冲击振动式物料位计原理与理论分析

通过理论分析与实验验证提出一种全新的完全非接触料位测量方法。对容器外壁施加机械激励 ,并对在容器外壁上检测到的机械波进行建模、参数估计 ,从而得出内部物料界面的信息。全部测量装置都在容器外部 ,高度冗余 ,是一种可靠 ,方便 ,无污染 ,廉价的完全非接触测量方法。

冲击振动式物料位计原理与实验研究

一种全新的完全非接触料位测量方法。对容器外壁施加机械激励 ,并对容器外壁上所产生的机械波进行检测。通过特征分析、提取 ,得出内部物料界面的信息。全部测量装置都在容器外部 ,实现无污染、方便。

数字式物位传感器的智能化研究

为了精确可靠地测量多种物料位,研发了一种新型智能式数字物位传感器。该传感器利用直接数字化检测原理,并运用物料自动识别电路和单片机使传感器具有智能化的功能。实验结果表明:该传感器任意2个检测点之间是盲区,绝对误差为±1 cm,分辨力为1 cm。

企业物料暂存区备料精益优化研究

装配车间的备料管理是影响装配线效率的重要因素。现为解决企业装配车间暂存区现存的备料不准确和物料库位不合理导致的成本浪费问题,通过对企业产线的生产能力及物料需求的综合分析,采用精益思想分析方法,对暂存区的备料量及物料区域库位进行精益规划,通过分析建立关于最佳物料备料量及暂存区规划的数学模型,并利用Matlab求得最佳解,得到暂存区的最佳备料量及最佳物料库位,使在暂存区的管理及配送物料至各对应装配线的运输成本最低。最后以H企业为例,验证方法的有效性。

The biofilm characteristics and enhanced performance of a marine microbial-electrolysis-cell-based biosensor under positive anodic potential

Microbial fuel cells have already been used as biosensors to monitor assimilable organic carbon(AOC).However,their signal production from AOC is known to be completely suppressed by dissoved oxygen(DO).In this study,two identical microbial electrolysis cell(MEC)based biosensors were inoculated with marine sediment and operated at two different anodic potentials,namely-300 mV and+250 mV relative to Ag/AgCl.The MEC biosensor operated under positive anodic potential conditions had electrochemically active microbial communities on the anode,including members of the Shewanellaceae,Pseudoalteromonadaceae,and Clostridiaceae families.However,the strictly anaerobic members of the Desulfuromonadaceae,Desulfobulbaceae and Desulfobacteraceae families were found only in the negative anodic potential MEC biosensor.The positive anodic potential MEC biosensor showed several other advantages as well,such as faster start-up,significantly higher maximum current production,fivefold improvement in the AOC detection limit,and tolerance of low dissolved oxygen,compared to those obtained from the negative anodic potential MEC biosensor.The developed positive anodic potential MEC biosensor can thus be used as a real-time and inexpensive detector of AOC concentrations in high saline and low DO seawater.

Understanding the roles of Brønsted/Lewis acid sites on manganese oxide-zeolite hybrid catalysts for low-temperature NH_(3)-SCR

Although metal oxide-zeolite hybrid materials have long been known to achieve enhanced catalytic activity and selectivity in NO_(x)removal reactions through the inter-particle diffusion of intermediate species,their subsequent reaction mechanism on acid sites is still unclear and requires investigation.In this study,the distribution of Brønsted/Lewis acid sites in the hybrid materials was precisely adjusted by introducing potassium ions,which not only selectively bind to Brønsted acid sites but also potentially affect the formation and diffusion of activated NO species.Systematic in situ diffuse reflectance infrared Fourier transform spectroscopy analyses coupled with selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR)reaction demonstrate that the Lewis acid sites over MnO_(x)are more active for NO reduction but have lower selectivity to N_(2)than Brønsted acids sites.Brønsted acid sites primarily produce N_(2),whereas Lewis acid sites primarily produce N_(2)O,contributing to unfavorable N_(2)selectivity.The Brønsted acid sites present in Y zeolite,which are stronger than those on MnO_(x),accelerate the NH_(3)-SCR reaction in which the nitrite/nitrate species diffused from the MnO_(x)particles rapidly convert into the N_(2).Therefore,it is important to design the catalyst so that the activated NO species formed in MnO_(x)diffuse to and are selectively decomposed on the Brønsted acid sites of H-Y zeolite rather than that of MnO_(x)particle.For the physically mixed H-MnO_(x)+H-Y sample,the abundant Brønsted/Lewis acid sites in H-MnO_(x)give rise to significant consumption of activated NO species before their inter-particle diffusion,thereby hindering the enhancement of the synergistic effects.Furthermore,we found that the intercalated K+in K-MnO_(x)has an unexpected favorable role in the NO reduction rate,probably owing to faster diffusion of the activated NO species on K-MnO_(x)than H-MnO_(x).This study will help to design promising metal oxide-zeolite hybrid catalysts by identifying the role of the acid sites in two different constituents.

