Study on virtual animation technology of sheet metal bending

板料折弯成形是指把薄板材料弯成一定角度的加工方法。本文通过分析折弯机结构参数,基于OPEngl ES在WInCE的平台上建立了数控折弯成形仿真的可视化界面,实现了板料折弯成形的3d动态仿真。以树状结构为基础,结合干涉检测等影响板料折弯成形的工艺因素,探讨了板料折弯成形的工艺改进以及工序搜索方法,计算判断出可行的板料折弯成形工序,再由OPEngl ES直观显示板料折弯加工工艺信息。板料折弯成形试验表明,该方法可以实现快速、精确的板料折弯成形。Sheet metal bending is a method to bend the sheet metal with a certain angle.Through analysis of the structural parameters of bending machine and based on OpenGL ES,the visual interface of NC bending animation was established on the WinCE platform,and the3D dynamic animation of sheet metal bending was achieved.Based on tree structure,the forming process development and search method of sheet metal bending were discussed combinated with interference detection and some else factors affecting the forming process.And a feasible procedure of sheet metal bending was achieved,then the information of sheet metal bending procedure was showed with OpenGL ES.And the forming method of sheet metal bending can achieve accurate,rapid and precise sheet metal forming with field machining

Generation and application of NC code for spiral wire

针对螺旋类线材的推弯成形,提出了一种数控代码自动生成方法,并以曲线模型相对复杂的等节距圆锥螺旋弹簧为例进行着重阐述。该方法通过提取线材几何建模参数,并结合推弯模具的结构尺寸和运动形式,建立线材推弯成形的数学模型,推导出送料轴、推弯轴和转臂轴三轴间的联动关系,最后采用等间距直线逼近法生成线材零件的数控加工代码并进行加工生产。试验证明,该方法编程效率高,修改方便,且加工零件可以满足精度要求。A way of automatically generating NC code for the push bending of spiral wire was introduced,and the equal-pitch conoid helical-coil spring whose curve model is relatively complex was emphatically discussed.Through extracting wire parameters of geometric modeling,and combining with the structure size and movement of push bending dies,the mathematical model of the push bending of spiral wire was made,and the linkage relationship among the feed axis,the push bending axis and the rotational axis was derived.Finally NC code was generated by equidistant linear approximation and the processing production was done.The experiment result shows that the programming efficiency of this method is high,the modification is easy,and the parts produced can meet the requirement of accuracy.国家科学技术部支撑项目(SQ2009GJC4001675

Research on planar spiral wire forming technology

金属线材成形零件种类繁多,其加工成形受到几何参数变化、材料特性等不同因素影响,致使加工精度难以准确控制。针对平面螺旋线材零件的圆弧半径变化现象提出了一种基于迭代思想的误差修正方法。通过分析加工对象的几何特性,建立了线材成形半径、弯曲角度以及线材送料长度三者之间的几何关系模型,建立了加工时送料轴与推弯轴的函数关系;以等半径线材圆弧零件的成形工艺为例,提出了平面螺旋线材的半径误差修正方法,并进行了试验加工,该方法能够有效提高线材加工精度。Forming parts of metallic wire are widely used,but its machining accuracy is difficult to be controlled because of the comprehensive influence of geometric parameters,material properties and other factors.For this phenomenon,an error correction method based on iterative mechanism was proposed by changing the radius of the planar spiral wire parts.Firstly,the geometric relationship among the wire forming radius,cumulative bending angle and wire feed length was derived by analyzing the geometric characteristics of the object to be processed.And then,the formula between the feed axis and the push bending axis was constructed.Finally,the radius error correction model of planar spiral wire was established and applied to the forming process of wire parts with equal radius.The machining result shows that the proposed method could improve the accuracy of wire processing effectively.国家科学技术部支撑项目(SQ2009GJC4001675

Synthesis and Raman Study of Hollow Core-Shell Ni1.2Co0.8P@N-C as an Anode Material for Sodium-Ion Batteries

