Main observation and conclusion A redox-neutral Fe-catalyzed intramolecular C-H amidation of N-benzoyloxyureas is described.This methodology employs a simple iron complex in situ generated from Fe(OTf)2 and bipyridine as the catalyst and N-benzoyloxyureas
随着空间技术日益成熟,商业领域不断出现更高空间分辨率、光谱以及更多时相的卫星影像。与此同时,航空影像在精度不断提高的同时,航测过程更趋于稳定、流程也更为规范。二者的充分发展并不意味着一方可以取代另外一方,在实际的项目中,根据对航片测图和卫星影像测图两者优势以及地理信息比例尺和所需测量范围的不同,或各取其中一种应用方式,或二者结合,往往能提高工作效率,降低测图成本。
使用分子动力学模拟方法在NVT系综下对结构完整CO2水合物以及结构缺陷CO2水合物进行了导热模拟计算.对于结构完整的CO2水合物,在200-230 K温度区间内,体系导热系数由0.4684 W
2020年10月,华为推出Mate 40系列旗舰手机,在全球范围内首次实现车道级导航功能,实时显示用户所在车道位置.rn2020年11月,小鹏汽车智能轿跑P7,通过OTA升级,在深圳、重庆、杭
Monitoring the structural transitions of individual molecules is of great significance because it helps to in depth explore the properties of molecules and prov
题目设0<θ≤2π.若存在实数φ,使得对于任意的正整数n,均有cos(nθ+φ)<√3/2。求所有这样的θ的个数.原高考填空题是求θ的最小值,用反证法不难解决.现在改为求θ的所有值,难点在于证明下文中的θ为有理数.
Carbohydrates have gained a lot of appreciation in the past few decades due to their important roles in numerous biological events.Acquiring a structurally well
李德仁院士是业内较早一批着力关注到国家对新基建重大部署,并持续宣导、奔走呼吁的专家之一,在近期很多重大场合,他把"新基建""5G/6G" "北斗+,+北斗""从数字化到智能化"统筹纳入《论时空智能的万物互联》报告中,设计出大量可为万物互联的数字中国和智慧社会作出更大贡献的学术方向和应用前景。他所处的高度,他所获取信息的渠道,他敏锐的所见和所思,伴随他的报告和呼吁奔涌而出。
Main observation and conclusion Through the intramolecular cyclization of N-methoxybenzamides,a simple and efficient method for constructing valuable isoindolinones under metal-free conditions was developed.The reaction was featured by employing low-cost
Main observation and conclusion Two new pairs of monoterpenoid indole alkaloids(MIAs)enantiomers as well as their new congeners were isolated from stems of Tabernaemontana bovina Lour.(Apocynaceae).Their structures were elucidated by spectroscopic analyse