Research on NC machining technology based on cutting tool creep-feed in feed direction

【中文文摘】通过对数控加工中存在的问题分析,提出了一种在数控加工中,刀具在被加工工件曲面上沿进给方向蠕动式切削加工的方法,通过刀具与工件时续分离和切削,改善了工艺系统的刚性,从而使工件的加工精度得到改善,并具体从被加工工件的几何形状、切削过程中刀具受力情况及切削区的切削热释放情况方面,分析了采用该方法对加工精度的改善情况。 【英文文摘】Based on analyzing problems that general NC machinining process exists, this paper proposes a machining method cutting tool creep-feed machining work piece in feed direction .When cutter is fed toward and away from work piece,it can improve the rigidity of mechanics system,so that machining precision is improved. Other advantages of this process include a superior surface finish,low tool pressure, and cutting heat released easily in the cutting section

春、秋季台湾海峡海-气CO2通量及其影响因素

于2014年的5月（春季）和9月（秋季）在台湾海峡及其邻近南海和东海海域,采用水气平衡法进行了2个航次的海表和大气pCO2连续走航观测,同时获取了海表温度、海表盐度、风速及气压等数据,并采用海-气CO2分压差减法估算了海-气CO2通量.结果显示,春、秋2个航次平均海表pCO2分别为387±16μatm和408±18μatm.温度是影响台湾海峡及其邻近海域海表pCO2的主控因子,水团混合和其他因素等也对海表pCO2有一定影响.2014年春、秋季节,对研究区域的海-气CO2释放通量的估算结果分别为0.11±1.60 mmol/（m2·d）和2.51±1.10 mmol/（m2·d）.台湾海峡海表pCO2既存在显著的季节变化,又存在较大的空间差异.国家海洋局第三海洋研究所基本科研业务费资助项目(海三科2011015);;厦门南方海洋研究中心资助项目(14GHS016NF16,14PST63NF27

痤疮发病机制及其药物治疗的研究进展

目的：了解痤疮的发病机制及其药物治疗的研究进展,为其临床治疗提供参考。方法：查阅近年来国内外相关文献,就痤疮的发病机制及其药物治疗的研究进展进行归纳和总结。结果：痤疮的发病机制主要为雄激素分泌异常、痤疮丙酸杆菌的大量繁殖、炎症损害和免疫失常及毛囊皮脂腺导管角化异常等。痤疮的局部治疗药物中维A酸类药物与抗菌药物可联用于治疗轻、中度痤疮,其中全反式维A酸、阿达帕林与他扎罗汀是治疗轻度痤疮的首选药物,全反式维A酸常联合外用抗菌药物治疗中度痤疮,阿达帕林和克林霉素分别与过氧化苯甲酰联用、果酸参与的联合给药方案也用于治疗痤疮。口服治疗药物中维A酸类药物主要用于重度痤疮,第一代的异维A酸较第二代疗效更好,但均有致畸作用;口服抗菌药物适用于中、重度痤疮患者,多西环素与米诺环素是首选药物,米诺环素联用过氧化苯甲酰疗效好;大环内酯类抗菌药物口服后不良反应较多,故常作为外用药;口服激素类药物中的抗雄激素类药物用于女性患者,但长期使用会引发高胰岛素血症;螺内酯有潜在的安全问题,西咪替丁抗雄激素效果较弱,不作为治疗痤疮的常用药物;糖皮质激素类药物常用于暴发性痤疮或聚合性痤疮的治疗,使用剂量须严格控制。结论：痤疮的治疗应根据痤疮的发生原因和严重程度选择合理的用药方案,增加疗效并减少不良反应的发生,并注意药物相互作用,提高用药安全性。军队医疗机构制剂标准提高科研专项课题（No.14ZJZ17

Development of a New Temperature and Humidity Sensitive Integrated Sensor

研制成由硅温敏二极管和聚酸亚胺湿敏电容集成的温湿度传感器。介绍了它的工作原理、结构设计、制作工艺、测试结果以及为提高它的性能所作的一些研究。An integrated temperature and humidity sensor consisting of the silicon diode and the polyimide-based capacitive humidity sensor has been deve-loped.The sensor working principle, structure design, manufacturing technology, measurement results and some studies of improving the sensor characteristics have been introduced.福建省科技资

4H-Cyclo­penta­[def]phenanthren-4-one

In the title compound, C15H8O, the asymmetric unit contains four independent mol­ecules and crystallizes with aromatic π–π stacking inter­actions[centroid–centroid distances = 3.5326 (18) Å]

Synthesis of C-3v-(C64H4)-C-#1911 using a low-pressure benzene/oxygen diffusion flame: Another pathway toward non-IPR fullerenes

通讯作者地址: Huang, RB (通讯作者), Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, 422 S Shimin Rd, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 2. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 电子邮件地址: [email protected] addition to the traditional Kratschmer-Huffman graphite arc-discharge method, a combustion method has been developed to synthesize fullerenes that defy the isolated pentagon rule (IPR). The C-3v-symmetric (C64H4)-C-#1911, as well as other non-IPR fullerenes such as the possible non-IPR C-60 isomer, have been synthesized as fullerene hydrides in a low-pressure benzene/oxygen diffusion flame. The non-IPR structure of the chromatographically isolated C-64 species was unambiguously identified by its HPLC retention time, UV absorption and mass spectrum by comparison with the reference material C3v-#1911C64H4. The synthesis, isolation and identification of C-3v-(#1911) C64H4, as described in this work, show that this combustion method is successful, is energy efficient and is a promising candidate for the macroscopic synthesis of non-IPR fullerenes. (C) 2009 The Combustion Institute. Published by Elsevier Inc. All rights reserved.Institute of Chemistry, Chinese Academy of Sciences 20571062 20721001 20525103 National Basic Research Program (973 Program) of China 2007CB81530

