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Engineering The Neck Hinge Reshapes The Processive Movement of Kinesin-3
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作者 LI Dong REN Jin-Qi +2 位作者 SONG Yin-Long LIANG Xin FENG Wei 《生物化学与生物物理进展》 SCIE CAS CSCD 北大核心 2024年第10期2730-2740,共11页
Objective In kinesin-3,the neck coil correlates with the following segments to form an extended neck that contains a characteristic hinge diverse from a proline in KIF13B to a long flexible linker in KIF1A.The functio... Objective In kinesin-3,the neck coil correlates with the following segments to form an extended neck that contains a characteristic hinge diverse from a proline in KIF13B to a long flexible linker in KIF1A.The function of this neck hinge for controlling processive movement,however,remains unclear.Methods We made a series of modifications to the neck hinges of KIF13B and KIF1A and tested their movement using a single-molecule motility assay.Results In KIF13B,the insertion of flexible residues before or after the proline differentially impacts the processivity or velocity,while the removal of this proline increases the both.In KIF1A,the deletion of entire flexible neck hinge merely enhances the processivity.The engineering of these hinge-truncated necks of kinesin-3 into kinesin-1 similarly boosts the processive movement of kinesin-1.Conclusion The neck hinge in kinesin-3 controls its processive movement and proper modifications tune the motor motility,which provides a novel strategy to reshape the processive movement of kinesin motors. 展开更多
关键词 intracellular transport molecular motor kinesin-3 neck hinge processive movement
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Cookie Baking Process Optimization and Quality Analysis Based on Food 3D Printing
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作者 Liu Chenghai Li Jingyi +2 位作者 Wu Chunsheng Zhao Xinglong Zheng Xianzhe 《Journal of Northeast Agricultural University(English Edition)》 CAS 2024年第1期61-73,共13页
In order to obtain better quality cookies, food 3D printing technology was employed to prepare cookies. The texture, color, deformation, moisture content, and temperature of the cookie as evaluation indicators, the in... In order to obtain better quality cookies, food 3D printing technology was employed to prepare cookies. The texture, color, deformation, moisture content, and temperature of the cookie as evaluation indicators, the influences of baking process parameters, such as baking time, surface heating temperature and bottom heating temperature, on the quality of the cookie were studied to optimize the baking process parameters. The results showed that the baking process parameters had obvious effects on the texture, color, deformation, moisture content, and temperature of the cookie. All of the roasting surface heating temperature, bottom heating temperature and baking time had positive influences on the hardness, crunchiness, crispiness, and the total color difference(ΔE) of the cookie. When the heating temperatures of the surfac and