearly transformed coherent states are obtained both numerically and analytically. This paper concludes that, although this technique is novel, its implementations for more extended systems are needed. 展开更多
关键词 Taylor Series Unitary Transformation Temporal Evolution Displaced State Coherent State Squeezed State Two-Mode Squeezed State Holstein-Primakoff State
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Quantum Dynamics via a Hidden Liouville Space
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作者 Gombojav O. Ariunbold 《Journal of Applied Mathematics and Physics》 2023年第7期1871-1880,共10页
The traditional simulations may occasionally turn out to be challenging for the quantum dynamics, particularly those governed by the nonlinear Hamiltonians. In this work, we introduce a nonstandard iterative technique... The traditional simulations may occasionally turn out to be challenging for the quantum dynamics, particularly those governed by the nonlinear Hamiltonians. In this work, we introduce a nonstandard iterative technique where the Liouville space is briefly expanded with an additional (virtual) space only within ultrashort subintervals. This tremendously reduces the cost of time-consuming calculations. We implement our technique for an example of a charged particle in both harmonic and anharmonic potentials. The temporal evolutions of the probability for the particle being in the ground state are obtained numerically and compared to the analytical solutions. We further discuss the physics insight of this technique based on a thought-experiment. Successive processes intrinsically “hitchhiking” via virtual space in discrete ultrashort time duration, are the hallmark of our technique. We believe that this technique has potential for solving numerous problems which often pose a challenge when using the traditional approach based on time-ordered exponentials. 展开更多
关键词 Liouville Space S-Operator Time-Ordered Exponentials Quantum Oscillators SQUEEZING Husimi Q-Function
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基于粒子群算法的多次反射飞行时间质量分析器电压优化
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作者 黄奇 任熠 +6 位作者 陈政阁 陈剑松 洪义 梁欣 李梅 黄正旭 周振 《质谱学报》 EI CAS CSCD 北大核心 2023年第5期667-675,I0004,共10页
多次反射飞行时间(MR-TOF)是一种新型的质量分析器,常用于分析短寿命离子、分离同重元素和存储离子。随着使用需求的增加,提高MR-TOF质量分析器的分辨能力越来越重要。然而,MR-TOF质量分析器电压参数的优化涉及高维度、高精细度和非线... 多次反射飞行时间(MR-TOF)是一种新型的质量分析器,常用于分析短寿命离子、分离同重元素和存储离子。随着使用需求的增加,提高MR-TOF质量分析器的分辨能力越来越重要。然而,MR-TOF质量分析器电压参数的优化涉及高维度、高精细度和非线性的问题,很难用解析方法得到最优参数。本研究提出了一种基于粒子群(PSO)算法的MR-TOF质量分析器电压参数优化方法,并对粒子群算法进行改进。在SIMION离子光学仿真平台上对优化方法进行测试,比较了标准粒子群算法和改进粒子群算法的优化结果。结果表明,改进粒子群算法能够获得超过810000的极限质量分辨率,相比标准粒子群算法有更好的性能。该方法具有操作简单、优化速度快、求解效果好等优点,可为MR-TOF质量分析器的电压优化提供方法参考,从而提高MR-TOF质量分析器的开发效率。 展开更多
关键词 多次反射飞行时间质量分析器 粒子群算法(PSO) 电压优化 离子光学模拟
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Building Detection and Counting in Convoluted Areas Using Multiclass Datasets with Unmanned Aerial Vehicles (UAVs) Imagery
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作者 Shital Adhikari Vaghawan Prasad Ojha 《Advances in Remote Sensing》 2023年第3期71-87,共17页
This paper studies the effect of breaking single-class building data into multi-class building data for semantic segmentation under end-to-end architecture such as UNet, UNet++, DeepLabV3, and DeepLabv3+. Although, th... This paper studies the effect of breaking single-class building data into multi-class building data for semantic segmentation under end-to-end architecture such as UNet, UNet++, DeepLabV3, and DeepLabv3+. Although, the already existing semantic segmentation methods for building detection work on the imagery of developed world, where the buildings are highly structured and there is a clearly distinguishable space present between the building instances, the same methods do not work as effectively on the developing world where there is often no clear differentiable spaces between instances of building thus reducing the number of detected instances. Hence as a noble approach, we have added building contours as new class along with building segmentation data, and detected the building contours and the inner building regions, hence giving the precise number of buildings existing in the input imagery especially in the convoluted areas where the boundary between the buildings are often hard to determine even for human eyes. Breaking down the building data into multi-class data increased the building detection precision and recall. This is useful in building detection where building instances are convoluted and are difficult for bare instance segmentation to detect all the instances. 展开更多
关键词 Multi-Class Segmentation Building Segmentation Remote Sensing Semantic Segmentation UNet
