基于一种互联网+喷粉加工设备的研制

喷粉机采用三菱PLC、触摸屏、无线服务器CMT-SVR-200等组成上下位机控制,通过手机或触屏控制喷粉炉温、喷粉量、流化气量、雾化气量、喷枪清洗气量、高压电流电压的大小等7种加工参数来进行喷粉调试加工。根据不同材质的金属制品喷涂需求,最多可预设编辑30种不同产品的组合加工参数,通过触屏或手机输入PLC寄存器中。喷粉加工时,只需选择对应的加工产品参数程序,便可由PLC程序将预设的7种加工参数调出来,提高产品喷涂的工作效率。

喷雾流化床微料包衣的实验研究

在喷雾流化床实验装置上选用Φ1mm的玻璃珠作为种粒,以糊精为包衣材料进行了微粒包衣的实验研究。着重考察了流化气速、进气温度和喷雾速率等操作参数对颗粒成长的影响。实验研究证实了流化气量、喷雾速率以及气体入口温度对微粒包衣增长速率的双重作用,并确定出所选实验条件下的最优值。

Characteristics of a Flow Transducer Based on Polarized Charge

In this paper we analyze the characteristics of a flow transducer based on polarized charge. The effects of the charged particles in pneumatic pipeline on the measurement pipe potential are discussed in detail and the equivalent circuits of the potential measurement are presented. On this bases, the relationships between mass flowrate and the electrical potential are obtained for different time constants of the measurement circuit. A satisfactory model is presented based on the characteristics of gas solid two phase flow. The linearity of the model is verified by the experiment results. The transducer, which is coaxially connected with the transport pipeline, does not disturb the flow state and has the features of ruggedness and durability, it is especially suitable for industry process control.

Variability of Surface Sensible Heat Flux over Northwest China

The present study documents the variability of surface sensible heat flux over Northwest China using station observations for the period 1961 2000.It is found that the afternoon and nighttime sensible heat flux variations are remarkably different.The variability of the instant flux in the afternoon is much larger than in the nighttime.The afternoon and nighttime flux anomalies tend to be opposite.The diurnal and seasonal dependence of sensible heat flux variations is closely related to the diurnal cycle of mean land-air temperature difference.The relationship of sensible heat flux with land-air temperature difference based on the instant value differs from that based on the daily mean.The present study indicates the importance for the models to properly simulate mean land-air temperature difference and its diurnal and seasonal variations in order to capture surface sensible heat flux variability over Northwest China and predicts its plausible impacts on climate.

Effect of CO Combustion Promoters on Combustion Air Partition in FCC under Nearly Complete Combustion

With CO combustion promoters, the role of combustion air flow rate for concerns of economics and control is important. The combustion air is conceptually divided to three parts: the air consumed by coke burning,the air consumed by CO combustion and the air unreacted. A mathematical model of a fluid catalytic cracking(FCC)unit, which includes a quantitative correlation of CO heterogeneous combustion and the amount of CO combustion promoters, is introduced to investigate the effects of promoters on the three parts of combustion air. The results show that the air consumed by coke burning is almost linear to combustion air flow rate, while the air consumed by CO combustion promoters tends to saturate as combustion air flow rate increases, indicating that higher air flow rate can only be used as a manipulated variable to control the oxygen content for an economic concern.

Water discharge variability of Changjiang(Yangtze) and Huanghe(Yellow) Rivers and its response to climatic changes

Influences of large-scale climatic phenomena, such as the E1Nifio/La Nifia-Southem Oscillation （ENSO） and the Pacific Decadal Oscillation （PDO）, on the temporal variations of the annual water discharge at the Lijin station in the Huanghe （Yellow） River and at the Datong station in the Changjiang （Yangtze） River were examined. Using the empirical mode decomposition-maximum entropy spectral analysis （EMD- MESA） method, the 2- to 3-year, 8- to 14-year, and 23-year cyclical variations of the annual water discharge at the two stations were discovered. Based on the analysis results, the hydrological time series on the inter- annual to interdecadal scales were constructed. The results indicate that from 1950 to 2011, a significant downward trend occurred in the natural annual water discharge in Huanghe River. However, the changes in water discharge in Changjiang River basin exhibited a slightly upward trend. It indicated that the changes in the river discharge in the Huanghe basin were driven primarily by precipitation. Other factors, such as the precipitation over the Changjiang River tributaries, ice melt and evaporation contributed much more to the increase in the Changjiang River basin. Especially, the impacts of the inter-annual and inter-decadal climate oscillations such as ENSO and PDO could change the long-term patterns of precipitation over the basins of the two major rivers. Generally, low amounts of basin-wide precipitation on interannual to interdecadal scales over the two rivers corresponded to most of the warm ENSO events and the warm phases of the PDO, and vice versa. The positive phases of the PDO and ENSO could lead to reduced precipitation and consequently affect the long-term scale water discharges at the two rivers.

