SCARA机器人实验平台视觉标定研究

文中针对eye-to-hand视觉标定中机械手的移动可能对目标造成遮挡的问题,利用eye-in-hand摄像机和eye-to-hand摄像机结合的方式,以SCARA工业机器人为研究对象,建立双摄像机视觉标定系统。同时,文中提出了一种简单有效的eye-in-hand的标定方式,以机器人末端坐标系为辅助坐标系,建立基坐标到辅助坐标再到摄像坐标的对应关系,从而为实验室平台下工业机器人的目标定位提供了一种有效的方式。

自然观审美语境下的中国传统瓷绘品类初探

文章以自然美学观在中国瓷绘艺术中的介入为研究视角,以中国传统瓷绘艺术的时间线性发展为脉络,浅析中国传统瓷绘艺术品类的源起、发展、高峰至嬗变历程中的典型类别,剖析自然美学观赋予中国陶瓷艺术,特别是在瓷绘方面的独特审美面向和艺术内涵,综合研究中国传统瓷绘艺术在文化传播过程中所产生的深远影响。

Recovery and separation of rare earth elements by molten salt electrolysis

With the increasing demand of rare earth metals in functional materials,recovery of rare earth elements(REEs)from secondary resources has become important for the green economy transition.Molten salt electrolysis has the advantages of low water consumption and low hazardous waste during REE recovery.This review systematically summarizes the separation and electroextraction of REEs on various reactive electrodes in different molten salts.It also highlights the relationship between the formed alloy phases and electrodeposition parameters,including applied potential,current,and ion concentration.Moreover,the feasibility of using LiF–NaF–KF electrolyte to recover REEs is evaluated through thermodynamic analysis.Problems related to REE separation/recovery the choice of electrolyte are discussed in detail to realize the low-energy and high current efficiency of practical applications.

Electrochemical behavior and underpotential deposition of Sm on reactive electrodes(Al,Ni,Cu and Zn)in a LiCl-KCl melt

Sm extraction from a LiCl-KCl melt was carried out by forming alloys on various electrodes,including Al,Ni,Cu,and liquid Zn,and the electrochemical behaviors of the resultant metal products were investigated using different electrochemical techniques.While Sm metal deposition via the conventional two-step reaction process was not noted on the inert electrode,underpotential deposition was observed on the reactive electrodes because of the latter's depolarization effect.The depolarization effects of the reactive electrodes on Sm showed the order Zn>Al>Ni>Cu.Sm-M(M=Al,Ni,Cu,Zn)alloys were deposited by galvanostatic and potentiostatic electrolysis.The products were fully characterized by X-ray diffractometry(XRD)and scanning electron microscopy(SEM)-energy dispersive spectrometry(EDS),and the stability of the obtained M-rich compounds was determined.Finally,the relationship between the electrode potential and type of Sm-M intermetallic compounds formed was assessed on the basis of the observed electrochemical properties and electrodeposits.

静态顶空-气相色谱-质谱法测定烟用丝束中丙酮残留量

为烟用丝束的产品质量安全提供技术支撑,建立烟用丝束中残余丙酮的静态顶空-气相色谱-质谱(SHS-GC-MS)外标定量测定方法。结果表明:最佳检测条件是基质校正剂为三乙酸甘油酯,样品经80℃、20 min静态顶空后,采用TG-624柱,GC-MS/选择离子监测(SIM)模式检测,外标法定量,该条件下,烟用丝束中丙酮的线性关系良好(R^2=0.9998),检出限(LOD)为0.12μg/g,加标回收率为102.22%~120.56%,相对标准偏差RSD<4.13%,该方法灵敏度高、准确性和精密度较好,可用于烟用丝束中残余丙酮的检测。

