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In situ synthesis of a spherical covalent organic framework as a stationary phase for capillary electrochromatography

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Journal of Pharmaceutical Analysis 2022年第4期12卷 610-616页

作者： Ning He zhentao li Changjun Hu Zilin Chen Department of Orthopedics Trauma and Microsurgery Zhongnan Hospital of Wuhan UniversitySchool of Pharmaceutical SciencesWuhan UniversityWuhan430072China Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Ministry of EducationHubei Province Engineering and Technology Research Center for Fluorinated PharmaceuticalsWuhan430071China

Covalent organic frameworks(COFs)are a novel type of crystalline porous organic polymer materials recently developed.It has several advantages in chromatographic separation field,such as high thermal stability,porosity,structural regularity,and large specific surface area.Here,a novel spherical COF 1,3,5-tris(4-aminophenyl)benzene(TAPB)and 2,5-bis(2-propyn-1-yloxy)-1,4-benzenedicarboxaldehyde(BPTA)was developed as an electrochromatographic stationary phase for capillary electrochromatography separation.The COF TAPB-BPTA modified capillary column was fabricated via a facile in situ growth method at room temperature.The characterization results of scanning electron microscopy(SEM),Fourier transform infrared(FT-IR)spectroscopy,and X-ray diffraction(XRD)confirmed that COF TAPB-BPTA were successfully modified onto the capillary inner surface.The electrochromatography separation performance of the COF TAPB-BPTA modified capillary was investigated.The prepared column demonstrated outstanding separation performance toward alkylbenzenes,phenols,and chlorobenzenes compounds.Furthermore,the baseline separations of non-steroidal anti-inflammatory drugs(NSAIDs)and parabens with good efficiency and high resolution were achieved.Also,the prepared column possessed satisfactory precision of the intra-day runs(n=5),inter-day runs(n=3),and parallel columns(n=3),and the relative standard deviations(RSDs)of the retention times of tested alkylbenzenes were all less than 2.58%.Thus,this new COF-based stationary phase shows tremendous application potential in chromatographic separation field.

关键词： Covalent organic frameworks In situ growth method Capillary electrochromatography Electrochromatographic separation

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A benzenesulfonic acid-modified organic polymer monolithic column with reversed-phase/hydrophilic bifunctional selectivity for capillary electrochromatography

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Journal of Pharmaceutical Analysis 2023年第2期13卷 209-215页

作者： Yikun liu Ning He Yingfang Lu Weiqiang li Xin He zhentao li Zilin Chen Department of Orthopedics Trauma and Microsurgery Zhongnan Hospital of Wuhan UniversitySchool of Pharmaceutical SciencesWuhan UniversityWuhan430072China Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Ministry of EducationHubei Province Engineering and Technology Research Center for Fluorinated PharmaceuticalsWuhan430071China

Here,a styrene-based polymer monolithic column poly(VBS-co-TAT-co-AHM)with reversed-phase/hydrophilic interaction liquid chromatography(RPLC/HIliC)bifunctional separation mode was success-fully prepared for capillary electrochromatography by the in situ polymerization of sodium p-styrene sulfonate(VBS)with cross-linkers 3-(acryloyloxy)-2-hydroxypropyl methacrylate(AHM)and 1,3,5-triacryloylhexahydro-1,3,5-triazine(TAT).The preparation conditions of the monolith were optimized.The morphology and formation of the poly(VBS-co-TAT-co-AHM)monolith were confirmed by scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FT-IR).The separation perfor-mances of the monolith were evaluated systematically.It should be noted that the incorporation of VBS functional monomer can provideπ-πinteractions,hydrophilic interactions,and ion-exchange in-teractions.Hence,the prepared poly(VBS-co-TAT-co-AHM)monolith can achieve efficient separation of thiourea compounds,benzene series,phenol compounds,aniline compounds and sulfonamides in RPLC or HIliC separation mode.The largest theoretical plate number for N,N0-dimethylthiourea reached 1.7×10^(5)plates/m.In addition,the poly(VBS-co-TAT-co-AHM)monolithic column showed excellent reproducibility and stability.This novel monolithic column has great application value and potential in capillary electrochromatography(CEC).

