BZ振荡反应实验的课程思政设计

传统BZ振荡反应实验着重于耗散结构知识的传授和诱导期反应活化能的测量。本案例基于同心圆生长过程呈现的丰富多彩的现象和蕴含的人生哲理,以耗散结构理论为支撑,对实验内容进行了创新设计,引入同心圆实验内容和翻转学习模式,在提升学生科学素养和研究能力的同时,引导学生分析实验中存在的安全隐患和对环境可能造成的影响,在实验过程中融入对人生的思考,在课后利用耗散结构相关原理去认识世界和改造世界。改进后实验将有助于树立学生正确的人生观和世界观。

基于改进A^(*)算法+LM-BZS算法的农业机器人路径规划

针对目前农业机器人在全局路径规划过程中存在规划效率低、规划路径折线段多、折线角度大、作业不稳定等问题,以果园履带机器人为运动学模型,提出一种基于改进A^(*)算法+低阶多段贝塞尔曲线拼接(Low-order multi-segment Bezier curve splicing,LM-BZS)算法的路径规划方法。首先,根据先验地图获取果园环境信息,将果树和障碍物视作不可通行区域,并结合机器人本体尺寸,对不可通行区域进行膨胀拟合处理;然后,利用改进A^(*)算法搜索路径,对初步生成路径进行树行节点调整;最后,采用LM-BZS算法对调整后的路径点进行优化处理,生成符合果园履带机器人作业要求的行驶路径。仿真试验结果表明,相较于传统A^(*)算法,本文所提出的改进算法在无障碍和有障碍环境中,路径规划时间分别减少76.75%、86.40%,节点评估数量分别减少36.68%、39.37%;经LM-BZS算法优化所得路径在无障碍环境中,相较于传统A^(*)算法和高阶贝塞尔算法,平均曲率分别降低45.81%、18.94%;在有障碍环境中平均曲率分别降低56.98%、27.81%。场地试验结果表明,果园履带机器人在对本文算法生成路径进行跟踪行驶时,在无障碍和有障碍环境中,最大横向误差分别为0.428、0.491 m,平均横向误差分别为0.232、0.276 m,平均航向偏差分别为11.06°、13.76°,符合果园履带机器人自主行驶条件。

河控型浅水三角洲前缘河道砂体结构特征--以渤海湾盆地黄河口凹陷BZ34油区明下段Ⅱ油组为例

新近系明化镇组下段(明下段,N1ml)为黄河口凹陷BZ34油区的主力含油层段,该时期主要发育河控型浅水三角洲前缘沉积。为更好地表征前缘砂体的结构特征及展布规律,以BZ34油区明下段Ⅱ油组为例,综合应用岩芯、地震属性和测井等资料,分析总结了该地区的砂体沉积类型、砂体结构及沉积模式。研究结果表明:BZ34油区明下段Ⅱ油组砂体以浅水三角洲前缘水下分流河道为主;依据测井形态和叠置关系,将其砂体结构类型划分为4种:块状切叠型河道、层状叠置型河道、层状孤立型河道和指状孤立型河道;砂体结构展布特征及成因主要受古地形、沉积物供给速率、基准面旋回和古气候等因素影响。BZ34油区的水下分流河道沉积,具有垂向上交错叠置、平面上摆动连片的分布特征,与鄱阳湖现代河控浅水三角洲河道的沉积特征类似。该研究对BZ34油区后期部署加密调整井和剩余油挖潜工作具有指导意义。

Synthesis of a benzoxazine monomer containing maleimide and allyloxy groups

A novel benzoxazine monomer 3-（4-allyloxy）phenyl-3,4-dihydro-2H-6-（N-maleimido）-l,3-benzoxazine （AMB） was synthesized and structure was confirmed by FT-IR, 1H NMR. Thermal analysis （DSC） of AMB showed the introduction of allyloxy group melting point and exhibited a narrow and symmetric curing exothermic window.

Theoretic Study of 3-(4-N-Maleimido)-phenyl-2,4-dihydro-2H-1,3-benzoxazine Molecular Structure,Spectrum and Thermodynamic Properties

The geometric structures,electronic absorption spectrum,and thermodynamic pro-perties of 3-（4-N-maleimido）-phenyl-2,4-dihydro-2H-1,3-benzoxazine molecule were studied at the B3LYP/6-311＋G＊ level by density functional theory.The results show that three rings of this molecule are in different planes.In gas,absorption wavelength of the lowest energy excitation was obtained at 503 nm,and solvents made it blue-shifted by 3-7 nm,both corresponding to the electron transition of HOMO → LUMO.At 298.15 K,the standard molar formed enthalpy and free energy of the title compound molecule were-549.43 and-273.37 kJ·mol-1,respectively.