Experimental Study on Gas-Solid Mass Transfer in Circulating Fluidized Beds

This study is devoted to gas-solid mass transfer behavior inheterogeneous two-phase flow. Experiments were carried out in a coldcirculating fluidized bed of 3.0 m in height and 72 mm in diameterwith naphthalene particles. Axial and radial distributions ofsublimated naphthalene concentration in air were measured with an on-line concentration monitoring system HP GC-MS. Mass transfercoefficients were obtained under various operating conditions,showing that heterogeneous flow structure strongly influences theaxial and radial profiles of mass transfer coefficients.

Application of pressure relief and permeability increased by slotting a coal seam with a rotary type cutter working across rock layers

Pressure relief to increase permeability significantly improves gas extraction efficiency from coal seams. In this paper we report results from simulations using FLAC3D code to analyze changes in coal displace- ment and stress after special drill slots were formed. We investigated the mechanism of pressure relief and permeability increase in a high-gas and low-permeability coal seam through the modeling of gas flow. This allows the development of the technology. Slotting across rock layers in the coal seam with a rotary type cutter was then applied in the field. The results show that pressure relief and permeability increases from slotting the coal seam can increase the transport and the fracture of the coal. This expands the range of pressure relief from the drilling and increases the exposed area of the seam. The total quan- tity of gas extracted from slotted bore holes was three times that seen with ordinary drilling. The concen- tration of gas extracted from the slotted drills was from two to three times that seen using ordinary drills. The gas flow was stable at 80%. Improved permeability and more efficient gas extraction are the result of the slotting. The roadway development rate is increased by 30-50% after gas drainage. This technology diminishes the lag between longwall production and roadway development and effectively prevents coal and gas outburst, which offers the Drosnect of broad anDlication.

Flow characteristics by particle image velocimetry in liquefied natural gas vaporizer model with several baffles

Shell-and-tube vaporizers are the most commonly used and dominated types of vaporizers in liquefied natural gas （LNG） realm. Due to efficient performance, shell-side flow in this type of vaporizers has received considerable attention and has been investigated extensively. However, the detailed flow structure in the shell needs to be determined for reliable and effective design. Therefore, the objective of this study was to clarify the flow structure in shell by particle image velocimetry （PIV）. Experiments were conducted using two types of model; 15% baffle cut having inlet and outlet positions !n the direction of 90° to the cut and 30% baffle cut having inlet and outlet positions in the direction of 180° to the cut. Each test section is 169 mm in inner diameter and 344.6 mm in length. The flow features were characterized in different baffle cuts with regards to the velocity vector field and velocity distribution. The results show that the flow characteristics of 15% baffle cut type vaporizer are comparable to those of 30% baffle cut type vaporizer.

Variations of Terrestrial Water Storage in the Yangtze River Basin under Climate Change Scenarios

In this study, the water balance-based Precipitation-Evapotranspiration-Runoff (PER) method combined with the land surface model Variable Infiltration Capacity (VIC) was used to estimate the spatiotemporal variations of terrestrial water storage (TWS) for two periods, 1982-2005 (baseline) and 2071-2100, under future climate scenarios A2 and B2 in the Yangtze River basin. The results show that the estimated TWS during the baseline period and under the two future climate scenarios have similar seasonal amplitudes of 60-70 mm. The higher values of TWS appear in June during the baseline period and under the B2 scenario, whereas the TWS under A2 shows two peaks in response to the related precipitation pattern. It also shows that the TWS is recharged from February to June during the baseline period, but it is replenished from March to June under the A2 and B2 scenarios. An analysis of the standard derivation of seasonal and interannual TWS time series under the three scenarios demonstrates that the seasonal TWS of the southeastern part of the Yangtze River basin varies remarkably and that the southeastern and central parts of the basin have higher variations in interannual TWS. With respect to the first mode of the Empirical Orthogonal Function (EOF), the inverse-phase change in seasonal TWS mainly appears across the Guizhou-Sichuan-Shaanxi belt, and the entire basin generally represents a synchronous change in interannual TWS. As a whole, the TWS under A2 presents a larger seasonal variation whereas that under B2 displays a greater interannual variation. These results imply that climate change could trigger severe disasters in the southeastern and central parts of the basin.