bottom increased, the diameter and thickness deformation rate of the cookie increased. However,with the extension of baking time, the diameter and thickness deformation rate of the cookie first increased and then decreased. With the surface heating temperature of 180 ℃, the bottom heating temperature of 150 ℃, and baking time of 15 min, the cookie was crisp and moderate with moderate deformation and uniform color. There was no burnt phenomenon with the desired quality. Research results provided a theoretical basis for cookie manufactory based on food 3D printing technology. 展开更多
关键词 food 3D printing baking process COOKIE quality analysis optimization of process parameter
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Mass Transfer-Promoted Fe^(2+)/Fe^(3+)Circulation Steered by 3D Flow-Through Co-Catalyst System Toward Sustainable Advanced Oxidation Processes
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作者 Weiyang Lv Hao Li +6 位作者 Jinhui Wang Lixin Wang Zenglong Wu Yuge Wang Wenkai Song Wenkai Cheng Yuyuan Yao 《Engineering》 SCIE EI CAS CSCD 2024年第5期264-275,共12页
Realizing fast and continuous generation of reactive oxygen species(ROSs)via iron-based advanced oxidation processes(AOPs)is significant in the environmental and biological fields.However,current AOPs assisted by co-c... Realizing fast and continuous generation of reactive oxygen species(ROSs)via iron-based advanced oxidation processes(AOPs)is significant in the environmental and biological fields.However,current AOPs assisted by co-catalysts still suffer from the poor mass/electron transfer and non-durable promotion effect,giving rise to the sluggish Fe^(2+)/Fe^(3+)cycle and low dynamic concentration of Fe^(2+)for ROS production.Herein,we present a three-dimensional(3D)macroscale co-catalyst functionalized with molybdenum disulfide(MoS_(2))to achieve ultra-efficient Fe^(2+)regeneration(equilibrium Fe^(2+)ratio of 82.4%)and remarkable stability(more than 20 cycles)via a circulating flow-through process.Unlike the conventional batch-type reactor,experiments and computational fluid dynamics simulations demonstrate that the optimal utilization of the 3D active area under the flow-through mode,initiated by the convectionenhanced mass/charge transfer for Fe^(2+)reduction and then strengthened by MoS_(2)-induced flow rotation for sufficient reactant mixing,is crucial for oxidant activation and subsequent ROS generation.Strikingly,the flow-through co-catalytic system with superwetting capabilities can even tackle the intricate oily wastewater stabilized by different surfactants without the loss of pollutant degradation efficiency.Our findings highlight an innovative co-catalyst system design to expand the applicability of AOPs based technology,especially in large-scale complex wastewater treatment. 展开更多
关键词 Advanced oxidation processes 3D co-catalyst Flow-through mode Enhanced mass transfer Complex wastewater treatment
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顾及BDS-3星钟约束的GNSS超快速轨道钟差解算方法 被引量:2