Synthesis of benzoxazine-based phenolic resin containing furan groups

A novel benzoxazine-based phenolic resin containing furan groups（PFB） was synthesized via simple two-step reactions and the structure of PFB was confirmed by FTIR and ~1H NMR spectra.Differential scanning calorimetry（DSC） showed that the polybenzoxazine cured from PFB had good heat resistance and lower polymerization temperature compared with that of benzoxazine-based phenolic resins.

Synthesis of a novel benzoxazine containing benzoxazole structure

A high-purity benzoxazine（Boz-BOA） containing benzoxazole structure was successfully synthesized by three-step synthetic method using 2-（4-aminophenyl）-1H-benzoxazole-5-amine（BOA） and ortho-hydroxybenzaldehyde.The structure of Boz-BOA was confirmed by FTIR and;H NMR spectra.The DSC was utilized to probe the curing behavior of Boz-BOA and exhibited a narrow melting peak and curing exothermic peak.

Synthesis of 3-Phenyl-6-formyl-3, 4-dihydro-2H-1, 3-benzoxazine

A novel benzoxazine monomer containing aldehyde group, 3-phenyl-6-formyl-3, 4-dihydro-2H-1, 3-benzoxazine （Ald-B）, was synthesized via the Mannich condensation of formaldehyde, p-hydroxybenzaldehyde and aniline. Its structure was characterized by Fourier transform infrared spectroscopy （FTIR）, proton nuclear magnetic resonance （^1HNMR）. The side reaction in the synthesis is discussed.

Terresoxazine,A Novel Compound with Benzoxazine Skeleton from Tribulus terrestris

Terresoxazine, a novel benzoxazine derivative was isolated from the fruits of Tribulus terrestris. Its structure was determined as 7-hydroxy-3, 3a-dihydro-5H-pyrrolo-[1,2-a] [3,1] -benzoxazin-1(2H)-one, on the basis of the spectral techniques and X-ray crystallographic analysis.

Morphological, mechanical and thermal properties of cyanate ester/benzoxazine resin composites reinforced by silane treated natural hemp fibers

This present study deals with the reinforcement of thermosetting resin blends composed of cyanate ester(CE) and benzoxazine(BOZ) resins with natural hemp fibers(NHFs). These NHFs were initially treated by using a silane coupling agent(SCA) in order to chiefly enhance their distributions as well as adhesions within the CE/BOZ resin matrix,then incorporated with various weight amounts ranging from 5 wt% to 20 wt% with a regular interval of 5 wt%. The obtained results showed that at the maximum treated fiber loading(20 wt%), distinctive enhancements in the mechanical properties in terms of flexural strength and microhardness were obtained. Besides, the thermal stability and glass transition temperature(Tg) were appreciably enhanced and were higher than those of the pure CE/BOZ resin properties. With respect to the astonishing properties of the NHFs, these enhancements could be possibly due to the good dispersion and adhesion of the treated NHFs inside the CE/BOZ resin achieved upon using the SCA. Therefore,we believe herein that these renewable and cheap NHFs have considerable potential to be used as reinfocer materials for CE/BOZ resin composites to be used in various industrial sectors.

Non-isothermal curing kinetics and thermal properties of benzoxazine-phenolic copolymers

Using novolac phenolic resin, aniline and formaldehyde as raw materials, benzoxazine-phenolic copolymers with different percentages of benzoxazine rings were prepared. FT-IR was adopted to characterize the molecular structure of the novolac-type phenolic resin and the benzoxazine-phenolic copolymer BP31. In order to understand the curing process of the copolymers, the curing behavior and curing kinetic characteristics were studied by differential scanning calorimetry （DSC）, and the catalytical effect of phenolic hydroxyl on the curing behavior of copolymers was investigated. To investigate the thermal properties of this resin, the thermal degradation behaviors of the cured samples were studied by thermal gravimetric （TG） method, and glass-transition temperatures （Tg） of the cured copolymers were also evaluated by DSC. The dynamic Ozawa method was adopted to determine the kinetic parameters of the curing process as well. The activation energy is 78.8 kJ/mol and the reaction rate constant is in the range from 40.0 to 5.2 （K/min）＂ according to reaction temperatures. The Ozawa exponent decreases from 2.4 to 0.7 with the increase of reaction temperature, and curing mechanism is expounded briefly according to the results. TG result shows that the highest char yield of copolymers is 50.3%. The highest Tg of copolymers is 489 K, which is much higher than that of pure benzoxazine resin.

