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文章速递切削参数对6061铝合金超声振动切削性能的影响 认领
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作者 李媛媛 韩双凤 +1 位作者 于晓 马玉华 《兵器材料科学与工程》 CAS CSCD 北大核心 2021年第1期78-83,共6页
为探索切削参数对6061铝合金超声振动切削性能的影响规律,用AdvantEdge软件对其进行超声振动切削仿真研究,与普通切削工艺进行对比,得到切削温度、切削力和残余应力随切削参数改变而变化规律。结果表明:随切削参数增大,两种加工方式下... 为探索切削参数对6061铝合金超声振动切削性能的影响规律,用AdvantEdge软件对其进行超声振动切削仿真研究,与普通切削工艺进行对比,得到切削温度、切削力和残余应力随切削参数改变而变化规律。结果表明:随切削参数增大,两种加工方式下切削温度均上升。超声振动切削相较于普通切削,在降低切削力方面有显著优势,同时,超声振动切削的残余应力曲线出现明显"勺形"变化,残余应力值和层深较大。最后,通过超声振动辅助车床对有限元结果进行试验验证,可得仿真值与试验值吻合良好。 展开更多
关键词 6061铝合金 超声振动 切削加工 切削参数 有限元
文章速递数控加工切削参数优化分析 认领
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作者 赵建军 《黑龙江科学》 2021年第2期100-101,共2页
为提升数控加工技术水平,合理选择切削参数,分析了数控加工中切削参数的影响因素。以某钛合金插铣加工切削参数优化为例,提出了优化方法。应做好约束条件、算法优化、模型优化,并分析优化结果。
关键词 加工 数控 切削 参数 优化
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文章速递Planting Techniques of Pennisetum giganteum in Huanghuai Area 认领
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作者 Jiancheng DING Guiying SHI +1 位作者 Xin ZHAO Qiguang ZHAO 《农业生物技术:英文版》 CAS 2021年第1期42-43,58,共3页
Pennisetum giganteum z. x. lin selected by the National Juncao Center is a high-yielding and high-quality Juncao variety. It is a high-quality horticultural variety that grows upright, and has tall plants with high yi... Pennisetum giganteum z. x. lin selected by the National Juncao Center is a high-yielding and high-quality Juncao variety. It is a high-quality horticultural variety that grows upright, and has tall plants with high yield and high value. Planting should be carried out in the right time to ensure the quality of planting and promote the seedlings to be tidy and strong, and according to the row spacing of 80 cm, plant spacing of 40 cm, 2 plants per hole, about 2 000 holes per 667 m2, with the need for furrowing. At the seedling stage, the soil should be kept moist, and watered in time when it is dry and lacking water. P. giganteum is fertilizer-tolerant and sensitive to fertilizers, and requires a reasonable and economical amount of fertilizer. 展开更多
关键词 Node section cutting Transplanting Water management Fertilizer management Reaping
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文章速递套种及割苔对柴胡皂苷含量的影响 认领
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作者 尹鑫 郝婷 +3 位作者 周志杰 薛乾鑫 冯楷斌 刘洋 《北方园艺》 CAS 北大核心 2021年第2期111-115,共5页
以三年生柴胡为试材,采用HPLC法,对柴胡进行割苔及与玉米、谷子作物套种后柴胡根主要生长指标、柴胡皂苷a含量、柴胡皂苷d含量进行测定,分析比较套种模式、割苔措施对柴胡皂苷含量的影响,以期为套种模式、割苔措施在柴胡栽培中的应用提... 以三年生柴胡为试材,采用HPLC法,对柴胡进行割苔及与玉米、谷子作物套种后柴胡根主要生长指标、柴胡皂苷a含量、柴胡皂苷d含量进行测定,分析比较套种模式、割苔措施对柴胡皂苷含量的影响,以期为套种模式、割苔措施在柴胡栽培中的应用提供参考依据。结果表明:采用套种和割苔措施提高了柴胡的单株根长、根粗及根干质量,提高了柴胡的商品性;套种措施显著降低了三年生柴胡的柴胡皂苷含量,而柴胡皂苷a+d含量均高于0.30%;割苔15 cm柴胡皂苷a含量显著提高了21.95%(P<0.05),割苔15 cm柴胡皂苷a+d含量提高了1.12%(P>0.05)。综上所述,套种模式适合柴胡主产区的大规模生产,既能提高柴胡出苗率、保苗率,又能降低了种植风险与成本。建议栽培时及时清理套种作物的秸秆,同时做好病虫害的联合防治;生产中割苔15 cm为佳。 展开更多
关键词 柴胡 套种 割苔 含量测定
不同种类及浓度的植物生长调节剂对具鳞水柏枝扦插生根的影响 认领
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作者 李波 魏科宇 王丽华 《西南林业大学学报:自然科学》 CAS 北大核心 2021年第1期33-38,共6页
