基于组扫描的PLC开关量采集方法设计

PLC已经在工控领域得到了广泛应用,针对大量开关量信号输入问题,本文介绍了一种基于组扫描输入的PLC开关量采集方法设计,该方法通过外部的接口板,可以实现多个开关量输入信号接入PLC单个输入点,大大节省PLC的输入点数,提高了PLC的信息采集效率,对降低控制系统成本具有重要意义。

MR成像中群组扫描序列的探讨

目的 :为了研究群组扫描序列获得图像乱序的原因。方法 :我们对一工作者进行 4次对比扫描 ,分别利用t1 - tse- tra,t2 - tse- tra,T2 - TSE- TRA 3个群组扫描序列得到 4组横断位图像。结果 :我们发现 T2 - TSE- TRA群组序列扫描的图像顺序发生了颠倒。结论 :在定义 T2 - TSE- TRA群组序列时 ,没有严格按照从上到下定义组。

基于PDF417扫描模组的条码识别技术研究与实现

传统扫描方式不仅硬件结构复杂,并且依赖电脑设备,携带不方便,不利于移动办公。因此研究一种基于移动智能终端设备实现的扫码系统,其携带使用方便,扫描效果好,不受环境及人为因素的影响。

基于定焦扫描和软解码算法技术的高速扫描模组研究

一般采用手机的普通摄像头进行扫描,扫描效率低、准确率低,所以目前行业终端大都采用专业扫描头,但专业扫描头体积大、成本高。因此研究出一种基于定焦手机摄像头的可以取代或者接近专业扫描头水准的扫描系统及方法,其特点在于减小扫描头体积,并确保了扫码效率及准确率。

浮点多字节重叠扫描乘法运算方法

在扫描运算的基础上，介绍了一种重叠扫描算法来提高浮点多字节乘法运算的速度。

HL-2A装置的ECRH实验和偏滤器特性

用HL-2A装置下偏滤器靶板上的14组嵌入式静电三探针阵列和外偏滤器室的电动扫描四探针组,测量了同一环向截面的内外中性化板上的电子温度、密度、悬浮电位及其分布,以及电子回旋加热(ECRH)实验期间的等离子体行为。研究了偏滤器中等离子体参数的分布及非对称性以及等离子体的形成、物理特性和改善粒子的约束特性。

Optimal configuration of firewall, IDS and vulnerability scan by game theory

The integrated linkage control problem based on attack detection is solved with the analyses of the security model including firewall, intrusion detection system （IDS） and vulnerability scan by game theory. The Nash equilibrium for two portfolios of only deploying IDS and vulnerability scan and deploying all the technologies is investigated by backward induction. The results show that when the detection rates of IDS and vulnerability scan are low, the firm will not only inspect every user who raises an alarm, but also a fraction of users that do not raise an alarm; when the detection rates of IDS and vulnerability scan are sufficiently high, the firm will not inspect any user who does not raise an alarm, but only inspect a fraction of users that raise an alarm. Adding firewall into the information system impacts on the benefits of firms and hackers, but does not change the optimal strategies of hackers, and the optimal investigation strategies of IDS are only changed in certain cases. Moreover, the interactions between IDS ＆ vulnerability scan and firewall ＆ IDS are discussed in detail.

Extramedullary plasmocytoma associated with a massive deposit of amyloid in the duodenum

We report a rare case of extramedullary plasmocytoma associated with a massive deposit of amyloid in the duodenum. A 72-year-old Japanese man was admitted to our hospital presenting with a 3-mo history of epigastric pain, vomiting and weight loss. On computed tomography （CT） a wall thickening of the fourth part of the duodenum was observed. Multiple biopsies obtained from the lesion showed infiltration of plasma cells and lymphocytes, but they were not conclusive. The patient underwent resection of the lesion and, on histopathological examination, the lesion consisted of a dense and diffuse infiltrate of plasma cells and a few admixed lymphocytes with reactive follicles extending to the muscular propria. An extensive deposition of amyloid was also observed. Immunohistochemical stains revealed that a few plasmacytoid cells showed λ light chain staining, though most were κ： light chain positive. These cells also were positive for CD138 and CD56 but negative for CD20 and CD79. The findings were consistent with extramedullary plasmocytoma associated with a massive deposit of amyloid in duodenum. A subsequent workup for multiple myeloma was completely negative. The patient showed no signs of local recurrence or dissemination of the disease after 12 mo follow-up. Because of the association of plasmocytoma and amyloidosis, the patient must be followed up because of the possible systemic involvement of the neoplasm and amyloidosis in future.

