提高煤质化验分析准确性研究探索

对发电厂而言,煤质化验是保障燃煤质量的重要手段,通过对燃煤中硫、碳等元素及其发热量、水分、灰份等基本属性进行化验分析来加快燃煤生产与销售等环节的流通速度,以此推动发电厂快速发展。通常,发电厂对使用的燃煤有明确的质量指标,使用锅炉的不同对燃煤质量有着不同要求,通过进行煤质化验分析来强化燃煤燃烧效果。煤质化验具有较强的专业性和理论性,为保证煤质化验分析结果的准确,需要加强对化验工作的全面管理,不断规范煤质化验工作流程,从而提高煤质化验分析水平。本文着重从煤质化验分析的准确性角度出发,针对煤质化验工作内容、流程及化验方法展开全方位分析研究,进一步阐明各类要素与煤质化验分析准确性间的关联,从而提出具体的观点和建议以供参考。

气相色谱仪气路改进

大庆油田研究院中心化验室于1985年5月引进日本岛津公司产GC-9A气相色谱仪,用于天然气组分分析,该仪器的气路部分为双气路结构,在载气流速一定的条件下,与单气路气相色谱仪相比,前者载气消耗多一倍.

Characterization of pancreatic stem cells derived from adult human pancreas ducts by fluorescence activated cell sorting

AIM： To isolate putative pancreatic stem cells （PSCs） from human adult tissues of pancreas duct using serumfree, conditioned medium. The characterization of surface phenotype of these PSCs was analyzed by flow cytometry. The potential for pancreatic lineage and the capability of β-cell differentiation in these PSCs were evaluated as well. METHODS： By using serum-free medium supplemented with essential growth factors, we attempted to isolate the putative PSCs which has been reported to express nestin and pdx-1. The MatrigelTM was employed to evaluate the differential capacity of isolated cells. Dithizone staining, insulin content/secretion measurement, and immunohistochemistry staining were used to monitor the differentiation. Fluorescence activated cell sorting （FACS） was used to detect the phenotypic markers of putative PSCs. RESULTS： A monolayer of spindle-like cells was cultivated. The putative PSCs expressed pdx-1 and nestin. They were also able to differentiate into insulin-, glucagon-, and somatostatin-positive cells. The spectrum of phenotypic markers in PSCs was investigated; a similarity was revealed when using human bone marrow-derived stem cells as the comparative experiment, such as CD29, CD44, CD49, CD50, CD51, CD62E, PDGFR-α, CD73 （SH2）, CD81, CD105（SH3）. CONCLUSION： In this study, we successfully isolated PSCs from adult human pancreatic duct by using serumfree medium. These PSCs not only expressed nestin and pdx-1 but also exhibited markers attributable to mesenchymal stem cells. Although work is needed to elucidate the role of these cells, the application of these PSCs might be therapeutic strategies for diabetes mellitus.

Skeletal myogenesis by human embryonic stem cells

We have examined the myogenic potential of human embryonic stem （hES） cells in a xeno-transplantation animal model. Here we show that precursors differentiated from hES cells can undergo myogenesis in an adult environment and give rise to a range of cell types in the myogenic lineage. This study provides direct evidences that hES cells can regenerate both muscle and satellite cells in vivo and are another promising cell type for treating muscle degenerative disorders in addition to other myogenic cell types.

Plant Test of Industrial Waste Disposal in a Cement Kiln

Destruction of industrial waste in cement rotary kilns (CRKs) is an alternative technology for the treatment of certain types of industrial waste (IW). In this paper, three typical types of industrial wastes were co-incinerated in the CRK at Beijing Cement Plant to determine the effects of waste disposal (especially solid waste disposal) on the quality of clinker and the concentration of pollutants in air emission. Experimental results show that (1) waste disposal does not affect the quality of clinker and fly ash, and fly ash after the IW disposal can still be used in the cement production, (2) heavy metals from IW are immobilized and stabilized in the clinker and cement, and (3) concentration of pollutants in air emission is far below than the permitted values in the China National Standard-Air Pollutants Emission Standard (GB 16297-1996).

Xeno-free derivation and culture of human embryonic stem cells： current status, problems and challenges

Human embryonic stem cells （hESC） not only hold great promise for the treatment of degenerative diseases but also provide a valuable tool for developmental studies. However, the clinical applications of hESC are at present limited by xeno-contamination during the in vitro derivation and propagation of these cells. In this review, we summarize the current methodologies for the derivation and the propagation of hESC in conditions that will eventually enable the generation of clinical-grade cells for future therapeutic applications.