为探讨不同种类及浓度的植物生长调节剂对具鳞水柏枝嫩枝扦插生根效果,以1年生具鳞水柏枝当年生嫩枝为研究对象,采用完全随机分组设计,以不同浓度梯度的3种植物生长调节剂处理插穗,对比和分析不同处理下的生根率及其根系相关指标。结果... 为探讨不同种类及浓度的植物生长调节剂对具鳞水柏枝嫩枝扦插生根效果,以1年生具鳞水柏枝当年生嫩枝为研究对象,采用完全随机分组设计,以不同浓度梯度的3种植物生长调节剂处理插穗,对比和分析不同处理下的生根率及其根系相关指标。结果表明:短时间内,IBA能够有效地提高具鳞水柏枝的生根速度及效率;植物生长调节剂下的生根率顺序为SA>IBA> CK> NAA,其生根效果之间不存在显著性差异;使用50 mg/L NAA处理插穗,生根系数量显著高于其他处理组,达16.68条。可见,植物生长调节剂对具鳞水柏枝嫩枝扦插效果显著,但不同生长调节剂生根效果存异,其中50 mg/L IBA对具鳞水柏枝嫩枝生根效果最佳。 展开更多
关键词 具鳞水柏枝 嫩枝 扦插 植物生长调节剂 浓度 生根
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颗粒流切削润滑研究现状及展望 认领
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作者 马利杰 逄明华 +3 位作者 冯启高 王占奎 苏建修 刘贯军 《表面技术》 EI CAS 北大核心 2021年第1期208-220,共13页
切削润滑是实现高速、精密切削的必要条件,然而传统切削润滑技术与绿色制造要求之间的矛盾越来越突出,而颗粒流润滑是一种具有广阔应用前景的绿色切削润滑技术。首先,指出了传统浇注式切削润滑的问题和不足,最小量润滑(Minimum Quantity... 切削润滑是实现高速、精密切削的必要条件,然而传统切削润滑技术与绿色制造要求之间的矛盾越来越突出,而颗粒流润滑是一种具有广阔应用前景的绿色切削润滑技术。首先,指出了传统浇注式切削润滑的问题和不足,最小量润滑(Minimum Quantity Lubrication,MQL)、液氮冷却等常见绿色切削润滑技术的优势和缺点,以及颗粒流润滑的特点。然后,论述了颗粒流切削润滑的颗粒介质输送和导入方式,包括填涂式、铺粉式、送粉式、流化式和雾化式。从车削、铣削、磨削、钻削四种加工工艺,综述了颗粒流切削润滑的工艺效果及参数优化。从颗粒介质的界面作用机理和颗粒润滑液的物理性能两个角度,概括了颗粒流切削润滑能够实现连续润滑和冷却的基本机理。在此基础上,分析了颗粒流切削润滑技术的优势及其发展过程中的问题。最后,从促进实践应用的角度,对颗粒流切削润滑技术进行了展望,从而为该技术的成熟和推广提供参考。 展开更多
关键词 颗粒流 切削 润滑 颗粒润滑剂供给 工艺效果 作用机理
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不同茬次和高度热研四号王草的乳酸菌分布及青贮发酵品质 认领
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作者 陈鑫珠 张建国 《草业学报》 北大核心 2021年第1期150-158,共9页
为探明茬次和高度对热研四号王草的乳酸菌分布和青贮发酵品质的影响,本研究对热研四号王草进行连续刈割3茬,每茬分别在1.0、1.5和2.0 m高度时采样,进行营养成分分析、青贮调制、乳酸菌计数及分离鉴定。结果表明,随着刈割高度的增加,原... 为探明茬次和高度对热研四号王草的乳酸菌分布和青贮发酵品质的影响,本研究对热研四号王草进行连续刈割3茬,每茬分别在1.0、1.5和2.0 m高度时采样,进行营养成分分析、青贮调制、乳酸菌计数及分离鉴定。结果表明,随着刈割高度的增加,原料的干物质(DM)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量显著(P<0.05)升高,粗蛋白(CP)含量和pH值显著(P<0.05)降低;第2茬的DM含量显著(P<0.05)高于第1和3茬,第1茬的CP、可溶性碳水化合物(WSC)和ADF含量最高,NDF含量最低;第2茬的青贮发酵品质优于第1和3茬;2.0 m青贮品质优于1.0和1.5 m;第2和3茬乳酸菌的数量显著(P<0.05)高于第1茬;2.0 m高度乳酸菌数量较多,但不同高度间无显著(P>0.05)差异。培养法发现植物乳杆菌和融合乳杆菌是热研四号王草的高频乳酸菌,第1茬只分离到2种乳酸菌,第3茬分离到4种乳酸菌。 展开更多
关键词 热研四号王草 茬次 高度 乳酸菌
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3种植物生长调节剂对粤椹大10桑扦插生根的影响 认领
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作者 郑妹 罗浩城 +2 位作者 曾国堂 杨崇城 李润唐 《现代农业科技》 2021年第1期136-139,共4页
为了探讨植物生长调节剂对粤椹大10桑树枝条扦插生根的影响,选用ABT 1号生根粉、IBA、NAA各配制成100、150、200 mg/L 3种浓度,以清水为对照,浸泡木质化枝条4 h,以河沙、河沙蛭石、黄心土为基质分别进行了3次扦插试验。结果表明:IBA以20... 为了探讨植物生长调节剂对粤椹大10桑树枝条扦插生根的影响,选用ABT 1号生根粉、IBA、NAA各配制成100、150、200 mg/L 3种浓度,以清水为对照,浸泡木质化枝条4 h,以河沙、河沙蛭石、黄心土为基质分别进行了3次扦插试验。结果表明:IBA以200 mg/L处理效果最好,平均生根数量达6.69条,根系平均长度8.65 mm,根系平均直径达到0.62 mm,平均成活率81.33%;NAA以100 mg/L处理效果最好,平均生根数量达5.50条,根系平均长度为7.12 mm,根系平均直径达0.60 mm,平均成活率65.38%;ABT 1号以200 mg/L处理效果最好,平均生根数量为2.10条,根系平均长度4.53 mm,根系平均直径0.45 mm,平均成活率44.96%。3种植物生长调节剂之间比较,IBA处理效果优于NAA处理,NAA处理效果优于ABT 1号生根粉处理。多因素影响下的扦插最优条件组合,有待今后进一步开展研究。 展开更多
关键词 桑树 粤椹大10 扦插 植物生长调节剂 生根 成活率
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山药枝条扦插快繁试验研究 认领
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作者 肖颖 郭凤领 +3 位作者 周洁 符家平 徐志超 吴金平 《长江蔬菜》 2021年第2期68-70,共3页
