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Multi-functional layered double hydroxides supported by nanoporous gold toward overall hydrazine splitting

Frontiers of Chemical Science and Engineering 2024年第1期18卷 61-69页

作者： Yongji Qin Huijie Cao Qian Liu Shaoqing Yang Xincai Feng Hao Wang Meiling Lian dongxing zhang Hua Wang Jun Luo Xijun Liu ShenSi Lab Shenzhen Institute for Advanced StudyUniversity of Electronic Science and Technology of ChinaShenzhen 518110China Institute for New Energy Materials and Low-Carbon Technologies School of Materials Science and EngineeringTianjin University of TechnologyTianjin 300384China State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured MaterialsSchool of ResourcesEnvironment and MaterialsGuangxi UniversityNanning 530004China Institute for Advanced Study Chengdu UniversityChengdu 610106China China National Coal Group Corporation Beijing 100120China Tianjin Engineering Research Center of Civil Aviation Energy Environment and Green Development School of Transportation Science and EngineeringCivil Aviation University of ChinaTianjin 300300China

Layered double hydroxides have demonstrated great potential for the oxygen evolution reaction,which is a crucial half-reaction of overall water splitting.However,it remains challenging to apply layered double hydroxides in other electrochemical reactions with high efficiency and stability.Herein,we report two-dimensional multifunctional layered double hydroxides derived from metalorganic framework sheet precursors supported by nanoporous gold with high porosity,which exhibit appealing performances toward oxygen/hydrogen evolution reactions,hydrazine oxidation reaction,and overall hydrazine splitting.The as-prepared catalyst only requires an overpotential of 233 mV to reach 10 mA·cm^(-2) toward oxygen evolution reaction.The overall hydrazine splitting cell only needs a cell voltage of 0.984 V to deliver 10 mA·cm^(-2),which is far more superior than that of the overall water splitting system(1.849 V).The appealing performances of the catalyst can be contributed to the synergistic effect between the metal components of the layered double hydroxides and the supporting effect of the nanoporous gold substrate,which could endow the sample with high surface area and excellent conductivity,resulting in superior activity and stability.

关键词： layered double hydroxide oxygen evolution reaction hydrazine oxidation reaction overall hydrazine splitting hydrogen production

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Performance of no-till corn precision planter equipped with row cleaners

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International Journal of Agricultural and Biological Engineering 2015年第5期8卷 15-25页

作者： Yang Li zhang Rui Gao Nana Cui Tao Liu Quanwei zhang dongxing College of Engineering China Agricultural UniversityBeijing 100083China

In the continuous annual wheat-corn cropping area of North China Plain,no-till planting that promotes soil conservation and crop yield while reducing operation cost has been gradually accepted by local farmers.However,previous wheat residue is the main limiting factor affecting the performance of existing planters in placing seeds at uniform spacing and optimum depth in residue covered fields.In order to solve this problem,a kind of ground-wheel-driven row cleaner was designed,developed and mounted on row units of a four-row pneumatic precision planter.The planter has two adjacent row units equipped with the newly designed row cleaners and the other two adjacent row units equipped with the commonly used inactive row cleaners.This was used for planting at three forward speeds(4 km/h,6 km/h and 8 km/h)into half residue(HR)and whole residue(WR)plots.The amount of residue removal,seeding depth,emergence rate and indices of uniformity in seed spacing(missing-seeding index,quality of feeding index and precision index)were measured.The newly designed row cleaner performed better with regard to residue removal,with the average percentage of residue cleared as 63.0%compared to 40.3%for the inactive row cleaner.For the HR and WR plots,percentage of residue cleared of the newly designed row cleaner reached 57.1%and 68.9%respectively,suggesting that the newly designed row cleaner can work more effectively at high residue level.By contrast,with the percentage of residue cleared of the inactive row cleaner as 43.1%and 37.5%in HR and WR plots,suggesting that the inactive row cleaner just can work effectively under low residue condition.Values of missing-seeding index,QFI,precision index,coefficient of variation of depth and percent emergence for the newly designed row cleaner under whole residue level are comparable to those for the inactive row cleaner under half residue level.The result indicates that the effect of using the newly designed row cleaner is equal to that of reducing surface residue,and can help to maintain the u

关键词： row cleaner corn production no-till planter wheat residue management annual double cropping system

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Development of mechatronic driving system for seed meters equipped on conventional precision corn planter

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International Journal of Agricultural and Biological Engineering 2015年第4期8卷 1-9页

作者： Yang Li He Xiantao Cui Tao zhang dongxing Shi Song zhang Rui Wang Mantao College of Engineering China Agricultural UniversityBeijing 100083China

