DMMP在纳米分子筛敏感薄膜中的解吸附特性

分子筛膜的脱附困难是制约纳米分子筛敏感膜传感器发展的主要技术瓶颈之一,传统的高温脱附和纯氮气吹洗的方法无法有效地使纳米分子筛膜得到再生。针对Silicalite—1,ZSM—5和Cu-ZSM—5 3种纳米分子筛,利用石英晶体微天平(QCM)技术,研究了氮气吹洗法、高温脱附法和高频交变电场脱附法对甲基磷酸二甲酯(DMMP)气体的脱附特性。结果显示:超声频交变电场脱附法可以使脱附时间从传统方法的20 min缩短到60 s以内,并达到85%以上的脱附率,使传感器的重复性很快得到再现。     

基于石油套管壁厚检测的多聚焦探头研究

为了实现对石油套管的全覆盖壁厚自动化检测,提出由阵列式多聚焦探头围绕石油套管旋转组成自动化壁厚检测系统。根据超声聚焦探头的测厚原理,分析聚焦探头的焦距和晶片尺寸与聚焦声束的关系,选择合适的聚焦探头组成阵列式多探头自动化壁厚检测系统,进一步研究探头与石油套管之间的最佳距离和阵列式多探头与扫描速度之间的关系。实验结果表明：自动化壁厚检测系统可以准确、可靠、快速地实现对石油套管的检测,检测系统满足实际生产的API标准。     

基于运动学模型的细胞拨动方法

提出了一种基于运动学模型的细胞拨动方法以实现生物操作中细胞姿态的自动调整.首先对细胞拨动过程进行了运动学建模,并利用该模型对拨动幅度和拨动过程效率的关系进行了分析;然后设计了一种注射针的圆弧形的拨动轨迹以提高拨动幅度的控制精度;在以上工作基础上,运用图像处理和注射针运动控制算法最终实现了批量细胞的自动拨动流程;最后,本文利用该拨动方法进行了家猪卵母细胞的自动拨动实验.实验结果表明:使用该方法进行细胞拨动的操作成功率为90%,单个细胞平均操作时间为26.7s;细胞拨动幅度的平均控制误差为2.6?,明显小于传统手动操作方法的8.1?.本文方法可以实现生物操作中的家畜卵母细胞的姿态的准确自动调整.     

面向多读/写头磁畴壁存储器的优化研究

当前,大数据及人工智能技术向嵌入式系统发展,对嵌入式系统的存储访问能力提出了更高要求.磁畴壁存储器凭借其高读写速度、高密度以及低功耗等优点,可以用于嵌入式系统以满足数据密集型应用对访问速度、容量及能耗的需求.但是磁畴壁存储器在进行数据访问之前需要进行移动操作,这将极大的影响其存储访问性能.而减少移动操作可以有效提升磁畴壁存储器的性能.本文面向运行数据密集型应用的多读/写头磁畴壁存储器系统,研究减少移动操作的最优指令调度与数据放置技术.本文首先提出了可获得最小移动次数的ILP模型.由于ILP模型不能在多项式时间内求得最优解,所以提出了多项式时间的启发式算法——生成指令调度和数据放置（GISDP）算法.实验结果表明ILP模型和GISDP算法可以有效的减少移动操作次数.在配备8个读/写头的磁畴壁存储器上,GISDP算法生成的指令调度与数据放置方案相较其他算法可以平均减少89.7%的移动操作,并且GISDP算法的结果接近ILP模型的最优解.     

基于阻抗匹配的超声手术刀频率跟踪方法研究

随着科技的发展,超声手术刀在医疗上的运用越来越广泛。在实际应用中,为了让超声手术刀的换能器能尽可能高效率地将电能转换成机械能,利用并联阻抗匹配实现了超声手术刀的阻抗匹配,让超声手术刀的换能器呈现纯阻抗,从而使换能器的输出功率最大,并且减少了换能器的发热,延长了使用寿命。另外超声手术刀的换能器在使用过程中,换能器的各项参数会随着温度以及环境等发生改变,因此设计了一种针对换能器的谐振频率进行变频的频率跟踪方法,通过对电流和电压的相位差进行跟踪,然后送入到FPGA进行运算,得到一个相位差,当相位发生偏差的时候,则采用一个变频公式调整输出频率,从而达到频率跟踪的效果。通过实际验证,所设计的超声手术刀阻抗匹配和频率跟踪方法可以很好地实现在不同负载下的频率自动跟踪,并且运行可靠。     

适用于高压液体的超声液面传感器

<正> 一种设计新颖的超声液面传感器可以连续地测量高压液体(约为4×10~7Pa)的液面。这种传感器作为一种组合共振器操作,是用标准的高压插头制作的。平底洞是沿着插头的中心线经机械加工制成的。超声换能器刚性地粘在底壁的内表面     