为研究不同山药品种插穗在不同浓度、不同类型生根剂处理下的生根情况,特开展山药枝条扦插快繁试验。试验结果表明,山药插穗的生根率随NAA和IBA溶液浓度的降低而升高,其中十堰田薯(SY)用50 mg/L IBA处理时插穗生根率最高,为83.33%;广州... 为研究不同山药品种插穗在不同浓度、不同类型生根剂处理下的生根情况,特开展山药枝条扦插快繁试验。试验结果表明,山药插穗的生根率随NAA和IBA溶液浓度的降低而升高,其中十堰田薯(SY)用50 mg/L IBA处理时插穗生根率最高,为83.33%;广州田薯(GZ)用50 mg/L NAA处理时插穗生根率最高,为70.00%;生根剂处理下不同山药品种的生根率为51.67%~71.67%,而对照组不同山药品种的生根率为46.60%~58.33%。因此,认为不同山药品种插穗生根率与生根剂浓度和种类有关,实际生产中建议根据品种采用不同的生根剂进行处理。 展开更多
关键词 山药 扦插快繁 插穗 生根
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Study on Cutting Force,Cutting Temperature and Machining Residual Stress in Precision Turning of Pure Iron with Different Grain Sizes 认领
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作者 Yinfei Yang Lu Jin +2 位作者 Jinpeng Zhu Jinxing Kong Liang Li 《中国机械工程学报:英文版》 SCIE EI CAS CSCD 2020年第4期159-167,共9页
Pure iron is one of the difficult-to-machine materials due to its large chip deformation,adhesion,work-hardening,and built-up edges formation during machining.This leads to a large workpiece deformation and challenge ... Pure iron is one of the difficult-to-machine materials due to its large chip deformation,adhesion,work-hardening,and built-up edges formation during machining.This leads to a large workpiece deformation and challenge to meet the required technical indicators.Therefore,under varying the grain size of pure iron,the influence of cutting speed,feed,and depth of cut on the cutting force,heat generation,and machining residual stresses were explored in the turning process to improve the machinability without compromising the mechanical properties of the material.The experimental findings have depicted that the influence of grain size on cutting force in the precision turning process is not apparent.However,the cutting temperature and residual stress of machining fine-grain iron were much smaller than the coarse grain at all levels of cutting parameters. 展开更多
关键词 Pure iron Grain size Cutting parameter Cutting force Cutting temperature Residual stress
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Effects of Anthropometry Variations on Physiological Parameters of Heart Rate, Oxygen Consumption, Aerobic Power While Performing Manual Operation at Fixed Vice Height 认领
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作者 Olusegun Gideon Akanbi Bukola Olanrewaju Afolabi Omowumi Adegboye 《工程(英文)(1947-3931)》 2020年第1期47-57,共11页
This study investigated the effect of fixed height standing-workstation on different people with diverse anthropometry dimensions. Measurements of some anthropometric and physiological parameters are carried out as ba... This study investigated the effect of fixed height standing-workstation on different people with diverse anthropometry dimensions. Measurements of some anthropometric and physiological parameters are carried out as bases for the calculation of body mass index (BMI) and the determination of the maximum heart rate (HRmax) and aerobic power (VO2max) of individual subject while performing manual cutting operation with hacksaw on fixed vice height of 940 mm. Twenty subjects (S1 to S20) parted 2 mm thick square-pipe of 25 mm × 25 mm. Each subject carried out cutting operation in 5 replicates and their physiological parameters during activities are measured to determine their expended energy (EE) and oxygen consumption rate (VO2). The results showed that subject S4 with BMI of 20.76 kg/m2 has maximum cutting rate of 5.33 stroke/s, while subject S8 with BMI of 23.39 kg/m2 has minimum cutting rate of 0.92 stroke/s. There was a statistically significant effect on the interaction between BMI, EE and Cutting rate, with F = 827.54, P = 0.000, R2 = 0.967 and S = 1.749 units. Subject S11 was discovered to have VO2 (28.54 l/min) and VO2max (24.36 ml/min/kg), with highest value of EE (2.94 kcal/min). Wear rates of 1.86 teeth/s and 9.55 teeth/s have the same energy cost (EE = 0.87 kcal/min) but different cutting time of 36.65 s (S18) and 10.89 s (S20) respectively. This could explain in-part that excess 25.76 s utilized in operation time by subject S18 is responsible for keeping approximately 7.7 teeth intact as regards tool management. EE and Tool Wear Rate in one-way analysis of variance, were statistically significant (F = 45.87, P = 0.000, R2 = 54.69% and S = 1.617 units) at 0.05 level. 展开更多
关键词 ANTHROPOMETRY Variation Cutting Operation Fixed VICE HEIGHT PHYSIOLOGICAL Parameters Wear Rate
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大型不锈钢零件的加工方法 认领
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作者 钟晓鸥 沙奉奎 谭飞 《模具工业》 2020年第11期73-77,81,共6页
分析了不锈钢材料难切削、变形大的特性,针对大型不锈钢零件难加工及精度较难控制的问题,采取大型零件分解成若干实体模型的方法,实现了大型零件的简单加工,降低了材料成本和加工难度。单件加工完成后再装配成整体,通过焊接工艺连接,最... 分析了不锈钢材料难切削、变形大的特性,针对大型不锈钢零件难加工及精度较难控制的问题,采取大型零件分解成若干实体模型的方法,实现了大型零件的简单加工,降低了材料成本和加工难度。单件加工完成后再装配成整体,通过焊接工艺连接,最后对关键特征尺寸进行精加工。实际生产应用表明,该方法可实现对大型不锈钢零件加工精度的管控,满足其技术要求。 展开更多
关键词 不锈钢 切削 焊接 线切割 加强筋
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Modeling of the minimum cutting thickness in micro cutting with consideration of the friction around the cutting zone 认领
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作者 Tianfeng ZHOU Ying WANG +2 位作者 Benshuai RUAN Zhiqiang LIANG Xibin WANG 《机械工程前沿:英文版》 SCIE CSCD 2020年第1期81-88,共8页
Friction modeling between the tool and the workpiece plays an important role in predicting the minimum cutting thickness during TC4 micro machining and finite element method(FEM)cutting simulation.In this study,a new ... Friction modeling between the tool and the workpiece plays an important role in predicting the minimum cutting thickness during TC4 micro machining and finite element method(FEM)cutting simulation.In this study,a new three-region friction modeling is proposed to illustrate the material flow mechanism around the friction zone in micro cutting;estimate the stress distributions on the rake,edge,and clearance faces of the tool;and predict the stagnation point location and the minimum cutting thickness.The friction modeling is established by determining the distribution of normal and shear stress.Then,it is applied