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作者 胡超 王潜心 《测绘学报》 EI CSCD 北大核心 2024年第3期413-424,共12页
BDS-3高稳定星载原子钟作为北斗星座的显著技术优势,在GNSS数据处理中尚未得到充分利用。针对严格时效性限制下GNSS超快速轨道钟差参数精度受限问题,本文提出顾及BDS-3星钟约束的GNSS超快速轨道钟差解算方法。首先,以GNSS轨道钟差参数... BDS-3高稳定星载原子钟作为北斗星座的显著技术优势,在GNSS数据处理中尚未得到充分利用。针对严格时效性限制下GNSS超快速轨道钟差参数精度受限问题,本文提出顾及BDS-3星钟约束的GNSS超快速轨道钟差解算方法。首先,以GNSS轨道钟差参数间相关性为基础,构建顾及BDS-3星钟参数特性的GNSS定轨模型;然后,基于GNSS精密钟差产品,分析星钟约束对GNSS轨道钟差参数精度的影响规律;最后,为克服预报钟差精度与约束筛选对定轨影响,建立BDS-3星钟建模与GNSS超快速轨道钟差估计的同步处理方法。试验结果表明,在BDS-3星钟参数最优约束下,BDS-3与GPS轨道钟差精度可分别提升27.5%、5.1%和20.2%、5.2%;且较传统BDS-3星钟单历元处理策略,基于BDS-3星钟建模与GNSS超快速定轨同步处理方法,GNSS超快速轨道钟差精度可分别提升至4.8%与34.2%,轨道精度实现了毫米级改善。因此,顾及BDS-3星钟约束的GNSS超快速轨道钟差解算方法可有效对BDS-3高稳星钟信息模型化,并实现GNSS超快速轨道钟差精度的优化处理。 展开更多
关键词 BDS-3星钟 GNSS超快速轨道钟差 精密定轨 约束模型 同步处理
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^(10)BF_(3)制备H_(3)^(10)BO_(3)反应进程在线监测
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作者 周文辉 胡石林 +1 位作者 张彦彪 周秀林 《原子能科学技术》 EI CAS CSCD 北大核心 2024年第6期1304-1310,共7页
工业规模生产富集^(10)B的硼酸(H_(3)^(10)BO_(3),^(10)B>19.8%)时需要监测反应的进行程度和判定反应的终点。为解决现有监测方法步骤繁琐、人为误差大、精准度低等问题,本文设计并建造了一套在线监测反应进行程度的实验装置,并采用... 工业规模生产富集^(10)B的硼酸(H_(3)^(10)BO_(3),^(10)B>19.8%)时需要监测反应的进行程度和判定反应的终点。为解决现有监测方法步骤繁琐、人为误差大、精准度低等问题,本文设计并建造了一套在线监测反应进行程度的实验装置,并采用该实验装置对通过富集^(10)B的三氟化硼(^(10)BF_(3),^(10)B>19.8%)与难溶于水的碳酸锶(SrCO_(3))反应制备H_(3)^(10)BO_(3)的实验进行原位、实时、在线监测。测试得到的溶液离子浓度随时间变化的数据曲线可以用c_(t)-c_(1)=c_(0)e^(-kt)公式进行拟合,其拟合系数R^(2)为1.00000。在相同条件下,进行了4次重复性测试实验,得到的4条溶液离子浓度随时间变化的数据曲线用c_(t)-c_(1)=c_(0)e^(-kt)公式拟合,其拟合系数R^(2)都为1.00000,说明用该实验装置进行长时间、多次测试,得到的数据精准度高、误差小、重现性好;且拟合方程的3个参数c1、c0、k的标准偏差(s)均小于0.3%,这说明用c_(t)-c_(1)=c_(0)e^(-kt)方程拟合的精密度高。c_(t)-c_(1)=c_(0)e^(-kt)方程可以用于^(10)BF_(3)制备H_(3)^(10)BO_(3)反应的进行程度监测。实验得到的离子浓度-时间曲线的拟合方程c_(t)-c_(1)=c_(0)e^(-kt)与化学反应的一级动力学方程ct=c_(0)e^(-kt)在表现形式上一致,表明用c_(t)-c_(1)=c_(0)e^(-kt)方程拟合^(10)BF_(3)制备H_(3)^(10)BO_(3)反应的进行程度符合化学反应进行实质,c_(t)-c_(1)=c_(0)e^(-kt)方程能够作为^(10)BF_(3)制备H_(3)^(10)BO_(3)反应进行程度和反应终点的判定依据。^(10)BF_(3)制备H_(3)^(10)BO_(3)较合理的加料方式是难溶固体粉末SrCO_(3)与H2O先混溶,搅拌下形成悬浮液,然后把悬浮液加热至设定温度并保持恒定,再向悬浮液中加入^(10)BF_(3)。在线监测结果表明,^(10)BF_(3)制备H_(3)^(10)BO_(3)需经过3步加羟基脱氟取代反应,其前两步反应是快反应,第3步反应是慢反应,即第3步反应是^(10)BF_(3)制备H_(3)^(10)BO_(3)反应的速率控制步骤。^(10)BF_(3)制备H_(3)^(10)BO_(3)反应为表观化学一级动力学反应。 展开更多
关键词 ^(10)BF_(3) H_(3)^(10)BO_(3) 反应进程 在线监测
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深圳沙河水质净化厂及3#调蓄池工艺设计要点及特点
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作者 黄文章 王子龙 《净水技术》 CAS 2024年第6期169-178,共10页
沙河水质净化厂设计规模为旱季10万m^(3)/d,雨季额外处理10万m^(3)/d初期雨水,3#调蓄池设计规模为15.3万m^(3)。污水及初期雨水处理采用预处理+多段厌氧-好氧(AO)+二沉池+磁混凝高效沉淀池+精密过滤+紫外消毒的工艺,出水水质执行深圳市... 沙河水质净化厂设计规模为旱季10万m^(3)/d,雨季额外处理10万m^(3)/d初期雨水,3#调蓄池设计规模为15.3万m^(3)。污水及初期雨水处理采用预处理+多段厌氧-好氧(AO)+二沉池+磁混凝高效沉淀池+精密过滤+紫外消毒的工艺,出水水质执行深圳市地方标准《水质净化厂出水水质规范》(DB 4403/T 64—2020)B级标准,其中总氮(TN)≤8 mg/L。污泥处理采用离心浓缩+低温热干化工艺,处理后含水率≤40%。作为国内首个将水质净化厂与初期雨水调蓄池深度融合的全地下式水污染治理综合体,项目采用多段AO耦合“3W法”(Wet-Weather-Wastewater法),并以此为核心提出了一种实现大规模污水及初期雨水高标准协同处理的系统解决方案,且无需大幅度增加污水处理设施体量、投资和运行成本。 展开更多
关键词 地下式水质净化厂 3#调蓄池 水污染治理综合体 协同处理 多段AO 3W法”
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Influence of tool rotational speed on mechanical and corrosion behaviour of friction stir processed AZ31/Al_(2)O_(3)nanocomposite 被引量:1
