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Design and experimental study of a planetary gearing mechanism based on twice unequal amplitude transmission ratio

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International Journal of Agricultural and Biological Engineering 2022年第1期15卷 155-163页

作者： Jiangang Liu Gaohong yu Zhipeng Tong yao hua School of Mechanical Engineering&Automation Zhejiang Sci-Tech UniversityHangzhou 310018China College of Mechanical and Electrical Engineering Wuyi UniversityWuyishan 354300FujianChina Zhejiang Province Key Laboratory of Transplanting Equipment and Technology Hangzhou 310018China

To obtain the optimal seedling taking trajectory,this study proposed the adjustment of the total transmission ratio curve by using human-computer *** the basis of this design method,a planetary non-circular gear mechanism was designed that can realize the twice unequal amplitude transmission ratio to meet the seedling harvesting *** cubic non-uniform B-spline curve was used to fit the twice unequal amplitude transmission ratio curve,and the transmission ratio was freely distributed in two *** seedling pick-up mechanism was designed by controlling the seedling taking track and the corresponding attitude directly through the local section of the total transmission ratio,and the gear pitch curve was directly controlled by the transmission *** kinematics model of the seedling pick-up mechanism was also ***,the influence of the total transmission ratio on the seedling picking track,the ratio of the wave crest to the amplitude,and the mechanism parameters were discussed.A human-computer interactive optimization software was developed using Matlab,and a set of optimal parameters for the seedling pick-up mechanism was obtained to meet the transplanting *** using the Adams software,the virtual prototype simulation of the seedling pick-up mechanism was completed,and the idle experiment for the track and attitude of the prototype was conducted through high-speed camera *** theoretical,simulated,and experimental trajectories were consistent with each *** revealed that the success rate of the seedling picking exceeded 90%when the rotation speeds were 40 r/min,50 r/min,and 60 r/min,and the qualified rate of the matrix decreased with the increase in rotating ***,the number of damaged plants increased with the increase in rotating *** experimental results showed that the seedling pick-up mechanism designed using the proposed method demonstrated a good effect and met the requir

关键词： seedling pick-up mechanism second unequal amplitude planetary gear train seedling picking experiment

Visible Light-Induced Methoxycarbonyldifluoromethylation of Trime-thylsilyl Enol Ethers and Allyltrimethylsilanes with FSO2CF2CO2Me

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Chinese Journal of Chemistry 2018年第11期36卷 1024-1030页

作者： Wei yu yao Ouyang Xiu-hua Xu Feng-Ling qing Key Laboratory of Organofluorine Chemistry Center for Excellence in Molecules Synthesis Shanghai Institute of Organic Chemistry Chinese Academy of Science 345 Lingling Lu Shanghai 200032 China Key Laboratory of Science and Technology of Eco-Textiles Ministry of Education College of Chemistry Chemical Engineering and Biotechnolo- gy Donghua University 2999 North Renmin Lu Shanghai 202620 China

A photocatalytic methoxycarbonyldifluoromethylation of trimethylsilyl enol ethers with FSO2CF2CO2Me in the presence of fac‐Ir(ppy)3 was developed. This reaction provided a practical strategy for the construction of various α‐CF2CO2R aromatic ketones, which are difficult to access by other methods. Furthermore, a series of methoxycarbonyldifluoromethylated allylic compounds could also be obtained from allyltrimethylsilanes using the same strategy. The resulting CF2CO2R‐containing products are useful building blocks and potentially valuable in medicinal chemistry and material sciences.