光敏BZ振荡封闭体系振荡频率关系的研究

溴离子是振荡反应的抑制剂,其浓度减小的速率决定了振荡周期中自催化诱导期持续的时间,而振荡周期的总时长则取决于自催化诱导期,因此,溴离子能够影响体系振荡周期。而体系初始存在溴离子时,体系振荡频率与光强的动力学关系尚未研究。因此,在这项工作中,建立了Ru(bpy)_(3)^(2+)催化Belousov-Zhabotinsky(BZ)均相封闭体系,研究溴离子存在时,体系振荡频率与光强的动力学关系,探究BZ反应物浓度对体系振荡频率曲线的影响。研究发现,初始存在溴离子时,体系振荡频率与光强之间仍然存在非单调关系。反应溶液中初始溴化钠浓度对于各反应物调制“振荡频率-光强”的效应起到不同作用:随着NaBrO_(3)浓度和MA浓度增高,体系振荡频率整体上向高频区域移动;随着HNO_(3)浓度的增加,体系振荡频率先向低频区域移动再向高频区域移动;随着NaBr浓度的增加,体系振荡频率向低频区域移动。这一研究为非线性系统的基础研究提供理论参考。

The Spatial and Electronic Effects of Substituent Groups on the Thermal Curing of Bio-Based Benzoxazines

To explore the influence of substituent groups on thermally induced curing,eight new bio-based benzoxazines containing different substituent groups with different electron negativity and volumes were synthesized.The thermal curing of these bio-based benzoxazines was studied in detail.Combined with the curing reaction kinetics,simulation and calculation of Highest Occupied Molecular and Lowest Unoccupied Molecular values,the spatial and electronic effects of different substituent groups on the curing of benzoxazine was explored.It was found that when the substituent was located at the position directly connected to the N atom,the steric hindrance effect of the group was dominant.When the substituent group was located on the benzene ring connected to the O atom,both the electronic effect and the spatial effect influenced the curing of benzoxazine.When an electron-withdrawing group was connected ortho position to the O atom,the curing reaction was promoted due to the decreased electron cloud density of O-on the oxazine ring,making the C-O bond easier to break.When an electron-donating group was connected to the meta position of the O atom it also promoted the curing reaction,possibly because it increased the electron cloud density of the+CH2 reaction site and thereby facilitated electrophilic substitution via attack of+CH2 on the cross linking reaction centre.This work provides a deeper understanding of how spatial and electronic effects of substituents affect the curing of benzoxazine.

Recent Advances in Flame Retardant Bio-Based Benzoxazine Resins

Benzoxazines have attracted wide attention from academics all over the world because of their unique properties.However,most of the production and preparation of benzoxazine resins depends on petroleum resources now,especially bisphenol A-based benzoxazine.Therefore,owing to the environmental impacts,the development of bio-based benzoxazines is gaining more and more interest to substitute petroleum-based benzoxazines.Similar to petroleum-based benzoxazines,most of bio-based benzoxazines suffer from flammability.Thus,it is necessary to endow bio-based benzoxazines with outstanding flame retardancy.The purpose of this review is to summarize the latest advance in flame retardant bio-based benzoxazines.First,three methods of the synthesis of bio-based benzoxazines are introduced briefly.Furthermore,the curing mechanism of benzoxazine and the effect of branched chains on the curing behavior are also discussed and summarized.Subsequently,this review focuses on fully bio-based benzoxazines,partly bio-based benzoxazines,and bio-based benzoxazine composite materials in terms of flame retardancy as well as thermal stability and some other special properties.Finally,we give a brief comment on the challenges and prospects of the future development of flame retardant bio-based benzoxazines.

