New methods to remove baseline drift in trapezoidal pulse shaping

Trapezoidal pulse shaping algorithm is widely applied to improve signal-to-noise ratio(SNR), throughput and energy resolution with the properties of noise suppression, pile-up pulse separation and ballistic deficit correction. The algorithm can be acquired by z transform method which is easier for derivation. However, the baseline drift of trapezoidal pulse appears because the noise superimposes on the input signal. In this paper,two new methods based on convergence analysis and noise suppression are proposed to remove the baseline drift resulting from trapezoidal pulse shaping. Simulations and experimental tests are carried out to verify the methods. The results demonstrate that the proposed methods can remove baseline drift in trapezoidal pulse shaping.

A new two-step variational model for multiplicative noise removal with applications to texture images

Multiplicative noise removal problems have attracted much attention in recent years.Unlike additive noise,multiplicative noise destroys almost all information of the original image,especially for texture images.Motivated by the TV-Stokes model,we propose a new two-step variational model to denoise the texture images corrupted by multiplicative noise with a good geometry explanation in this paper.In the first step,we convert the multiplicative denoising problem into an additive one by the logarithm transform and propagate the isophote directions in the tangential field smoothing.Once the isophote directions are constructed,an image is restored to fit the constructed directions in the second step.The existence and uniqueness of the solution to the variational problems are proved.In these two steps,we use the gradient descent method and construct finite difference schemes to solve the problems.Especially,the augmented Lagrangian method and the fast Fourier transform are adopted to accelerate the calculation.Experimental results show that the proposed model can remove the multiplicative noise efficiently and protect the texture well.

Discrepancies in Growth Measurement Methods of Mosses: An Example from Two Keystone Species Grown under Increased CO₂and N Supply in a Restored Peatland

Bryophytes dominate northern peatlands. Obtaining reliable measurements of moss-growth and how it may be affected by global changes are therefore important. Several methods have been used to measure moss-growth but it is unclear how comparable they are in different conditions and this uncertainty undermines comparisons among studies. In a field experiment we measured the growth and production of Sphagnum fallax (Sphagnum) and Polytrichum strictum (Polytrichum) using two handling methods, using cut and uncut plants, and three growth-variables, height-growth, length-growth, and mass-growth. We aimed “benchmarking” a combination of six methodological options against exactly the same set of factorial experiments: atmospheric CO2 enrichment and N addition. The two handling methods produced partly different results: in half of the cases, one method revealed a significant treatment effect but the other one did not: significant negative effects on growth were only observed on uncut plants for elevated CO2 and on cut plants for N addition. Furthermore, the correspondence between measurements made with various growth-variables depended on the species and, to a lesser extent, treatments. Sphagnum and Polytrichum growth was inhibited under elevated CO2, and correlated to higher ammonium values. Sphagnum was however less affected than Polytrichum and the height difference between the two species decreased. N addition reduced the P/N ratio and probably induced P-limiting conditions. Sphagnum growth was more inhibited than Polytrichum and the height difference between the two species increased. Our data show that such a problem indeed exists between the cut and uncut handling methods. Not only do the results differ in absolute terms by as much as 82% but also do their comparisons and interpretations depend on the handling method—and thus the interpretation would be biased—in half of the cases. These results call for caution when comparing factorial studies based on different handling methods.

Seasonal and Spatial Variability of Water Quality and Nutrient Removal Efficiency of Restored Wetland： A Case Study in Fujin National Wetland Park, China

To investigate the spatio-temporal and compositional variation of selected water quality parameters and understand the puri- fying effects of wetland in Fujin National Wetland Park （FNWP）, China, the trophic level index （TLI）, paired samples t-test and correla- tion analysis were used for the statistical analysis of a set of 10 water quality parameters. The analyses were based on water samples collected from 22 stations in FNWP between 2014 and 2016. Results initially reveal that total nitrogen （TN） concentrations are above class V levels （2 mg/L）, total phosphorus （TP） concentrations are below class III levels （0.2 mg/L）, and that all other parameters fall within standard ranges. Highest values for TN, pH, and Chlorophyll-a were recorded in 2016, while the levels of chemical oxygen de- mand （CODMn） and biochemical oxygen demand （BODs） were lowest during this year. Similarly, TN values were highest between 2014 and 2016 while dissolved oxygen （DO） concentrations were lowest in the summer and TP concentrations were highest in the autumn. Significant variations were also found in Secchi depth （SD）, TN, CODMn （P 〈 0.01）, TP, and DO levels （P 〈 0.05） between the inlet and outlet of the park. High-to-low levels of TN, TP, and TDS were found in cattails, reeds, and open water （the opposite trend was seen in SD levels）. Tested wetland water had a light eutrophication status in most cases and TN and TP removal rates were between 7.54%-84.36% and 37.50%-70.83%, respectively. Data also show no significant annual changes in water quality within this wetland, although obvious affects from surrounding agricultural drainage were nevertheless recorded. Results reveal a high major nutrient removal efficiency （N and P）. The upper limits of these phenomena should be addressed in future research alongside a more efficient and scientific agricultural layout for the regions in and around the FNWP.

