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直齿圆锥齿轮与弧齿圆锥齿轮轮齿应力比较
The Comparison of Straight Tooth Bevel Gear and Spiral Bevel Gear about the Stress of Gear Tooth
 [PDF]

, 宋爱平, 罗超, 海滨, 王树凤
Instrumentation and Equipments (IaE) , 2016, DOI: 10.12677/IaE.2016.42002
Abstract: 大型的数控龙门加工中心中,卧式主轴头通过一对直齿圆锥齿轮副来作为相交轴的传动部件。其加工中心在高速运转时,直齿圆锥齿轮副会发出大的噪声和冲击,导致加工中心的加工质量和精度下降。为了解决这一问题,提出采用弧齿圆锥轮副代替直齿圆锥齿轮副。基于ANSYS Workbench软件,分析直齿圆锥齿轮副与弧齿圆锥齿轮副的齿跟弯曲应力和齿面接触应力的状况,在此基础上,得出弧齿圆锥齿轮副在传动过程中其轮齿的综合力学性能要优越于直齿圆锥齿轮副相应的轮齿性能。这使得数控龙门加工中心可回转式卧式主轴头在更换前70分贝的噪声降至到60分贝,噪声得到了显著的降低。
In the large CNC gantry machining center, through a pair of straight bevel gear pair, the horizontal spindle head is used as a driving part for intersecting axes. When it in high-speed operation, straight tooth bevel gear pair makes a big noise and impact, which results in a decline in the quality and machining precision of the machining center. In order to solve this problem, it is proposed that the spiral bevel gear pair is used instead of the straight bevel gear pair. Based on ANSYS Workbench software, the status of straight tooth bevel gear pair’s and the spiral bevel gear pair’s the bending stress and contact stress are analysed. On this basis, it is concluded that spiral bevel gear pair, in the transmission process, of the comprehensive mechanical properties of the tooth is superior to the gear's performance of the corresponding straight tooth bevel gear pair. This makes CNC gantry machining center which can be rotary horizontal spindle head dropped to before re-placing 70 decibels of noise to the 60 decibels, which is significantly reduced.
利用预应力原理提升龙门机床横梁的抗弯强度
Promoting the Bending Strength of the Beam of Gantry Machine Tool by the Principle of Prestress
 [PDF]

罗超, 宋爱平, , 王树凤, 海滨
Mechanical Engineering and Technology (MET) , 2016, DOI: 10.12677/MET.2016.52017
Abstract:
横梁是龙门机床的重要部件之一,与其他部件相比,它所承受的力及弯矩较大且方向较为复杂。如果横梁的自身抗弯强度不足,会产生明显的向下变形,将给龙门机床的加工精度产生一定的影响。本文利用预应力原理提升横梁的抗弯强度,建立预应力横梁的受力模型,分析横梁挠度与预应力的关系,并利用有限元方法对预应力横梁进行验证。结果表明应用预应力原理提升横梁抗弯性能是切实可行的,中部挠度减小了约80%,有效的增加了龙门机床的加工精度。
Beam is one of the important parts of gantry machine tool; compared with other parts, it bears the force and bending moment that is larger and has more complex direction. If a beam of its bending strength is insufficient, it will produce obvious deformation down and bring about the processing precision of gantry machining center with a great influence. In this paper, based on the principle of prestressing, the bending strength of the beam is promoted, the force model of the prestressed beam is established, the relationship between the deflection of the beam and the prestress is analyzed, and the finite element method is used to verify the prestressed beam. The results show that it is feasible to apply the principle of prestress to improve the bending resistance of beams, and the deflection reduced about 80%, increasing the machining precision of the gantry machine tool effectively.
基于RSLN-2模型下的我国股票分红问题探究
Research on Dividend Policy of China’s Stock Market Based on RSLN-2 Model
 [PDF]

周斌, ,
Finance (FIN) , 2013, DOI: 10.12677/FIN.2013.34007
Abstract:

本文利用体制状态转移对数正态模型刻画股指与股息率,并以上证综指和S&P 500指数进行实证对比分析:在考虑了中美两国在股市平稳期和变动期两体制状态下,股指和股息率的变动情况,指出变动因素对于两国股市的影响结果截然不同,股息率对于股市整体的依赖程度在两国的证券市场也呈现明显差异。接着对我国上市公司分红的结构性问题进行探讨:指出我国股市与发达证券市场相比,具有股指高收益率和高波动率并存的现象;进一步分析现金红利的派发时,通过市盈率、股价现金流比率分析出股价过高是导致我国股息率偏低的重要原因,股息率和股息支付率两者同时偏低的根本原因在于我国上市公司整体盈利能力较弱。
This paper depicts stock index and dividend payout ratio by using regime-switching lognormal model. In practice, this model is applied to the stock market in China and United States, represented by Shanghai composite index and S&P 500 index separately. On the basis of stock index and dividend yield, we point out that the factor of variability in two countries’ stock market leads to different outcomes. The dependence of dividend yield on the whole stock market performance differs across borders in two countries’ security markets. Next, this paper makes further statistical descriptions of the cash dividend structure of the listed companies, points out that, in comparison to other developed securities markets, relative high price earnings ratio (PE) and price/cash flow ratio (P/C) coexist. When analyzing the situation of cash dividend sending, through PE and P/C, we indicate that high stock price is the important reason to the low dividend yield. However, the fundamental cause of the low PE and P/C in the meantime lies in the fact that listed companies in our country have relative weak profitability.

白地霉脂肪酶在毕赤酵母表面展示
陶站华,
生物技术通报 , 2011,
Abstract: 将白地霉脂肪酶基因N端与酿酒酵母FLO絮凝结构域序列融合,构建成脂肪酶毕赤酵母表面展示载体并转化毕赤酵母GS115。免疫荧光检测证实脂肪酶已展示于毕赤酵母细胞表面。甲醇诱导96h后展示酶活性达到81U/g干细胞,酶的热稳定性较游离酶有较大提高,50℃孵育4h后酶活仍保持初始酶活70%以上。
适于木本植物油脂的催化剂研究:纳米固体超强酸催化剂对游离脂肪酸的酯化
Study of Catalyst Appliable for Woody Plant Oil: Nano Solid Superacid Catalyzing the Esterification of Free Fatty Acid
 [PDF]

学俊, 张文坤,, 欧阳寒梅, 周蓉
World Journal of Forestry (WJF) , 2012, DOI: 10.12677/wjf.2012.11001
Abstract:

木本植物油脂与草本相比多为高酸价,用碱性催化剂进行酯交换时易发生皂化。两步法是先将游离脂肪酸酯化,再进行碱催化生产,可以提高资源的利用率,拓展原料的来源,降低成本。锡是少数几个可制备固体超强酸的金属。本文以掺锑二氧化锡纳米材料为基体,进行表面硫酸化。在330℃煅烧得到催化剂 /Sb-SnO2,酸性强(H0 ≥ –14.5),超过100%硫酸(–11.9)近1000倍,为固体超强酸。TEM照片显示为纳米催化剂。将其应用在高酸值米糠油的酯化反应中,在常压、常温(70℃)下进行游离脂肪酸的酯化催化反应,对游离酸的酯化率为95%以上,残余米糠油的酸值由58.94 mg/g降到3~4 mg/g,可用液体碱催化剂继续进行酯交换反应。从而证实该催化剂可用于高酸价木本油脂两步法生成生物柴油,提高资源的利用率。
Generally woody plant oil bears a higher acid value than the oil from herbaceous plant. Basic catalyst will lead to soap reaction in transesterification of oil. Tow step method divides the production of biodiesel into the esterification of free fatty acid and the transesterification of oil, which improves resource utilization greatly and broadens sources of oil, contributing to a low cost. Sin is a few metals by which solid superacid can be prepared. The present paper used nanocrystal of SnO2 doped with Sb as carrier to superficially sulfate on it. Nano-catalyst @Sb-SnO2 calcined at 330?C for 3 h is a solid superacid with a strong acidy, Hammett function H0 ≥ –14.5, stronger than 100% sulfuric acid (–11.9) near to 1000 times. The image of TEM showed the solid superacid is nano size. In esterification of rice bran oil with high acid value, the ratio of esterification of free fatty acid was up to 95% under normal pressure at 70?C, and the acid value of remains of rice bran oil decreased from 58.94 to 3 - 4 mg KOH/g. So the remains of rice bran oil can be directly used for transesterification by homogeneous basic catalyst, thereby the tow step method can be practiced and enhance the utilization of rate oil resources.