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Different Resistance Exercise Interventions for Handgrip Strength in Apparently Healthy Adults: A Systematic Review
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作者 Takashi Abe Ricardo B. Viana +1 位作者 Scott J. Dankel Jeremy P. Loenneke 《International Journal of Clinical Medicine》 2023年第12期552-581,共30页
Background: Although handgrip strength is a biomarker for morbidity/mor-tality, there is lack of evidence on the effects of resistance training on handgrip strength in healthy adults of all ages. Objective: The aim of... Background: Although handgrip strength is a biomarker for morbidity/mor-tality, there is lack of evidence on the effects of resistance training on handgrip strength in healthy adults of all ages. Objective: The aim of this systematic review was to assess the impact of resistance training on handgrip strength in healthy adults. Methods: Five databases/search engines were searched. Studies comparing different types of resistance exercise interventions versus a non-exercised control group on handgrip strength were included. The available data did not allow us to conduct the pre-planned meta-analyses;therefore, only descriptive statistics were performed to summarize the data. Results: Twenty studies (17 randomized and three non-randomized controlled trials) were included, most of which were conducted in older adults. Twelve studies reported no significant difference in the change in handgrip strength between the resistance training and control groups. Two studies showed increases in handgrip strength in the resistance training group compared with the control group. Other studies included results for multi-training groups or left/right hands and found increasing handgrip strength compared to controls, but only in one training group or one hand. Overall, the randomized and non-ran-domized clinical trials presented moderate risk of bias. Conclusions: Due to the lack of low risk-of-bias randomized controlled trials of young and middle-aged adults, different training protocols, and small sample sizes, the existing evidence appears insufficient to support resistance training for increasing handgrip strength in healthy adults. Future studies may seek to discern the optimal way to develop and employ resistance training to improve hand-grip strength. 展开更多
关键词 Grip Strength Strength Training BIOMARKER Healthy Adults
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Treatment and Maintenance of Interstitial Cystitis/Bladder Pain Syndrome in Female Patients with Cetirizine-Famotidine: A Case Series
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作者 Reed B. Hogan II Paul H. Moore III +1 位作者 Doug Paul Thomas P. Dooley 《Case Reports in Clinical Medicine》 2023年第2期61-71,共11页
Purpose: Interstitial cystitis/Bladder pain syndrome is an inflammatory disorder of the bladder, for which histamine has been implicated in the pathogenesis of the disease. The condition is often refractory to standar... Purpose: Interstitial cystitis/Bladder pain syndrome is an inflammatory disorder of the bladder, for which histamine has been implicated in the pathogenesis of the disease. The condition is often refractory to standard-of-care medical treatments, including the antihistamines hydroxyzine or cimetidine, and procedures. Herein we report a physician-sponsored proof-of-principle case series of four adult female patients with chronic painful bladder and frequent urination, who were treated once daily with a low dose H1 + H2 histamine receptor antagonist combination. Materials and Methods: Four adult females with Interstitial cystitis/Bladder pain syndrome were treated once daily with a compounded oral dosage form containing the H1 receptor antagonist-cetirizine 8 mg in combination with the H2 receptor antagonist-famotidine 22 mg. The case series consists of a retrospective review of the symptom severity prior to versus following H1 + H2 treatment. Results and Conclusions: The once daily dual histamine receptor antagonist therapy substantially reduced the pain and urination frequency, and prophylactically maintained all four patients long-term with substantially reduced disease severity. The reduction in symptom severity was achieved at amounts that do not exceed the US FDA approved and exceptionally safe daily doses for the two over-the-counter monotherapies. This case series provides proof-of-principle evidence that a dual antihistamine combination of cetirizine plus famotidine effectively treated and maintained female patients, who were previously refractory to standard-of-care medications and/or procedures. 展开更多
关键词 HISTAMINE ANTIHISTAMINE Bladder TREATMENT PROPHYLAXIS
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