Molten salt synthesis and supercapacitor properties of oxygen-vacancy LaMnO3-δ

Due to the unique structure of perovskite materials,their capacitance can be improved by introducing oxygen vacancy.In this paper,the LaMnO3-δ material containing oxygen vacancy was synthesized by molten salt method in KNO3-NaNO3-NaNO2 melt.The La-Mn-O crystal grows gradually in molten salt with the increase of temperature.It was confirmed that LaMnO3-δ with perovskite structure and incomplete oxygen content were synthesized by molten salt method and presented a three-dimensional shape.LaMnO3-δ stores energy by redox reaction and adsorption of OH-in electrolyte simultaneously.In comparison with the stoichiometric LaMnO3 prepared by the sol-gel method,LaMnO3-δ prepared by molten salt method proffered higher capacitance and better performance.The galvanostatic charge-discharge curve showed specific capacitance of 973.5 F/g under current density of 1 A/g in 6 M KOH.The capacitance of LaMn03-δ was 82.7%under condition of 5 A/g compared with the capacitance at the current of 1A/g,and the specific capacitances of 648.0 and 310.0 F/g were obtained after 2000 and 5000 cycles of galvanostatic charging-discharging,respectively.Molten salt synthesis method is relatively simple and suitable for industrial scale,presenting a promising prospect in the synthesis of perovskite oxide materials.

Cross-domain sequence labelling using language modelling and parameter generating

Sequence labelling(SL)tasks are currently widely studied in the field of natural language processing.Most sequence labelling methods are developed on a large amount of labelled training data via supervised learning,which is time-consuming and expensive.As an alternative,domain adaptation is proposed to train a deep-learning model for sequence labelling in a target domain by exploiting existing labelled training data in related source domains.To this end,the authors propose a Bi-LSTM model to extract more-related knowledge from multi-source domains and learn specific context from the target domain.Further,the language modelling training is also applied to cross-domain adaptability facilitating.The proposed model is extensively evaluated with the named entity recognition and part-of-speech tagging tasks.The empirical results demonstrate the effectiveness of the cross-domain adaption.Our model outperforms the state-of-the-art methods used in both cross-domain tasks and crowd annotation tasks.

湖北拟酵母发酵制备甘露糖赤藓糖醇脂的研究

甘露糖赤藓糖醇脂(MELs)是一种糖脂类生物表面活性剂。以湖北拟酵母(Pseudozyma Hubeiensis)为发酵菌株,探究不同碳源、有机氮源及二者的添加量对微生物合成甘露糖赤藓糖醇脂的影响,结果表明橄榄油和酵母提取物分别是最佳的碳源和有机氮源。此外以硝酸钠和酵母提取物进行氮源复配,进一步探究复合氮源对湖北拟酵母发酵合成甘露糖赤藓糖醇脂的影响。结果表明最优培养基组成为:橄榄油120 g/L、酵母提取物3.0 g/L、NaNO_(3)1.0 g/L、MgSO_(4)·7H_(2)O 0.30 g/L、KH_(2)PO_(4)0.30 g/L,发酵培养168 h后,甘露糖赤藓糖醇脂产量达到55.0 g/L。

Bayesian estimation-based sentiment word embedding model for sentiment analysis

Sentiment word embedding has been extensively studied and used in sentiment analysis tasks.However,most existing models have failed to differentiate high-frequency and low-frequency words.Accordingly,the sentiment information of low-frequency words is insufficiently captured,thus resulting in inaccurate sentiment word embedding and degradation of overall performance of sentiment analysis.A Bayesian estimation-based sentiment word embedding(BESWE)model,which aims to precisely extract the sentiment information of low-frequency words,has been proposed.In the model,a Bayesian estimator is constructed based on the co-occurrence probabilities and sentiment proba-bilities of words,and a novel loss function is defined for sentiment word embedding learning.The experimental results based on the sentiment lexicons and Movie Review dataset show that BESWE outperforms many state-of-the-art methods,for example,C&W,CBOW,GloVe,SE-HyRank and DLJT1,in sentiment analysis tasks,which demonstrate that Bayesian estimation can effectively capture the sentiment information of low-frequency words and integrate the sentiment information into the word embedding through the loss function.In addition,replacing the embedding of low-frequency words in the state-of-the-art methods with BESWE can significantly improve the performance of those methods in sentiment analysis tasks.