Photocatalytic Cr(Ⅵ) reduction and organic-pollutant degradation in a stable 2D coordination polymer

A new coordination polymer,Zn(bpy)L(BUC‐21),(H2L=cis‐1,3‐dibenzyl‐2‐imidazolidone‐4,5‐dicarboxylic acid,bpy=4,4′‐bipyridine),has been synthesized under hydrothermal conditions,and characterized by single‐crystal X‐ray analysis,Fourier transform infrared spectroscopy,thermogravimetric analyses,CNH elemental analysis and UV‐Vis diffuse reflectance spectroscopy.BUC‐21exhibited an excellent performance for photocatalytic Cr(VI)reduction with a conversion efficiency of96%,better than that of commercial P25(39%),under UV light irradiation for30min.BUC‐21could also be used to conduct photocatalytic degradation of organic dyes including methylene blue,rhodamine B,methyl orange and reactive red X‐3B.Also,the photocatalytic activity of BUC‐21remained high across a wide pH range from2.0to12.0.It is interesting to note,however,that BUC‐21was unable to achieve simultaneous reduction of Cr(VI)and degradation of an organic pollutant in a mixed matrix,which can be attributed to the competition between Cr(VI)and the organic dyes for access to the photo‐excited electrons.

激光技术在检测中的应用

激光具有亮度高,方向性好,相干长度长等特点,它不仅在光通信、条形码技术、激光唱机(LD、VCD、DVD)等方面已得到广泛的应用,而且正在逐步深入其他各领域形成大规模产业。 半导体激光器所达到的性能已经使它可以在许多应用的领域取代氦氖激光器,鉴于它体积小巧、电源电压低、安全性能好、器件寿命长等优点,这种趋势将加速延续下去。特别值得强调的是。

Assessment of rapid impact compaction in ground improvement from in-situ testing

Ground improvement has been used on many construction sites to densify granular materials, in other word, to improve soil properties and reduce potential settlement. This work presents a case study of ground improvement using rapid impact compaction （RIC）. The research site comprises the construction of workshop and depots as part of railway development project at Batu Gajah-Ipoh, Malaysia. In-situ testing results show that the subsurface soil comprises mainly of sand and silty sand through the investigated depth extended to 10 m. Groundwater is approximately 0.5 m below the ground surface. Evaluation of improvement was based on the results of pre- and post-improvement cone penetration test （CPT）. Interpretation software has been used to infer soil properties. Load test was conducted to estimate soil settlement. It is found that the technique succeeds in improving soil properties namely the relative density increases from 45% to 70%, the friction angle of soil is increased by an average of 3°, and the soil settlement is reduced by 50%： The technique succeeds in improving soil properties to approximately 5.0 m in depth depending on soil uniformity with depth.

Anisotropic Lattice Strain of Composite Materials of LiMnO2 and H/D-Substituted Chiral Cyanide-Bridged Ni（Ⅱ）-Fe（Ⅲ） Coordination Polymers

Composite materials composed of LiMnO2, a typical electrode material for lithium ion battery, and a chiral cyanide-bridged Ni（Ⅱ）-Fe（Ⅲ） coordination polymer [NiL2][Fe（CN）6]·4H2O （Ni-Fe, H-form） （L = （1R,2R）-（-）-1,2-cyclohexane-diamine） or its deuterium isomer, [NiL2][Fe（CN）6]·4D2O （Ni-Fe, D-form） have been prepared by the various ratios （w/w） of Ni-Fe：LiMnO2 = 10：0 （pure Ni-Fe）, 9：1, 8：2, 7：3, 6：4, 5：5, 4：6, 3：7, 2：8, 1：9 and 0：10 （pure LiMnO2）. Gradual shift of IR （infrared） spectra by changing the ratios and losing difference between H-form and D-form of Ni-Fe due to isotope effects revealed adsorption of Ni-Fe onto LiMnO2 to form composite materials. Formation of composite materials of Ni-Fe and LiMnO2 could be also proved losing ferromagnetic behavior of LiMnO2 on increasing of the ratios of Ni-Fe in each composite. In contrast to smoothly positive thermal expansion of pure LiMnO2 along the crystallographic b axis, variable temperature powder XRD （X-ray diffraction） patterns at 100-300 K of the composite materials exhibited thermally-accessible lattice distortion along the b axis with different ratios. It is also proved deviation of ideal linear correlation of an evaluation function, In K = a/T ＋ b （where, K = （d（T） - d（0））/d（T）, d（T） denotes nλ/（sin 2θ） at T （K））.

Optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distillation

Based on a previous investigation,a simulation model was used for optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distillation.An experimental setup was established to verify the simulated results.The effects of various operating variables,such as ethanol feed location,acetic acid feed location,feed stage of reaction mixture of acetic acid and n-butanol,reflux ratio of ethyl acetate reactive distillation column,and distillate to feed ratio of n-butyl acetate column,on the ethanol/n-butanol conversions,ethyl acetate/n-butyl acetate purity,and energy consumption were investigated.The optimal results in the simulation study are as follows:ethanol feed location,15th stage;acetic acid feed location,eighth stage;feed location of reaction mixture of acetic acid and n-butanol,eighth stage;reflux ratio of ethyl acetate reactive distillation column,2.0;and distillate to feed ratio of n-butyl acetate,0.6.

Numerical Simulation of the Porous Structure of Biomaterials

Porous biomaterials are widely used as bone replacement materials because of thers high biocompatibility and osteoconductivity property. Understanding of their porous structure (i.e. geometrical and topological characteristic) and studying how to the body fluid flow through them are essential to investigate the degradation behaviour at the surface-liquid interface. This research develops a numerical model to simulate the porous structure of biomaterials based on the stochastic approach in pore size distribution and interconnectivity.

物料编码转换对中石化管道储运分公司ERP系统提升的影响

介绍物料编码转换对管道储运分公司ERP系统的影响,着重强调物料编码转换对管道储运分公司ERP系统提升的意义。详细阐述物料编码转换的策略以及管道储运分公司物料编码转换工作。

Bacterial cellulose-regulated synthesis of metallic Ni catalysts for high-efficiency electrosynthesis of hydrogen peroxide

The decentralized production of H_(2)O_(2) via a twoelectron oxygen reduction reaction(2e^(-)ORR)has emerged as a promising alternative to the energy-intensive anthraquinone(AQ)process.However,its practical application requires 2eORR electrocatalysts with high activity and selectivity.Herein,we report the synthesis of metallic Ni nanoparticles anchored on bacterial cellulose-derived carbon fibers(Ni-NPs/BCCF)via a facile impregnation-pyrolysis method as efficient electrocatalysts for 2 e-ORR to H_(2)O_(2).By tuning the amount of Ni precursor,the best electrocatalytic performance toward 2 eORR was achieved for Ni-NPs/BCCF-20.7,affording a high H_(2)O_(2) selectivity of ~90% and an onset potential of 0.75 V vs.reversible hydrogen electrode(RHE)in an alkaline electrolyte.Ni-NPs/BCCF-20.7 achieved the largest H_(2)O_(2) yield rate of 162.7±13.7 mmol gcat^(-1)h^(-1) and the highest Faradaic efficiency of 93.9%±4.2% at 0.2 and 0.5 V vs.RHE from the bulk ORR system,respectively.Theoretical calculations revealed the more favorable"end-on"adsorption configuration of molecular oxygen on the exposed Ni(111)plane,which can effectively suppress the O-O bond dissociation,resulting in high selectivity for H_(2)O_(2) generation.

Memory for location and visual cues in white-eared hummingbirds Hylocharis leucotis

In nature hummingbirds face floral resources whose availability, quality and quantity can vary spatially and temporally. Thus, they must constantly make foraging decisions about which patches, plants and flowers to visit, partly as a function of the nectar reward. The uncertainty of these decisions would possibly be reduced if an individual could remember locations or use visual cues to avoid revisiting recently depleted flowers. In the present study, we carried out field experiments with white-eared hummingbirds Hylocharis leucotis, to evaluate their use of locations or visual cues when foraging on natural flowers Penstemon roseus. We evaluated the use of spatial memory by observing birds while they were foraging between two plants and within a single plant. Our results showed that hummingbirds prefer to use location when foraging in two plants, but they also use visual cues to efficiently locate unvisited rewarded flowers when they feed on a single plant. However, in absence of visual cues, in both experiments birds mainly used the location of previously visited flowers to make subsequent visits. Our data suggest that hummingbirds are capable of learning and employing this flexibility depending on the faced environmental conditions and the information acquired in previous visits [Current Zoology 57 （4）： 468-476, 2011].