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作者 Ashish Kumar V.P.Singh +5 位作者 Akhileshwar Nirala R.C.Singh Rajiv Chaudhary Abdel-Hamid I.Mourad B.K.Sahoo Deepak Kumar 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第7期2585-2599,共15页
Nano-sized reinforcements improved the mechanical characteristics efficiently by promoting more implicit particle hardening mechanisms compared to micron-sized reinforcements.Nano-sized particles lessen the critical p... Nano-sized reinforcements improved the mechanical characteristics efficiently by promoting more implicit particle hardening mechanisms compared to micron-sized reinforcements.Nano-sized particles lessen the critical particle solidification velocity for swamp and thus offers better dispersal.In the present investigation,the friction stir processing(FSP)is utilized to produce AZ31/Al_(2)O_(3)nanocomposites at various tool rotation speeds(i.e.,900,1200,and 1500 rpm)with an optimized 1.5%volume alumina(Al_(2)O_(3))reinforcement ratio.The mechanical and corrosion behavior of AZ31/Al_(2)O_(3)-developed nanocomposites was investigated and compared with that of the AZ31 base alloy.The AZ31 alloy experienced a comprehensive dynamic recrystallization during FSP,causing substantial grain refinement.Grain-size strengthening is the primary factor contributed to the enhancement in the strength of the fabricated nanocomposite.Tensile strength and yield strength values were lower than those for the base metal matrix,although an upward trend in both values has been observed with an increase in tool rotation speed.An 19.72%increase in hardness along with superior corrosion resistance was achieved compared to the base alloy at a tool rotational speed of 1500 rpm.The corrosion currents(Jcorr)of all samples dropped with increase in the rotational speed,in contrast to the corrosion potentials(Ecorr),which increased.The values of Jcorr of AZ31/Al_(2)O_(3)were 42.3%,56.8%,and 65.5%lower than those of AZ31 alloy at the chosen rotating speeds of 900,1200,and 1500 rpm,respectively.The corrosion behavior of friction stir processed nanocomposites have been addressed in this manuscript which has not been given sufficient attention in the existing literature.Further,this work offers an effective choice for the quality assurance of the FSP process of AZ31/Al_(2)O_(3)nanocomposites.The obtained results are relevant to the development of lightweight automobile and aerospace structures and components. 展开更多
关键词 Friction stir processing AZ31 alloy Al_(2)O_(3) NANOCOMPOSITE Mechanical properties Corrosion resistance
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达比加群酯-d_(3)的合成 被引量:1
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作者 王昌 梁林辉 +2 位作者 姚永秀 梁大伟 董金华 《化学试剂》 CAS 2024年第1期105-110,共6页
研究抗凝血药物达比加群酯-d_(3)的合成工艺。以4-氯-3-硝基苯甲酸甲酯为起始原料,氘代甲胺盐酸盐为氘代试剂,经氘代甲基化、取代、还原、缩合、环合、水解、亲核等反应得到关键氘化中间体3-{[(2-{[(4-氰基苯基)氨基]甲基}-1-(甲基-d_(... 研究抗凝血药物达比加群酯-d_(3)的合成工艺。以4-氯-3-硝基苯甲酸甲酯为起始原料,氘代甲胺盐酸盐为氘代试剂,经氘代甲基化、取代、还原、缩合、环合、水解、亲核等反应得到关键氘化中间体3-{[(2-{[(4-氰基苯基)氨基]甲基}-1-(甲基-d_(3))苯并咪唑-5-基)氧亚基](吡啶-2-基)氨基}丙酸乙酯,而后再经氨解和亲核反应,成功制备稳定的达比加群酯-d_(3),8步反应总产率为6.4%,目标化合物结构经NMR和MS确认,同位素丰度达99.7%。该合成方法原料简单易得、操作简便、重现性好,可用于达比加群酯-d_(3)的合成。 展开更多