气相色谱法测定污水中的烃类

用气相色谱法建立了污水中烃类的定量分析方法,可快速判定污水中烃类的峰面积,并通过红外测油仪定量分析污水中烃类的含量。将定量完成的样品作为标准样品,稀释形成梯度浓度,然后根据峰面积与含量做出校正曲线,计算出烃类的含量判定装置是否存在漏点。方法分析时间短,具有良好的重复性和较高的检测灵敏度,检出限最低可达0.8 mL/m^(3),定量的相对标准偏差小于5%(n=5)。

Association between Mycoplasma pneumoniae infection and acute coronary syndrome

Objective: To investigate the association between Mycoplasma pneumoniae (MP) infection and the occurrence of acute coronary syndromes (ACS), and its associated mechanism in ACS development. Methods: A total of 134 patients with confirmed ACS were selected as the ACS group, and another 102 healthy subjects were enrolled as the control group. Serum triglycerides (TG), cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein A1 (ApoA1), and apolipoprotein B (ApoB) were detected using immuno-transmission turbidimetry in the ACS and control groups. An enzyme-linked immunosorbent assay was used to detect MP-specific IgG antibodies in the serum. Results:The MP infection rate in the ACS group was significantly higher than that in of the healthy control group. Although there were significant differences in the expression of TC, HDL, LDL, and ApoB between the ACS and control groups, there were no significant differences between the MP IgG-positive and negative groups for any the six serum lipid indexes in the ACS patients. The level of high-sensitivity C-reactive protein (hs-CRP) expression in ACS patients was significantly higher in the MP IgG-positive group compared with the negative group. Conclusions: MP infection is associated with ACS and may be a risk factor for ACS. MP infection may not affect blood lipid levels but rather induce the development of ACS by affecting the long-term inflammatory environment.

A Coherent Pattern Mining Algorithm Based on All Contiguous Column Bicluster

Microarray contains a large matrix of information and has been widely used by biologists and bio data scientist for monitoring combinations of genes in different organisms.The coherent patterns in all continuous columns are mined in gene microarray data matrices.It is investigated,in this study,the coherent patterns in all continuous columns in gene microarray data matrix by developing the time series similarity measure for the coherent patterns in all continuous columns,as well as the evaluation function for verifying the proposed algorithm and the corresponding biclusters.The continuous time changes are taken into account in the coherent patterns in all continuous columns,and co-expression patterns in time series are searched.In order to use all the common information between sequences,a similarity measure for the coherent patterns in continuous columns is defined in this paper.To validate the efficiency of the similarity measure to mine biological information at continuous time points,an evaluation function is defined to measure biclusters,and an effective algorithm is proposed to mine the biclusters.Simulation experiments are conducted to verify the biological significance of the biclusters,which include synthetic datasets and real gene microarray datasets.The performance of the algorithm is analyzed,and the results show that the algorithm is highly efficient.

Electroextraction of neodymium from LiCl-KCl melt using binary liquid Ga-Al cathode

The electrochemical behaviour of Nd(Ⅲ)ion was investigated on inert W,active Ga and Ga-AI cathodes.It is established that the reduction of Nd(Ⅲ)ion on the inert electrode is a consecutive two-step process while that on the active electrodes is a one-step process.The apparent standard potential of the Nd(Ⅲ)/Nd redox couple at different temperatures was determined by open-circuit chronopotentiometry and semi-differential method,and the relationship between temperature and apparent standard potential was further discussed.The thermodynamic properties of Nd in Ga and Ga-Al electrodes such as activity coefficient and activity were evaluated via intermittent coulomb titration and temperature dependence test,and the effect of temperature on activity coefficient was verified.Finally,Nd was successfully extracted in form of alloy from molten salt by galvanostatic electrolysis,in which the current efficiency of91.7%for the electroextraction indicates that the binary liquid Ga-Al electrode has favorable performance.