本文设计制备了一种新型的氮掺杂碳包覆镍钴双金属磷化物中空核壳结构纳米立方体(Ni1.2Co0.8P@N-C)作为钠离子电池负极材料. 该材料以镍钴类普鲁士蓝(PBA)纳米粒子为模板,先后经水热法、磷化法和高温碳化处理后合成. 将其作为活性材料应用在钠离子电池中,该材料展现出优异的循环稳定性,当以100 mA·g-1的电流密度循环至200圈时,该材料的库仑效率保持在99.3%. 进一步通过对不同电位下Ni1.2Co0.8P@N-C材料中的氮掺杂碳进行原位拉曼光谱测试,结果显示钠离子在氮掺杂的碳壳中的脱嵌行为具有较大程度的可逆性,研究结果对钠离子电池充放电过程的后续电化学研究提供了有价值的信息.With the increasing demand for large-scale energy storage, great progress has been made in discovering new advanced energy storage materials. Sodium-ion batteries (SIBs) have attracted much attention in recent years due to their use of abundant sodium resources and their comparable electrochemical capacity to lithium-ion batteries (LIBs). In this paper, we developed novel hollow core-shell Ni-Co bimetallic phosphide nanocubes with N-doped carbon coatings (Ni1.2Co0.8P@N-C) as the anode material for SIBs. The material was synthesized through a low-temperature phosphorization method using resorcinol formaldehyde (RF) resin coating with a Ni-Co Prussian blue analogue (PBA) as a template and a subsequent thermal annealing process. The size of the as-obtained nanocubes was about 310 nm with a 19 nm N-doped carbon shell. When used as the anode material of SIBs, Ni1.2Co0.8P@N-C exhibited the excellent electrochemical cycling stability and demonstrated an especially high coulombic efficiency of 99.3%, even after 200 cycles with current density of 100 mA·g-1. Furthermore, in-situ Raman spectroscopy was used to investigate the electrode material in order to understand the electrochemical processes in the N-doped carbon shell of Ni1.2Co0.8P@N-C. The results showed that the intercalation and de-intercalation behavior of sodium ions in the N-doped carbon shell was almost reversible, providing valuable information about the charge and discharge processes in SIBs for the follow-up electrochemical studies.国家自然科学基金项目(No.21775127)、福建省自然科学基金项目(No.2018J05025)、厦门市科技局产学研协同创新及合作项目(No.3502Z20173017)资助通讯作者:许清池,李剑锋E-mail:[email protected];[email protected]:XUQing-chi,LIJian-fengE-mail:[email protected];[email protected]. 厦门大学物理科学与技术学院,福建 厦门 3610052. 厦门大学固体表面物理化学国家重点实验室,厦门大学化学化工学院,福建 厦门 3610051. College of Physical Science and Technology, Xiamen University, Xiamen 361005, Fujian, China2. State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, Chin

干旱内陆河灌区节水农业综合技术体系研究与集成

本课题从工程节水、农艺节水、管理节水三个方面,集成了农业高效节水、水肥盐调控、生态保护、监测与管理等关键技术,提出了干旱内陆河灌区农业节水技术集成体系与应用模式。提出了仅需根据水流推进过程确定土壤入渗参数和田面糙率系数的新方法,简化了地面灌溉设计。提出了根据土壤剖面含水率变化估算柽柳生长条件下潜水蒸发的理论方法与数学模型,为解决天然植被实际生态耗水问题提供了简易可行的方法