关键词 抗凝血药物 达比加群酯-d_(3) 合成工艺 优化 同位素标记
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还原氧化石墨烯膜负载Co_(3)O_(4)活化过硫酸氢钾降解罗丹明B 被引量:1
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作者 蔺甜 阎鑫 王嘉玮 《化学工程》 CSCD 北大核心 2024年第1期24-29,共6页
以RGO(还原氧化石墨烯膜)为载体,采用水热法制备RGO/Co_(3)O_(4)高效复合催化剂。通过XRD(X射线衍射仪)、SEM(扫描电子显微镜)和XPS(X射线光电子能谱仪)等手段对复合催化剂的结构、形貌和化学组成等进行表征,并以RhB(罗丹明B)为降解物... 以RGO(还原氧化石墨烯膜)为载体,采用水热法制备RGO/Co_(3)O_(4)高效复合催化剂。通过XRD(X射线衍射仪)、SEM(扫描电子显微镜)和XPS(X射线光电子能谱仪)等手段对复合催化剂的结构、形貌和化学组成等进行表征,并以RhB(罗丹明B)为降解物评价复合催化剂活化PMS(过硫酸氢钾)的反应活性。另外,考察了PMS质量浓度、RhB初始质量浓度、pH值及温度对催化剂活化PMS降解RhB的影响。结果表明:在PMS质量浓度为100 mg/L、RhB初始质量浓度为10 mg/L、pH值为7、温度为25℃时反应18 min对RhB降解率为98%。自由基捕获实验结合ESR(电子顺磁共振)结果表明体系中同时存在SO_(4)^(-·)和HO·2种活性自由基。循环实验结果显示催化剂经过5次循环使用后对RhB的降解率仍保持90%以上,显示优异的循环稳定性。 展开更多
关键词 还原氧化石墨烯膜 Co_(3)O_(4) 过硫酸氢钾 罗丹明B 高级氧化技术
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Effect of Refrigerant on the Performance of a C3/MRC Liquefaction Process
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作者 Xiao Wu Zhaoting Wang +2 位作者 Longfei Dong Yanping Xin Tianshu Yu 《Fluid Dynamics & Materials Processing》 EI 2023年第1期25-36,共12页
The Mixed Refrigerant(MR)component is an important factor influencing the performances of natural gas lique-faction processes.However,there is a lack of systematic research about the utilization of propane pre-cooled(... The Mixed Refrigerant(MR)component is an important factor influencing the performances of natural gas lique-faction processes.However,there is a lack of systematic research about the utilization of propane pre-cooled(C3/MRC).In this paper,this mixed refrigerant cycle liquefaction process is simulated using the HYSYS software and the main influential parameters involved in the process are varied to analyze their influence on the liquefaction rate and power consumption.The results show that an effective way for lowering the power consumption of the compressor consists of reducing the flow through the compressor through optimization of the percentage of mixed refrigerant.The power consumption of the compressor in the hybrid refrigeration process is affected by both flow and pressure ratios.Its specific power consumption can be reduced by increasing the flow and decreasing the pressure ratio at the same time.The increase in refrigerant pressure at the high-pressure end can significantly mitigate the energy loss of the heat exchanger and compressor. 展开更多
关键词 REFRIGERANT C3/MRC process liquefaction performance power consumption pressure ratio hybrid refrigeration process
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南京地区局地积累型和外来输送型O_(3)污染模拟研究
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作者 裴宇儇 彭薇 +5 位作者 王红磊 卢文 赵天良 刘思晗 武自豪 可玥 《地球与环境》 CAS CSCD 北大核心 2024年第2期154-165,共12页