Time-Frequency Signal Processing for Gas-Liquid Two Phase Flow Through a Horizontal Venturi Based on Adaptive Optimal-Kernel Theory

A time-frequency signal processing method for two-phase flow through a horizontal Venturi based on adaptive optimal-kernel （AOK） was presented in this paper.First,the collected dynamic differential pressure signal of gas-liquid two-phase flow was preprocessed,and then the AOK theory was used to analyze the dynamic differ-ential pressure signal.The mechanism of two-phase flow was discussed through the time-frequency spectrum.On the condition of steady water flow rate,with the increasing of gas flow rate,the flow pattern changes from bubbly flow to slug flow,then to plug flow,meanwhile,the energy distribution of signal fluctuations show significant change that energy transfer from 15-35 Hz band to 0-8 Hz band;moreover,when the flow pattern is slug flow,there are two wave peaks showed in the time-frequency spectrum.Finally,a number of characteristic variables were defined by using the time-frequency spectrum and the ridge of AOK.When the characteristic variables were visu-ally analyzed,the relationship between different combination of characteristic variables and flow patterns would be gotten.The results show that,this method can explain the law of flow in different flow patterns.And characteristic variables,defined by this method,can get a clear description of the flow information.This method provides a new way for the flow pattern identification,and the percentage of correct prediction is up to 91.11%.

Effects of sintered metal distributor on fluidization quality of the air dense medium fluidized bed

Dry coal beneficiation using an air dense medium fluidized bed (ADMFB) requires the formation of a sta- ble and uniform bed from the dense medium. Others have shown that the structure and geometric parameters of the air distributor have a significant influence on the experimentally observed fluidization quality. In this study we used a sintered metal distributor (SMD) in the ADMFB separator and study its effect on the fluidization quality. The results show that for the same open area ratio (OAR), a smaller aper- ture in the SMD will provide improved fluidization quality. If aperture size is held constant bigger open area ratios result in improved fluidization quality. And, the fluidization quality also improves when the pressure drop across the SMD increases. A model relating distributor pressure drop and the geometric parameters of the SMD is also proposed.

Streamflow response to shrinking glaciers under changing climate in the Lidder Valley,Kashmir Himalayas

The study investigated the streamflow response to the shrinking cryosphere under changing climate in the Lidder valley, Upper Indus Basin(UIB), Kashmir Himalayas. We used a combination of multitemporal satellite data and topographic maps to evaluate the changes in area, length and volume of the glaciers from 1962 to 2013. A total of 37 glaciers from the Lidder valley, with an area of 39.76 km^2 in 1962 were selected for research in this study. It was observed that the glaciers in the valley have lost ~28.89 ±0.1% of the area and ~19.65 ±0.069% of the volume during the last 51 years, with variable interdecadal recession rates. Geomorphic and climatic influences on the shrinking glacier resources were studied. 30-years temperature records(1980-2010) in the study area showed a significant increasing trend in all the seasons. However, the total annual precipitation during the same period showed a nonsignificant decreasing trend except during the late summer months(July, August and September), when the increasing trend is significant. The depletion of glaciers has led to the significant depletion of the streamflows under the changing climate in the valley. Summer streamflows(1971-2012) have increased significantly till mid-nineties but decreased significantly thereafter, suggesting that the tipping point of streamflow peak, due to the enhanced glacier-melt contribution under increasing global temperatures, may have been already reached in the basin. The observed glacier recession and climate change patterns, if continued in future, would further deplete the streamflows with serious implications on water supplies for different uses in the region.

Application of least squares vector machines in modelling water vapor and carbon dioxide fluxes over a cropland

Least squares support vector machines (LS-SVMs), a nonlinear kemel based machine was introduced to investigate the prospects of application of this approach in modelling water vapor and carbon dioxide fluxes above a summer maize field using the dataset obtained in the North China Plain with eddy covariance technique. The performances of the LS-SVMs were compared to the corresponding models obtained with radial basis function (RBF) neural networks. The results indicated the trained LS-SVMs with a radial basis function kernel had satisfactory performance in modelling surface fluxes; its excellent approximation and generalization property shed new light on the study on complex processes in ecosystem.

Influence of atmospheric circulation on precipitation in Altai Mountains

We analyzed the changes in precipitation regime in the Altai Mountains for 1959-2014 and estimate the influence of atmospheric circulations on these changes. Our study showed that during last 56 years the changes in the precipitation regime had a positive trend for the warm seasons(April-October),but weakly positive or negative trends for the cold seasons(November-March). It was found that these changes correspond to the decreasing contribution of "Northern meridional and Stationary anticyclone(Nm-Sa)" and "Northern meridional and East zonal(Nm-Ez)" circulation groups and to the increasing contribution of "West zonal and Southern meridional(Wz-Sm)" circulation groups,accordingly to the Dzerdzeevskii classification. In addition,it was found that the variation of precipitation has a step change point in 1980. For the warm seasons,the precipitation change at this point is associated with the reduced influence of "West zonal(Wz)","Northern meridional and Stationary anticyclone(Nm-Sa)" and "Northern meridional and Southern meridional(Nm-Sm)" circulation groups. For the cold seasons,a substantialincrease of "Wz-Sm" and a decrease of "Nm-Sa","Nm-Ez" circulation groups are responsible for the precipitation change in the two time periods(1959-1980 and 1981-2014).

