Theoretical Analysis and Experiment on Flow Allocation Characteristics of Dual Discharging Axial Piston Pump

通过改变缸体结构、柱塞数、端盖油路、配流盘形状等,设计了双排油内外环并联配流结构的轴向柱塞泵,实现了单柱塞泵两路高压供油。针对单环柱塞数减少,腔; 内压力冲击增大,脉动变大等问题,对配流结构进行重新设计。在排油腰形槽和吸油腰形槽过渡区取消卸荷槽,利用加大配错角,在排油完毕未接通吸油时,腔内封; 闭体积增大,未排尽的高压油液压力降低;在吸油腰形槽和排油腰形槽过渡区,排油卸荷槽利用阶梯变化通流面积代替原连续变化的通流面积,削弱了卸荷槽几何形; 状要求。重新设计后的双排油配流结构,以45mL轴向柱塞泵结构为参考,对配流结构进行了理论分析,建立了双排油轴向柱塞泵仿真模型。以单柱塞腔内压力; 冲击、输出流量进行分析研究,得外环压力冲击小,与传统配流结构相比较双排油输出口压力脉动变化率变小,并试制双排油轴向柱塞泵。对试制泵进行压力脉动测; 试、容积效率测试和噪声测试,结果表明,与45mL轴向柱塞泵进行对比,压力脉动降低了约30%,噪声也降低,容积效率不低于0.92。该双排油轴向柱; 塞泵可以代替双联泵,使系统结构简化,能耗降低。When providing two-way independent high-pressure high-flow oil sources,; hydraulic system generally adopts two separate piston pumps or coaxial; ones in series, causing complex structure and high cost. Therefore,; single piston pump was proposed to achieve two-way high-pressure oil; supply. Axial piston pump was designed with dual discharging inter-outer; ring parallel allocation structure by changing cylinder structure,; piston number, cap circuit and valve plate shape. Flow allocation; structure was redesigned due to decreased single ring piston number,; increased pressure shock and fluctuation in the chamber. Relief notch; was cancelled in transition region from oil-discharging to oil-absorbing; waist slots. After that, mismatch angle was increased to enlarge closed; volume in chamber and reduce the pressure of unexhausted high-pressure; oil in the interval between oil extraction and absorption. In transition; region from oil-absorbing to oil-discharging waist slots, stepped flow; area was used to replace original continuous flow area to weaken; geometry requirements of relief notch. The optimized dual discharging; flow allocation structure was conducted with theoretical analysis to; establish dual discharging axial piston pump simulation model based on; 45mL axial piston pump structure. There was small pressure shock in; outer race by analyzing pressure shock and output flow in single piston; chamber. Compared with traditional flow allocation structure, dual; discharging oil output had smaller pressure fluctuation rate. Based on; this, the designed dual discharging axial piston pump was piloted. The; pilot dual discharging oil pump was compared with the original 45mL; pump through pressure fluctuation, volumetric efficiency and noise; tests. Result showed that the former had lower pressure fluctuation; (decreased by 30%) and noise level, while its volumetric efficiency was; not smaller than 92%. In general, the dual discharging axial piston pump; can replace duplex pump to simplify system structure and reduce energy; consumption. This new pump can also be used in closed circuit and; differential cylinder hydraulic systems to make the system simpler and; cost-effective.山西省自然科学基金项目; 国家自然科学基金项

Progress of Organic Chemistry(2011～2012)

本文综述了中国大陆地区有机化学研究人员2011至2012年两年内在合成方法学、有机合成化学、元素有机化学以及天然产物化学等领域获得的重要成果。文章中共引用参考文献355篇,其中110多篇手性金属配合物和有机小分子催化的不对称反应、金属催化的碳氢键活化等合成方法学论文和30余篇氟有机化学论文基本来源于德国《应用化学》(国际版)和《美国化学杂志》。本文汇集了中国有机化学家两年中合成的150多个具有生物活性和化学结构多样性的天然产物,其中不乏具有高度挑战性的复杂天然分子。在近两年中中国有机化学家从陆地和海洋的生物体内发现各种不同类型新天然产物90多个。This biennale report reviewed the major achievements of organic chemistry involved to synthetic methodologies,synthetic chemistry,element-organic chemistry,and natural product chemistry in Mainland of China.There were 355 references cited in this report.Among them,about 110 papers related to the synthetic methodologies as well as about 30 papers of organofluorine chemistry reported herein were collected solely from ACIE and JACS.The report presented the synthesis of more than 150 natural products with diverse chemical structures and bioactivities,including some complex molecules with high synthetic challenge as well as the isolation of more than 90 new natural products with various structural types from continental or /and marine creatures,which were reported by Chinese chemists in 2011 ~ 2012