关键词： methoxycarbonyldifluoromethylation silyl enol ether allylsilane ketones allylic compounds radical reactions

Research on fast solid state DC breaker based on a natural current zero-crossing point

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Journal of Modern Power Systems and Clean Energy 2014年第1期2卷 30-38页

作者： Wang XIANG yu hua Jinyu WEN Meiqi yao Naihu LI State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and TechnologyWuhan 430074China Alstom Grid China Technology Center(CTC) Minhang DistrictShanghai 201114China

The DC fault characteristics of voltage source converter based high voltage direct current(VSC-HVDC)systems are analyzed in this *** phenomenon whereby the capacitor on DC side discharges quickly during a DC fault contributes to a large short-circuit fault *** traditional DC breakers nor DC switches can cut off the fault current under this condition.A fast solid state DC breaker design method is proposed in this *** method is based on the fault current characteristics of the inverter in multi-terminal HVDC systems(MTDC),where a fault current appears at the natural zerocrossing point near the *** this point,by coordinating the AC breakers near the rectifier,the DC breaker could reliably cut off the DC fault current and protect the system.A detailed model for this fast solid state DC breaker and its operation sequence are studied,based on this design *** modeling a five-terminal meshed DC grid and a fast DC breaker were carried out with PSCAD/EMTDC using this design *** results from the simulations confirmed the validity of the design method.

关键词： VSC-HVDC Multi-terminal HVDC DC short circuit fault DC breaker

利用RNAi技术抑制马铃薯类受体激酶基因(StRLK)表达的研究

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华北农学报 2012年第4期27卷 18-22页

作者：朱云樊娜娜于耀华张柏顺杨煜晁祥建郭宝太金黎平郭晓李广存青岛农业大学生命科学院山东青岛266109 山东省农业科学院蔬菜研究所国家蔬菜改良中心山东分中心山东省设施蔬菜分子生物学重点实验室山东济南250100 中国农业科学院蔬菜花卉研究所北京100081

植物类受体蛋白激酶(Receptor-like protein kinase,RLK)是蛋白激酶的一个亚家族,参与植物的信号转导,在植物生长发育、抗病等过程中起重要作用。在前期研究中自二倍体马铃薯高抗青枯病基因型ED13中获得了类受体蛋白激酶基因StRLK。利用... 详细信息

植物类受体蛋白激酶(Receptor-like protein kinase,RLK)是蛋白激酶的一个亚家族,参与植物的信号转导,在植物生长发育、抗病等过程中起重要作用。在前期研究中自二倍体马铃薯高抗青枯病基因型ED13中获得了类受体蛋白激酶基因StRLK。利用StRLK基因的特异区段,以pUCCRNAi为中间克隆载体、pCHF1为植物表达载体,构建了该基因的RNA干扰载体pCHF1-StRLK。进一步以ED13的茎段为外植体,利用农杆菌介导法将pCHF1-StRLK导入ED13中,获得了5株再生植株。用CaMV35S启动子特异引物对5株再生植株进行PCR扩增,均得到大小约500 bp的特异性条带,初步证明pCHF1-StRLK成功转入ED13。以ED13为对照,利用StRLK基因的特异引物对这5株再生植株进行半定量RT-PCR分析,结果表明,该基因的表达在5个转基因植株中均受到了不同程度的抑制,说明导入的pCHF1-StRLK发挥了干扰活性,且干扰效果与基因的插入位点有关,为进一步研究StRLK基因的功能提供依据。

关键词：二倍体马铃薯 StRLK基因遗传转化 RNA干扰

Investigation on the Natural Modes of A Semi-Closed Floating Tank

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China Ocean Engineering 2023年第4期37卷 580-587页

作者： WANG Guo KONG yao-hua GE Jun-bo MA yu-xiang SUN Lei State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China Marine Design and Research Institute of China Shanghai 200011China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China

Vessels with semi-closed tanks(i.e.,well docks)are widely applied in the military operation and maritime *** water is bound by the semi-closed floating tank and forced by both the incident waves and ship’s *** free surface oscillations inside the flooded well dock is thus distinctive and very *** far,the natural modes of semi-closed floating tanks have not yet been *** paper investigates the characteristics of natural modes of a floating semi-closed tank by combining a mode-resolving model based on mild-slope equations and a hydrodynamic model based on computational fluid *** show that the first three natural periods(i.e.,74,23.6,and 14 s)of the tank fall into the band of swell and infragravity waves and they could be triggered under certain ***-period free surface oscillations are observed inside the tank,including the longest natural period(i.e.,74 s),though the incident waves are monochromatic.A possible generation mechanism for the long-period mode is explained on the basis of liquid sloshing and harbor ***,a long-period component with a period close to the natural mode of well dock is observed in the ship motions,which is generated by the interaction between the waves and ship.