类泛素蛋白及其中文命名

泛素家族包括泛素及类泛素蛋白,约20种成员蛋白.近年来,泛素家族领域取得了迅猛发展,并已与生物学及医学研究的各个领域相互交叉.泛素家族介导的蛋白质降解和细胞自噬机制的发现分别于2004和2016年获得诺贝尔奖.但是,类泛素蛋白并没有统一规范的中文译名. 2018年4月9日在苏州召开的《泛素家族介导的蛋白质降解和细胞自噬》专著的编委会上,部分作者讨论了类泛素蛋白的中文命名问题,并在随后的\"泛素家族、自噬与疾病\"(Ubiquitinfamily,autophagy anddiseases)苏州会议上提出了类泛素蛋白中文翻译草案,此草案在参加该会议的国内学者及海外华人学者间取得了高度共识.冷泉港亚洲\"泛素家族、自噬与疾病\"苏州会议是由美国冷泉港实验室主办、两年一度、面向全球的英文会议.该会议在海内外华人学者中具有广泛影响,因此,参会华人学者的意见具有一定的代表性.本文介绍了10个类别的类泛素蛋白的中文命名,系统总结了它们的结构特点,并比较了参与各种类泛素化修饰的酶和它们的生物学功能.文章由45名从事该领域研究的专家合作撰写,其中包括中国工程院院士1名,相关学者4名,长江学者3名,国家杰出青年科学基金获得者18名和美国知名高校华人教授4名.他们绝大多数是参加编写即将由科学出版社出版的专著《泛素家族介导的蛋白质降解和细胞自噬》的专家

First Sagittarius A* Event Horizon Telescope Results. VIII. Physical Interpretation of the Polarized Ring

In a companion paper, we present the first spatially resolved polarized image of Sagittarius A* on event horizon scales, captured using the Event Horizon Telescope, a global very long baseline interferometric array operating at a wavelength of 1.3 mm. Here we interpret this image using both simple analytic models and numerical general relativistic magnetohydrodynamic (GRMHD) simulations. The large spatially resolved linear polarization fraction (24%–28%, peaking at ∼40%) is the most stringent constraint on parameter space, disfavoring models that are too Faraday depolarized. Similar to our studies of M87*, polarimetric constraints reinforce a preference for GRMHD models with dynamically important magnetic fields. Although the spiral morphology of the polarization pattern is known to constrain the spin and inclination angle, the time-variable rotation measure (RM) of Sgr A* (equivalent to ≈46° ± 12° rotation at 228 GHz) limits its present utility as a constraint. If we attribute the RM to internal Faraday rotation, then the motion of accreting material is inferred to be counterclockwise, contrary to inferences based on historical polarized flares, and no model satisfies all polarimetric and total intensity constraints. On the other hand, if we attribute the mean RM to an external Faraday screen, then the motion of accreting material is inferred to be clockwise, and one model passes all applied total intensity and polarimetric constraints: a model with strong magnetic fields, a spin parameter of 0.94, and an inclination of 150°. We discuss how future 345 GHz and dynamical imaging will mitigate our present uncertainties and provide additional constraints on the black hole and its accretion flow

CALCULATION AND ANALYSIS OF SEVERAL HIGH AUCCURACY SCHEMES FOR SOLVING;ODE EIGENPROBLEM ON NON-UNIFORM GRID

本文针对不等距网格,从Rayleigh商(Rayleigh quotient)角度出发,构造了若干求解ODE特征值问题的高阶格式,并进行误差分析.文中高阶格式的构造是基于线性有限元及其对应的差分格式进行的 .单纯的线性有限元及其对应的差分格式求解PDE特征值问题都只有二阶精度,我们利用质量集中和加权组合的思想通过将二者结合得到四阶精度的算法.本文从 理论和实验的角度构造高阶格式并进行了相应的误差分析.通过在五种网格上计算四阶精度格式的误差阶系数,将四阶格式加权组合的新格式甚至可以达到六阶精度 .最后用数值实验验证了构造的高阶格式的误差阶同时,本文构造的两种四阶格式相对于传统的线性有限元方法,在同等量级误差的要求下, 需要的网格数有量级的减少.From the perspective of Rayleigh quotient, we constructed several high-order accuracy schemes to solve the ODE eigenproblem on non-uniform grid, and analyze the error. Purely linear finite element scheme and finite difference scheme to solve corresponding ODE eigenproblem are only second order accuracy, Use a weighted combination of the two and error compensation or mass lumping method to construct the fourth-order accuracy schemes. We construct high-order accuracy schemes and analyse the corresponding error both in theoretical and experimental levels. Through numerical experiments on five kinds of grid, we construct new schemes even up to sixth-order accuracy, by computing the coefficient of the specific error-order of the fourth-order accuracy schemes. At last, we use numerical experiment to verify the accuracy order of these new schemes. At the request of the same order of magnitude error, the number of-grid that our two fourth-order schemes need have a magnitude of decrease compared to the traditional linear finite element method