to calculate the stagnation point location on the edge face and predict the minimum cutting thickness.The stagnation point and the minimum cutting thickness are also observed and illustrated in the FEM simulation.Micro cutting experiments are conducted to validate the accuracy of the friction and the minimum cutting thickness modeling.Comparison results show that the proposed friction model illustrates the relationship between the normal and sheer stress on the tool surface,thereby validating the modeling method of the minimum cutting thickness in micro cutting. 展开更多
关键词 TOOL FRICTION minimum CUTTING thickness finite element method TOOL edge RADIUS micro CUTTING
Identifying Optimal Cutting Parameters in Drilling of Titanium Aluminum Vanadium Using Finite Element Analysis 认领
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作者 M. M. Reddy S. R. Kostka N. S. Reddy 《表面工程材料与先进技术期刊(英文)》 2020年第3期55-62,共8页
Titanium alloys are widely used in the aerospace industries because of their excellent strength-to-weight ratio, high resistance to corrosion, high chemical reactivity and low thermal conductivity and ability to withs... Titanium alloys are widely used in the aerospace industries because of their excellent strength-to-weight ratio, high resistance to corrosion, high chemical reactivity and low thermal conductivity and ability to withstand high temperatures. However, these properties make titanium alloys difficult to machine. Drilling of titanium alloy may generate high temperature and high cutting forces. This paper is aimed at determining the suitable cutting parameters in the drilling of titanium alloys to minimize the cutting temperature and cutting forces. A finite element 3D model of the drilling process is simulated in this research. A combination of drilling speeds and feed rates are simulated to obtain the resulting responses of cutting force and temperature. The central composite design (CCD) is used to generate different combinations of cutting parameters to reduce the number of experiments and optimize the temperature and cutting force responses. Results show at the drilling speed of 5000 rpm with a feed rate of 0.1 mm/rev, temperature and cutting force significantly reduced. 展开更多
关键词 Titanium Alloys Design of Experiments DRILLING Cutting Force
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Mechanical Properties of Remote-Laser Cut CFRP and Thermographic Laser-Process Monitoring 认领
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作者 Michael Rose Sebastian Schettler +2 位作者 Florian Klemm Eckhard Beyer Martina Zimmermann 《材料科学与应用期刊(英文)》 2020年第8期560-575,共16页
