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Effect of Excited-state Substituent Constant on the UV Spectra of 1,4-disubstituted Benzenes 被引量:9
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作者 陈冠凡 曹晨忠 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2009年第4期366-370,447,共6页
A correlation equation between the UV absorption wavenumbers of 1,4-disubstituted benzenes and the excited-state substituent constant was obtained. For 80 sorts of 1,4- disubstituted benzenes, the correlation coeffici... A correlation equation between the UV absorption wavenumbers of 1,4-disubstituted benzenes and the excited-state substituent constant was obtained. For 80 sorts of 1,4- disubstituted benzenes, the correlation coefficient was 0.9805, and the standard deviation was only 672.27 cm^-1. The results imply that the excited-state substituent constant can be used productively for research on UV energy of 1,4-disubstituted benzenes. The present method provides a new avenue to study the UV absorption spectra of aromatic systems with the excited-state substituent constant, and it is helpful to understand the effect of substituent electrostatic effects on the chemical and physical properties of conjugated compounds with multiple substituents in excited state. 展开更多
关键词 Excited-state substituent constant 1 4-disubstituted benzene UV absorption wavenumber Interaction of substituent
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Synthesis and Infrared Spectra Computation of Sterically Congested 2,2-Disubstituted Indane-1,3-dione Derivatives 被引量:2
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作者 Seyed Mohammad Shoaei Ali Reza Kazemizadeh Ali Ramazani 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2011年第4期568-574,共7页
Sterically congested 2,2-disubstituted indane-1,3-dione derivatives have been syn-thesized and characterized by 1H NMR,13C NMR,FT-IR and elemental analysis.The B3LYP/HF calculations for computation of IR spectra have ... Sterically congested 2,2-disubstituted indane-1,3-dione derivatives have been syn-thesized and characterized by 1H NMR,13C NMR,FT-IR and elemental analysis.The B3LYP/HF calculations for computation of IR spectra have been carried out for the title compounds at the 6-31G and 6-311++G basis set levels.Predicted vibrational frequencies have been assigned and compared with the experimental FT-IR spectra and they are supported each other. 展开更多
关键词 vibrational frequency DFT HF FT-IR spectra 2 2-disubstituted indane-1 3-dione ISOCYAnIDE
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One-pot Synthesis of 2,5-Disubstituted Oxazoles Using Poly[styrene(iodosodiacetate)] 被引量:1
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作者 JiangMinCHEN LuLingWU XianHUANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第2期143-144,共2页
Disubstituted oxazoles were prepared conveniently by treatment of aromatic -methyl ketones and nitriles with poly[styrene(iodosodiacetate)] in one-pot process.
关键词 Poly[styrene(iodosodiacetate)] one-pot synthesis 2 5-disubstituted oxazoles.
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SYNTHESIS AND ANTIBACTERIAL ACTIVITY OF 3,6-DISUBSTITUTED S-TRIAZOLO[3,4-b]-1,3,4-THIADIAZOLES 被引量:1
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作者 Zi Yi ZHANG Xin CHEN Department of Chemistry,Lanzhou University,Lanzhou 730000 《Chinese Chemical Letters》 SCIE CAS CSCD 1991年第4期277-278,共2页
A series of 3,6-disubstituted s-triazolo[3,4-b]-1,3,4-thiadiazoles have been synthesized,whose structures were determined by elemental and spectral analyses;all the new compounds showed significant antibacterial activ... A series of 3,6-disubstituted s-triazolo[3,4-b]-1,3,4-thiadiazoles have been synthesized,whose structures were determined by elemental and spectral analyses;all the new compounds showed significant antibacterial activity. 展开更多