关键词： Sodium p-styrene sulfona Stationary phase Monolithic column Capillary electrochromatography Bifunctional interaction

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Multi-stage gas diffusion and its implications for the productivity of coalbed methane in the southern Qinshui Basin, north China

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Frontiers of Earth Science 2023年第1期17卷 109-120页

作者： Hui WANG Yanbin YAO zhentao li Yanhui YANG Junjie YI Yongkai QIU Shengqiang ZHOU School of Energy Resource China University of GeosciencesBeijing 100083China Coal Reservoir Laboratory of National Engineering Research Center of CBM Development&Utilization China University of GeosciencesBeijing 100083China State Key Laboratory of Organic Geochemistry Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China PetroChina Huabei Oilfield Company Renqiu 062552China Institute of Mineral Resources Research Beijing 101300China

The behavior of coalbed methane(CBM)diffusion considerably influences gas productivity.Based on the multi-porous diffusion model and on-site CBM desorption data of coal cores,the behavior of CBM diffusion and its implications on the gas productivity of No.3 coal seam in the southern Qinshui Basin(SQB)were elaborately analyzed.Results indicate that CBM diffusion of No.3 coal seam demonstrates noticeable three-stage characteristics,including the fast diffusion,transitional diffusion,and slow diffusion stages.During the gas diffusion process,the gas content and/or the degree of developed pores and fractures/cleats in coal seams can affect the desorption of CBM and the amount of diffused CBM by influencing the changes in gas pressure in pores,thus controlling the behavior of gas diffusion in different stages.Because gas content and the developed degree of pores and fractures/cleats are closely associated with the deformation degree of the coal seams,variably deformed coal seams exhibit unique characteristics of gas diffusion.The low-deformation degree of the coal seams have a relatively uniform distribution of gas production over the history of a well.By contrast,the moderate-deformation degree of the coal seams have a relatively high rate and amount of gas diffusion in the fast and transitional diffusion stages,producing most of the gas in the early-to-intermediate stages of the wells.Finally,the high-deformation degree of the coal seams has a high rate and amount in the fast diffusion stage,indicating that most of the production stage occurs during the early stage of the gas production history of a well.In summary,the behavior of gas diffusion can be used for predicting gas production potential.

关键词： coalbed methane gas diffusion CBM production coal deformation Qinshui Basin

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基于磁编码器和窄带解调的太阳轮故障检测

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振动．测试与诊断 2024年第2期44卷 365-371,414页

作者：尹兴超郭瑜李震焘华健翔昆明理工大学机电工程学院昆明650500

绝对式磁编码器具有价格低、安装方便等优势,适合于工程应用,但在低转速工况下其角度信号受测量误差的影响较大,需要对角度信号进行拟合以消除测量误差带来的干扰。传统的分段拟合方法在分段点处易出现不连续现象,角度信号的不连续导致... 详细信息

绝对式磁编码器具有价格低、安装方便等优势,适合于工程应用,但在低转速工况下其角度信号受测量误差的影响较大,需要对角度信号进行拟合以消除测量误差带来的干扰。传统的分段拟合方法在分段点处易出现不连续现象,角度信号的不连续导致由其计算的瞬时角速度(instantaneous angular speed,简称IAS)信号中出现虚假冲击,并对基于IAS信号的故障特征提取造成干扰。针对此问题,提出一种基于绝对式磁编码器IAS估计和窄带解调的太阳轮故障检测方法。首先,为保证IAS信号的连续性与平滑性,提出基于最小二乘拟合与5次Hermite插值的方法,实现了对IAS信号的拟合估计和平滑处理;其次,结合窄带解调技术实现了对行星齿轮减速器太阳轮故障特征的有效提取;最后,通过对正常与故障太阳轮的绝对式磁编码器信号分析对比,验证了所提方法的有效性。

关键词：磁编码器行星齿轮箱瞬时角速度信号窄带解调角域同步平均

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一种级间运放共享的MASH结构Σ-Δ调制器

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微电子学 2024年第1期54卷 38-44页

作者：彭蠡霄汪东李振涛邓欢龙睿湘潭大学物理与光电工程学院湖南湘潭411105 湖南毂梁微电子有限公司长沙410005

基于55 nm CMOS工艺,设计了一种级间运放共享的级联噪声整形(MASH)结构Σ-Δ调制器。采用2-2 MASH结构对调制器参数进行了设计。对经典结构的开关电容积分器进行了改进,并应用到调制器电路的设计中,实现了两级调制器之间的运放共享,在... 详细信息

基于55 nm CMOS工艺,设计了一种级间运放共享的级联噪声整形(MASH)结构Σ-Δ调制器。采用2-2 MASH结构对调制器参数进行了设计。对经典结构的开关电容积分器进行了改进,并应用到调制器电路的设计中,实现了两级调制器之间的运放共享,在达到高精度的同时减少了运放的数量,显著降低了MASH结构调制器的功耗。仿真结果表明,在3.3 V电源电压下,调制器信噪失真比为111.7 dB,无杂散动态范围为113.6 dB,整体功耗为16.84 mW。