Oxidative stress-triggered Wnt signaling perturbation characterizes the tipping point of lung adeno-to-squamous transdifferentiation

Lkb1 deficiency confers the Kras-mutant lung cancer with strong plasticity and the potential for adeno-to-squamous transdifferentiation(AST).However,it remains largely unknown how Lkb1 deficiency dynamically regulates AST.Using the classical AST mouse model(Kras LSL-G12D/+;Lkb1flox/flox,KL),we here comprehensively analyze the temporal transcriptomic dynamics of lung tumors at different stages by dynamic network biomarker(DNB)and identify the tipping point at which the Wnt signaling is abruptly suppressed by the excessive accumulation of reactive oxygen species(ROS)through its downstream effector FOXO3A.Bidirectional genetic perturbation of the Wnt pathway using two different Ctnnb1 conditional knockout mouse strains confirms its essential role in the negative regulation of AST.Importantly,pharmacological activation of the Wnt pathway before but not after the tipping point inhibits squamous transdifferentiation,highlighting the irreversibility of AST after crossing the tipping point.Through comparative transcriptomic analyses of mouse and human tumors,we find that the lineage-specific transcription factors(TFs)of adenocarcinoma and squamous cell carcinoma form a“Yin-Yang”counteracting network.Interestingly,inactivation of the Wnt pathway preferentially suppresses the adenomatous lineage TF network and thus disrupts the“Yin-Yang”homeostasis to lean towards the squamous lineage,whereas ectopic expression of NKX2-1,an adenomatous lineage TF,significantly dampens such phenotypic transition accelerated by the Wnt pathway inactivation.The negative correlation between the Wnt pathway and AST is further observed in a large cohort of human lung adenosquamous carcinoma.Collectively,our study identifies the tipping point of AST and highlights an essential role of the ROS-Wnt axis in dynamically orchestrating the homeostasis between adeno-and squamous-specific TF networks at the AST tipping point.

高速超分辨结构光照明显微的关键技术及应用

光学显微成像技术无论是在临床诊疗还是在基础科学研究上都发挥着重要的作用。伴随着新型荧光探针、光学控制、探测器件的不断发展,超分辨光学显微技术突破了传统光学衍射极限的限制,为现代生物医学研究提供了新的工具。在超分辨显微成像技术中,结构光照明显微镜(SIM)通过空间编码的结构光照明样品,将样品部分超出衍射极限的高频信息调制到低频中,从而通过光学系统实现超分辨成像。SIM具有成像速度快,光漂白和光毒性弱以及对荧光染料的非特异性需求等优点,被广泛应用于活细胞超分辨光学显微成像。本文回顾了SIM技术的重要原理与技术进步,重点介绍了SIM硬件设计与图像重构算法中关键的实验要点与技术难点,列举了现阶段SIM在生物成像中的部分应用,探讨了SIM未来的发展方向。期望本文能为SIM的设计和使用者提供一定的指导。

乳腔镜辅助保留乳头乳晕的乳腺切除术及乳房重建术在早期乳腺癌中的应用

目的 探讨乳腔镜辅助保留乳头乳晕的乳腺切除术及乳房重建术在早期乳腺癌中应用效果。方法 选取2020年1月—2021年12月唐山市人民医院乳腺外科收治的86例诊断为早期乳腺癌的患者作为研究对象进行回顾分析,按照患者采取的术式不同分为观察组45例和对照组41例。对照组采用标准的乳腺癌改良根治手术,观察组则在乳腔镜辅助下行保留乳头乳晕的乳腺切除术及乳房重建术。比较二组患者手术情况,术后并发症,外观美观率及生活质量。结果 观察组患者术中出血量、术后引流量以及住院时间均明显少于或短于对照组,差异均有统计学意义(P<0.05)。术后并发症发生率观察组也明显少于对照组,差异均有统计学意义(P<0.05)。观察组术后美观率以及生活质量均明显优于对照组,差异均有统计学意义(P<0.05)。结论 对于早期乳腺癌的外科治疗,采取乳腔镜辅助保留乳头乳晕的乳腺切除术及乳房重建术外形美观,并发症少,创伤小。

High-entropy(La_(0.2)Nd_(0.2)Sm_(0.2)Eu_(0.2)Gd_(0.2))_(2)Ce_(2)O_(7):A potential thermal barrier material with improved thermo-physical properties