关键词 DMF 甲酰胺 SYnTHESIS AnD AnTIBACTERIAL ACTIVITY OF 3 6-disubstituted S-TRIAZOLO[3 4-b THIADIAZOLES
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Synthesis and <i>in Vitro</i>Biological Activities of 4,5-Disubstituted 1,2,4-Triazole-3-Thiols 被引量:1
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作者 Humaira Nadeem Muhammad Mohsin +3 位作者 Hasan Afzaal Sadaf Riaz Ammar Zahid Syed Aun Muhammad 《Advances in Microbiology》 2013年第4期366-375,共10页
Purpose: The triazole nucleus is an important part of the therapeutically interesting drug candidate as antimicrobial, analgesic, anticancer, anticonvulsant and anti-inflammatory agents. Methods: Therefore, in this st... Purpose: The triazole nucleus is an important part of the therapeutically interesting drug candidate as antimicrobial, analgesic, anticancer, anticonvulsant and anti-inflammatory agents. Methods: Therefore, in this study, twelve 4,5-disubstituted-1,2,4-triazole-3-thiols were synthesized by the reaction of substituted isothiocyanates and hydrazides using the common method of base catalysed intramolecular dehydrative cyclization of substituted thiosemicarbazides 3(a-f) and 4(a-f). The structures of these compounds were characterized by means of FT-IR, 1H-NMR, and elemental analysis data. All these compounds were screened for antibacterial, antioxidant, antitumor and cytotoxic activities. Results: Among these compounds: 5c, 5f and 6f were found active against gram positive cocci, the compounds 5a, 5b, 5d, 6a and 6f showed 85% free radical scavenging effect at 3 ppm when tested for antioxidant activity, 75% tumors inhibition was recorded using 5c, 5d and 6a and brine shrimps lethality assay declared 5a, 5b and 6d was 129.62 μg/ml, 161.577 μg/ml and 81.56 μg/ml respectively. Conclusion: Compounds carrying significant bioactivity can be further studied using animal models to establish their safety profile prior to initiating clinical trials. 展开更多
关键词 4 5-disubstituted 1 2 4-Triazole-3-Thiols Antibacterial Antitumor Antioxidant Cytotoxic
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Synthesis of 2,5-disubstituted tetrahydrofurans from organozinc halides and lactones
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作者 Dan Feng Huang Hai Feng Wang +2 位作者 Chang Ming Xu Teng Niu Yu Lai Hu 《Chinese Chemical Letters》 SCIE CAS CSCD 2010年第5期511-514,共4页
2,5-Disubstituted tetrahydrofurans were obtained from lactones and organozinc halides in moderate to high yield in the presence of Lewis acids.
关键词 Organozinc halides LACTOnES Lactols 2 5-disubstituted tetrahydrofurans Lewis acid
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SOLID-PHASE SYNTHESIS OF 4,5-DISUBSTITUTED 1,2,3-TRIAZOLES
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作者 Chen Xi LI Wen Qiang HUANG Yu LU Bing Lin HE Institute of Polymer Chemistry, Nankai University, Tianjin, 300071 《Chinese Chemical Letters》 SCIE CAS CSCD 1991年第10期773-774,共2页
4-Aryl-5-ethoxycarbonyl-1-H-1,2,3-triazoles have been prepared by treatment of ethyl polystyrylsulfonylacetate with substituted benzaldehydes and then sodium azide.
关键词 OC IR nH KBR SOLID-PHASE SYnTHESIS OF 4 5-disubstituted 1 2 3-TRIAZOLES Ph
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Synthesis of New 1,6-disubstituted Fulvenes
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作者 Hu XIAO Shu Feng CHEN and Xiao Tian LIANG(Institute of Materia Medica, Chinese Academy of Medical Sciences, Beijing, 100050) 《Chinese Chemical Letters》 SCIE CAS CSCD 1996年第10期881-883,共3页
Sixteen new 1,6-disubstituted fulvenes have been prepared by acylation of cyclopentadienyl sodium and the result of preliminary pharmacological tests showed that several of them have antineoplastic activity.