关键词： floating semi-closed tank water free surface oscillations natural period natural mode mild-slope equa-tions computational fluid dynamics

基于反应气混合物的ICP-MS/MS测定原油中的钒和镍

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光谱学与光谱分析 2025年第1期45卷 101-106页

作者：蔡松韬黄莹秀袁亮代宇宣莫垚坤黄建华湖南工学院材料科学与工程学院湖南衡阳421002 湖南省中医药研究院中药研究所湖南长沙410013

原油中金属元素钒和镍(V和Ni)的含量和比值可为深入了解原油的沉积环境特征和有机质类型发挥重要作用。在原油炼制过程中,V和Ni作为原油催化裂化过程中的有害金属元素,会降低催化剂的活性,严重时会导致催化剂中毒,会严重腐蚀设备,在精... 详细信息

原油中金属元素钒和镍(V和Ni)的含量和比值可为深入了解原油的沉积环境特征和有机质类型发挥重要作用。在原油炼制过程中,V和Ni作为原油催化裂化过程中的有害金属元素,会降低催化剂的活性,严重时会导致催化剂中毒,会严重腐蚀设备,在精炼之前必须对原油中的V和Ni进行脱除处理。V和Ni具有致突变性和致癌性,识别或监测原油中V和Ni进入环境的潜在危险变得越来越重要,对原油中V和Ni的含量进行高灵敏精准测定具有重要意义。采用电感耦合等离子体串联质谱(ICP-MS/MS)测定原油中V和Ni的新策略。原油样品经航空煤油简单稀释后直接采用ICP-MS/MS进行分析,针对V和Ni受到的质谱干扰,在MS/MS模式下,采用由NH_(3)/He(He为缓冲气)和H_(2)组成的反应气混合物(NH_(3)/He/H_(2))作为反应气,基于V^(+)与NH_(3)/He/H_(2)不发生反应,而V^(+)的干扰离子与NH_(3)/He/H_(2)发生反应,采用原位质量法消除干扰,选择V^(+)进行测定;基于Ni^(+)与NH_(3)/He/H_(2)发生反应,采用质量转移法消除干扰,选择无干扰团簇离子Ni(NH_(3))_(3)^(+)进行测定。通过与NH_(3)/He反应模式进行对比研究发现,对于V的测定,加入H_(2)为反应气能快速去除氩基离子的干扰,并能协同NH_(3)消除氧化物离子的干扰;对于Ni的测定,加入H_(2)为反应气能促进全氢加合物(-NH_(3))的形成,从而提高生成Ni(NH_(3))_(3)^(+)的产率。在NH_(3)/He/H_(2)反应模式下,V和Ni的背景等效浓度(BEC)更低,Ni的灵敏度更高,V和Ni的检出限(LOD)分别低至0.83和3.76 ng·kg^(-1),定量限(LOQ)分别为2.77和12.5 ng·kg^(-1)。通过分析标准参考物质NIST SRM 1634c并进行加标回收实验评价方法的准确度和精密度,结果显示,方法的测定结果与标准参考物质的认证值基本一致,V和Ni的加标回收率分别为97.7%和103%,相对标准偏差(RSD)分别为1.8%和1.9%。所建立的分析方法避免了繁琐的样品预处理过程,具有操作简单快速、灵敏度高、准确度和精密度好的特点,适用于原油中V和Ni的检测,能为原油深加工中V和Ni的脱除提供理论依据。

关键词：原油电感耦合等离子体串联质谱钒(V) 镍(Ni) 氨气/氦气/氢气(NH_(3)/He/H_(2))

