电弧熔丝增材制造过程传感与控制研究进展及展望

电弧熔丝增材制造(Wire and arc additive manufacturing,WAAM)作为金属增材制造技术的一个重要分支,以电弧为载能束逐层熔化金属丝材,适合中大尺寸复杂金属构件的快速制造,在航空航天、国防领域展现出广阔的应用前景。然而,成形精度低、过程稳定性差、缺陷控制难等问题限制了该技术的高效、高质量发展与应用。为满足高可靠、高自动化与高质量制造的要求,对WAAM全过程实施在线监测与闭环控制已势在必行。分析了WAAM成形质量的特征参量及其主要影响因素,阐述了WAAM过程传感方法的原理与研究现状,总结了WAAM成形质量控制方法,指出了未来WAAM过程传感与控制技术的主要发展方向。

光谱增感过程化学(续)

光谱增感过程化学（续）［俄］皮·依·沙比罗（莫斯科照相化学设计研究院）３．染料的自身减感过程减感过程不仅发生在光激发ＡｇＸ时，当光激发光谱增感剂时也有减感过程。染料的自身减感反应是指光谱增感剂对其自身光谱区的减感作用。直接定量评定染料本身对光谱感光度...

社会比较理论视角下企业员工创新身份“双刃剑”效应形成机制探讨——基于追踪问卷调查有效数据的实证检验

企业员工创新身份的“双刃剑”效应缘于对其工作行为共存的创新行为效应和偏离行为效应。笔者基于社会比较理论,在构建了一个企业员工创新身份“双刃剑”效应研究模型的基础上,以来自对高新技术企业员工三个时点追踪调查问卷的有效数据,运用路径分析和bootstrap方法,实证检验了企业员工创新身份与其创新行为和偏离行为之“双刃剑”效应的关联性。检验结果证实:企业员工创新身份通过创新过程参与感与其创新行为正相关;企业员工创新身份通过心理特权感与其偏离行为正相关;企业员工创新身份的“双刃剑”效应,受制于创新普遍性氛围且因之高、低不同而调节方向相反。本研究通过尝试性地将员工创新过程参与感、心理特权感和创新普遍性氛围等相关变量引入探究企业员工创新身份与其创新行为和偏离行为相对应之积极影响和消极影响的关联中,扩展了社会比较理论的应用边界,丰富了组织行为学研究领域的现有相关文献,研究结论有助于为企业有效管理员工创新身份提供理论依据。

经络信息系统穴位及传导区结构特征的理论模型

目的:现代科学技术实验初步证明了经络的客观存在,但无法得到明确专一的经络生物组织结构支持,经络需要更多的深入研究。本研究从理论上分析经络的特征结构。方法:基于符合物理化学原理和生物遗传变异信息原理的经络信息产生传导方程,及经络通过的生理组织特性进行研究。结果:理论表明经络必须存在穴位和信息传导区,经典经络理论中的感传一体为感传交替过程。经络穴位之间的传导区域大小主要决定于经络物质信息在经络组织侧面渗漏率。相同或相似生理组织区域,经络穴位间距相近。而不同生理组织区域,经络穴位之间的尺度变化明显。经络中的生物信息传感器高密度集中于穴位的近点状区域,而传导线上的密度极低。结论:本研究首次从理论上证明了经络结构的基本特征。同时建立了穴位之间尺度的定量变化规律。证明及修正了传统的经络信息产生传导假说。这也从理论上证明了经络的客观存在。

二胡基本功教学用语中的几个关键词

本文是作者对其几十年二胡教学中,关于基本功训练方法经常对学生所讲的指导意义较强的部分关键词,分别从词义、在二胡技术训练中的具体要求和练习方法等方面所做的深入浅出的解释和分析。

光纤传感过程分析法评价不同厂家氨茶碱片的体外溶出度

目的:采用光纤传感过程分析法评价不同厂家氨茶碱片的体外溶出度,以考察不同厂家样品的质量差异。方法:采用对照品法,对5个厂家的片剂在4种溶出介质(水、pH1.2盐酸溶液、pH4.5醋酸盐缓冲液和pH6.8磷酸盐缓冲液)中的溶出行为进行测定,并以相似因子法进行比较。结果:氨茶碱片在不同溶剂中的溶出行为不一致,只有B厂样品在4种介质中均具有较好的溶出度;以B厂样品为参比制剂,其他4个厂样品与其比较的相似因子值均小于50%。结论:光纤传感过程分析法能够准确、方便地提供药物的溶出数据、反映药物的溶出行为,为全面考察药物的内在质量提供了良好的检测手段;不同厂家氨茶碱片质量有明显差异。