关键词 Synthesis of new 1 6-disubstituted Fulvenes
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THE KINETIC STUDIES ON THE PHOTOISOMERIZATION OF 1,2-DISUBSTITUTED ETHYLENES
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作者 Ling Jiang CHENG~(1,2) Qing Qi CHEN~1 Han Cheng YUAN~3 Jin Shi MA~1 Bao Zhen YAN~3 Guang Zhi XU~2 1 Institute of Photographic Chemistry,Chinese Academy Of Sciences,Beijing 100101 2 Institute of Chemistry,Chinese Academy of Sciences,Beijing 100080 3 Department of Applied Chemistry,Beijing Institute of Chemical Technology,Beijing 100029 《Chinese Chemical Letters》 SCIE CAS CSCD 1993年第4期335-338,共4页
An NMR study on the kinetics of photoisomerization of some important 1,2-disubstituted ethylenes are presented in this study.
关键词 THE KInETIC STUDIES On THE PHOTOISOMERIZATIOn OF 1 2-disubstituted ETHYLEnES THAn LInE
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Solid-Phase Stereoselective Synthesis of (E)-1, 2-Disubstituted Ethenes from Polymer-Sopported a-Selenoaldehydes
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作者 ShouRiSHENG LuLingWU XianHUANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第10期991-992,共2页
Reaction of polymer-supported a-selenoaldehydes with Grignard reagents afforded polymer-bound B-hydroxyalkyl selenides, which treated with thionyl chloride and triethylamine leading to (E)-1, 2-disubstituted ethenes i... Reaction of polymer-supported a-selenoaldehydes with Grignard reagents afforded polymer-bound B-hydroxyalkyl selenides, which treated with thionyl chloride and triethylamine leading to (E)-1, 2-disubstituted ethenes in good yield. 展开更多
关键词 Solid phase organic synthesis a-selenoaldehyde (E)-1 2-disubstituted ethene.
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SYNTHESIS OF 4,6-DISUBSTITUTED 5-THIOXO-1,2,4-TRIAZIN-3-ONE FROM BENZOTHIOFORMANILIDE
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作者 Zhong E LU Tian Lin XU Xiao Dong SHI Department of Chemistry,Suzhou University,Suzhou,215006 《Chinese Chemical Letters》 SCIE CAS CSCD 1991年第7期525-526,共2页
A method of synthesis of 4,6-disubstituted 5-thioxo-1,2,4-triazin- 3-ones from benzothioformanilides and semicarbazide is described.And six new compounds were synthesized by this method.
关键词 SYnTHESIS OF 4 6-disubstituted 5-THIOXO-1 2 4-TRIAZIn-3-OnE FROM BEnZOTHIOFORMAnILIDE
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A Study on the Inclusion of α-Cyclodextrin with Mono-and 1,4-Disubstituted Benzenes by Neural Networks