Spatial batch optimal design based on self-learning Gaussian process models for LPCVD processes

Low pressure chemical vapor deposition(LPCVD) is one of the most important processes during semiconductor manufacturing.However,the spatial distribution of internal temperature and extremely few samples makes it hard to build a good-quality model of this batch process.Besides,due to the properties of this process,the reliability of the model must be taken into consideration when optimizing the MVs.In this work,an optimal design strategy based on the self-learning Gaussian process model(GPM) is proposed to control this kind of spatial batch process.The GPM is utilized as the internal model to predict the thicknesses of thin films on all spatial-distributed wafers using the limited data.Unlike the conventional model based design,the uncertainties of predictions provided by GPM are taken into consideration to guide the optimal design of manipulated variables so that the designing can be more prudent Besides,the GPM is also actively enhanced using as little data as possible based on the predictive uncertainties.The effectiveness of the proposed strategy is successfully demonstrated in an LPCVD process.

Rapid Elimination of Black Odor in Rivers by Oxygen Aeration

Laboratory research and engineering applications demonstrated that oxygen aeration can rapidly increase the level of dissolved oxygen in the water of severely polluted rivers. This method was capable of eliminating the odorous substances from black odorous water and reducing the color shade of water, but could not remove the NH3-N, COD, TP or other common pollutants. Therefore, oxygen aeration can be implemented to rapidly eliminate black odorous from rivers, lakes and reservoirs, but cannot be used as a permanent method for treating pollution of rivers.

Advances in Nitrogen Denitrification and N_2O Emission in Agro-ecosystem

Nitrification and denitrification are two key links of nitrogen flow cycle in soil.N2O and N2,generated from biochemical process of nitrogen,can cause not only the nitrogen losses and reduction of nitrogen use efficiency,but also the boosted concentration of greenhouse gases,severely endangering the environment.Accordingly,nitrification-denitrification has been more and more concerned from whether an agricultural view,or an environmental one.Referring to the related literatures published at home and abroad in recent years,we overviewed the denitrification-caused N loss and N2O emission in various agro-ecosystems,and based on which we put forward countermeasures to reduce the denitrification-caused N loss and N2O emission and its research prospects in the future.

Responses of Hydrological Processes to Climate Change in the Zhujiang River Basin in the 21st Century

In this study, discharge at the outlet of Xijiang River, the biggest sub-basin of the Zhujiang River, was simulated and projected from 1961 to 2099 using the hydrological model HBV-D. The model uses precipitation and temperature data from CISRO/MK3 5, MPI/ECHAM5, and NCAR/CCSM3 under three greenhouse gas emission scenarios (SRES A2, A1B, B1). The results in water resources and flood frequency suggest that annual precipitation and annual runoff would increase after 2050 relative to the reference period of 1961-1990. In addition, increasing trends have been projected in area averaged monthly precipitation and runoff from May to October, while decreasing trends in those from December to February. More often and larger floods would occur in future. Potential increase in runoff during the low-flow season could ease the pressure of water demand until 2030, but the increase in runoff in the high-flow season, with more often and larger floods, more pressure on flood control after 2050 is expected.

Use of Fractals Channels to Improve a Proton Exchange Membrane Fuel Cell Performance

One of the most important and effective hardware elements for improvement of efficiency and power density of proton exchange membrane fuel cells is the flow field plate. The design and the pattern of the flow field plate have a considerable effect on the effectiveness of mass transport as well as on the electrochemical reactions inside the cell. The configuration of the flow field plate aims at ensuring a low pressure-drop over all channels in the stack. In this work, a FPFFP （fractal parallel flow field plate）, with bio-inspired configuration by insertion of fractals in a classic PFFP （parallel flow field plate）, is proposed, increasing the flow area of the hydrogen at anode side without increasing the section＇s area of the flow field plate. By simulating was observed that, the use of channels in fractal shape can increase the hydrogen flow area without occuring pressure loss in the cell. The fluid dynamic behavior in the FPFFP at smaller scales was replicated in the same plate, with better advantage of the active area of the electrode. Increasing the hydrogen flow area without causing pressure loss could be a good tactic to increase the power density of fuel cells, and consequently improving the cell performance.