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Search Results: 1 - 10 of 5116 matches for " Xiyuan Liao "
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Parametric Decomposition of the Malmquist Index in Output-Oriented Distance Function: Productivity in Chinese Agriculture  [PDF]
Bingxin Yu, Xiyuan Liao, Hongfang Shen
Modern Economy (ME) , 2014, DOI: 10.4236/me.2014.51009

This paper decomposes the Malmquist productivity index into several assembling components: technical change (further break down into technical change magnitude, input bias and output bias), technical efficiency change, scale efficiency change, and output-mix effect. A translog output distance function is chosen to represent the production technology and each component of the Malmquist index is computed using the estimated parameters. This parametric approach allows us to statistically test the hypothesis regarding different components of the Malmquist index and the natural of production technology. The empirical application in Chinese agriculture shows that the average productivity grows at 2 percent per year during 1978-2010. This growth is mostly driven by technical change, which is found to be neutral.

Combined Beamforming with Alamouti Coding Using Double Antenna Array Group for Multiuser Interference Cancellation
Yong Wang;Guisheng Liao;Zi Ye;Xiyuan Wang
PIER , 2008, DOI: 10.2528/PIER08102702
Abstract: This paper propose a new multiple-input multiple-output (MIMO) signal processing scheme that combines optimum transmit and receive beamforming with the Alamouti space-time block code (STBC) transmission and modifies the decoding process. The scheme uses double antenna array groups to achieve stable performance regardless of direction of arrived (DOA) and angular spread (AS). In a multiuser MIMO communications scenario, the beamforming suppresses co-channel interference (CCI) by maximizing the uplink signal-to-noise-plus-interference-ratio (SINR) and suppress CCI independently while preserving orthogonality of the MIMO channel. It is shown that the beamforming process provides array gain by increasing the bit-error-rate (BER) performance and maximizes the available uplink channel capacity for each user in the presence of CCI.
Potential of Pteris vittata L. for phytoremediation of sites co-contaminated with cadmium and arsenic: The tolerance and accumulation
Potential of Pteris vittata L. for phytoremediation of sites co-contaminated with cadmium and arsenic: The tolerance and accumulation

XIAO Xiyuan,CHEN Tongbin,AN Zhizhuang,LEI Mei,HUANG Zechun,LIAO Xiaoyong,LIU Yingru,
XIAO Xiyuan
,CHEN Tongbin,AN Zhizhuang,LEI Mei,HUANG Zechun,LIAO Xiaoyong,LIU Yingru

环境科学学报(英文版) , 2008,
Abstract: Field investigation and greenhouse experiments were conducted to study the tolerance of Pteris vittata L. (Chinese brake) to cadmium (Cd) and its feasibility for remediating sites co-contaminated with Cd and arsenic (As). The results showed that P. vittata could survive in pot soils spiked with 80 mg/kg of Cd and tolerated as great as 301 mg/kg of total Cd and 26.8 mg/kg of diethyltriaminepenta acetic acid (DTPA)-extractable Cd under field conditions. The highest concentration of Cd in fronds was 186 mg/kg under a total soil concentration of 920 mg As/kg and 98.6 mg Cd/kg in the field, whereas just 2.6 mg/kg under greenhouse conditions. Ecotypes of P. vittata were differentiated in tolerance and accumulation of Cd, and some of them could not only tolerate high concentrations of soil Cd, but also accumulated high concentrations of Cd in their fronds. Arsenic uptake and transportation by P. vittata was not inhibited at lower levels (( 20 mg/kg) of Cd addition. Compared to the treatment without addition of Cd, the frond As concentration was increased by 103.8% at 20 mg Cd/kg, with the highest level of 6434 mg/kg. The results suggested that the Cd-tolerant ecotype of P. vittata extracted effectively As and Cd from the site co-contaminated with Cd and As, and might be used to remediate and revegetate this type of site.
Subcellular distribution and compartmentalization of arsenic in Pteris vittata L.
Tongbin Chen,Xiulan Yan,Xiaoyong Liao,Xiyuan Xiao,Zechun Huang,Hua Xie,Limei Zhai
Chinese Science Bulletin , 2005, DOI: 10.1360/982005-943
Abstract: The subcellular distribution of arsenic (As) in Pteris vittata L., an As-hyperaccumulator, was studied to determine As compartmentalization and to explore the mechanisms that confer As tolerance. When the plant was grown in a nutrient solution without additional As, most of the accumulated As was isolated to the cell wall. However, in plants growing in a nutrient solution containing 0.1 or 0.2 mmol/L As, approximately 78% of the total As accumulated within the pinna. The proportions of As accumulation in the cytoplasmic supernatant fraction were 78% of that in the pinna and 61% of that in the plant. In either treatment group (0.1 or 0.2 mmol/L As), the fraction containing the lowest level of As was the organelle fraction. These results suggest that As accumulates in the pinna where it is primarily distributed in the cytoplasmic supernatant fraction. The role of As compartmentalization may be intricately linked with As detoxification in P. vittata L.
Heavy metal pollution of soils and vegetables in the midstream and downstream of the Xiangjiang River, Hunan Province