Optimization of Wetland Plant Selection and Configuration in Urban Water Environment Ecological Restoration Projects

In urban water ecological restoration projects,the selection and configuration of wetland plants are crucial for water quality improvement,ecological diversity enhancement,and landscape beautification.Different plants have different characteristics,and a scientific and rational selection and optimization of plant species is needed.This paper proposes an optimized plant selection and configuration scheme for urban water ecological restoration based on the ecological characteristics and pollutant removal performance of wetland plants.It analyzes the diversity,removal mechanisms,and configuration modes of wetland plants,taking into account ecology,aesthetics,and cost-effectiveness,to provide scientific evidence for wetland plant configuration and support water environment management decision-making.

Optimization of Protein Removal Method and Condition of Polysaccharide from Phellinus Linteus

[Objective] The research aimed at optimizing protein removal method and condition of polysaccharide extracts from Phellinus Linteus and comparing the effects of two methods on protein removal.[Method] Free proteins in polysaccharide from Phellinus Linteus were removed using Sevag method and TCA method.[Result] The TCA method was better than Sevag method,and the optimum protein removal condition was treated with 5% TCA for 30 min and for three times,under that condition,the protein removal rate attained 82% while the polysaccharide loss rate was only 10.8%.[Conclusion] The TCA method was a better way to remove proteins of polysaccharide from Phellinus Linteus.

The anti-correlation method for removing harmonic distortion in vibroseis slip-sweep data

The slip-sweep technique is one of the high-efficiency, high-fidelity, and environmental vibroseis seismic prospecting techniques which consists of a vibrator group sweeping without waiting for the previous group＇s sweep to terminate. The cycle time can be reduced drastically and hence the production efficiency can be increased significantly but harmonic distortion of one sweep will leak into the record of the other sweep. In this paper, we propose an anti-correlation method for removing harmonic distortion in vibroseis data. This method is based on decomposition of the ground force signal into fundamental and harmonic components. Then the corresponding anti-correlation operator can be computed to estimate the energy of each harmonic after correlating the vibroseis data with the corresponding harmonic component. Finally, the vibroseis harmonic noise to be removed can be obtained by subtracting the extracted harmonic noise from the traces of the previous group＇s sweep. The advantage of the proposed method is that it can process both uncorrelated and correlated vibroseis seismic data. Moreover, the algorithm is simple, stable, and computationally fast. Especially, the significant contribution of this method is a considerable reduction in the harmonic without any alteration of the desired signals. The method was tested on both synthetic and field data sets to validate the good harmonic noise suppression results.

Mountain tunnel under earthquake force:A review of possible causes of damages and restoration methods

Accurate seismic assessment and proper aseismic design of underground structures require a comprehensive understanding of seismic performance and response of underground structures under earthquake force.In order to understand the seismic behavior of tunnels during an earthquake,a wide collection of case histories has been reviewed from the available literature with respect to damage classification,to discuss the possible causes of damage,such as earthquake parameters,structural form and geological conditions.In addition,a case of Tawarayama tunnel subjected to the 2016 Kumamoto earthquake is studied.Discussion on the possible influence factors aims at improving the performancebased aseismic design of tunnels.Finally,restoration design criterion and methods are presented taking Tawarayama tunnel as an example.

MODIFIED LAYER REMOVAL METHOD FOR MEASUREMENT OF RESIDUAL STRESS DISTRIBUTION IN THICK PRE-STRETCHED ALUMINUM PLATE

The integrated structure parts are widely used in aircraft. The distortion caused by residual stresses in thick pre-stretched aluminum plates during machining integrated parts is a common and serious problem. To predict and control the machining distortion, the residual stress distribution in the thick plate must be measured firstly. The modified removal method for measuring residual stress in thick pre-stretched aluminum plates is proposed and the stress-strain relation matrix is deduced by elasticity theory. The residual stress distribution in specimen of 7050T7451 plate is measured by using the method, and measurement results are analyzed and compared with data obtained by other methods. The method is effective to measure the residual stress.