关键词： Σ-Δ调制器级间运放共享级联噪声整形低功耗

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型槽参数对斜直线槽液膜密封性能的影响

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润滑与密封 2024年第3期49卷 7-14页

作者：李振涛庞敏敏魏慧娟周扬理厉晓英郝木明山东石油化工学院智能制造与控制工程学院山东东营257061 绿色制造与智能控制山东省工程研究中心山东东营257061 烟台工程职业技术学院山东烟台264006 东营市海科瑞林化工有限公司山东东营257200 中国石油大学(华东)新能源学院山东青岛266580

为进一步探索斜直线型槽对密封性能的影响机制,基于质量守恒边界并定义液膜密度比,建立斜直线槽液膜密封动压润滑模型;采用有限差分离散方程,对比分析液膜空化理论与实验值,验证计算模型与程序准确性;研究斜直线型槽参数包括槽数、槽深... 详细信息

为进一步探索斜直线型槽对密封性能的影响机制,基于质量守恒边界并定义液膜密度比,建立斜直线槽液膜密封动压润滑模型;采用有限差分离散方程,对比分析液膜空化理论与实验值,验证计算模型与程序准确性;研究斜直线型槽参数包括槽数、槽深、径向和周向槽宽比对密封性能的影响。结果表明:不同倾斜角时,在临界范围内,增加槽数或增大槽深均有助于提升液膜承载力、增大泄漏量并有效降低液膜空化,尤其在较大倾斜角下;在一定范围内,虽均增大径向和周向槽宽比可提升液膜承载力、促进液膜空化发生及增大泄漏量,但影响规律不尽相同。以提升液膜承载力为目标,得出的最优型槽参数为槽数42、槽深25μm、径向和周向槽宽比分别为0.7和0.6。

关键词：斜直线型槽液膜密封密封性能空化效应液膜承载力

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婴幼儿脑室出血后脑积水的危险因素分析

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临床小儿外科杂志 2024年第3期23卷 242-246页

作者：刘祎秦齐张佳冯孟昭李振涛董辉郑州大学第三附属医院神经外科郑州450052

目的探讨婴幼儿脑室出血后脑积水(posthemorrhagic hydrocephalus,PHH)的相关因素。方法回顾性分析2013年6月至2022年1月郑州大学第三附属医院神经外科收治的112例脑室出血(intraventricular hemorrhage,IVH)患儿临床资料,通过随访IVH... 详细信息

目的探讨婴幼儿脑室出血后脑积水(posthemorrhagic hydrocephalus,PHH)的相关因素。方法回顾性分析2013年6月至2022年1月郑州大学第三附属医院神经外科收治的112例脑室出血(intraventricular hemorrhage,IVH)患儿临床资料,通过随访IVH患儿是否发展为脑积水来探讨PHH的相关因素。将随访过程中出现脑积水者纳入PHH组,未出现脑积水纳入无脑室扩张(resolved ventricular dilation,RVD)组。采用单因素分析及多因素Logistic回归分析探讨IVH后发生脑积水的相关因素。结果112例中,55例(55/112,49%)发生PHH;58例(51.79%)行单纯保守对症治疗,28例(25%)行腰椎穿刺,26例(23.21%)行VPS治疗。5例(4.46%)死亡,其中2例死于肺功能不全,3例死于多器官功能衰竭;107例存活患儿中,随访期间出现3例(2.80%)癫痫,1例(0.93%)视力障碍,6例(5.61%)听力障碍,5例(4.67%)脑性瘫痪。多因素Logistic回归分析结果显示:出生时胎龄28~32周(OR=19.078,95%CI:2.408~151.140,P=0.005)、产前未使用类固醇(OR=20.642,95%CI:1.882~226.404,P=0.013)、脑室出血级别高(OR=94.193,95%CI:16.583~535.043,P<0.001)是PHH发生的独立危险因素。结论IVH患儿低胎龄,脑室出血级别高,产前未使用类固醇均与婴幼儿PHH存在关联。围术期应关注IVH患儿胎龄、产前使用类固醇情况及脑室出血级别,及时干预,避免其发展为PHH,从而改善患儿预后。

关键词：婴幼儿脑积水脑室出血危险因素外科手术

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Influence of cerium and yttrium addition on strength and electrical conductivity of pure aluminum alloys

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Journal of Rare Earths 2024年第3期42卷 600-611,I0006页

作者： Guojian lin Lu li Zhengwei Guo Xianjun Jia Xiao Wang zhentao Yuan Guoxing Zhang Yun Zhan Quan Shan Zulai li Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming650093China Research Center for Analysis and Measurement Kunming University of Science and TechnologyKunming650093China City College Kunming University of Science and TechnologyKunming650051China