CCCCC pentadentate chelates with planar Möbius aromaticity and unique properties

本课题充分发挥了厦门大学多学科协同研究优势，通讯作者为夏海平教授（合成、表征）、刘刚教授（生物医学应用）和吕鑫教授（理论计算）。合成实验和结构表征由朱从青（第一作者，目前在麻省理工学院、2005年诺贝尔化学奖得主Richard Schrock教授课题组从事博士后研究）完成；生物医学应用由杨彩霞（共同第一作者）、林凎、杨宇惠、王晓勇合作完成；理论计算由朱军、王永恒、朱从青完成。美国NIH的陈小元教授参与了生物医学应用的讨论。该研究工作得到国家自然科学基金委、科技部项目的支持。The coordinating atoms in polydentate chelates are primarily heteroatoms. We present the first examples of pentadentate chelates with all binding atoms of the chelating agent being carbon atoms, denoted as CCCCC chelates. Having up to five metal-carbon bonds in the equatorial plane has not been previously observed in transition metal chemistry. Density functional theory calculations showed that the planar metallacycle has extended Craig-Möbius aromaticity arising from 12-center–12-electron dπ-pπ π-conjugation. These planar chelates have broad absorption in the ultraviolet-visible–near-infrared region and, thus, notable photothermal performance upon irradiation by an 808-nm laser, indicating that these chelates have potential applications in photothermal therapy. The combination of facile synthesis, high stability, and broad absorption of these complexes could make the polydentate carbon chain a novel building block in coordination chemistry.the National Basic Research Program of China (nos. 2012CB821600 and 2014CB744503) , the National Science Foundation of China (nos. 21332002, 81422023, 51273165, 21490573, and 21573179)

水利施工中围堰技术的运用与施工技术要点分析

在社会快速发展的影响下，各个领域的发展都取得了良好的成绩。水利工程不但与社会发展存在密切的关联，并且也与民众生活息息相关，所以我们需要在实施水利工程建设工作的时候，从各个细节入手来对施工质量加以根本保障。在组织开展水利工程各项施工工作的过程中，往往需要运用到诸多的专业施工技术，其中围堰技术的作用是非常重要的，围堰技术的水平与整个水利工程质量存在密切的关联。但是就当下实际情况来说，因为各个水利工程项目之间是存在明显的差别的，如果水利工程围堰施工技术整体水平较差，那么必然会对整个水利工程项目施工质量和施工安全造成巨大的损害。鉴于此，这篇文章主要围绕水利工程围堰施工技术的实践运用展开全面深入的研究分析，希望能够对我国水利工程行业的未来良好发展有所帮助。</jats:p

simulation on time and space characteristic of blast-off platform for space-earth integration task

针对天地一体化任务的实际需要,建立了卫星轨道计算与升空平台时空特性分析模型,在卫星轨道计算与星地可通信性分析的基础上,提出了升空平台执行天地一体化任务的时空条件分析以及升空平台的任务执行时机和位置的选取方法。以无人机作为升空平台,构建并实现了升空平台用于天地一体化任务的时空覆盖分析与仿真程序。验证了仿真程序的轨道计算数据的可用性,并对仿真结果中的无人机航迹数据进行了比较与分析

中国建设社会主义新农村的思考——四川建设社会主义新农村模式初探

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Non-contact full-automatic shell body coaxiality detection device

本发明涉及炮弹的位置公差检测设备，具体地说是一种非接触弹体同轴度全自动检测设备，底座两端分别安装有定位装置和卡紧驱动装置，定位装置和卡紧驱动装置之间安装有浮动托盘装置，浮动托盘装置可拖住弹体并具有旋转自由度，浮动托盘装置和卡紧驱动装置可做横向移动，激光CCD传感器安装在底座侧面，同轴度检测时将被测弹体放置在浮动托盘装置上，卡紧驱动装置横向挤紧弹体靠紧定位装置并带动弹体做旋转运动，调节激光CCD传感器与待测弹体的回转轴线的距离至指定位置，采集弹体旋转时弹体表面与激光CCD传感器的距离，根据采集的数据可实现同轴度的检测。本发明具有结构可靠、稳定性高、分辨率高、检测快速、非接触、操作安全等优点

残采水平保留巷道在矿井通风系统优化中的研究与应用

在煤矿开采过程中，没有一个良好的通风系统，就会给工作人员带来一定的安全威胁。因此，在进行通风系统的优化过程中，将对残采水平保留巷道在矿井通风系统当中进行调整，以最小的工程进行投入，实现通风系统的优化改造，确保系统的稳定可靠，从而提高矿井的防灾能力。</jats:p

浅谈煤矿采矿工程巷道掘进和支护技术的应用分析

煤炭作为中国重要的资源和能源，在社会发展和人民生活中发挥着重要而积极的作用。尽管随着供给侧结构性改革的深入，对煤炭资源的需求持续减少，但这仍然不能影响煤炭资源在国民社会中的重要地位。因此，相关企业和部门必须继续重视煤炭资源的开采和开发，以及隧道开挖和支护技术在煤矿工程中的应用。论文对巷道开挖支护技术在煤矿工程中的应用进行了分析。</jats:p

保持矿井通风质量的通风安全控制系统研究

科技发展，信息化加快，管理手段多变成了现如今解决井下安全问题的新思路。如何运用现代科技手段，有效管理井下通风，保证工人安全生产、公司经济效益、避免各类灾害事故发生，成了重要课题。本文通过对井下通风系统运转，做好及时让领导及主管部门掌握，及时决策通风情况中引起的各类事故原因，并对如何通过通风安全来解决井下人力、物力、财力的统一整合进行分析。</jats:p