Contrast-enhanced ultrasonography assessment of gastric cancer response to neoadjuvant chemotherapy

AIM:To quantitatively assess the ability of double contrast-enhanced ultrasound(DCUS) to detect tumor early response to pre-operative chemotherapy.METHODS:Forty-three patients with gastric cancer treated with neoadjuvant chemotherapy followed by curative resection between September 2011 and February 2012 were analyzed.Pre-operative chemotherapy regimens of fluorouracil + oxaliplatin or S-1 + oxaliplatin were administered in 2-4 cycles over 6-12 wk periods.All patients underwent contrast-enhanced computed tomography(CT) scan and DCUS before and after two courses of pre-operative chemotherapy.The therapeutic response was assessed by CT using the response evaluation criteria in solid tumors(RECIST 1.1) criteria.Tumor area was assessed by DCUS as enhanced appearance of gastric carcinoma due to tumor vascularity during the contrast phase as compared to the normal gastric wall.Histopathologic analysis was carried out according to the Mandard tumor regression grade criteria and used as the reference standard.Receiver operating characteristic(ROC) analysis was used to evaluate the efficacy of DCUS parameters in differentiating histopathological responders from non-responders.RESULTS:The study population consisted of 32 men and 11 women,with mean age of 59.7 ± 11.4 years.Neither age,sex,histologic type,tumor site,T stage,nor N stage was associated with pathological response.The responders had significantly smaller mean tumor size than the non-responders(15.7 ± 7.4 cm vs 33.3 ± 14.1 cm,P < 0.01).According to Mandard's criteria,27 patients were classified as responders,with 11(40.7%) showing decreased tumor size by DCUS.In contrast,only three(18.8%) of the 16 non-responders showed decreased tumor size by DCUS(P < 0.01).The area under the ROC curve was 0.64,with a 95%CI of 0.46-0.81.The effects of several cut-off points on diagnostic parameters were calculated in the ROC curve analysis.By maximizing Youden's index(sensitivity + specificity-1),the best cut-off point for distinguishing responders from non-responders was determined,which had optimal sensitivity of 62.9% and specificity of 56.3%.Using this cut-off point,the positive and negative predictive values of DCUS for distinguishing responders from non-responders were 70.8% and 47.4%,respectively.The overall accuracy of DCUS for therapeutic response assessment was 60.5%,slightly higher than the 53.5% for CT response assessment with RECIST criteria(P = 0.663).Although the advantage was not statistically significant,likely due to the small number of cases assessed.DCUS was able to identify decreased perfusion in responders who showed no morphological change by CT imaging,which can be occluded by such treatment effects as fibrosis and edema.CONCLUSION:DCUS may represent an innovative tool for more accurately predicting histopathological response to neoadjuvant chemotherapy before surgical resection in patients with locally-advanced gastric cancer.

Densification,microstructural features and tensile properties of selective laser melted AlMgSiScZr alloy from single track to block specimen

The selective laser melting(SLM)processed aluminum alloys have already aroused researchers’attention in aerospace,rail transport and petrochemical engineering due to the comprehensive advantages of low density,good corrosion resistance and high mechanical performance.In this paper,an Al-14.1Mg-0.47Si-0.31Sc-0.17Zr alloy was fabricated via SLM.The characteristics of single track at different process parameters,and the influence of hatch spacing on densification,microstructural features and tensile properties of block specimens were systematically studied.The hatch spacing has an influence on the overlap ratio of single track,and further affects the internal forming quality of printed specimen.At a laser power of 160 W and scanning speed of 400 mm/s,the densification of block specimen increased first and then decreased with the increase of hatch spacing.The nearly full dense specimen(98.7%)with a tensile strength of 452 MPa was fabricated at a hatch spacing of 80μm.Typical characteristics of dimple and cleavage on the tensile fracture of the AlMgSiScZr alloy showed the mixed fracture of ductility and brittleness.