A New and Efficient Synthesis of 2H-3, 1-Benzoxazine Compounds

2H-3, 1-Benzoxazine derivatives were synthesized by cyclocondensation of 5-nitro-2- cyanoaniline with relative ketone or aldehyde with ZnCl2 as a catalyst. This is a new efficient synthetic route of 2H-3, 1-benzoxazine cyclic compounds.

Thermal Polymerization of Cyanate Ester-Benzoxazine:Study of a Functional Model Compound

A novel benzoxazine(BOZ)monomer is synthesized by a pot method with solvent-free to blend with cyanate ester(CE).A soluble intermediate is obtained after being cured for 20 h at 80℃.The two model compound and the blends are analyzed with the infrared radiation(IR),nuclear magnetic resonance(NMR)spectroscopy,and differential scanning calorimetry(DSC).The results show that an intermediate of the iminocarbonate and BOZ structures is formed by the ring-open BOZ reacting with the cyanate groups and ring-unopened BOZ.Moreover,rearrangement and ring-opening occur in the postcure of the intermediate to form the alkyl isocyanurate structure with polybenzoxazine.

Synthesis of some new N,N'-diarylsubstituted methylene-bis-dihydro-2H-1,3-benzoxazines

The synthesis of a new series of six-membered N,N′-diarylsubstituted methylene-bis-dihydro-2H-1,3-benzoxazines （5a-e） was achieved in excellent yields by Mannich-type condensation of N,N′-diarylsubstituted methylene-bis-o-hydroxybenzyl amines （4a- e） with formaldehyde in chloroform at reflux. These amines （4a-e） were obtained by the reduction of N, Nr-diarylsubstituted methylene-bis-o-hydroxybenzyl imines （3a-e） with NaBH4, which inturn were obtained by the condensation of methylene-bissalicylaldehyde （2） with various substituted arylamines.

渤海BZ油田沙三中段沉积演化特征及有利储层预测

渤海BZ油田沙三中段为特低渗油藏,发育扇三角洲沉积,由于储层横向变化复杂及对“甜点层”认识不清,制约了油田开发进程。本文重点研究沙三中段沉积演化并对其有利储层进行预测,以指导特低渗油藏的开发。综合区域沉积特征、钻井及地震资料,利用残余厚度法和印模法相结合的方法进行古地貌研究的结果认为,沙三中段主要发育古洼陷、古斜坡、古沟谷和古凸起4种古地貌单元;通过岩芯观察和测井相分析认为,沙三中段主要发育分流河道、河口坝、浊流、分流间湾和前扇三角洲泥沉积微相。综合研究认为,小层沉积微相及厚度与古地貌形态具有较好的相关性。古洼陷储层主要发育分流河道及河口坝优质微相且沉积厚度最大,古斜坡和古沟谷次之,古凸起最差。综合古地貌、沉积微相及演化特征分析,有利储层主要受控于古地貌及沉积微相。以储层厚度和物性综合确定出沙三中段的“甜点”区分布,为特低渗油藏不同井区采取不同的开发策略提供了地质依据。

利用BZ化学振荡体系检测中草药中的姜黄素

试验建立了一种在规则振荡的KBrO3-CH2(COOH)2-Ce(SO4)2-H2SO4化学振荡体系中加入不同浓度的姜黄素,根据体系振幅的变化量与姜黄素浓度之间的关系定量测定姜黄素的新方法,并分析了姜黄素对体系的扰动机理.结果表明:当姜黄素的浓度在2.00×10-6～2.04×10-4 mol/L范围内时,其浓度的对数与体系振幅的变化值存在良好的线性关系,检测限达7.80×10-7 mol/L;利用非线性化学振荡体系对姜黄提取液中姜黄素的含量进行测定,其结果与紫外-可见分光光度法一致.因此,非线性化学振荡体系是一种简单快速检测姜黄素的新方法.

BZ反应系非理想性对化学振荡动力学区域的影响

基于Ｄｅｂｙｅ－Ｈｕｃｋｅｌ强电解质溶液活度系数理论、反应速度的活化络合物理论以及三变量微分方程奇点理论，探讨了非理想性对ＢＺ反应体系振荡动力学区域的影响．以Ｏｒｅｇｏｎａｔｏｒ为模型建立了均匀体系非理想ＢＺ反应的系统动力学方程，计算并绘制了化学振荡的临界“溴酸钠浓度－离子强度”阈值图谱，划分了不同的动力学区域，并进行了一系列实验研究。