A METHOD TO APPROACH OPTIMAL RESTORATION IN IMAGE RESTORATION PROBLEMS WITHOUT NOISE ENERGY INFORMATION

This paper proposes a new image restoration technique, in which the resulting regularized image approximates the optimal solution steadily. The affect of the regular-ization operator and parameter on the lower band and upper band energy of the residue of the regularized image is theoretically analyzed by employing wavelet transform. This paper shows that regularization operator should generally be lowstop and highpass. So this paper chooses a lowstop and highpass operator as regularization operator, and construct an optimization model which minimizes the mean squares residue of regularized solution to determine regularization parameter. Although the model is random, on the condition of this paper, it can be solved and yields regularization parameter and regularized solution. Otherwise, the technique has a mechanism to predict noise energy. So, without noise information, it can also work and yield good restoration results.

MIBK Removal from Aqueous Solution by Aeration method

In order to develop an effective MIBK removal method of H 2TaF 7 solution in tantalum extraction process, MIBK removal from aqueous solution by the aeration method was investigated by using an aeration column with the dimensions of 78 mm in inner diameter and 1 100 mm in length. The effects of aeration conditions on aerating efficiency were investigated in the ranges of temperature 303 333 K, airflow rate 50 300 L/h,volume of solution 1 600 3 200 mL. Aerating efficiency increases with the increase of temperature and airflow rate. MIBK in aqueous solution can be removed from 0.058 mol/L to 0.002 mol/L at 50 ℃,airflow rate 200 L/h, volume of solution 2 400 mL and aeration time 1h. The experimental results show that MIBK can be removed effectively from aqueous solution by the aeration method.

Evaluation of Four Methods for Restoring a Degraded Swamp Forest

Swamp Forests occur in permanently wet soils, with specific ecosystem which contributes to the conservation of biodiversity and water resources. However, there are many gaps in knowledge about the restoration of these forests. The present study was conducted in a degraded wetland in the town of Mineiros do Tietê, located in the state of S?o Paulo, Brazil, in order to test the efficiency of four methods for restoring a Swamp Forest (small mound, acclimated seedling, dry season and conventional tillage), using six forest tree species typical of this type of forest: Calophyllum brasiliense Cambess., Citharexylon myrianthum Cham., Cedrela odorata L., Tapirira guianensis Aubl., Ficus insipida Willd. and Croton urucurana Baill. The least favorable methods for all plant species were: conventional and soil pit tillageindry seasons. Analyzing the plant species individually, the best results in descending order were: Croton urucurana Baill. (acclimated seedling tillage in dry season), followed by Calophyllum brasiliense Cambess. (insmall mounds), Citharexylon mirianthum Cham. (with acclimated seedlings), Ficus insipida Willd. and Tapirira guianensis Aubl. (insmall mounds). Cedrela odorata L. presented low performance in all conditions, probably because it suffered the Hypsipyla grandella Zeller. The results have been successful for the establishment of Swamp Forest restoration strategies.

Effects of Planting Methods on Root Yield and Nutrient Removal of Five Cassava Cultivars Planted in Late Rainy Season in Northeastern Thailand

The objectives of this study were to evaluate growth, yield and nutrients removal of five cassava cultivars planted by different planting methods in late rainy season of northeastern Thailand. A split plot design was used in this study. The planting methods (vertical and horizontal) were assigned as main-plots. Cassava cultivars (Rayong-7, Rayong-11, Rayong-72, Huaybong-80 and E-dum) were assigned as sub-plots with four replications. Results showed that vertical planting gave significantly higher fresh storage root yield than those of horizontal planting, across five cassava cultivars. The cultivar Rayong-7 produced maximum fresh storage root yield across two planting methods, but not significantly different from Rayong 11, Huaybong 80 and Edum cultivars. Irrespective of nutrient removal, N, P and K removed ranges from 2.9 - 3.6, 0.8 - 1.3 and 5.3 - 7.9 kg per ton fresh root weight, respectively depending on cassava cultivar. The cultivar Rayong-7 removed the highest quantities of N, and the cultivar Rayong-11 removed maximum of P and K in the present study. Regardless of nutrient removal at different plant parts;N, P and K removed maximum quantities in leaf, stem and storage root, respectively. Planting method had no significant effect on N and P removal, but significant effect on K removal. The vertical planting removed K higher than those of horizontal planting.

Influence Factors of Phosphorus Removal by Chemical Method in Sewage Treatment System

[Objective] The research aimed to study influence factors of phosphorus removal by chemical method in sewage treatment system. [ Method] In different reaction systems, removal effect of the phosphorus in sewage by dosing lime and influence of the constraint factor were stud- ied. [ Result] Lime precipitation method treating high-concentration phosphorus wastewater could not only decline cost of phosphorus removal by chemical method, but also reach better treatment effect under suitable stirring and precipitation conditions by controlling alkalinity and pH. Phosphor- us content of chemical sludge after treatment could reach 9% -12%, with higher recyclable value. E Conclusion] Lime method treating phosphorus- rich sewage was more economic than low-concentration phosphorus sewage, and had very great potential for recycling phosphorus.