Enhanced CT and CT virtual endoscopy in diagnosis of heterotopic pancreas

AIM:To improve the diagnosis of heterotopic pancreas by the use of contrastenhanced computed tomography(CT)imaging and CT virtual endoscopy(CTVE).METHODS:A total of six patients with heterotopic pancreas,as confirmed by clinical pathology and immunohistochemistry in the Sixth Affiliated People's Hospital of Shanghai Jiao Tong University,Shanghai,China,were included.Nonenhanced CT and enhanced CT scanning were performed,and the resulting images were reviewed and analyzed using threedimensional postprocessing software,including CTVE.RESULTS:Four males and two females were enrolled.Several heterotopic pancreas sites were involved;three occurred in the stomach,including the gastric antrum(n =2)and lesser curvature(n=1),and two were in the duodenal bulb.Only one case of heterotopic pancreas lesion occurred in the mesentery.Four cases had a solid yet soft tissue density that had a homogeneous pattern when viewed by enhanced CT.Additionally,their CT values were similar to that of the pancreas.The ducts of the heterotopic pancreas tissue,one of the characteristic CT features of heterotopic pancreas tissue,were detected in the CT images of two patients.CTVE images showed normal mucosa around the tissue,which is also an important indicator of a heterotopic pancreas.However,none of the CTVE images showed the typical signs of central dimpling or umbilication.CONCLUSION:CT,enhanced CT and CTVE techniques provide useful information about the location,growth pattern,vascularity,and condition of the gastrointestinal wall around heterotopic pancreatic tissue.

Antibacterial activities and corrosion behavior of novel PEO/nanostructured ZrO_2 coating on Mg alloy

Plasma electrolytic oxidation（PEO） was developed as a bond coat for air plasma sprayed（APS） nanostructure ZrO2 as top coat to enhance the corrosion resistance and antibacterial activity of Mg alloy. Corrosion behavior and antibacterial activities of coated and uncoated samples were assessed by electrochemical tests and agar diffusion method toward Escherichia coli（E. coli） bacterial pathogens, respectively. The lowest corrosion current density and the highest charge transfer resistance, phase angle and impedance modulus were observed for PEO/nano-ZrO2 coated sample compared with those of PEO coated and bare Mg alloys. Nano-ZrO2 top coat which has completely sealed PEO bond coat is able to considerably delay aggressive ions transportation towards Mg alloy surface and significantly enhances corrosion resistance of Mg alloy in simulated body fluid（SBF） solution. Moreover, higher antibacterial activity was also observed in PEO/nano-ZrO2 coating against bacterial strains than that of the PEO coated and bare Mg alloys. This observation was attributed to the presence of ZrO2 nanoparticles which decelerate E. coli growth as a result of E. coli membranes.

Tailoring the Self-assembly of Melamine on Au（111） via Doping with Cu Atoms

The doping effect of Cu on the self-assembly film of melamine on an Au（111） surface has been investigated with scanning tunneling microscopy （STM）. The evaporated Cu adatoms occupy the positions underneath the amino groups and change the hydrogen bonding pat- tern between the melamine molecules. Accordingly, the self-assembly structure has changed stepwise from a well-defined honeycomb into a track-like and then a triangular structure depending on the amount of Cu adatoms. The interaction between Cu adatom and melamine is moderate thus the Cu adatoms can be released upon mild heating to around 100 ℃. These findings are different from previous observations of either the coordination assembly or the physically trapped metal adatoms.