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作者 Qing Xiang GUO Shi Dong CHU +2 位作者 Yong Min WANG Zhong Xiao PAN Mao Sen ZHANG and You Cheng LIU(Department of Chemical Physics, University of Science and Technology of China, Hefei 230026) 《Chinese Chemical Letters》 SCIE CAS CSCD 1997年第2期145-148,共4页
The association constant (Ka) values were calculated by the function-strengthen ing neural networks (FNN) for the inclusion complexation of α-CD with mono- and 1,4-disubstituted benzenes. The lnKa predicted by FNN fr... The association constant (Ka) values were calculated by the function-strengthen ing neural networks (FNN) for the inclusion complexation of α-CD with mono- and 1,4-disubstituted benzenes. The lnKa predicted by FNN from Rm, π and σ constants of substituents are in great agreement with the experimental data. 展开更多
关键词 MOnO A Study on the Inclusion of Cyclodextrin with Mono-and 1 4-disubstituted Benzenes by neural networks
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Synthesis and Antibacterial Activities of 1,4-Disubstituted Phenyl-5-(halo-2-hydroxyphenyl)imino-1,2,3-triazole
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作者 ZHAO Xu LU Jun-rui +6 位作者 XIN Chun-wei LU Bo-wei BAO Xiu-rong LI Jian-fa LIU Ya YANG Xu-yun YUAN Yi 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2012年第3期424-429,共6页
According to the superposition principle of reinforcement of biological activities, 24 novel 1,4- disubstituted phenyl-5-(halo-2-hydroxyphenyl)imino-l,2,3-triazoles was synthesized and characterized by 1H NMR, ^13C ... According to the superposition principle of reinforcement of biological activities, 24 novel 1,4- disubstituted phenyl-5-(halo-2-hydroxyphenyl)imino-l,2,3-triazoles was synthesized and characterized by 1H NMR, ^13C NMR, elemental analysis and IR. All the target compounds were screened for their antibacterial potential in vitro against Monilia albican, Escherichia coli and Staphylococcus aureus. It was shown that all the compounds possessed efficient antibacterial activities at a concentration of 0.1 mg/mL, even at a concentration of 0.01 mg/mL, some of the compounds still exhibited antibacterial activities against Escherichia coli and Monilia albican. At last, the struc- ture-activity relationship was discussed based on the antibacterial results. 展开更多
关键词 1 4-disubstituted phenyl-5-(halo-2-hydroxyphenyl)imino-l 2 3-triazole Antibacterial activity Structure-activity relationship
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Application of Wolff Rearrangement in the Synthesis of Enantiomerically Pure 4,5-Disubstituted Pyrrolidinones
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作者 候益华 吴鹏 曲朝晖 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 1999年第S1期137-137,共1页