Catalytic Partial Oxidation of Methane with Air to Syngas in a Pilot-Plant-Scale Spouted Bed Reactor

On the basis of hydrodynamic and scaling-up studies, a pilot-plant-scale thermal spouted bed reactor (50 mm in ID and 1500 mm in height) was designed and fabricated by scaling-down cold simulators. It was tested for making syngas via catalytic partial oxidation (CPO) of methane by air. The effects of various operating conditions such as operating pressure and temperature, feed composition, and gas flowrate etc. on the CPO process were investigated. CH4 conversion of 92.2% and selectivity of 92.3% and 83.3% to CO and H2, respectively, were achieved at the pressure of 2.1 MPa. It was found that when the spouted bed reactor was operated within the stable spouting flow regime, the temperature profiles along the bed axis were much more uniform than those operated within the fixed-bed regime. The CH4 conversion and syngas selectivity were found to be close to thermodynamic equilibrium limits. The results of the present investigation showed that spouted bed could be considered as a potential type of chemical reactor for the CPO process of methane.

Anti-synchronization Between Lorenz and Liu Hyperchaotic Systems

Anti-synchronization between different hyperchaotic systems is presented using Lorenz and Liu systems. When the parameters of two systems are known, one can use active synchronization. When the parameters are unknown or uncertain, the adaptive synchronization is applied. The simulation results verify the effectiveness of the proposed two schemes for anti-synchronization between different hyperchaotic systems.

Experimental and Theoretical Analysis of the Impinging Stream Drying

The experiments of one-stage semi-circular and two-stage semi-circular impinging stream drying as well as the vertical and semi-circular combined impinging stream drying were carried out. The velocity distribution and the mean residence time of particles, and the influence of various factors on drying characteristics were studied. A mathematical model of granular material drying in a semi-circular impinging stream dryer was proposed, in which the flow characteristics as well as the heat and mass transfer mechanisms were considered. Reasonable numerical methods were used to solve the equations. Under various conditions, the calculated results agree well with the experimental data. The unsteady-state drying dynamic equation, as well as the variations of drying rate and moisture content versus time were obtained. The results indicate that constant drying rate period does not exist in a semi-circular impinging stream dryer. Appropriate semi-circular stage number and curvature radius, flow-rate ratio, air velocity, and higher inlet air temperature should be used for enhancing the drying process.

Protective effects of 5,4'-dihydroxy-3',5'- dimethoxy-7-O-β-D -glucopyranosyloxy-flavone on experimental hepatic injury

AIM: To investigate the pharmacological effects of rice flavone (5,4'-dihydroxy-3',5'-dimethoxy-7-0-β-D-glucopyranosyloxy-flavone, RF) separated from panicle-differentiating to flowing rice on rat experimental hepatic injury. METHODS: Models of rat acute hepatic injury induced by carbon tetrachloride (CCl4) administration, rat hepatic fibrosis induced by thioacetamide, injury of primary cultured rat hepatocytes induced by CCl4, respectively, were established. After treated with RF, content of serum alanine transaminase (ALT), aspartate aminotransferase (AST) and albumin (Alb), hyaluronic acid (HA), the activity of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and hydroxyproline (Hyp) were measured and liver tissue was observed pathologically by hematoxylin-eosin (HE) staining. Effects of RF on pathological changes, function index, enzyme of scavenging free radicals and blood rheology were evaluated. RESULTS: In model of rat acute hepatic injury induced by CCI4, RF can significantly decrease the contents of serum ALT, AST, increase the content of Alb, improve the dropsy and fat denaturalization of hepatocytes. In model of rat hepatic fibrosis induced by thioacetamide, RF can inhibit the increase of HA, Hyp and whole blood viscosity, and improve the activities of GSH-Px and SOD, and inauricular microcirculation. CONCLUSION: RF has apparent protective effects on hepatic injury by increasing activity of GSH-Px and SOD, scavenging free radicals produced by CCI4, reducing blood viscosity, and improving microcirculation and blood supply.

An Experimental Investigation of Agglomeration with One and Two Nozzle Atomisation

Water-droplet size and velocity measurements were taken throughout two different sprays produced by a single nozzle and two nozzles pointed towards each other. The aim of this investigation was to understand the manner in which the motion of the droplets in a spray leads to agglomeration of these droplets. It appears that the inertia of the droplets plays an important role in the redistribution of droplets throughout a spray. Larger droplets tend to concentrate at the outer portions of the spray, because they are able to maintain their radial momentum farther downstream of a nozzle, while the smaller droplets follow the airflow more closely and thus collect in the core of the spray. Agglomeration can result from both turbulent collisions and collisions due to the relative velocities of the droplets. The difference between the agglomeration rates in the sprays from a single nozzle and two-nozzles pointed towards each other was difficult to resolve in these experiments, although the results suggest that the outer portions of both sprays should be investigated more closely for evidence of agglomeration.