利用观测资料和WRF-Chem空气质量模式对南京地区局地积累型和外来输送型O_(3)污染过程的时空分布特征和潜在机制进行了研究。结果表明:(1)水平分布特征,在两次O_(3)污染整体过程中,外来输送型O_(3)污染浓度高值区分布范围相比局地积累... 利用观测资料和WRF-Chem空气质量模式对南京地区局地积累型和外来输送型O_(3)污染过程的时空分布特征和潜在机制进行了研究。结果表明:(1)水平分布特征,在两次O_(3)污染整体过程中,外来输送型O_(3)污染浓度高值区分布范围相比局地积累型更大且较为分散。但在两次O_(3)污染过程中最严重的白天,局地积累型O_(3)污染浓度高值区分布范围大且集中,O_(3)浓度大部分均超过160μg/m^(3);而外来输送型O_(3)污染浓度高值区分布范围更小且更为分散,O_(3)浓度在120~160μg/m^(3)的地区范围显著大于局地积累型O_(3)污染;(2)垂直分布特征,在污染过程前期,局地积累型O_(3)污染在2 km以下高度处有着高浓度O_(3),浓度最高超250μg/m^(3),而外来输送型O_(3)污染浓度高值区主要集中在2~2.5 km高度处,且高值区浓度最高不超过200μg/m^(3);在污染过程中期,局地积累型O_(3)污染浓度高值区集中在2 km高度下,且在1 km左右高度处O_(3)浓度出现最大值;而外来输送型O_(3)污染浓度高值区最高可达到2.6 km左右,并且浓度最大值集中在1.5 km高度以下,均超过250μg/m^(3);在污染过程后期,局地积累型O_(3)污染浓度高值区逐渐消散,但外来输送型O_(3)污染在0.5~3 km高度内仍出现大范围O_(3)浓度高值区;(3)在生成机理方面,近地面O_(3)的高浓度在局地积累型O_(3)污染中主要依赖于垂直混合,96h内总贡献为451.7μg/m^(3),在总过程量中占比为66.2%,而在外来输送型O_(3)污染中主要依赖于水平平流和垂直混合,72h内总贡献分别为1050.2μg/m^(3)和799.1μg/m^(3),总量在总过程量中占比为61.5%。在500 m高度处,局地积累型O_(3)污染前期O_(3)的高浓度主要依赖于垂直平流和化学过程,中期只依赖于化学过程,后期则主要依赖于水平平流和化学过程。但在外来输送型O_(3)污染前中后期中高O_(3)浓度均主要依赖于水平平流和化学过程。在1000 m高度处,两个过程中O_(3)浓度的正贡献均主要受化学过程控制。 展开更多
关键词 O_(3) 观测分析 WRF-Chem 过程分析 南京
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鱼油n-3 PUFA富集、稳态化技术及生物活性研究进展
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作者 刘书源 郭明珠 +2 位作者 马爱进 桑亚新 孙纪录 《中国食品学报》 EI CAS CSCD 北大核心 2024年第2期467-478,共12页
鱼油富含人体所需的多不饱和脂肪酸,在科研与应用领域具有广泛价值。本文重点围绕其n-3 PUFA富集工艺、稳态化技术及生物活性进行综述,阐述不同方法的优、缺点,分析工业化生产的可行性,展望未来鱼油加工领域的发展趋势,旨在为鱼油类资... 鱼油富含人体所需的多不饱和脂肪酸,在科研与应用领域具有广泛价值。本文重点围绕其n-3 PUFA富集工艺、稳态化技术及生物活性进行综述,阐述不同方法的优、缺点,分析工业化生产的可行性,展望未来鱼油加工领域的发展趋势,旨在为鱼油类资源的合理、健康、可持续发展提供理论依据。 展开更多
关键词 鱼油 富集工艺 稳态化 n-3 PUFA
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水下搅拌摩擦加工Ti-15-3合金的组织及超塑性变形
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作者 倪立锦 王文 +3 位作者 韩鹏 乔柯 强凤鸣 王快社 《兵器材料科学与工程》 CAS CSCD 北大核心 2024年第4期59-63,共5页
采用水下搅拌摩擦加工技术制备细晶Ti-15V-3Al-3Cr-3Sn(Ti-15-3)合金。通过电子背散射衍射对搅拌区(stirring zone,SZ)晶粒细化机制进行分析。用电子万能试验机对SZ试样进行超塑性拉伸。结果表明:SZ高角度晶界比例为74.5%,平均晶粒尺寸... 采用水下搅拌摩擦加工技术制备细晶Ti-15V-3Al-3Cr-3Sn(Ti-15-3)合金。通过电子背散射衍射对搅拌区(stirring zone,SZ)晶粒细化机制进行分析。用电子万能试验机对SZ试样进行超塑性拉伸。结果表明:SZ高角度晶界比例为74.5%,平均晶粒尺寸为1.8μm,主要的晶粒细化机制为连续动态再结晶;在变形温度为675℃,应变率为3×10^(-4)s^(-1)时,SZ试样的伸长率达到了465%,为超塑性,主要变形机制为晶界滑移,同时伴随连续动态再结晶和β→α相变。 展开更多
关键词 水下搅拌摩擦加工 TI-15-3合金 显微组织 超塑性 晶界滑移
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一种3-溴芴酮的合成工艺
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作者 韩蒙蒙 马欣 +4 位作者 李瑞 陈鹏丽 李奎 杨振强 申奥 《化工技术与开发》 CAS 2024年第10期11-13,22,共4页
3-溴芴酮是制备有机电致发光材料、太阳能电池材料等功能性材料的重要中间体。本文以2-氨基芴为起始原料,经溴代反应、重氮化反应和氧化反应合成了3-溴芴酮产物。针对氧化过程中溶剂及碱的种类对收率的影响进行了优化选择。较佳的反应... 3-溴芴酮是制备有机电致发光材料、太阳能电池材料等功能性材料的重要中间体。本文以2-氨基芴为起始原料,经溴代反应、重氮化反应和氧化反应合成了3-溴芴酮产物。针对氧化过程中溶剂及碱的种类对收率的影响进行了优化选择。较佳的反应条件是:以四氢呋喃作为溶剂,氢氧化钾作为碱时,3-溴芴酮的收率较高,纯度达到99.9%,产品的质量好,生产成本较低,适合工业化生产。 展开更多
关键词 2-氨基芴 3-溴芴酮 合成工艺
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弥散铜/35Cr电触头材料的热变形行为
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作者 马紫鹏 田保红 +4 位作者 殷婷 周孟 李恒 景柯 刘勇 《中国有色金属学报》 EI CAS CSCD 北大核心 2024年第5期1589-1598,共10页
通过快速热压烧结和内氧化法相结合制备了Al_(2)O_(3)-Cu/35Cr复合材料,在变形温度和试验速率分别为650~950℃和0.001~1 s^(-1)下,采用Gleeble−1500D型试验机对材料进行热变形试验,通过其真应力−真应变曲线分析了两种试验参数对流变应... 通过快速热压烧结和内氧化法相结合制备了Al_(2)O_(3)-Cu/35Cr复合材料,在变形温度和试验速率分别为650~950℃和0.001~1 s^(-1)下,采用Gleeble−1500D型试验机对材料进行热变形试验,通过其真应力−真应变曲线分析了两种试验参数对流变应力的影响,并构建了复合材料的本构方程和热加工图,分析其热加工参数。结果表明:复合材料的Cr颗粒均匀分布在纳米γ-Al_(2)O_(3)弥散强化Cu基体上,其烧结态致密度、导电率和显微硬度分别为98.9%、44.4%IACS和145HV。Al_(2)O_(3)-Cu/35Cr复合材料具有热敏感性和正应变速率相关性,并且在变形量为0.3~0.5时最佳变形温度和应变速率参数分别为650~680℃、0.55~1 s^(-1)和810~950℃、0.007~0.123 s^(-1)。 展开更多