High-entropy oxides(HEOs)are widely researched as potential materials for thermal barrier coatings(TBCs).However,the relatively low thermal expansion coefficient(TEC)of those materials severely restricts their practical application.In order to improve the poor thermal expansion property and further reduce the thermal conductivity,high-entropy(La_(0.2)Nd_(0.2)Sm_(0.2)Eu_(0.2)Gd_(0.2))_(2)Ce_(2)O_(7) is designed and synthesized in this work.The as-prepared multicomponent material is formed in a simple disordered fluorite structure due to the high-entropy stabilization effect.Notably,it exhibits a much higher TEC of approximately 12.0×10^(−6) K^(−1) compared with those of other high-entropy oxides reported in the field of TBCs.Besides,it presents prominent thermal insulation behavior with a low intrinsic thermal conductivity of 0.92 W·m^(−1)·K^(−1) at 1400℃,which can be explained by the existence of high concentration oxygen vacancies and highly disordered arrangement of multicomponent cations in the unique high-entropy configuration.Through high-temperature in-situ X-ray diffraction(XRD)measurement,this material shows excellent phase stability up to 1400℃.Benefiting from the solid solution strengthening effect,it shows a higher hardness of 8.72 GPa than the corresponding single component compounds.The superior thermo-physical performance above enables(La_(0.2)Nd_(0.2)Sm_(0.2)Eu_(0.2)Gd_(0.2))_(2)Ce_(2)O_(7) a promising TBC material.

PI3K/Akt/mTOR signaling orchestrates the phenotypic transition and chemo-resistance of small cell lung cancer

Small cell lung cancer(SCLC)is a phenotypically heterogeneous disease with an extremely poor prognosis,which is mainly attributed to the rapid development of resistance to chemotherapy.However,the relation between the growth phenotypes and chemo-resistance of SCLC remains largely unclear.Through comprehensive bioinformatic analyses,we found that the heterogeneity of SCLC phenotype was significantly associated with different sensitivity to chemotherapy.Adherent or semiadherent SCLC cells were enriched with activation of the PI3K/Akt/mTOR pathway and were highly chemoresistant.Mechanistically,activation of the PI3K/Akt/mTOR pathway promotes the phenotypic transition from suspension to adhesion growth pattern and confers SCLC cells with chemo-resistance.Such chemo-resistance could be largely overcome by combining chemotherapy with PI3K/Akt/mTOR pathway inhibitors.Our findings support that the PI3K/Akt/mTOR pathway plays an important role in SCLC phenotype transition and chemo-resistance,which holds important clinical implications for improving SCLC treatment.

Effect of microstructure evolution of Ti6Al4V alloy on its cavitation erosion and corrosion resistance in artificial seawater

The investigate about the effect of the microstructure of Ti6Al4V alloy on its cavitation erosion and corrosion properties in marine can provide the key basis for the application.On the basis of as-received Ti6Al4V(TC4)alloy,FC-TC4 and AC-TC4 alloys were prepared by heat treatment with the cooling method of a furnace and atmospheric environment,respectively.Then the microstructure evolutions of three samples were scrutinized and the effect of microstructure on their cavitation erosion and corrosion resistance was explored.The results showed that more recrystallized grains formed as well as its content of α grains and high-angle grain boundaries increased in AC-TC4 alloy.To FC-TC4 alloy,there was obvious grain growth apart from recrystallization.Moreover,many nanotwins of Ti V and Ti Al_(3)were formed separately in FC-TC4 and AC-TC4 alloys due to the dislocation migration during heat treatment.The microstructure evolution led the hardness and elastic modulus of AC-TC4 alloy were the best,followed by FC-TC4 alloy,that of TC4 were the worst.Similarly,passivating ability of AC-TC4 alloy was the best among three samples because of its microstructure.Although cracks extended along the grain boundaries under the action of continual cavitation erosion,the passivation film formed by TiO_(2) and Al_(2)O_(3) would enhance their resistance to further corrosion and cavitation erosion in artificial seawater.