Aripiprazole versus other atypical antipsychotics for schizophrenia

BACKGROUND: In most western industrialised countries, second generation (atypical) antipsychotics are recommended as first line drug treatments for people with schizophrenia. In this review we specifically examine how the efficacy and tolerability of one such agent - aripiprazole - differs from that of other comparable second generation antipsychotics. OBJECTIVES: To evaluate the effects of aripiprazole compared with other atypical antipsychotics for people with schizophrenia and schizophrenia-like psychoses. SEARCH METHODS: We searched the Cochrane Schizophrenia Group Trials Register (November 2011), inspected references of all identified studies for further trials, and contacted relevant pharmaceutical companies, drug approval agencies and authors of trials for additional information. SELECTION CRITERIA: We included all randomised clinical trials (RCTs) comparing aripiprazole (oral) with oral and parenteral forms of amisulpride, clozapine, olanzapine, quetiapine, risperidone, sertindole, ziprasidone or zotepine for people with schizophrenia or schizophrenia-like psychoses. DATA COLLECTION AND ANALYSIS: We extracted data independently. For dichotomous data we calculated risk ratios (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random-effects model. Where possible, we calculated illustrative comparative risks for primary outcomes. For continuous data, we calculated mean differences (MD), again based on a random-effects model. We assessed risk of bias for each included study. MAIN RESULTS: We included 12 trials involving 6389 patients. Aripiprazole was compared to olanzapine, risperidone and ziprasidone. All trials were sponsored by an interested drug manufacturer. The overall number of participants leaving studies early was 30% to 40%, limiting validity (no differences between groups).When compared with olanzapine no differences were apparent for global state (no clinically important change: n = 703, 1 RCT, RR short-term 1.00 95% CI 0.81 to 1.22; n = 317, 1 RCT, RR medium-term 1.08 95% CI 0.95 to 1.22) but mental state tended to favour olanzapine (n = 1360, 3 RCTs, MD total Positive and Negative Syndrome Scale (PANSS) 4.68 95% CI 2.21 to 7.16). There was no significant difference in extrapyramidal symptoms (n = 529, 2 RCTs, RR 0.99 95% CI 0.62 to 1.59) but fewer in the aripiprazole group had increased cholesterol levels (n = 223, 1 RCT, RR 0.32 95% CI 0.19 to 0.54) or weight gain of 7% or more of total body weight (n = 1095, 3 RCTs, RR 0.39 95% CI 0.28 to 0.54).When compared with risperidone, aripiprazole showed no advantage in terms of global state (n = 384, 2 RCTs, RR no important improvement 1.14 95% CI 0.81 to 1.60) or mental state (n = 372, 2 RCTs, MD total PANSS 1.50 95% CI -2.96 to 5.96).One study compared aripiprazole with ziprasidone (n = 247) and both the groups reported similar change in the global state (n = 247, 1 RCT, MD average change in Clinical Global Impression-Severity (CGI-S) score -0.03 95% CI -0.28 to 0.22) and mental state (n = 247, 1 RCT, MD change PANSS -3.00 95% CI -7.29 to 1.29).When compared with any one of several new generation antipsychotic drugs the aripiprazole group showed improvement in global state in energy (n = 523, 1 RCT, RR 0.69 95% CI 0.56 to 0.84), mood (n = 523, 1 RCT, RR 0.77 95% CI 0.65 to 0.92), negative symptoms (n = 523, 1 RCT, RR 0.82 95% CI 0.68 to 0.99), somnolence (n = 523, 1 RCT, RR 0.80 95% CI 0.69 to 0.93) and weight gain (n = 523, 1 RCT, RR 0.84 95% CI 0.76 to 0.94). Significantly more people given aripiprazole reported symptoms of nausea (n = 2881, 3 RCTs, RR 3.13 95% CI 2.12 to 4.61) but weight gain (7% or more of total body weight) was less common in people allocated aripiprazole (n = 330, 1 RCT, RR 0.35 95% CI 0.19 to 0.64). Aripiprazole may have value in aggression but data are limited. This will be the focus of another review. AUTHORS' CONCLUSIONS: Information on all comparisons are of limited quality, are incomplete and problematic to apply clinically. Aripiprazole is an antipsychotic drug with a variant but not absent adverse effect profile. Long-term data are sparse and there is considerable scope for another update of this review as new data emerges from the many Chinese studies as well as from ongoing larger, independent pragmatic trials