Precision planters are more and more widely used for planting corn in China.Seed meters of conventional precision corn planters are usually driven by ground wheel and chain and sprocket system at present.Because of the slippage of ground wheels and vibration of chains,planting accuracy cannot be ensured,especially at higher forward speed.To improve the planting performance of precision planters,a mechatronic driving system was designed and its field working performance was evaluated in this research.A two-row pneumatic precision planter was modified to allow simultaneously using two different driving systems,i.e,with one row unit equipped with the newly designed mechatronic driving system and the other row unit equipped with conventional mechanical driving system,and used for planting at three forward speeds(9,11 and 12 km/h)on no-tillage and rotary-tillage lands.The distances between adjacent seeds in each plot were measured and the indices of uniformity in seed spacing,quality of feeding index(QFI),missing-seeding index and precision index were analyzed.With the average 4.70%increase of QFI and 3.54%decrease of missing-seeding index,the mechatronic driving system performed better than the mechanical driving system both on no-tillage and rotary-tillage lands at each forward speed.The values of QFI,missing-seeding index and precision index of the mechatronic driving system on rotary-tillage land are comparable to those on no-tillage land,by contrast,these indices of the mechanical driving system on rotary-tillage land are significantly worse than those on no-tillage land.The result indicates that the mechatronic driving system can eliminate the effect of ground wheel slippage on planting quality and maintain the uniformity of seed distribution.Although the QFI,missing-seeding index and precision index become worse with the increase of forward speed,with the worst values of QFI of 89.93%,missing-seeding index of 5.08%and precision index of 18.92%at the highest forward speed of 12 km/h,the mechatronic driving syste

关键词： precision planter seed meter mechatronic driving system control motor wheel slippage

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离心式高速玉米精量排种器T形槽型孔设计与试验

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农业工程学报 2024年第7期40卷 50-60页

作者：杨丽李治民张东兴李川崔涛和贤桃中国农业大学工学院北京100083 农业农村部土壤-机器-植物系统技术重点实验室北京100083

针对离心式高速玉米精量排种器双粒种子并排填充导致重播严重的问题,该研究提出利用型孔槽对称凸台结构降低玉米种子并排填充概率的方法,设计了一种T形槽型孔。通过构建充种阶段玉米种子的力学模型,并结合玉米种子的形状特征确定了T形... 详细信息

针对离心式高速玉米精量排种器双粒种子并排填充导致重播严重的问题,该研究提出利用型孔槽对称凸台结构降低玉米种子并排填充概率的方法,设计了一种T形槽型孔。通过构建充种阶段玉米种子的力学模型,并结合玉米种子的形状特征确定了T形槽型孔基本结构参数。借助EDEM离散元仿真软件,以型孔槽前端长度、型孔槽后端面倾斜角以及型孔槽底部倾斜角为因素,以合格指数、重播指数与漏播指数为评价指标,设计二次正交旋转回归组合仿真试验。仿真试验结果表明:在作业速度18 km/h条件下,型孔槽前端长度为9.31 mm,型孔槽后端面倾斜角为43.37°与型孔槽底部倾斜角为70.5°时,排种质量最优,排种合格指数、重播指数与漏播指数分别为94.03%、1.72%与4.25%。台架验证试验结果表明:作业速度为15 km/h时,T形槽型孔的合格指数最高为95.16%,在此作业速度下,排种器的重播指数为1.42%,漏播指数为3.42%,满足高速精量播种要求;作业速度在12~21 km/h内时,T形槽型孔的平均合格指数为94.77%,相较于矩形槽型孔提升了3.13个百分点,相较于蹄型槽型孔提升了1.80个百分点,T形槽型孔的平均重播指数为2.06%,相较于矩形槽型孔降低了3.41个百分点,相较于蹄型槽型孔降低了2.49个百分点。该研究可为离心式高速玉米精量排种器优化提供参考。

关键词：农业机械仿真玉米高速播种型孔 EDEM

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球磨时间对Ti-13Nb-5Sn牙科合金耐蚀与耐磨性能的影响

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材料工程 2024年第3期52卷 100-108页

作者：颉芳霞陆东兴黄家兵张文成孙琪超何雪明江南大学机械工程学院江苏无锡214122 江苏省食品先进制造装备技术重点实验室江苏无锡214122

采用粉末冶金法制备了Ti-13Nb-5Sn牙科合金,研究了不同球磨时间(3,12,24,48 h)对粉末特性、材料微观结构、电化学腐蚀和摩擦学行为的影响规律。结果表明:随着球磨时间从3 h增加至48 h,粉末形貌由大块状逐渐变成细小颗粒,部分Nb和Sn原子... 详细信息