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高粱红色素的超声波提取及其真丝染色

印染 2017年第5期43卷 32-36页

作者：梁娟吴晋川韩丽娟罗艳辉赵坤伟黄玉华蒲宗耀四川省纺织科技情报中心站四川成都610072 四川省纺织科学研究院四川成都610072 高技术有机纤维四川省重点实验室四川成都610072

采用超声波技术提取高粱红色素,研究了提取工艺对提取效果的影响,确定了合适的提取工艺为:超声波功率180 W,超声处理时间30 min。将提取的高粱红色素用于阳离子改性真丝染色,经固色处理后真丝织物的耐摩擦色牢度达到4~5级,耐皂洗色牢度... 详细信息

采用超声波技术提取高粱红色素,研究了提取工艺对提取效果的影响,确定了合适的提取工艺为:超声波功率180 W,超声处理时间30 min。将提取的高粱红色素用于阳离子改性真丝染色,经固色处理后真丝织物的耐摩擦色牢度达到4~5级,耐皂洗色牢度4~5级。

关键词：天然染料染色高梁红色素超声波提取工艺丝织物

Crystal Structure of (R)-3,3′-Bis(benzyloxymethyl)-1,1′-bi-2,2′-naphthol and Its Applications in Enantioselective Lewis Acid Catalyzed Addition of Diethylzinc to Aldehydes

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Chinese Journal of Structural Chemistry 2007年第2期26卷 133-138页

作者： LIU Guo-hua yu Han XUE yun-Ning yao Mei FANG Hai-Bin Department of Chemistry College of Life and Environmental Science Shanghai Normal University Shanghai 200234 China

The title compound （R）-3,3＇-bis（benzyloxymethyl）-1,1＇-bi-2,2＇-naphthol （R）-3 has been synthesized through the deprotection of MOM group by iprOH/HCl in 83% isolated yield and the suitable single crystals for X-ray diffraction were obtained by recrystallization at room temperature from the mixture solvents. Crystallographic data for （R）-3： C36H30O4, Mr = 526.60, triclinic, space group P1, a = 10.057（6）, b = 11.934（7）, c = 12.314（6） A, α = 85.52（2）, β = 70.245（13）, γ = 76.554（11）°, Z= 2, V 1352.8（13） A^3, Dc = 1.293 g/cm^3, F（000） = 556, R = 0.0745, wR = 0.1933 and #（MoKa） = 0.083 mm^-1. The title compound （R）-3 was found to be effective in the enantioselective addition of diethylzinc to aldehydes both in the presence and absence of Ti（Oipr）4. In the latter case, （R）-3 showed much higher catalytic activity and enantioselectivity than （R）-BINOL＇s.

关键词： crystal structure BINOL derivative asymmetric addition

适变与应变:“十五五”时期人口发展规划的新格局、新挑战及其实践路径

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河北学刊 2025年第1期45卷 130-139页

作者：陆杰华冯雨欣北京大学中国社会与发展研究中心北京大学社会学系

“十五五”时期是中国基本实现社会主义现代化承上启下的关键时期,同时也是人口发展深度转型的重要节点。“十五五”人口发展规划的制定必须准确识别人口规模、结构、素质、分布等要素呈现的趋势性变化,及时把握当前人口发展的潜在机遇... 详细信息

“十五五”时期是中国基本实现社会主义现代化承上启下的关键时期,同时也是人口发展深度转型的重要节点。“十五五”人口发展规划的制定必须准确识别人口规模、结构、素质、分布等要素呈现的趋势性变化,及时把握当前人口发展的潜在机遇和堵点难点,根据人口发展新格局适时调整应变思路,不断推进人口自身均衡发展,以及人口与经济社会、资源环境的协调发展。从长远来看,人口发展规划的制定还需要纵向锚定人口高质量发展的战略目标,形成应对未来人口发展新变化的超前预案。

关键词： “十五五” 人口发展规划人口高质量发展适变与应变