Nonlinear optical material of a low-dimensional coordination polymer:Synthesis,structure,NLO and fluorescence properties

Employing unsymmetrical 2-mercapto-5-methyl-1,3,4-thiadiazole and 2,2′-bipyridine as mixed ligands, a new low-dimensional coordination polymer [Zn(MMTA) 2 (2,2′-bipy)] n (MMTA = 2-mercapto-5-methyl-1,3,4-thiadiazole, 2,2′-bipy = 2,2′-bipyridine), has been synthesized under solvothermal condition and characterized by single crystal X-ray diffraction. This compound crys- tallizes in the noncentrosymmetric space group Cc, with cell parameters: a = 8.291(4) , b = 15.483(9) , c = 15.620(6) , = 96.00(5)°, V = 1994.1(2) 3 , and Z = 4. The mixed ligands link the zinc center into a mononuclear unit, which is futher linked by weak C-H···N and C-H···S hydrogen bonds into a three-dimensional noncentrosymmetric framework. The compound exhibits intense photoluminescence and distinct NLO properties at room temperature. The intensity of the green light produced by the powder sample of the compound is about 3.2 times that produced by KDP powder. On the basis of the results of TG analysis, the structure is thermally stable up to ～260 °C.

Bimetallic oxide coupled with B-doped graphene as highly efficient electrocatalyst for oxygen evolution reaction

Developing electrocatalysts with high performance and low cost for the oxygen evolution reaction(OER)is of great importance for fabricating renewable energy storage and conversion devices.Here,a series of boron-doped graphene(BG)-supported bimetallic oxides of Co and Ni were obtained and served as OER electrocatalysts.Surprisingly,the annealed Co-Ni-Ox/BG with a Co/Ni ratio of 1:1 exhibits high performance toward oxygen evolution in alkaline electrolyte.The overpotential is only 310 mV at the current density of 10 mA cm-2,superior to many mono-metallic oxides reported before,and even comparable to the commercial RuO2.The regulation of charge distribution in bimetallic oxides and the strong synergistic coupling effects together contribute to the superior electrocatalytic performance of the Co-Ni-Ox/BG toward OER.This study also offers several effective ways to design high-performance OER electrocatalysts for water splitting.

Defect engineered 2D mesoporous Mo-Co-O nanosheets with crystalline-amorphous composite structure for efficient oxygen evolution

Two-dimensional(2D)mesoporous metal-oxide(hydroxide)nanomaterials with defects are promising towards the realization of efficient electrocatalysis.Herein,we report a facile and effective one-pot solvothermal route to synthesize mesoporous Mo_(x)-Co-O hybrid nanosheets(NSs)which is composed of crystalline Mo_(4)O_(11) and amorphous cobalt hydroxide.Due to the corrosion of 1-octylamine at high temperatures,abundant mesoporous holes are created in situ over the Mo_(x)-Co-O hybrid NSs during the solvothermal process,which is beneficial to increasing the electrochemical surface area.The dimension of the Mox-Co-O NSs,size of mesoporous and the concentration of defects can be easily modulated by controlling the molar ratio of Mo/Co.Electrochemical measurements reveal that the 2D mesoporous Mo_(x)-Co-O NSs show an excellent activity for the oxygen evolution reaction with the highest catalytic activity of η_(10)=276 mV at 10 mA cm^(−2)in 1 mol L^(−1)KOH.Enhanced adsorption of intermediates and abundant oxygen vacancies achieved by appropriate Mo doping are the two main factors that contribute to the excellent catalytic activity of Mo_(0.2)-Co-O NSs.This work,with the construction of 2D metal-oxide(hydroxide)crystallineamorphous nanomaterials possessing abundant holes,oxygen vacancies and enhanced adsorption of intermediates,provides important insight on the design of more efficient catalysts.

Oxygen vacancies in metal oxides: recent progresstowards advanced catalyst design

Energy crisis and environmental problems urgently drive the proposal of new strategies to improve human wellbeing and assist sustainable development.To this end,scientists have explored many metal oxides-based photocatalysts with high stability,low cost,earth abundance,and potentially high catalytic activity relevant for key applications such as H2O splitting,CO2 reduction,N2 fixation,and advanced oxidation of pollutants.In these metal oxides,oxygen vacancies(OVs)are ubiquitous and intrinsic defects with pronounced impacts on the physicochemical properties of the catalysts,which may open new opportunities for obtaining efficient metal oxides.The thorough understanding of the structural and electronic nature of OVs is necessary to determine how they serve as catalytically active sites.In this review,we summarize the origin of OVs,the strategies to introduce OVs,as well as the fundamental structure-activity relationships to relate these crystal defects to catalyst properties including light absorption,charge separation,etc.We emphasize the mechanism of OVs formation and their effects on the intrinsic catalytic characteristics of the metal oxides.We also present some multicomponent catalytic platforms where OVs contribute to catalysis via synergy.Finally,opportunities and challenges on engineering defects in photocatalysts are summarized to highlight the future directions of this research field.