WANG Lixia,GUO Zhaohui,XIAO Xiyuan,CHEN Tongbin,LIAO Xiaoyong,SONG Jie,WU Bin,

地理学报 , 2008,
Abstract: A total of 219 agricultural soil and 48 vegetable samples were collected from the midstream and downstream of the Xiangjiang River (the Hengyang–Changsha section) in Hunan Province. The accumulation characteristics, spatial distribution and potential risk of heavy metals in the agricultural soils and vegetables were depicted. There are higher accu-mulations of heavy metals such as As, Cd, Cu, Ni, Pb and Zn in agricultural soils, and the contents of Cd (2.44 mg kg-1), Pb (65.00 mg kg-1) and Zn (144.13 mg kg-1) are 7.97, 3.69 and 1.63 times the corresponding background contents in soils of Hunan Province, respectively. 13.2% of As, 68.5% of Cd, 2.7% of Cu, 2.7% of Ni, 8.7% of Pb and 15.1% of Zn in soil sam-ples from the investigated sites exceeded the maximum allowable heavy metal contents in the China Environmental Quality Standard for Soils (GB15618-1995, Grade II). The pollution characteristics of multi-metals in soils are mainly due to Cd. The contents of As, Cd, Cu, Pb and Zn in vegetable soils are significantly higher than the contents in paddy soils. 95.8%, 68.8%, 10.4% and 95.8% of vegetable samples exceeded the Maximum Levels of Contami-nants in Foods (GB2762-2005) for As, Cd, Ni and Pb concentrations, respectively. There are significantly positive correlations between the concentrations of Cd, Pb and Zn in vegetables and the concentrations in the corresponding vegetable soils (p<0.01). It is very necessary to focus on the potential risk of heavy metals for food safety and human health in agricultural soils and vegetables in the midstream and downstream of the Xiangjiang River, Hunan Province of China.
Effect of application of P fertilizer on efficiency of As removal from As-contaminated soil using phytoremediation: Field study