The clinical trial research of preoperative induced hypertension chemotherapy on the III staging cardia or fundus of stomach carcinoma

Objective： To observation the therapeutic effect and the adverse reaction of preoperative induced hypertension chemotherapy （IHC） on the Ⅲ staging cardia or fundus of stomach carcinoma. Methods： 49 cases of the Ⅲ staging cardia or fundus of stomach carcinoma were divided into two groups at random. The observation group included 19 cases and the control group included 30 cases. Every case used one cycle chemotherapy. The observation group （IHC group） used chemotherapy and AT Ⅱ. The control group （simple chemotherapy group） used simple chemotherapy. All cases of the two groups operated after 3 weeks rest. The specimen＇s DNA was analyzed by flow cytometry. Results： The effective power of observation group was 63.2% （12/19）, exairesis ratio was 84.2% （16/19）. The effective power of control group was 30% （9/30）, exairesis ratio was 63.3% （19/30）. DNA ploid determination： 13 cases were diploid and 5 cases were heteropioid in the observation group, 9 cases were diploid and 16 cases were heteroploid in the control group. The operative complications and risks of the two groups did not increase. Conclusion： IHC can increase the therapeutic effect of Ⅲ staging cardia or fundus of stomach carcinoma obviously. IHC is one of the chemotherapy methods that have good future, it has good value of clinic enlarge trial.

Aerobic oxidation behavior of α-ionone catalyzed by N-hydroxyphthalimide combined with acetylacetone cobalt(Ⅱ)

A practical catalytic method to oxidize α-ionone with molecular oxygen using N-hydroxyphthalimide(NHPI)combined with acetylacetone cobatt(Ⅱ)(Co(acac)2)was developed,and the probable catalytic mechanism was proposed.The influences of the reaction conditions on conversion of α-ionone and the selectivity of the major product(5-keto-α-ionone)were investigated,and the technical parameters for 5-keto-α-ionone were optimized.The results show that the primary product is 5-keto-α-ionone,and by-products include epoxy-α-ionone,as well as rearrangement products 4-keto-β-ionone and epoxy-β-ionone,which are characterized by infrared spectra,proton nuclear magnetic resonance spectra,mass spectra and elemental analysis.The selectivity of 5-keto-α-ionone and the conversion of α-ionone are 55.0% and 97.0%,respectively,when 30%(molar fraction)NHPI,1.0%(molar fraction)Co(acac)2 and no solvent are employed under O2 pressure of 1.0 MPa and the reaction temperature of 65℃for 11 h.The procedure shows good reproducibility in the parallel experiments.

Development and Experimental Research of kW-scale Molten Carbonate Fuel Cells

A kW-scale molten carbonate fuel cells stack was developed and 800-hours’ operating test and performance experimental research had been done. Utilizing domestic materials completely, we developed NiO cathode and Ni-Al anode with the active area of 336cm 2 and Υ-LiAlO 2 electrolyte tile and bipolar plate with the area of 900cm 2. The stack was composed of thirty cells, with 62%Li 2CO 3+38%K 2CO 3 as its electrolyte. During the 800 hours’ continuous operating, the performance of the stack was stable. With 99.7%(mole fraction) H 2 as fuel and O 2 from air as oxidant, the average operating voltage of a cell was about 0.72 V. The maximal current density attained to 165mA/cm 2, and the maximal output power attained to 1080 Watt. The whole performance of the stack approached to the international level in the early 90’s. This paper gives the main works and experiments results.

Migration of Infiltrated NH_4 and NO_3 in a Soil and Groundwater System Simulated by a Soil Tank

The infiltration of water contaminants into soil and groundwater systems can greatly affect the quality of groundwater. A laboratory-designed large soil tank with periodic and continuous infiltration models, respectively, was used to simulate the migration of the contaminants NH4 and NO3 in a soil and groundwater system, including unsaturated and saturated zones. The unsaturated soil zone had a significant effect on removing NH4 and NO3 infiltrated from the surface water. The patterns of breakthrough curves of NH4 and NO3 in the unsaturated zone were related to the infiltration time. A short infiltration time resulted in a single sharp peak in the breakthrough curve, while a long infiltration time led to a plateau curve. When NH4 and NO3 migrated from the unsaturated zone to the saturated zone, an interracial retardation was formed, resulting in an increased contaminant concentration on the interface. Under the influence of horizontal groundwater movement, the infiltrated contaminants formed a contamination-prone area downstream. As the contaminants migrated downstream, their concentrations were significantly reduced. Under the same infiltration concentration, the concentration of NO3 was greater than that of NH4 at every corresponding cross-section in the soil and groundwater tank, suggesting that the removal efficiency of NH4 was greater than that of NO3 in the soil and groundwater system.