采用粉末冶金法制备了Ti-13Nb-5Sn牙科合金,研究了不同球磨时间(3,12,24,48 h)对粉末特性、材料微观结构、电化学腐蚀和摩擦学行为的影响规律。结果表明:随着球磨时间从3 h增加至48 h,粉末形貌由大块状逐渐变成细小颗粒,部分Nb和Sn原子扩散到Ti晶格中,形成了一定体积的Ti(Nb)和Ti(NbSn)固溶体;等轴α-Ti减少转变为柱状的晶界α-Ti,网篮组织转变为魏氏组织;动电位极化曲线显示,合金在人工唾液(AS)和模拟体液(SBF)中的腐蚀电位(E_(corr))和极化电阻(R_(p))呈上升趋势,腐蚀电流密度(I_(corr))呈下降趋势,α-Ti减少,β-Ti增多,使得合金耐腐蚀性能提升;合金的硬度升高,而摩擦因数、磨痕深度和磨损率逐渐降低,细化粉末在烧结中会产生更多的晶界,使得合金的耐磨性能提升。机械合金化结合模压烧结制备的Ti-13Nb-5Sn合金显示了良好的耐蚀与耐磨性能,在牙科领域具有潜在的应用前景。

关键词：钛合金机械合金化微观组织耐腐蚀性耐磨性

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天津滨海湿地土壤有机碳和有效磷的盐度响应及影响因素

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生态学杂志 2024年第5期43卷 1381-1389页

作者：李苏青管冬兴李希媛张坚超滕辉天津大学地球系统科学学院表层地球系统科学研究院天津300072 浙江大学环境与资源学院杭州310058 天津大学天津市环渤海关键带科学与可持续发展重点实验室天津300072

滨海湿地是脆弱的生态敏感区,正面临着海平面上升等严峻的环境挑战。海水的入侵导致了土壤盐度升高,带来土壤养分失衡、生产力水平降低等一系列负面效应。为探究土壤盐度对土壤有机碳(SOC)和有效磷(AP)含量的影响,采集了天津市典型滨海... 详细信息

滨海湿地是脆弱的生态敏感区,正面临着海平面上升等严峻的环境挑战。海水的入侵导致了土壤盐度升高,带来土壤养分失衡、生产力水平降低等一系列负面效应。为探究土壤盐度对土壤有机碳(SOC)和有效磷(AP)含量的影响,采集了天津市典型滨海湿地土壤,对土壤样品中SOC、AP和不同形态磷的含量及土壤盐度、pH、粒径、碱性磷酸酶活性等指标进行了测定分析。结果表明:研究区内SOC含量为1.88~8.51 g·kg^(-1),AP包含H2O提取态磷和NaHCO3提取态磷,其含量为10.50~56.07 mg·kg^(-1);天津滨海湿地土壤中的无机磷以HCl提取的Ca结合态磷为主;随着盐度的升高,SOC和AP含量呈现先升高后降低的趋势;SOC含量与土壤总氮含量、碱性磷酸酶活性呈极显著正相关(P<0.01),与NaOH-P含量呈显著正相关(P<0.05),与土壤砂粒含量呈显著负相关(P<0.05);AP含量与土壤总磷、NaHCO_(3)-P、NaOH-P含量呈极显著正相关(P<0.01),与H_(2)O-P含量呈显著正相关(P<0.05),与土壤砂粒含量呈显著负相关(P<0.05)。本研究揭示了滨海湿地SOC和AP含量的盐度响应变化特征与影响因素,对于全球变化背景下滨海湿地的养分管理具有一定的参考价值。

关键词：滨海湿地盐度土壤有机碳植物可利用磷

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基于代理模型估值不确定度的昂贵多目标优化问题研究

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石河子大学学报（自然科学版） 2024年第1期42卷 110-116页

作者：张晶裴东兴马瑾沈大伟山西财贸职业技术学院物联网技术系山西太原030031 中北大学电子测试技术国家重点实验室山西太原030051 中北大学仪器科学与动态测试教育部重点实验室山西太原030051.

针对代理模型辅助的多目标优化算法中个体不确定度之间相互冲突的问题,本文提出个体每个目标估值不确定的填充准则,同时,为了减少训练模型消耗的计算资源,提出基于非支配排序的样本选择算法。为了验证该算法的可行性,采用DTLZ和WFG测试... 详细信息

针对代理模型辅助的多目标优化算法中个体不确定度之间相互冲突的问题,本文提出个体每个目标估值不确定的填充准则,同时,为了减少训练模型消耗的计算资源,提出基于非支配排序的样本选择算法。为了验证该算法的可行性,采用DTLZ和WFG测试函数进行测试,得出结果与近些年发表5种具有代表性的同类型算法进行对比,结果说明该算法可以有效的解决昂贵高维高目标优化问题。