LIAO Xiaoyong,CHEN Tongbin,XIE Hua,XIAO Xiyuan,

环境科学学报 , 2004,
Abstract: Phytoremediation is a promising new technology that using hyperaccumulating plants to remove heavy metals. A field experiment was conducted to study the effect of P fertilizer on growth of and As accumulation in Pteris vittata L., an As-hyperaccumulator. Yields of P. vittata were enhanced with increasing P addition, however there was no further increase when rate of P addition was more than 200kg·hm-2. Application of P fertilizer could enhance As concentration, and As concentration in the aboveground of P. vittata was depressed because of excessive P addition. Theoretically, As concentration of plant reaches a maximum of 1622mg·kg-1 when rate of P addition is 340kg·hm-2. There was a significantly positive relationship between rates of P addition and P concentrations in the aboveground. Plant treated with 200 kg(P)·hm-2, accumulated 3.74 kg(As)·hm-2 in its aboveground part, which was 2.4 times more than the control and 1.2 times more than that in plant treated with 600 kg (P)·hm-2. After 7 months of the experiment, soil As concentrations were significantly reduced in all treatments at harvest compared to those before transplanting. When rate of P addition was 200kg·hm-2, efficiency of As removal was the highest (7.84%), while efficiencies of As removal at control and 600 kg·hm-2 treatments were 2.31% and 6.63%, respectively. The highest efficiency of As removal in theory could be achieved at 369kg·hm-2 P addition. Moreover, the results also showed that P application was helpful to maintain a balance of available As between before transplanting and after harvest. Application of P fertilizer is necessary for phytoremediation using As-hyperaccumulator; and optimized P application could significantly enhance the efficiency of As removal from contaminated soils.
Analysis of Influencing Factors on Survival Time of Patients with Heart Failure  [PDF]
Jianwei Sheng, Xiyuan Qian, Tong Ruan
Open Journal of Statistics (OJS) , 2018, DOI: 10.4236/ojs.2018.84042
Abstract: To explore the influencing factors of survival time of patients with heart failure, a total of 1789 patients with heart failure were collected from Shanghai Shuguang Hospital. The Cox proportional hazards model and the mixed effects Cox model were used to analyze the factors on survival time of patients. The results of Cox proportional hazards model showed that age (RR = 1.32), hypertension (RR = 0.67), ARB (RR = 0.55), diuretic (RR = 1.48) and antiplatelet (RR = 0.53) have significant impacts on the survival time of patients. The results of mixed effects Cox model showed that age (RR = 1.16), hypertension (RR = 0.61), lung infection (RR = 1.43), ARB (RR = 0.64), β-blockers (RR = 0.77) and antiplatelet (RR = 0.69) have a significant impact on the survival time of patients. The results are consistent with the covariates age, hypertension, ARB and antiplatelet but inconsistent with the covariates lung infection and β-blockers.
Tolerance of Pteris vittata L. to Pb, Cu and Zn

AN Zhizhuang,CHEN Tongbin,LEI Mei,XIAO Xiyuan,LIAO Xiaoyong,

生态学报 , 2003,
Abstract: Combination contamination of heavy metals is one of important soil contamination types. A greenhouse experiment was carried out to determine the degree of tolerance of Pteris vittata L. to Pb, Cu, and Zn and whether it could be applied to phytoremediation and revegetation of soils contaminated with As and other heavy metals such as Pb, Cu, and Zn. In the presence of As with 400 mg/kg, they were added at rates of 0, 250, 500, 1000, 1500, 2000 mg/kg of Pb as Pb(CH_3COO)_2), 0, 500, 750, 1000, 1500 mg/kg of Cu...
Physiological effects of air temperature and sink-source volume at milk-filling stage of rice on its grain quality

TAO Longxing,WANG Xi,LIAO Xiyuan,SHEN Bo,TAN Huijuan,HUANG Shiwen,

应用生态学报 , 2006,
Abstract: This paper studied the grain quality and Q-enzyme activity of three rice varieties and their combinations as affected by air temperature and sink-source volume. The results showed that at the early stage of milk filling, the grains of fully milk filling under high temperature had a higher chalkiness, lower transparency, and lower rate of white rice. Compared with the grain of early-rice, that of late rice had higher gel consistency and transparency, and higher rate of white rice, Planting rice at early-or late season had no significant effect on the amylose and protein contents of rice grain, Leaf-cutting to limit source decreased grain quality markedly, while grain-thinning to decrease sink improved grain quality significantly.
A calculation method for low dynamic vehicle velocitybased on fusion of optical flow and feature point matching
Liu Di, Chen Xiyuan
- , 2017, DOI: 10.3969/j.issn.1003-7985.2017.04.006
Abstract: Aiming at the problem of the low accuracy of low dynamic vehicle velocity under the environment of uneven distribution of light intensity, an improved adaptive Kalman filter method for the velocity error estimate by the fusion of optical flow tracking and scale invariant feature transform(SIFT)is proposed. The algorithm introduces a nonlinear fuzzy membership function and the filter residual for the noise covariance matrix in the adaptive adjustment process. In the process of calculating the velocity of the vehicle, the tracking and matching of the inter-frame displacement and the vehicle velocity calculation are carried out by using the optical flow tracing and the SIFT methods, respectively. Meanwhile, the velocity difference between the outputs of these two methods is used as the observation of the improved adaptive Kalman filter. Finally, the velocity calculated by the optical flow method is corrected by using the velocity error estimate of the output of the modified adaptive Kalman filter. The results of semi-physical experiments show that the maximum velocity error of the fusion algorithm is decreased by 29% than that of the optical flow method, and the computation time is reduced by 80% compared with the SIFT method.
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