Efficient Extraction and Isolation of Mangiferin from Mango Leaves by Ethyl Acetate Impurity Removal Method

[Objectives] To optimize the ethyl acetate impurity removal method for extracting and isolating mangiferin from mango leaves,and provide raw materials and technical support for development and use of mangiferin related products. [Methods]Five steps( material crushing→ ethyl acetate impurity removing → concentrated extract washing → extracting with methanol → crystallization and precipitation) were used.The single factor experiment and L9( 34) orthogonal experiment was carried out to optimize the process parameters including extraction time,ultrasonic power,extraction times,and extraction temperature.[Results] The optimum process of ethyl acetate impurity removal method for extracting and isolating mangiferin from mango leaves was as follows: the mango leaves were crushed and sieved; 3 m L/g of ethyl acetate was added,sealed and soaked for 4 h,ultrasonically shaken for 20 min( 50℃,350 W),filtered at room temperature,filtered with 100 mesh sieve,and extracted three times; added 100% methanol to the residue at 3 m L/g,extract by ultrasonic vibration for 20 min( 350 W,55℃)for four times,filtered with 100 mesh sieve when it was still hot; mixed the extract of each time,condensed by vacuum decompression to get the extract; added 100% methanol at 4 m L/g,mixed and washed for 5 min at room temperature,placed for 10 min,filtered with 100 mesh sieve,washed 3 times repeatedly,and dried the filter residue at 60℃ to obtain the crude mangiferin; added 100% methanol at 4 m L/g,mixed and washed at 50℃ for 5 min,placed at 6℃ for 8 h,dried the filter residue at 60℃,and repeatedly crystallized two times. According to the above process,crude and pure mangiferin products could be obtained,the purity of mangiferin of the crude product was higher than 64. 00%,the total recovery rate was 83. 90%,and the purity of mangiferin of the pure product was higher than 98. 00%,and the total recovery rate was about 66. 40%. [Conclusions] The optimized ethyl acetate impurity removal method is easy in operation,low in cost,and high in efficiency for extracting and isolating mangiferin,and can be applied for actual production of mangiferin.

Calculation Method of Passive Residual Heat Removal Heat Exchanger and Numerical Simulation

The tube inside and outside heat transfer mechanism of Passive Residual Heat Removal Heat Exchanger (PRHR HX) was analyzed. The calculation method of this special heat exchanger under natural convection condition in In-containment Refueling Water Storage Tank (IRWST) was carried out. The single-tube coupling model three-dimensional natural circulation in the IRWST was simulated numerically using Fluent. The heat transfer and flow characteristics of the fluid in IRWST were obtained. The comparison of the results between theoretical arithmetic and numerical simulation showed that the theoretical calculation method is suitable for the heat transfer calculation of PRHR HX.

Preconditioned Iterative Methods for Algebraic Systems from Multiplicative Half-Quadratic Regularization Image Restorations

Image restoration is often solved by minimizing an energy function consisting of a data-fidelity term and a regularization term.A regularized convex term can usually preserve the image edges well in the restored image.In this paper,we consider a class of convex and edge-preserving regularization functions,i.e.,multiplicative half-quadratic regularizations,and we use the Newton method to solve the correspondingly reduced systems of nonlinear equations.At each Newton iterate,the preconditioned conjugate gradient method,incorporated with a constraint preconditioner,is employed to solve the structured Newton equation that has a symmetric positive definite coefficient matrix. The eigenvalue bounds of the preconditioned matrix are deliberately derived,which can be used to estimate the convergence speed of the preconditioned conjugate gradient method.We use experimental results to demonstrate that this new approach is efficient, and the effect of image restoration is reasonably well.

A Novel Method for Detection and Removal of Line Scratch in High Resolution Digital Film

With increasing need of high quality movie, more and more standard resolution films are upconverted to the high-resolution films. After this operation, the defects exist in the old movie are more obvious because they are enlarged in size, therefore, an efficient artifacts detection method with more precise result and lower computational complexity is in need. This paper provided a line scratch mathematical model, which derives from the Kokaram model and Bruni model, and then gave a detection method to meet the requirements of the high-resolution video application.

Stochastic response analysis of noisy system with non-negative real-power restoring force by generalized cell mapping method

The stochastic response of a noisy system with non-negative restoring force is investigated. The generalized cell mapping （GCM） method compute the transient and stationary probability density functions （PDFs） real-power is used to Combined with the global properties of the noise-free system, the evolutionary process of the tran- sient PDFs is revealed. The results show that stochastic P-bifurcation occurs when the system parameter varies in the response analysis and the stationary PDF evolves from bimodal to unimodal along the unstable manifold during the bifurcation.