基于工业机器人的超声换能器回波自动测量系统设计

针对医用超声换能器回波测量中存在的自动化水平低、测试人员主观判断对结果产生很大影响等问题,基于工业机器人设计了一套超声换能器回波自动测量系统。详细阐述了回波自动测量系统设计思路,对系统构建的关键——自动对位功能的实现方案进行了对比分析,在Matlab环境中开发了完整的参数设置、自动对位和回波采集与处理程序,对自动对位算法进行了详细描述。试验结果表明该系统达到了设计指标,灵敏度测量的偏移系数小于0.5%,能够满足日常工作中的测试需要。本工作为医用超声换能器研发、生产全流程的智能制造打下了良好的基础。     

基于横向场激励的高频压电超声换能器

介绍了一种基于横向场激励模式的高频压电超声换能器及其设计、分析和制作过程。采用扩展的Christoffel-Bech-mann方法对LiNbO3、LiTaO3和PMN-33PT三种不同压电材料的a模式横向场压电耦合系数进行了计算,发现这三种材料中LiNbO3具有最大的LFE a模式压电耦合系数,为28%。采用具有最大压电耦合系数的X切LiNbO3设计并制作了基于横向场激励的高频超声换能器,并采用传统的Pulse-Echo方法测试了该超声换能器的中心频率和带宽。实验测得该LFE高频超声换能器的中心频率为34MHz,-6dB带宽为14.4%。从理论和实验上证明了横向场激励模式可以应用于高频超声换能器。     

硅基高通量单细胞阵列芯片制备与研究

采用微机电系统(MEMS)技术结合金属辅助化学腐蚀工艺制作出关键结构为纳米氧化硅的阵列芯片,细胞可以定点黏附在纳米氧化硅上.通过实验计算和分析得知,在0.7~23μm内,纳米线长度约为3μm时深宽比适宜,有利于黏附蛋白充分铺展,黏附效率达到最高85%.改变培养时间(5~480 min)和细胞浓度(0.5~4.0),发现培养时间在不低于4 h,细胞浓度在1.5时,由于伪足充分缠绕于纳米线上,阵列饱和度达到最高83%.实验结果表明:制作出的单细胞阵列芯片具有较高的黏附效率和阵列饱和度,达到了高通量的标准.     

基于APDL宏和VB封装的水声换能器有限元分析

为了有效地避免水声换能器有限元优化设计过程中的重复操作,以及降低对设计者专业技术门槛的限制,对AN-SYS的二次开发技术进行了研究。通过APDL(ANSYS parametric design language)宏和VB封装技术的结合使用,在后台调用ANSYS批处理模式执行相应的宏文件,实现了水声换能器的交互式参数化设计。以I类凹筒型弯张换能器为例开发的软件应用情况表明,换能器交互式参数化设计有效可行,并且操作简单,显示直观,具有十分重要的工程应用价值。     

A simplified form of condensed detachment

This paper gives a simple, elegant statement of the condensed detachment rule that is independent of most general unifiers and proves that this is equivalent to the longer, more usual, formulation. Statement of exclusive submission. This paper has not been submitted elsewhere in identical or similar form.     

Gentle cell handling with an ultra-slow instrument: creep-manipulation of cells

In biotechnology, medicine and cell biological research, tasks like the advancement of a probe into a cell aggregate without causing cellular damage or the selection and removal of a specific cell or group from a culture surface or from a cell aggregate without undue stress require gentle cell manipulation. Currently, this requires mechanical or biochemical treatment, usually trypsination. However, these current techniques do induce cell stress and physiological reactions. We surmised that these tasks might be gently performed if the probe or recovery tool were moved sufficiently slowly, i.e. at a speed matched to the cell dynamics. Here, we show that it is possible to move an ultra-slow probe through a monolayer of cultured cells or into a 3D cell aggregate without causing obvious damage. We also demonstrate that a cell can be detached from a culture substrate by an ultra-slow probe (moving 1/500 to 1/1000 times slower than typical for a micro pipette) in the absence of any chemical treatment. This is the first time ultra-slow probes have been used to our knowledge. Finally, the practical relevance of such slow instrument movements in medicine, biotechnology and cell biology as well as possible applications and perspectives are discussed.     

Finding Shortest Proofs: An Application of Linked Inference Rules

In this article, we describe a procedure for systematically searching for shortest proofs in logical systems based on the inference rule condensed detachment. The procedure relies on applications of linked UR-resolution and uses demodulation to categorize derivations. Although the procedure is exhaustive in nature – and therefore realistically is applicable only to relatively small problems – it is shown to overcome the obstacles to finding shortest proofs presented by ordinary resolution-style theorem proving.     