Experimental Research on Single-Pass SHG from Periodically Poled LiNbO_3 Crystal

Quasi phase matching (QPM) periodical poled LiNbO 3(PPLN) is designed and successfully fabricated to enable second harmonic generation(SHG).The samples were Z cut 0.5 mm thick and grating period is Λ=6.8 μm for the first order QPM of continual wave λ=1.064 μm which is emitted by Nd∶YAG laser at room temperature 27 ℃. The output single pass SHG power was tested by an authorized optical system. The normalized max conversion efficiency is calculated to be 0.25 0 0(W·cm) -1 .The fabrication and parameters calculated method are introduced, and testing scheme is described in this paper. Even some ideas to improve conversion efficiency are offered.

Three-dimensional Ordered Silica Colloidal Film Self-assembly Deposited on a VerticalSubstrate

A method for preparation of particle crystal film constructed from monodisperse silica colloidal particles in diameter of about 300 nm is reported. The films were prepared from an ethanol suspension by vertical deposition that relies on capillary forces to assemble colloidal crystal particles on a vertical substrate. The 3D ordered films were characterized by transmission spectra and scanning electric microscope (SEM). The effect of evaporation temperature, particle concentration and sintered temperature on the quality of colloidal particle crystal film was investigated.

Experiment study of forming and activation of conductive film of the surface conduction electron emitter display

The forming and activation of the conductive films are studied experimentally. The power supply, a peak-to-peak 30 V triangle profile voltage, is applied to three kinds of conductive films that contain 0.25%, 0.5%, and 1% of palladium respectively. In the experiments we contrasted the values of related parameter in different conditions, observed the lumi- nous spots on the anode panel, dealt with and analyzed the related data, and compared the positions and the amount of the luminous spots. We have gotten the conclusion that there is a threshold value Uth. The emission current Ie will increase rapidly when the device voltage Uf is greater than Uth. And the emission current Ie could be controlled by the device voltage Uf. The positions of the luminous spots on the anode panel are related with the device voltage Uf.

The Experimental Research on the Frameless Registration of DSA/CT Images

DSA images show vessels with clarity and CT images show bones distinctly. In this paper, we present an experimental research on the frameless registration of DSA/CT images based on localization algorithm. With four external markers, the vessels and bones in human brain can be integrated. The mean accuracy of simulated experiment is about 2.0 mm. The experiment proved that the 3D images composed cerebral anatomy and vasculature could help neurosurgeons perform accurate diagnosis and make right operation planning.

Microhabitat use by white-footed mice Peromyscus leucopus in forested and old-field habitats occupied by Morrow's honeysuckle Lonicera morrowii

We quantified microhabitat use by white-footed mice Peromyscus leucopus in forest and old-field habitats occupied by Morrow＇ s honeysuckle Lonicera morrowii, an invasive exotic shrub imported from Japan. Microhabitat characteristics were compared between trails used by mice （ n = 124） and randomly selected trails （ n = 127） in 4 study plots located at Fort Necessity National Battlefield, Farmington, Pennsylvania, USA. We compared 10 mierohabitat variables between used and random trails using non-metric multidimensional scaling （NMDS） and classification and regression tree （CART） analysis. Trails used by mice were statistically different from randomly selected trails in both forested plots （ P 〈 0. 008） and old-field plots （ P 〈 0. 001 ）. In the forested plots, trails of white-footed mice were more often associated with a greater percent cover （% cover） of coarse woody debris （CWD） than were randomly selected trails. In the old-field plots, mouse trails were commonly characterized by having a lower % cover of exotic herbaceous vegetation, a greater % cover of shrubs, and a greater % cover of Morrow＇ s honeysuckle than randomly selected trails. Our study indicates that white-footed mice do not move randomly and prefer areas of high structural complexity, thereby showing significant microhabitat preference. The preference of white-footed mice for areas with a relatively high percent cover of Morrow＇s honeysuckle could 1 ） be a factor in the aggressive nature of the exotic honeysuckle shrub＇s spread throughout the Battlefield or 2） cause the shrub to spread even faster into adjacent areas not yet occupied by Morrow＇ s honeysuckle