Comparison of pore characteristics in the coal and shale reservoirs of Taiyuan Formation, Qinshui Basin, China

Coal and shale are both unconventional gas reservoirs. Comparison of pore characteristics in shale and coal would help understand organic pore structure in shale and investigate co-exploration of shale gas and coalbed methane in coal bearing strata. In this study, five shale samples and three coal samples of Taiyuan Formation were collected from Qinshui Basin, China. High pressure mercury injection, scanning electronic microscopy, and fractal theory have been used to compare pore characteristics in shale and coal. The results show that pore volumes in coal are much larger than that in shale, especially pores 3-100 nm. In coal, there are many semi-closed pores in micro pores （〈10 nm） and transition pores （10-100 nm）. On the contrary, micro pores and transition pores are mainly with open pores in shale. The fractal curves show that pores larger than 65 nm in coal and shale reservoir both have obvious self-similarity and the fractal dimension values in shale and coal are similar. But the fractal characteristics of pores smaller than 65 nm in shale reservoir are quite different from that in coal.

Primary hepatic carcinoid:A case report and literature review

Carcinoids are tumors derived from neuroendocrine cells and often produce functional peptide hormones.Approximately 54.5% arise in the gastrointestinal tract and frequently metastasize to the liver.Primary hepatic carcinoid tumors(PHCT) are extremely rare;only 95 cases have been reported.A 65-year-old man came to our attention due to occasional ultrasound findings in absence of clinical manifestations.His previous medical history,since 2003,included an echotomography of the dishomogeneous parenchymal area but no focal lesions.A computed tomography scan performed in 2005 showed an enhanced pseudonodular-like lesion of about 2 cm.Cholangio-magnetic resonance imaging identified the lesion as a possible cholangiocarcinoma.No positive findings were obtained with positron emission tomography.Histology suggested a secondary localization in the liver caused by a low-grade malignant neuroendocrine tumor.Immunohistochemistry was positive for anti chromogranin antibodies,Ki67 antibodies and synaptophysin.Octreoscan scintigraphy indicated intense activity in the lesion.Endoscopic investigations were performed to exclude the presence of extrahepatic neoplasms.Diagnosis of PHCT was established.The patient underwent left hepatectomy,followed by hormone therapy with sandostatine LAR.Two months after surgery he had a lymph nodal relapse along the celiac trunk and caudate lobe,which was histologically confirmed.The postoperative clinical course was uneventful,with a negative follow-up for hematochemical,clinical and radiological investigations at 18 mo post-surgery.Diagnosis of PHCT is based principally on the histopathological confi rmation of a carcinoid tumor and the exclusion of a non-hepatic primary tumor.Surgical resection is the recommended primary treatment for PHCT.Recurrence rate and survival rate in patients treated with resection were 18% and 74%,respectively.

Self-assembly of α-6T Molecule on Ag（100） and Related STM Induced Luminescence

We have investigated the self-assembly and light emission properties of organic α- sexithiophene （α-6T） molecules on Ag（100） under different coverage by scanning tunneling microscopy （STM）. At very low coverage, the α-6T molecules form a unique enantiomer by grouping four molecules into a windmill supermolecular structure. As the coverage is increased,α-6T molecules tend to pack side by side into a denser stripe structure. Further increase of the coverage will lead to the layer-by-layer growth of molecules on Ag（100） with the lower-layer stripe pattern serving as a template. Molecular fluorescence for α-6T molecules on Ag（100） at a coverage of five monolayers has been detected by light excitations, which indicates a well decoupled electronic states for the top-layer α-6T molecules. However, the STM induced luminescent spectra for the same sample reveal only plasmonic-like emission. The absence of intramolecular fluorescence in this case suggests that the electronic decoupling is not a sufficient condition for generating photon emission from molecules. For intramolecular fluorescence to occur, the orientation of the dynamic dipole moment of molecules and the energy-level alignment at the molecule-metal interface are also important so that molecules can be effectively excited through efficient dipolar coupling with local plasmons and by injecting holes into the molecules.