A Legacy Recalled and a Tradition Continued

Since the first presentation of classical sentential logic as an axiomatic system by Frege in 1879, the study of a variety of sentential calculi has flourished. One major area of investigation, initiated by ukasiewicz and his colleagues in the first half of the twentieth century and carried into the second half by Meredith, Thomas, Prior, et al., focuses on alternative axiom sets for such logics, and on formal proofs within them. This paper recalls a sampling of the results obtained heretofore, noting along the way how the papers in this special issue of the Journal of Automated Reasoning fit into that larger tradition of which they now form a part. It also suggests a number of further questions, open problems, and projects to which the methods developed in these papers seem ideally suited and might well be fruitfully applied.     

Condensed detachment is complete for relevance logic: A computer-aided proof

The condensed detachment ruleD is a combination of modus ponens with a minimal amount of substitution. EarlierD has been shown to be complete for intuitionistic and classical implicational logic but incomplete forBCK andBCI logic. We show thatD is complete for the relevance logic. One of the main steps is the proof of the formula ((a a) a) a found in interaction with our resolution theorem prover. Various strategies of generating consequences of the axioms and choosing best ones for the next iteration were tried until the proof was found.     

Vanquishing the XCB Question: The Methodological Discovery of the Last Shortest Single Axiom for the Equivalential Calculus

With the inclusion of an effective methodology, this article answers in detail a question that, for a quarter of a century, remained open despite intense study by various researchers. Is the formula XCB=e(x,e(e(e(x,y),e(z,y)),z)) a single axiom for the classical equivalential calculus when the rules of inference consist of detachment (modus ponens) and substitution Where the function e represents equivalence, this calculus can be axiomatized quite naturally with the formulas e(x,x), e(e(x,y),e(y,x)), and e(e(x,y),e(e(y,z),e(x,z))), which correspond to reflexivity, symmetry, and transitivity, respectively. (We note that e(x,x) is dependent on the other two axioms.) Heretofore, thirteen shortest single axioms for classical equivalence of length eleven had been discovered, and XCB was the only remaining formula of that length whose status was undetermined. To show that XCB is indeed such a single axiom, we focus on the rule of condensed detachment, a rule that captures detachment together with an appropriately general, but restricted, form of substitution. The proof we present in this paper consists of twenty-five applications of condensed detachment, completing with the deduction of transitivity followed by a deduction of symmetry. We also discuss some factors that may explain in part why XCB resisted relinquishing its treasure for so long. Our approach relied on diverse strategies applied by the automated reasoning program OTTER. Thus ends the search for shortest single axioms for the equivalential calculus.     

Solving Open Questions and Other Challenge Problems Using Proof Sketches

In this article, we describe a set of procedures and strategies for searching for proofs in logical systems based on the inference rule condensed detachment. The procedures and strategies rely on the derivation of proof sketches – sequences of formulas that are used as hints to guide the search for sound proofs. In the simplest case, a proof sketch consists of a subproof – key lemmas to prove, for example – and the proof is completed by filling in the missing steps. In the more general case, a proof sketch consists of a sequence of formulas sufficient to find a proof, but it may include formulas that are not provable in the current theory. We find that even in this more general case, proof sketches can provide valuable guidance in finding sound proofs. Proof sketches have been used successfully for numerous problems coming from a variety of problem areas. We have, for example, used proof sketches to find several new two-axiom systems for Boolean algebra using the Sheffer stroke.     

Automated discovery of new axiomatizations of the left group and right group calculi

This paper shows how the automated theorem-proving program OTTER was used to discover new axiomatizations, including single axioms, for the left group and righ group calculi. J. A. Kalman's original axiomatizations of the two calculi each contain five axioms. Three of Kalman's axioms (L1, L4, and L5) for the left group calculus were shown to be dependent on the remaining two axioms. Four of Kalman's axioms (R1, R3, R4, and R5) for the right group calculus were shown to be dependent on the remaining axiom. Alternative simpler axiomatizations were discovered for both calculi, including a single axiom for the left group calculus and five additional single axioms for the right group calculus. The program OTTER was vital in discovering candidate axiomatizations as well as in finding proofs of new axiomatizations. All of the relevant OTTER proofs are included.This work was supported by the Applied Mathematical Sciences subprogram of the Office of Energy Research, U.S. Department of Energy, under Contract W-31-109-Eng-38.     

基于dsPIC的高精度介质损耗测量仪

基于市场上对全自动、数字化以及优良抗干扰能力为典型特征的介质损耗测量仪的迫切需要,采用了45 Hz和55 Hz两种频率的变频电源来避开工频干扰,用这两种频率下的介质损耗的平均值作为被测试品的介质损耗值,并给出了简洁实用的快速数字基波相位分离算法。以dsPIC30F6012数字信号控制器为核心,搭建了产品开发试验平台。试验结果表明,这种介质损耗测量仪具有平台搭建容易、运算速度快、测量精度高、抗干扰能力强等特点,具有广阔的应用前景。