关键词 Al_(2)O_(3)-Cu/35Cr复合材料 热变形 本构方程 热加工图
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Thermodynamic Analysis and Optimization of the C3/MRC Liquefaction Process
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作者 Guisheng Wang 《Energy Engineering》 EI 2023年第6期1503-1514,共12页
In the natural gas liquefaction process,the mixed refrigerant natural gas liquefaction process is widely used in LNG liquefaction plants because of its advantages of low energy consumption.This paper focuses on the in... In the natural gas liquefaction process,the mixed refrigerant natural gas liquefaction process is widely used in LNG liquefaction plants because of its advantages of low energy consumption.This paper focuses on the influences of important parameters in the C3/MRC liquefaction process,that is,the comparison between propane precooling temperature and the number of moles of methane in mixed refrigerant,power consumption and loss.In addition,the total process was optimized with the optimizer and manual adjustment in HYSYS software to minimize the total power consumption.The results show that with increasing propane precooling temperature,the propane flow rate is almost unchanged,while the mixed refrigerant flow rate decreases significantly,and the loss of the heat exchanger increases significantly.The power consumption of the propane precooling cycle and hybrid refrigeration cycle increases with increasing methane content in the refrigerant,so the power consumption of the whole process increases accordingly.The effect of the methane content in the mixed refrigerant on the process evaluation index is more significant than that of the propane precooling temperature. 展开更多
关键词 C3/MRC process propane precooling temperature methane content OPTIMIZATION
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Point Cloud Processing Methods for 3D Point Cloud Detection Tasks
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作者 WANG Chongchong LI Yao +2 位作者 WANG Beibei CAO Hong ZHANG Yanyong 《ZTE Communications》 2023年第4期38-46,共9页
Light detection and ranging(LiDAR)sensors play a vital role in acquiring 3D point cloud data and extracting valuable information about objects for tasks such as autonomous driving,robotics,and virtual reality(VR).Howe... Light detection and ranging(LiDAR)sensors play a vital role in acquiring 3D point cloud data and extracting valuable information about objects for tasks such as autonomous driving,robotics,and virtual reality(VR).However,the sparse and disordered nature of the 3D point cloud poses significant challenges to feature extraction.Overcoming limitations is critical for 3D point cloud processing.3D point cloud object detection is a very challenging and crucial task,in which point cloud processing and feature extraction methods play a crucial role and have a significant impact on subsequent object detection performance.In this overview of