Remote-laser beam cutting is a productive technology without tool wear. Especially when cutting carbon fiber reinforced polymers (CFRP), it offers constant manufacturing quality. Since it is a thermal process, a heat-... Remote-laser beam cutting is a productive technology without tool wear. Especially when cutting carbon fiber reinforced polymers (CFRP), it offers constant manufacturing quality. Since it is a thermal process, a heat-affected zone (HAZ) is formed at the edge of the cut. Based on quasi-static and cyclic mechanical tests on open-hole specimens, the influence of the process on the mechanical properties of CFRP is shown. The quasi-static tests are in good correlation with results from other researchers by indicating an increase in the maximum tensile stress of the test specimens, cut by remote-laser. The reason is the rearrangement of the shear stresses and a reduction of the notch stress concentration. However, the results of the present study show that excessive expansion of the HAZ leads to a reduction in the maximum tensile stress compared to milled test specimens. Under cyclic load conditions, remote-laser beam cutting does not lead to a more pronounced degradation than milling. The mechanical properties of the notched test pieces are sensitive to the expansion of the HAZ. For the production of components it is therefore necessary that the remote-laser beam cutting is carried out under controlled and documentable conditions. For this purpose, process thermography was tested as a tool for quality assurance. The results show that the technology is basically suitable for this task. 展开更多
关键词 CFRP Remote Laser Cutting FATIGUE Process Thermography Process Monitoring
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护坡插杆微创造林技术 认领
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作者 铁万梅 陵军成 《福建林业科技》 2020年第2期73-76,81,共5页
为了绿化陡峭坡面,2017年3月中旬在甘肃省天祝藏族自治县城北侧华藏寺镇南山村G 338国道3 km+700 m处护坡地带,采用在坡面上钻孔,注水后带泥浆插入易生根的旱柳(Salix matsudana Koidz)插杆进行扦插造林(简称插杆微创造林)。结果表明,... 为了绿化陡峭坡面,2017年3月中旬在甘肃省天祝藏族自治县城北侧华藏寺镇南山村G 338国道3 km+700 m处护坡地带,采用在坡面上钻孔,注水后带泥浆插入易生根的旱柳(Salix matsudana Koidz)插杆进行扦插造林(简称插杆微创造林)。结果表明,护坡插杆微创造林均能形成一定的植株和盖度,达到固土和绿化坡面的目的。其中插杆截留长度80 cm,垂直坡面(角度90°)插洞深60 cm,扦插后插杆顶端在坡面外露20 cm的栽植成活率、单株萌芽数、新梢长度、保存率、覆盖度最高,分别为92.18%、5.04个·株-1、282.46 cm,90.35%、85.82%,且绿化效果评价为优,在坡面绿化中可应用和借鉴。 展开更多
关键词 护坡 旱柳 插杆 插洞 扦插造林
径向切割技术在海上气田修井作业中的应用 认领
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作者 徐太保 肖泽蔚 《石油工业技术监督》 2020年第12期1-5,共5页
在油气田钻井过程中,卡钻问题时有发生,严重影响着石油工业效率和成本。一般作业者会采用一些标准操作程序来尝试解卡:上下活动钻具;旋转钻具;在卡钻位置泡不同性能泥浆,使用震击器震击解卡等。通用解决办法不起作用时,切割则成为最后... 在油气田钻井过程中,卡钻问题时有发生,严重影响着石油工业效率和成本。一般作业者会采用一些标准操作程序来尝试解卡:上下活动钻具;旋转钻具;在卡钻位置泡不同性能泥浆,使用震击器震击解卡等。通用解决办法不起作用时,切割则成为最后手段。在油气田生产后期的修井动管柱作业中,若油管无法正常拔出,同样需要用到切割。为保证切割成功,预估钻具自由点和选择切割方式至关重要。在分析常用切割方式优缺点的基础上,介绍了径向切割炬的工艺原理、切割工艺流程及其优缺点等,并在南海某气田进行现场应用,取得较好的效果,为海上气田修井作业提供参考。 展开更多
关键词 卡钻 切割 RCT
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不同处理对春云实扦插生根的影响 认领
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作者 叶林妹 陈友吾 +3 位作者 沈建军 胡传久 杜国坚 宋其岩 《浙江林业科技》 2020年第4期78-82,共5页
为了获得春云实Caesalpinia vernalis适宜的扦插繁殖方法,以春云实当年生半木质化嫩枝和1年生木质化枝条为试验材料进行不同扦插枝条试验,并分别以基质类型(河沙,红壤,泥炭∶珍珠岩1∶1)、插穗长度(5~10 cm,>10~15 cm,>15 cm)和A... 为了获得春云实Caesalpinia vernalis适宜的扦插繁殖方法,以春云实当年生半木质化嫩枝和1年生木质化枝条为试验材料进行不同扦插枝条试验,并分别以基质类型(河沙,红壤,泥炭∶珍珠岩1∶1)、插穗长度(5~10 cm,>10~15 cm,>15 cm)和ABT1生根粉浓度(50 mg·kg^-1,100 mg·kg^-1,200 mg·kg^-1)为试验因素进行春云实扦插正交试验。结果表明:春云实适合采用1年生木质化枝条进行春季扦插;生根粉浓度和插穗长度对扦插后各指标的影响均未达到显著水平,基质类型对扦插生根率和不定根长度的影响达到显著水平(P<0.05)。综合考虑,春云实扦插宜在春季选取10~15 cm长度1年生木质化枝条为插穗,于100 mg·kg^-1的ABT1生根粉中浸泡1 h,再扦插于消毒后的河沙基质,可获得较好的生根效果,其生根率可达71.85%。 展开更多