关键词：进化算法昂贵多目标优化问题代理模型填充准则不确定度

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药食同源物质防治阿尔茨海默病作用机制的研究进展

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食品工业科技 2024年第12期45卷 18-27页

作者：康瑶唐瑗张东星王磊王鑫苏子孟於洪建天津中医药大学中药学院天津301617 天津益倍生物集团有限公司天津300457

阿尔茨海默病(Alzheimer's disease,AD)是一种起病隐匿、进行性发展的神经退行性疾病,常见于老年群体且发病率逐年升高,目前仍没有有效的治疗手段。药食同源物质是指既是食品又是中药材的物质,因其安全性和良好的治疗保健效果,受到了广... 详细信息

阿尔茨海默病(Alzheimer's disease,AD)是一种起病隐匿、进行性发展的神经退行性疾病,常见于老年群体且发病率逐年升高,目前仍没有有效的治疗手段。药食同源物质是指既是食品又是中药材的物质,因其安全性和良好的治疗保健效果,受到了广泛的关注。本文阐述了AD的发病机制,从减缓β-淀粉样蛋白沉积、抑制Tau蛋白过度磷酸化、改善胆碱能系统、抗氧化、抗炎和保护神经元和突触等方面总结了药食同源物质抗AD的作用机制,为药食同源物质产品的开发与应用提供参考。

关键词：药食同源物质阿尔茨海默病作用机制

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Effect of travel speed on seed spacing uniformity of corn seed meter

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International Journal of Agricultural and Biological Engineering 2017年第4期10卷 98-106页

作者： Liu Quanwei He Xiantao Yang Li zhang dongxing Cui Tao Qu Zhe Yan Bingxin Wang Mantao zhang Tianliang College of Engineering China Agricultural UniversityBeijing 100083China Soil-Machine-Plant Key Laboratory of the Ministry of Agriculture Beijing 100083China

Both seeding performance of seed metering unit and travel speed of seed planter have significant effects on seeding quality,thereby affecting crop growth and yields.In order to determine the effects of different travel speeds on seed spacing uniformity,four different types of seed meters were evaluated at five different travel speeds on seed meter test bench and in field.The tested seed meters included a finger pickup seed meter,a scoop-wheel seed meter,an air-pressure type seed meter and an air-blowing type seed meter.The seeding performance of the horizontal distribution of seeds within a row was described by using the coefficient of variation,the quality of feed index,the multiple index and the miss-seeding index.Experiments were performed in laboratory and field,respectively.Results indicated that different travel speeds have statistically significant effects on seed spacing uniformity.The four types of seed meters performed better on the seed meter test bench than in the field.Coefficient of variation increases and quality of feed index decreases as the travel speed of seed planter increases.The best seed spacing uniformity was obtained with the air-pressure type seed meter,followed with the air-blowing type seed meter,the finger pickup seed meter and the scoop-wheel seed meter.There were considerable differences between the performances of the scoop-wheel seed meter in the bench test and field test;the seeding qualities were much better in the bench test than in the field test.The scoop-wheel seed meter is more sensitive to vibration than the other types of seed meters.

关键词： corn seed meter travel speed seed spacing uniformity precision corn planter field test test bench

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L型加筋土挡墙地震动力响应理论分析

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自然灾害学报 2024年第1期33卷 212-221页

作者：彭涛张晓曦柯灵任东兴何思明中冶成都勘察研究总院有限公司四川成都610023 中国科学院、成都山地灾害与环境研究所四川成都610299

将L型挡墙与加筋土2种柔性支挡结构相结合,充分利用其良好的抗震性能,可用于地震多发区和高烈度区的支挡工程中。研究地震荷载作用下L型加筋土挡墙的破坏机制与动力响应问题。根据第二、第三滑裂面产生条件,提出踵板长度临界系数λ_(cr)... 详细信息

将L型挡墙与加筋土2种柔性支挡结构相结合,充分利用其良好的抗震性能,可用于地震多发区和高烈度区的支挡工程中。研究地震荷载作用下L型加筋土挡墙的破坏机制与动力响应问题。根据第二、第三滑裂面产生条件,提出踵板长度临界系数λ_(cr),以界定长踵板式和短踵板式2种破坏模式。假设填土滑裂面为直线,应用极限分析上限定理,采用Mohr-Coulomb破坏准则,分别建立2种破坏模式下L型加筋土挡墙临界状态方程,推导其地震屈服加速度系数。根据极值原理给出最优解,得到临界屈服加速度系数及其对应的填土滑裂面倾角,分析破坏模式与临界屈服加速度系数受几何参数、物理力学参数和加筋作用的影响。通过算例分析可知:加筋作用可有效地提高L型挡墙的抗震能力,改变其破坏模式;当设计筋材拉伸强度较大时,L型加筋土挡墙只发生长踵板式破坏。

关键词：加筋土 L型挡土墙临界屈服加速度破坏机制上限定理

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