光纤传感过程分析比较不同厂家缬沙坦胶囊的溶出度

目的:考察不同厂家缬沙坦胶囊体外溶出度曲线,比较不同厂家药品的内在质量,为药品质量控制和临床用药提供参考。方法:用光纤传感过程分析技术监测4个厂家缬沙坦胶囊在pH 6.8,pH 4.5,pH 1.2及水4种溶出介质的溶出过程。采用f2因子法对溶出曲线的相似性进行评价。结果:4个厂家缬沙坦胶囊在pH 6.8磷酸盐缓冲液中30 min时溶出度均大于80%符合药典规定,但溶出曲线差异很大;在其他3种介质中的溶出度偏低且存在较大差异;比较结果说明不同药厂缬沙坦胶囊的质量存在显著性差异。结论:采用FODT法过程分析检测固体制剂的溶出曲线比单点溶出度测定更能直观反映不同厂家制剂工艺、均匀度和药品质量的差异。对不同来源的相同制剂考察不同溶出介质的溶出曲线是非常有必要的。

灸法的选穴要点与三种灸法的功效简介(三)

1.灸架结构 A.顶管:内部夹有弹片,可以上下移动,并适于粗细不同的艾条。 B.支架:是支持艾条的主体,既便于清除灰尘,又利用通风助燃。 C.防护网:是防止艾火脱落发生烫伤的,但并不十分重要,如旋开底座将其去除,反可使火力增强。 D.底袢:是固定支架的重要部分,防止掼坏。 E.橡皮带:用以固定底袢,长短各一。

基于单片机技术测量微弱电流信号系统的研究

随着微电子技术的迅速发展,电子产品已经进入了国民经济的各个领域。展望21世纪,信息高速公路的开通,以计算机为核心的多媒体信息网将进入千家万户,对人类社会的生活方式将再一次进行重大变革,其前途不可限量。同时,对于测量技术也是一样的,当测量电路与计算机接轨以后,以其测量精度高、测量的速度快、以及操作的简便性价比高而得到了广泛的发展和应用。

光纤传感过程分析利巴韦林片的溶出度

目的:建立过程分析利巴韦林片溶出度的方法。方法:参照《美国药典》中利巴韦林片的溶出条件,采用光纤传感药物溶出度实时测定仪建立利巴韦林片的溶出度分析方法(简称FODT法),并与《美国药典》方法进行比较;同时建立可测定3种不同规格(0.02、0.05、0.1 g)利巴韦林片溶出度的FODT法条件(探头规格、检测波长);另外对11批不同厂家产品进行了考察。结果:两种方法所得溶出度结果均符合要求,但采用FODT法可以观察不同厂家样品及同一厂家不同片之间药物实时溶出情况的差异;3种规格样品采用FODT法时的探头规格和检测波长分别为5、2、1 mm和210、228、234 nm。结论:所建立的测定利巴韦林片溶出度的FODT法能够直观有效地监测药物的溶出过程,连续定量地反映了样品的体外溶出特性。

Faulty Sensor Detection and Reconstruction for a PVC Making Process

Based on principal component analysis, this paper presents an application of faulty sensor detection and reconstruction in a batch process, polyvinylchloride (PVC) making process. To deal with inconsistency in process data, it is proposed to use the dynamic time warping technique to make the historical data synchronized first,then build a consistent multi-way principal component analysis model. Fault detection is carried out based on squared prediction error statistical control plot. By defining principal component subspace, residual subspace and sensor validity index, faulty sensor can be reconstructed and identified along the fault direction. Finally, application results are illustrated in detail by use of the real data of an industrial PVC making process.

Fuzzy Neural Network Model of 4-CBA Concentration for Industrial Purified Terephthalic Acid Oxidation Process

A fuzzy neural network (FNN) model is developed to predict the 4-CBA concentration of the oxidation unit in purified terephthalic acid process. Several technologies are used to deal with the process data before modeling.First,a set of preliminary input variables is selected according to prior knowledge and experience. Secondly,a method based on the maximum correlation coefficient is proposed to detect the dead time between the process variables and response variables. Finally, the fuzzy curve method is used to reduce the unimportant input variables.The simulation results based on industrial data show that the relative error range of the FNN model is narrower than that of the American Oil Company (AMOCO) model. Furthermore, the FNN model can predict the trend of the 4-CBA concentration more accurately.