关键词 春云实 扦插 基质 插穗长度 生根粉
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A cortical bone milling force model based on orthogonal cutting distribution method 认领
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作者 Qi-Sen Chen Li Dai +1 位作者 Yu Liu Qiu-Xiang Shi 《先进制造进展:英文版》 SCIE CAS CSCD 2020年第2期204-215,共12页
In orthopedic surgery,the bone milling force has attracted attention owing to its significant influence on bone cracks and the breaking of tools.It is necessary to build a milling force model to improve the process of... In orthopedic surgery,the bone milling force has attracted attention owing to its significant influence on bone cracks and the breaking of tools.It is necessary to build a milling force model to improve the process of bone milling.This paper proposes a cortical bone milling force model based on the orthogonal cutting distribution method(OCDM),explaining the effect of anisotropic bone materials on milling force.According to the model,the bone milling force could be represented by the equivalent effect of a transient cutting force in a rotating period,and the transient milling force could be calculated by the transient milling force coefficients,cutting thickness,and cutting width.Based on the OCDM,the change in transient cutting force coefficients during slotting can be described by using a quadratic polynomial.Subsequently,the force model is updated for robotic bone milling,considering the low stiffness of the robot arm.Next,an experimental platform for robotic bone milling is built to simulate the milling process in clinical operation,and the machining signal is employed to calculate the milling force.Finally,according to the experimental result,the rationality of the force model is verified by the contrast between the measured and predicted forces.The milling force model can satisfy the accuracy requirement for predicting the milling force in the different processing directions,and it could promote the development of force control in orthopedic surgery. 展开更多
关键词 Robotic milling force Cortical bone Cutting force coefficient Orthogonal cutting distribution
车削加工硫化锌晶体工艺 认领
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作者 李世杰 徐超 +2 位作者 黄岳田 王守义 刘卫国 《红外与激光工程》 EI CSCD 北大核心 2020年第7期187-194,共8页
随着硫化锌晶体光学元件在红外光学系统中的广泛应用,对其表面质量的要求越来越高,但由于该材料的脆性特点,很难获得高质量的表面粗糙度。为了获得高质量的硫化锌晶体表面,首先,介绍了基于单点金刚石车床的车削加工与飞切加工的技术原理... 随着硫化锌晶体光学元件在红外光学系统中的广泛应用,对其表面质量的要求越来越高,但由于该材料的脆性特点,很难获得高质量的表面粗糙度。为了获得高质量的硫化锌晶体表面,首先,介绍了基于单点金刚石车床的车削加工与飞切加工的技术原理,以及影响表面粗糙度的因素。然后,通过工艺实验,采用单一变量法,研究了不同参数的金刚石刀具和不同的加工参数对硫化锌平面元件的表面粗糙度的影响。采用显微镜和白光干涉仪对加工表面的质量进行了检测,并反馈了优化加工参数。最后,基于最优加工参数,采用两种加工方式均获得了表面粗糙度Sa为1 nm左右的高质量硫化锌平面光学元件。该研究结果对高质量硫化锌光学元件的研制提供了技术支持,具有广泛的工程应用价值。 展开更多
关键词 硫化锌晶体 车削加工 飞切加工 表面粗糙度
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