In Situ Growth of 3D Hierarchical ZnO@Ni_xCo_(1-x)(OH)_y Core/Shell Nanowire/Nanosheet Arrays on Ni Foam for High-Performance Aqueous Hybrid Supercapacitors

In this study, we designed and synthesized a novel battery-type electrode featuring three-dimensional(3D) hierarchical ZnO@Ni_xCo_(1-x)(OH)_y core/shell nanowire/nanosheet arrays arranged on Nifoam substrate via a two-step protocol including a wet chemical process followed by electro-deposition. We then characterized its composition, structure and surface morphology by X-ray diff raction, energy-dispersive X-ray spectrometry(EDS), X-ray photoelectron spectroscopy, scanning electron microscopy(SEM), transmission electron microscopy, EDS elemental mapping. Our electrochemical measurements show that the ZnO@Ni_(0.67)Co_(0.33)(OH)_y electrode material exhibited a noticeably high specific capacity of as much as 255(mA ·h)/g at 1 A/g. Additionally, it demonstrated a superior rate capability, as well as an excellent cycling stability with 81.6% capacity retention over 2000 cycles at 5 A/g. This sample delivered a high energy density of 64 W·h/kg and a power density of 250 W/kg at a current density of 1 A/g. With such remarkable electrochemical properties, we expect the 3D hierarchical hybrid electrode material presented in this work to have promising applications for the next generation of energy storage systems.

Feasibility of replacing the 3-coach with a 1.5-coach grouping trainmodel in wind tunnel experiment at different yaw angles

The effects of different yaw angles on the aerodynamic performance of city electric multiple units(EMUs)were investigated in a wind tunnel using a 1:16.8 scaled model.Pressure scanning valve and six-component box-type aerodynamic balance were used to test the pressure distribution and aerodynamic force of the head car respectively from the 1.5-and 3-coach grouping city EMU models.Meanwhile,the effects of the yaw angles on the pressure distribution of the streamlined head as well as the aerodynamic forces of the train were analyzed.The experimental results showed that the pressure coefficient was the smallest at the maximum slope of the main shape-line.The side force coefficient and pressure coefficient along the head car cross-section were most affected by crosswind when the yaw angle was 55°,and replacing a 3-coach grouping with a 1.5-coach grouping had obvious advantages for wind tunnel testing when the yaw angle was within 24.2°.In addition,the relative errors of lift coefficient C_(L),roll moment coefficient C_(Mx),side force coefficient C_(S),and drag coefficient C_(D) between the 1.5-and 3-coach cases were below 5.95%,which all met the requirements of the experimental accuracy.

Microstructure and mechanical properties of A356 thixoformed alloys in comparison with gravity cast ones using new criterion

The effect of thixoforming process on morphologies of silicon particles that affect fracture mode of A356 alloy was investigated.Microstructure and fracture surfaces of thixoformed samples were investigated by image analyzing technique and scanning electron microscopy.A new combination parameter, called silicon density ratio (SDR) index, was introduced.SDR index approximates the collective effects of morphological characteristics of silicon particles on microstructure transparency of alloy in crossing the dislocation.It is suggested that samples with lower SDR index have superior mechanical properties, especially elongation, and consequently intergranular fracture mode.On the contrary, samples with higher SDR index have inferior mechanical properties and fracture path tends to propagate along the cell boundaries leading to transgranular fracture.

Characterization of microstructure evolution of cement paste by micro computed tomography

Micro computed tomography (Micro-CT) was applied to obtain three-dimensional images of the microstructure of cement paste (water-to-cement mass ratio of 0.5) at different ages. By using the Amira software, component phases of the cement paste such as pores, hydration products, and unhydrated clinker particles were segmented from each other based on their 3D image grey levels; their relative contents were also calculated with the software, and the data are 61.2%, 0% and 38.8% at the beginning of hydration and 11.8%, 78.5% and 9.7% at 28 d age, respectively. The hydration degree of cement paste at different ages was compared with the experimental data acquired by loss on ignition (LOI) tests. The results show that the calculated and measured data reasonably agree with each other, which indicates that micro-CT is a useful and reliable approach to characterize the micro structure evolution of hydrating cement paste.