Energy Aware Spectrum Access in Cognitive Radio Networks with Imperfect Channel Sensing

Due to the problem of spectrum underuti-lization and energy inefficiency in wireless commu-nications, the research on energy efficient Cogni-tive Radio Networks （CRNs） has received signifi-cant attention in both industry and academia. In this paper, we consider the problem of optimal spectrum selection and transmission parameters de-sign with the objective of minimizing energy con-sumption in CRNs. Since the system state cannot be directly observed due to miss detections and estimation errors, we formulate the optimal spec-trum access problem as a Partially Observable Markov Decision Process （POMDP）. In particular, the proposed scheme selects the optimal spectrum, modulation and coding scheme, transmission pow-er, and link layer frame size in each time slot ac-cording to the belief state, which captures all the history information of past actions and observa- tions. The optimal policy can be acquired by sol-ving POMDP problem with linear programming based algorithm Sinmlation results show that sig-nificant energy savings can be achieved by the proposed scheme.

A Preliminary Global Analysis of Remotely Sensed Radiation Characteristics of Ground Features: Ⅰ. Methodology and Results

A Landsat data transformation method which was proposed by the author was applied to extract useful information from data of 769 ground feature classification units of worldwide scope.Three most important characteristic values--the general radiance level L,the visible-infrared radiation balance B and the band radiance variation vector (direction and speed) V were calculated.Then the 769 class units were sorted into 106 groups based on their natural characteristics.The means and standard deviations of L,B and V values for all the groups were calculated.The distributions of the 106 groups or the 769 units on the number axes of L,B and V,in the planes of L-B,L-V and B-V,and in the space of L-B-V were investigated.Finally,the typical numerical characteristics of the various ground features are discussed in consideration of their worldwide variations in the present paper.

外翻肠囊模型结合光纤传感过程分析蒜氨酸在家兔肠道的吸收

目的:考察大蒜提取物蒜氨酸在家兔肠道内的吸收特性,为新药研究提供实验数据。方法:采用家兔,利用外翻肠囊模型与光纤传感过程分析系统结合,实时原位测定蒜氨酸在家兔肠道内的浓度变化。研究蒜氨酸在家兔十二指肠、空肠、回肠、结肠的4个肠段,高、中、低3个浓度的吸收,每个肠段的每个浓度进行6样本(6只家兔,共计18只家兔)分析,每个肠段接触蒜氨酸的浓度根据半数致死量确定,配制蒜氨酸溶液的质量浓度分别为(700,50,30 mg·L-1),于光纤传感过程分析仪上进行检测。结果:家兔不同肠段对蒜氨酸的吸收能力大小:回肠>空肠>结肠>十二指肠;不同浓度下各肠段的吸收数An值空肠分别为(2.59±0.21,5.40±0.11,3.81±0.27);回肠分别为(5.25±0.07,3.02±0.19,4.09±0.18),各浓度An值均大于1.15,十二指肠分别为(0,0.95±0.16,1.09±0.28);结肠分别为(0.50±0.13,0.90±0.22,1.08±0.24),各浓度An值均<1.15。各浓度在4个肠段的Ke值除十二指肠段外(0,0.007±0.02,0.004±0.09)其余肠段的Ke值都<0.01 cm·min-1。结论:利用光纤传感系统实时测定蒜氨酸原料药在肠道的浓度变化,从而研究其在各肠段的吸收,结果表明蒜氨酸在除十二指肠段外其余肠段的渗透性很好。

A Magnetic Induction Tomography System for Prospective Industrial Processing Applications

Magnetic induction tomography(MIT) is one of the newest industrial process imaging techniques.Main industrial applications of the MIT imaging are in high conductive flow imaging.However,recently it has been shown that the MIT may be useful for low conductive process imaging.This paper presents a cost effective hardware design for MIT in industrial applications,called Bath-MKI industrial MIT system.The system comprises 8 inductor coils and has the possibility of expansion to 16 coils.The excitation signals and the measured voltages are generated and measured using a LabView based system.Two 16 by 1 multiplexers are used to select between the coils.Measurements,excitation and multiplexing are all controlled by a National Instrument(NI) USB based DAQ:USB-6259 and a signal generator.Using the same electronics,the prototype is tested with two different coil arrays;one is a small scale ferrite core coil and one larger scale air cored coil.Experimental image reconstruction results are shown using both small scale and large scale coil arrays.