关键词 Application of Wolff Rearrangement in the Synthesis of Enantiomerically Pure 4 5-disubstituted Pyrrolidinones
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SYNTHESIS OF N,N'-DISUBSTITUTED MONOTHIOXAMIDE AND STUDY OF THEIR REACTIONS WITH DIAMINES
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作者 Yu Ren YUAN Da Qing SUN Ke Qian CHEN Zhong E LU Department of Chemistry, Suzhou University, Suzhou, 215006 Hal Kang YANG The Central Laboratory, Suzhou University, Suzhou, 215006 《Chinese Chemical Letters》 SCIE CAS CSCD 1993年第5期379-380,共2页
In this paper, six N,N'-disubstituted aonothioxamides were synthesized and the reactions between these monothioxamines and diamines (1,2-diamino ethane and 1,3-diamino propane) were studied. Some new compounds wer... In this paper, six N,N'-disubstituted aonothioxamides were synthesized and the reactions between these monothioxamines and diamines (1,2-diamino ethane and 1,3-diamino propane) were studied. Some new compounds were synthesized by using these reactions. 展开更多
关键词 OU DISUBSTITUTED MOnOTHIOXAMIDE AnD STUDY OF THEIR REACTIOnS WITH DIAMInES SYnTHESIS OF n n LR UC Za
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Mn基低温脱硝催化剂性能优化研究进展
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作者 许芸 邬博宇 +5 位作者 庄柯 张乾 徐静馨 张深根 朱法华 张柏林 《工程科学学报》 EI 北大核心 2025年第1期142-157,共16页
氮氧化物(NO_(x))是我国首要大气污染物,主要采用选择性催化还原(SCR)技术进行排放控制.研发高效、稳定的低温脱硝催化剂可避免高能耗的烟气再热,具有显著的节能降碳效益.锰氧化物(MnO_(x))因多变的化学态和丰富的晶格缺陷而表现出优良... 氮氧化物(NO_(x))是我国首要大气污染物,主要采用选择性催化还原(SCR)技术进行排放控制.研发高效、稳定的低温脱硝催化剂可避免高能耗的烟气再热,具有显著的节能降碳效益.锰氧化物(MnO_(x))因多变的化学态和丰富的晶格缺陷而表现出优良的氧化还原性能,并具有极强的表面酸性,在催化还原NO_(x)反应中表现出良好的低温活性,但N_(2)选择性低、抗H_(2)O/SO_(2)性能差,难以实现长期的高效稳定脱硝.近年来,改性提升Mn基催化剂的研究十分广泛,加快了Mn基催化剂工业应用的步伐.本文从低温活性、N_(2)选择性和稳定性三个方面,总结了Mn基催化剂的脱硝反应机理、元素掺杂改性、催化剂结构设计等最新研究进展,指出了当前的研究重点和难点,可为下一步研究提供参考. 展开更多
关键词 氮氧化物 选择性催化还原 锰基催化剂 n2选择性 稳定性 元素掺杂
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莫来石-Ti(C,N)复合材料的制备及其力学性能研究 被引量:1
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作者 陈博 董博 +7 位作者 邓承继 邹起良 丁军 朱万政 王前 张雍 祝洪喜 余超 《陶瓷学报》 CAS 北大核心 2024年第1期133-138,共6页
以TiO_(2)粉、石墨粉、Al/Si/Al_(2)O_(3)复合粉体为原料,在氮气气氛下经1400℃~1600℃保温2 h,采用碳热还原氮化法制备得到莫来石-Ti(C,N)复合材料,研究了烧成温度对复合材料物相组成、微观结构与力学性能的影响。结果表明:经1400℃热... 以TiO_(2)粉、石墨粉、Al/Si/Al_(2)O_(3)复合粉体为原料,在氮气气氛下经1400℃~1600℃保温2 h,采用碳热还原氮化法制备得到莫来石-Ti(C,N)复合材料,研究了烧成温度对复合材料物相组成、微观结构与力学性能的影响。结果表明:经1400℃热处理后,试样的物相组成为Ti(C,N)、SiO_(2)和硅线石。随热处理温度升高至1450℃~1600℃,硅线石消失的同时,试样出现了短柱状莫来石,并与无定形SiO_(2)紧密连接,形成有效的化学结合。当烧成温度为1500℃时,大量开口气孔随颗粒重排、界面移动而消失,材料颗粒间结合较为紧密,气孔数量明显减少,该烧成温度下试样具有最佳综合性能,其体积密度、弹性模量、抗折强度和维氏硬度分别为(3.48±0.02) g·cm-3、(138.5±0.1) GPa、(158.0±0.03) MPa和(21.01±0.01) GPa。 展开更多