 

自我参照加工与情绪性诱词的关联性错误记忆
The Research of Self-Reference Effect on the Associative False Memory
 [PDF]

王依楠,
Advances in Psychology (AP) , 2013, DOI: 10.12677/AP.2013.35035
Abstract: 本研究结合DRM错误记忆范式(Deese-Roediger-McDermott paradigm)和自我参照效应的研究范式,以女大学生为被试,采用口头造句任务考察了关键诱词的情绪效价和不同参照加工条件对关联性错误记忆的影响。研究结果表明:1) 诱词的情绪效价影响了关联性错误记忆,表现为正性诱词比中性和负性诱词显示了更高的错误再认率;2) 相对于他人参照,自我参照加工具有诱发更强烈错误记忆的趋势。
The present study investigated how self-referential process influenced the associative false mem- ory for affective lures by combining the research paradigm of DRM with that of the self-reference effect. The following conclusions were drawn from the study: 1) The valence of the critical lures influenced the false memory. That is, the false recognition rate of the positive lures was higher than negative lures and neutral lures. 2) Compared to the other-referential processing condition, the recognition of critical lures has a ten- dency to increase under the self-referential processing condition.
简单形状的情绪效应
The Affective Effect of Simple Geometric Shapes
 [PDF]

王依楠,
Advances in Psychology (AP) , 2015, DOI: 10.12677/AP.2015.58061
Abstract: 本研究采用情绪启动范式,以首都师范大学在校生为被试,检验了简单形状的情绪效应。实验一发现快乐表情的情绪一致性效应,圆形启动刺激促进对快乐表情的判断,倒三角形启动刺激干扰表情判断。实验二发现形状的情绪一致性影响,倒三角形促进对消极词语的加工,干扰对积极词语的加工,圆形产生相反的作用。实验表明,圆形表征着积极意义,倒三角形表征消极意义,且这种情绪意义可以被自动激活,对认知操作产生不同的影响。
Selecting undergraduates of Capital Normal University as participants, the present work sought to examine the emotional meaning of simple geometric shapes with an affective priming paradigm. In Experiment 1, we found an effect of affective congruency on happy faces. Results showed that the happy faces were recognized faster after circle than inverted triangle primes. Experiment 2 revealed a significant effect of affective congruency. The inverted triangle facilitated the processing of negative words and interfered with the processing of positive words. The shape of circle had an opposite effect. The present findings support that inverted triangles represent an unpleasant or threatening meaning, whereas circles are perceived as pleasant stimuli. This meaning could be ac-tivated automatically and exert different influences on cognitive performance.