Plant drought tolerance trait is the key parameter in improving the modeling of terrestrial transpiration in arid and semi-arid regions

The prediction of precipitation depends on accurate modeling of terrestrial transpiration.In recent decades,the trait-based plant hydraulic stress scheme has been developed in land surface models,in order to better predict the hydraulic constraint on terrestrial transpiration.However,the role that each plant functional trait plays in the modeling of transpiration remains unknown.The importance of different plant functional traits for modeled transpiration needs to be addressed.Here,the Morris sensitivity analysis method was implemented in the Common Land Model with the plant hydraulic stress scheme(CoLM-P_(50)HS).Traits related to drought tolerance(P_(50);),stomata,and photosynthesis were screened as the most critical from all 17 plant traits.Among 12 FLUXNET sites,the importance of P_(50);,measured by normalized sensitivity scores,increased towards lower precipitation,whereas the importance of stomatal traits and photosynthetic traits decreased towards drier climate conditions.P_(50);was more important than stomatal traits and photosynthetic traits in arid or semi-arid sites,which implies that hydraulic safety strategies are more crucial than plant growth strategies when plants frequently experience drought.Large variation in drought tolerance traits further proved the coexistence of multiple plant strategies of hydraulic safety.Ignoring the variation in drought tolerance traits may potentially bias the modeling of transpiration.More measurements of drought tolerance traits are therefore necessary to help better represent the diversity of plant hydraulic functions.

Increased presence of effector lymphocytes during Helicobacter hepaticus-induced colitis

AIM： To identify and characterize drosophila mothers against decapentaplegic （SMAD）3-dependent changes in immune cell populations following infection with He- Iicobacter hepaticus （H. hepaticus）. METHODS： SMAD3/ （n = L9） and colitis-resistant SMAD3＋/ （n = 24） mice （8-10 wk of age） were in- fected with/-/, hepaticus and changes in immune cell populations [T lymphocytes, natural killer （NK） cells, T regulatory cells] were measured in the spleen and mesenteric lymph nodes （MsLNs） at 0 d, 3 d, 7 d and 28 d post-infection using flow cytometry. Genotype-dependent changes in T lymphocytes and granzyme B＋ cells were also assessed after 28 d in proximal colon tissue using immunohistochemistry. RESULTS： As previously observed, SMAD3＋, but not SMAD3＋/- mice, developed colitis, peaking at 4 wk post-infection. No significant changes in T cell subsets were observed in the spleen or in the MsLNs between genotypes at any time point. However, CD4＋ and CD8＋/ CD62L＋＋ cells, an effector T lymphocyte population, as well as NK cells （NKp46/DX5＋） were significantly higher in the MsLNs of SMAD3/ mice at 7 d and 28 d post-in- fection. In the colon, a higher number of CD3＋ cells were present in SMAD3＋ compared to SMAD3＋/- mice at base- line, which did not significantly change during infection. However, the number of granzyme B＋ cells, a marker of cytolytic lymphoo/tes, significantly increased in SMAD3＋ mice 28 d post-infection compared to both SMAD3＋/- mice and to baseline values. This was consistent with more severe colitis development in these animals. CONCLUSION： Data suggest that defects in SMAD3 signaling increase susceptibility to H. hepaticus-induced colitis through aberrant activation and/or dysregulation of effector lymphoo/tes.

Dynamic soft sensor development based on Gaussian mixture regression for fermentation processes

The dynamic soft sensor based on a single Gaussian process regression(GPR) model has been developed in fermentation processes.However,limitations of single regression models,for multiphase/multimode fermentation processes,may result in large prediction errors and complexity of the soft sensor.Therefore,a dynamic soft sensor based on Gaussian mixture regression(GMR) was proposed to overcome the problems.Two structure parameters,the number of Gaussian components and the order of the model,are crucial to the soft sensor model.To achieve a simple and effective soft sensor,an iterative strategy was proposed to optimize the two structure parameters synchronously.For the aim of comparisons,the proposed dynamic GMR soft sensor and the existing dynamic GPR soft sensor were both investigated to estimate biomass concentration in a Penicillin simulation process and an industrial Erythromycin fermentation process.Results show that the proposed dynamic GMR soft sensor has higher prediction accuracy and is more suitable for dynamic multiphase/multimode fermentation processes.

Stimuli-responsive Membranes： Smart Tools for Controllable Mass-transfer and Separation Processes

As emerging artificial biomimetic membranes, smart or intelligent membranes that are able to respond to environmental stimuli are attracting ever-increasing interests from various fields. Their permeation properties including hydraulic permeability and diffusional permeability can be dramatically controlled or adjusted self-regulatively in response to small chemical and/or physical stimuli in their environments. Such environmental stimuli-responsive smart membranes could find myriad applications in numerous fields ranging from controlled release to separations. Here the trans-membrane mass-transfer and membrane separation is introduced as the beginning to initiate the requirement of smart membranes, and then bio-inspired design of environmental stimuli-responsive smart membranes and four essential elements for smart membranes are introduced and discussed. Next, smart membrane types and their applications as smart tools for controllable mass-transfer in controlled release and separations are reviewed. The research tooics in the near future are also suggested.