outstanding work in object detection from the 3D point cloud,we specifically focus on summarizing methods employed in 3D point cloud processing.We introduce the way point clouds are processed in classical 3D object detection algorithms,and their improvements to solve the problems existing in point cloud processing.Different voxelization methods and point cloud sampling strategies will influence the extracted features,thereby impacting the final detection performance. 展开更多
关键词 point cloud processing 3D object detection point cloud voxelization bird's eye view deep learning
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Al_(2)O_(3)-Cu/25Cr复合材料的热变形行为与热加工图
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作者 李恒 田保红 +3 位作者 周孟 马紫鹏 景柯 刘勇 《材料热处理学报》 CAS CSCD 北大核心 2024年第6期139-146,共8页
采用内氧化-快速热压烧结方法制备了Al_(2)O_(3)-Cu/25Cr复合材料,利用Gleeble-1500D型热模拟试验机对其进行热变形试验(变形温度为600~900℃,变形速率为0.001~1 s^(-1)),绘制了其真应力-真应变曲线,根据双曲正弦模型计算了复合材料的... 采用内氧化-快速热压烧结方法制备了Al_(2)O_(3)-Cu/25Cr复合材料,利用Gleeble-1500D型热模拟试验机对其进行热变形试验(变形温度为600~900℃,变形速率为0.001~1 s^(-1)),绘制了其真应力-真应变曲线,根据双曲正弦模型计算了复合材料的热变形激活能和本构方程,得到了Al_(2)O_(3)-Cu/25Cr复合材料热变形过程的热加工图。结果表明:Al_(2)O_(3)-Cu/25Cr复合材料的热变形激活能为287.227 kJ/mol,根据热加工图,确定了复合材料最佳的热加工工艺参数为变形温度为800~900℃、变形速率为0.25~1 s^(-1)。 展开更多
关键词 Al_(2)O_(3)-Cu/25Cr复合材料 热变形 本构方程 热加工图
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H_(2)O_(2)对O_(3)-PMS体系降解碘帕醇的效能优化
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作者 程莹 臧纪 +2 位作者 李伟平 谢荣焕 刘桂建 《环境化学》 CAS CSCD 北大核心 2024年第6期2133-2141,共9页
碘化造影剂(ICMs)作为一种典型的药品和个人护理品(PPCPs)广泛应用于医疗行业,常规的水处理工艺很难将其有效去除,而目前报道中多采用的高级氧化工艺也仍存在不足.以碘帕醇(IPM)为例,通过实验模拟研究O_(3)、O_(3)-PMS、O_(3)-PMS-H_(2)... 碘化造影剂(ICMs)作为一种典型的药品和个人护理品(PPCPs)广泛应用于医疗行业,常规的水处理工艺很难将其有效去除,而目前报道中多采用的高级氧化工艺也仍存在不足.以碘帕醇(IPM)为例,通过实验模拟研究O_(3)、O_(3)-PMS、O_(3)-PMS-H_(2)O_(2)3种高级氧化体系的降解规律及消毒副产物生成情况,探究了H_(2)O_(2)浓度、初始pH、氯离子、碳酸氢根离子、有机质对IPM降解效果的影响,并对IPM的可能降解途径进行了分析.结果表明,在O_(3)-PMS体系中投加H_(2)O_(2)可以提升对IPM的降解效率,还能减少溴酸盐的产生;O_(3)-PMS-H_(2)O_(2)体系在不同pH条件下对IPM均表现出良好的降解效果;Cl^(-)、天然有机质的存在对O_(3)-PMS-H_(2)O_(2)体系均具有抑制作用;CO_(3)^(2-)/HCO_(3)−形成缓冲体系则可以显著促进IPM的降解;O_(3)-PMS-H_(2)O_(2)体系可以通过强氧化作用和取代脱碘的路径将IPM进行有效降解.本研究可以为ICMs污染水体的修复提供理论依据. 展开更多
关键词 过氧化氢 O_(3)-PMS 高级氧化 碘帕醇 溴酸盐
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固定化脂肪酶ANL-MARE催化酸解合成1-油酸-2-棕榈酸-3-亚油酸甘油三酯
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作者 康梦 何家强 +7 位作者 冯孔龙 黄早成 李一峰 苗建银 符姜燕 朱泽榕 刘果 曹庸 《现代食品科技》 CAS 北大核心 2024年第2期109-119,共11页
1-油酸-2-棕榈酸-3-亚油酸甘油三酯(OPL)是人乳中主要的脂质组成,为满足婴幼儿配方食品母乳化需求,该试验探究了新型固定化脂肪酶ANL-MARE催化制备OPL的方法。试验成功制备和表征了固定化酶ANLMARE,并以ANL-MARE为生物催化剂,建立了一... 1-油酸-2-棕榈酸-3-亚油酸甘油三酯(OPL)是人乳中主要的脂质组成,为满足婴幼儿配方食品母乳化需求,该试验探究了新型固定化脂肪酶ANL-MARE催化制备OPL的方法。试验成功制备和表征了固定化酶ANLMARE,并以ANL-MARE为生物催化剂,建立了一种用三棕榈酸甘油三酯(PPP)、油酸(OA)和亚油酸(LA)高效酶催化制备富含OPL结构脂的方法。经单因素和响应面试验优化,获得OPL最优合成工艺为:PPP与总脂肪酸的摩尔比1:14.27,OA与LA摩尔比为1:0.76,脂肪酶添加量12.70%,反应温度50℃,反应4 h,此条件下产物中OPL相对含量为47.93%,2位棕榈酸(sn-2 PA)占总棕榈酸(PA)的质量分数(sn-2 PA相对含量)为71.69%。此外,固定化酶ANL-MARE与商业脂肪酶相比,表现出较好的催化合成OPL的活性。综上所述,固定化酶ANL-MARE具有催化制备OPL结构脂的重大潜力,为人乳脂替代脂的高效制备提供了新策略和理论基础。 展开更多
关键词 1-油酸-2-棕榈酸-3-亚油酸甘油三酯 酶促酸解法 固定化脂肪酶 ANL-MARE 工艺优化
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