To develop pure aluminum alloys with high conductivity and strength, Al-0.2Ce and Al-0.2Ce-0.1Y alloys were prepared by rolling and annealing processes in this study. The effects of trace rare earth elements on the strength and electrical conductivity of the pure aluminum alloys were investigated. It is revealed that the addition of Ce and Y to pure aluminum can effectively enhance the strength and electrical conductivity of the alloys. In Al-0.2Ce, the addition of Ce can effectively refine the grain size of a-Al, with an average grain size of 90.68 μm in the as-cast state. The grain size of the alloy is further reduced to 87.55 μm by the simultaneous addition of Y. The synergistic addition of Ce and Y changes the properties of the alloy. The addition of Ce and Y also produces the Al_(11)Ce_(3) and Al_(3)Y second phases, which have coherent relationship with a-Al. The two-dimensional mismatch degree was calculated to be only 4.43%and 0.85%, respectively, which can provide a certain amount of nucleation substrate for a-Al in the incubation stage. The interfacial match between the L1_(2)structure of Al_(3)Y and a-Al was calculated using first-principles simulations. The results indicate that Al_(3)Y has a strong bonding effect with a-Al. Nanoscale second phases at grain boundaries can be effective in reducing resistivity due to dislocation motion.Nanoscale second phases with better matching interfaces to the substrate have no positive effect on the scattering motion of electrons.

关键词： Pure aluminum Rare earths Impurity purification First-principles calculations Strength-conductivity contradiction

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Application of controlled-release urea increases maize N uptake,environmental benefits and economic returns via optimizing temporal and spatial distributions of soil mineral N

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Pedosphere 2024年第1期34卷 222-235页

作者： Mingxue SUN Juan li lili ZHANG Xiaomeng SU Ning liU Xiaori HAN Songjiang WU zhentao SUN Xiangdong YANG Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences/State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China/Key Laboratory of Plant Nutrition and FertilizerMinistry of Agriculture and Rural AffairsBeijing 100081China Agricultural Development Service Center of Zhuanghe Zhuanghe 116499China Agricultural Technology Extension Center Wafangdian 116300China College of Land and Environment Shenyang Agricultural UniversityShenyang 100866China

The creation of controlled-release urea (CRU) is a potent substitute for conventional fertilizers in order to preserve the availability of nitrogen (N) in soil,prevent environmental pollution,and move toward green agriculture.The main objectives of this study were to assess the impacts of CRU’s full application on maize production and to clarify the connection between the nutrient release pattern of CRU and maize nutrient uptake.In order to learn more about the effects of CRU application on maize yields,N uptake,mineral N (N_(min)) dynamics,N balance in soil-crop systems,and economic returns,a series of field experiments were carried out in 2018–2020 in Dalian City,liaoning Province,China.There were 4 different treatments in the experiments:no N fertilizer input (control,CK);application of common urea at 210 kg ha^(-1)(U),the ideal fertilization management level for the study site;application of polyurethane-coated urea at the same N input rate as U (PCU);and application of PCU at a 20% reduction in N input rate (0.8PCU).Our findings showed that using CRU (i.e.,PCU and 0.8 PCU) may considerably increase maize N absorption,maintain maize yields,and increase N use efficiency (NUE) compared to U.The grain yield showed considerable positive correlations with total N uptake in leaf in U and 0.8 PCU,but negative correlations with that in PCU,indicating that PCU caused excessive maize absorption while 0.8 PCU could achieve a better yield response to N supply.Besides,PCU was able to maintain N fertilizer in the soil profile 0–20 cm away from the fertilization point,and higher N_(min)content was observed in the 0–20 cm soil layer at various growth stages,particularly at the middle and late growing stages,optimizing the temporal and spatial distributions of N_(min).Additionally,compared to that in U,the apparent N loss rate in PCU was reduced by 36.2%,and applying CRU (PCU and 0.8 PCU) increased net profit by 8.5% to 15.2% with less labor and fertilization frequency.It was concluded that using CRU could be an effective N f

关键词： apparent N loss fertilization management green agriculture maize yield N balance N use efficiency

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InCl_3-mediated intramolecular Friedel-Crafts-type cyclization and its application to construct the [6-7-5-6] tetracyclic scaffold of liphagal

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Science China Chemistry 2012年第1期55卷 36-42页

作者： JIANG Hao TIAN LuFeng li zhentao liU Qi li ChuangChuang YAO XinSheng YANG Zhen Institute of Traditional Chinese Medicine and Natural Products Jinan UniversityGuangzhou 510632China Laboratory of Chemical Genomics Shenzhen Graduate School of Peking UniversityShenzhen 518055China and Center for life Sciences Beijing 100871China

A unified strategy toward the construction of the [5.7.6]tricyclic skeleton of liphagal is reported,featuring InCl3-mediated intramolecular Friedel-Crafts-type cyclization.

关键词：分子介导脚手架应用环和 InCl3

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