关键词 TI(C n) 碳热还原氮化 莫来石 微观结构 力学性能
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地特胰岛素与诺和灵N治疗妊娠期糖尿病的疗效观察 被引量:1
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作者 赵瑞娥 王庆铭 李莉 《中国医药指南》 2024年第8期35-37,共3页
目的 进行妊娠期糖尿病临床治疗方案地特胰岛素与诺和灵N的疗效对比观察。方法 选取太仓市第一人民医院2019年1月至2023年10月收治的71例妊娠期糖尿病患者为本次研究对象,应用随机数字表法进行分组,接受诺和灵N治疗的35例组成对照组,地... 目的 进行妊娠期糖尿病临床治疗方案地特胰岛素与诺和灵N的疗效对比观察。方法 选取太仓市第一人民医院2019年1月至2023年10月收治的71例妊娠期糖尿病患者为本次研究对象,应用随机数字表法进行分组,接受诺和灵N治疗的35例组成对照组,地特胰岛素治疗的36例组成观察组。比较临床疗效、血糖、胰岛功能、不良妊娠结局及不良反应。结果 观察组临床疗效有效率、HOMA-β水平均高于对照组(均P <0.05);观察组治疗后空腹血糖、餐后2 h血糖水平、HOMA-IR水平以及不良妊娠结局发生率均低于对照组(均P <0.05);观察组、对照组不良反应分别8.33%、5.71%,对比差异无统计学意义(P <0.05)。结论治疗妊娠期糖尿病对患者应用地特胰岛素疗效比诺和灵N好,可有效控制血糖,改善胰岛功能,能够获得理想的妊娠结局,用药有较高的安全性。 展开更多
关键词 妊娠期糖尿病 诺和灵n 地特胰岛素
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基于改进COF-YOLO v8n的油茶果静态与动态检测计数方法 被引量:5
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作者 王金鹏 何萌 +1 位作者 甄乾广 周宏平 《农业机械学报》 EI CAS CSCD 北大核心 2024年第4期193-203,共11页
针对自然环境下油茶果存在严重遮挡、近景色、小目标等现象,使用YOLO网络存在检测精度低、漏检现象严重等问题,提出对YOLO v8n网络进行改进。首先使用MPDIOU作为YOLO v8n的损失函数,有效解决因为果实重叠导致的漏检问题;其次调整网络,... 针对自然环境下油茶果存在严重遮挡、近景色、小目标等现象,使用YOLO网络存在检测精度低、漏检现象严重等问题,提出对YOLO v8n网络进行改进。首先使用MPDIOU作为YOLO v8n的损失函数,有效解决因为果实重叠导致的漏检问题;其次调整网络,向其中加入小目标检测层,使网络能够关注小目标油茶以及被树叶遮挡的油茶;最后使用SCConv作为特征提取网络,既能兼顾检测精度又能兼顾检测速度。改进COF-YOLO v8n网络精确率、召回率、平均精度均值分别达到97.7%、97%、99%,比未改进的YOLO v8n分别提高3.2、4.8、2.4个百分点,其中严重遮挡情况下油茶检测精确率、召回率、平均精度均值分别达到95.9%、95%、98.5%,分别比YOLO v8n提高4.0、9.1、4.6个百分点。因此改进后COF-YOLO v8n网络能够明显提高油茶在严重遮挡、近景色、小目标均存在情况下的识别精度,减小油茶的漏检。此外,模型能够实现动、静态输入条件下油茶果计数。动态计数借鉴DeepSORT算法的多目标跟踪思想,将改进后COF-YOLO v8n的识别输出作为DeepSORT的输入,实现油茶果实的追踪计数。所得改进模型具有很好的鲁棒性,且模型简单可以嵌入到边缘设备中,不仅可用于指导自动化采收,还可用于果园产量估计,为果园物流分配提供可靠借鉴。 展开更多
关键词 油茶果 机器视觉 COF-YOLO v8n 计数 产量估计
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探讨基于核心指标集构建中医特色的射血分数保留心力衰竭1+N模式疗效评价体系 被引量:1
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作者 董国菊 刘永成 +7 位作者 刘思雨 李知轩 石玉姣 梁小雨 杨晨光 乔文博 张贺 李立志 《环球中医药》 CAS 2024年第6期1022-1027,共6页
核心指标集是就某一特定研究领域达成的所有临床研究都应该测量和报告的最少的临床结局,核心指标集可以提高临床疗效评价的规范性和可比性,是循证医学发展的必然、是中医药临床疗效评价的重要抓手、是推动中医药疗效评价与国际接轨的关... 核心指标集是就某一特定研究领域达成的所有临床研究都应该测量和报告的最少的临床结局,核心指标集可以提高临床疗效评价的规范性和可比性,是循证医学发展的必然、是中医药临床疗效评价的重要抓手、是推动中医药疗效评价与国际接轨的关键。如何运用核心指标集实现临床疗效国际化、标准化的同时,又能遵循中医诊疗特点体现自身优势是中医临床疗效评价的难点。针对这一难点,项目组创新性地提出了1+N模式的射血分数保留心衰(heart failure with preserved ejection fraction, HFpEF)疗效评价体系,即通用的核心指标集“1”+个性化指标集“N”,以满足循证医学和中医学疗效评价的双重需求。本文初探HFpEF疗效评价构建模式,主张在规范化基础上体现多样化和个性化的研究目的需求。结合HFpEF临床疗效评价的现状,综合业内专家意见,探讨了HFpEF 1+N模式疗效评价构建中核心指标集“1”的取舍以及“N”体系的构建思路,以期最大程度的形成符合中医药特色的临床评价体系新范式,推动中医药国际化进程。 展开更多
关键词 核心指标集 射血分数保留心力衰竭 1+n模式 中医临床疗效评价 疗效评价新范式
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