海南岛几个重要土类在不同利用下放线菌的分布与拮抗性的研究
贺庸,臧向瑩,克谦
微生物学报 , 1965,
Abstract: (一)热带季雨林、灌木林的放线菌数量较多(最高643万/克土)、原森林地与海滨土壤放筱菌数量最少(2—8万/克土)。季雨林垦为农地后放彼菌数量降低至1/2一1/3。种植经济林后的变化没有农地显著。 (二)在同一剖面内枯枝落叶层放线菌数量最高,如保亭地区枯枝落叶层高达1500—2000万/克士,随着土层加深,有机质含量减少,放彼菌数量亦相应降低(0一lo厘米为208—643万/克土,20—30厘米为9—80万/克土,60—70厘米仅有2—3万/克土)。 (三)放线菌种粗的分布亦以热带季雨林最多,整个剖面包括有所划分之垒部16个种粗。楹济林、农地和水田灾之,而以原始森林和海滨土壤最少,仅分布有6—8个种粗。从土层深度划分,以0—30厘米土层所含放植菌种租最多(14一15个种组),枯枝落叶层与底土较少。 (四)在放线菌拮抗性能的分布上,旱地土壤单帝屯抗真菌的放枝菌比例较大(占整个}吉抗菌株的58.9%);水稻土及海滨土壤单纯抗和菌的菌株较多(占整个拮抗菌株的50%)。在各类土壤中抗革兰氏阳性菌(枯草杆菌)的又较抗革兰氏阴性菌(大腸杆菌)的为多,抗革兰氏阳性菌的此例占对细菌有拮抗作用菌株的50—95%。 (五)在进行放线菌种粗的划分中发现有静多放线菌不能在r.巾.高泽氏1号培养基上生长,或者在其上不长气生菌丝,或者生长微弱,无法利用高泽氏种粗划分原则进行分祖。因此作者将其另划为一个种组(第16种粗),井发现此类放线菌在60一70厘米土层中仍存在有相当数量,且具有鞍大拮抗作用。作者认为在拮抗性放线菌过筛工作中应予以注意。
基于广义Hoek-Brown强度准则的PEM节理边坡可靠性分析
王宇,黄力华,李腾飞,
煤田地质与勘探 , 2012,
Abstract: 广义Hoek-Brown强度准则(简称GH-B准则)作为估计完整岩石或节理岩体剪切强度的半经验准则,已成为岩体强度预测及数值计算领域中应用最广的准则之一。经验公式中涉及3个与岩体特性有关的材料参数mb、s和a,实际应用中还不能直接对这3个参数进行精确取值,只能通过中间变量推导或结合地质经验来确定。为尽可能大地消除因用Hoek-Brown经验公式(简称H-B经验公式)的中间变量推导带来的累积误差,消除边坡稳定性评价结果的偏差,提出了从基本随机变量着手,考虑基本变量的可变性与不确定性,借助可靠性理论来综合分析评价边坡潜在破坏概率和风险程度的方法。研究基于GH-B准则的节理岩质边坡的可靠性问题,首先从决定H-B经验公式的4个基本参数GSI、σci、mi和D出发,研究变量的分布概型及取值范围,然后引入到H-B经验公式中去,利用有效地可靠性计算方法求解边坡的失稳概率,将统计矩点估计法(PEM法)引入到节理岩质边坡失稳概率的求解中,通过对一开挖桥墩承台边坡的可靠性分析表明,基于GH-B准则的PEM方法提高了稳定性评价的客观性,结果更加真实可靠。
甘蓝型油菜ogucms1575a4个恢复系分子标记的初步研究
,董军刚?,胡永敏
西北农林科技大学学报(自然科学版) , 2014,
Abstract: 【目的】对甘蓝型油菜ogucms恢复基因(rfo)设计的特异分子标记进行检测,为选育有别于国外的同类恢复材料提供依据。【方法】以甘蓝型油菜ogucms1575a的保持系及其恢复系1601、sr36、sr58、1628为材料,选取1个基于ogucms恢复基因设计的特异分子标记和5个与恢复基因连锁的萝卜标记,对甘蓝型油菜ogucms1575a的4个恢复系进行恢复基因rfo分子标记检测,并与国外同类恢复系rrh1、r113、r2000的检测结果进行初步比较。【结果】甘蓝型油菜ogucms1575a的4个恢复系1601、sr36、sr58、1628均存在ogucms恢复基因。与rfo连锁的萝卜基因区段的分子标记检测比较表明,恢复系1601、1628连锁的萝卜片段长度短于国外同类恢复系r113;恢复系sr36、sr58与rrh1连锁的萝卜片段长度相近,但是sr58却缺少1601、1628、sr36共有的1个标记sg34。【结论】甘蓝型油菜ogucms1575a的恢复系1601、sr58、1628可能是有别于国外同类恢复系rrh1、r113、r2000的萝卜质恢复材料。
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