On basis of “3414” experiment, regression analysis was conducted on rel- ative yield and fertilizer quant;.ty, and a regression equation was established, as fol- lows： Y=I 699,09 ＋52.89N -3i82P ＋59.27K-1.17N2 -0....On basis of “3414” experiment, regression analysis was conducted on rel- ative yield and fertilizer quant;.ty, and a regression equation was established, as fol- lows： Y=I 699,09 ＋52.89N -3i82P ＋59.27K-1.17N2 -0.11 p2 ＋0.06K2 ＋2.02NP-2.16NK- 1.97PK （FF=0,98）. The results of regression analysis showed F〉F0.05, indicating that fertilizer quantity is of significant regression relationship with yield. It was analyzed that yield-increasing range of N fertilizer was directly proportional to fertilizer quanti- ty, and negative yield even occurs if excessive P fertilizer is applied. In general, fertilizer effects from high to low were N fertilizer〉K ferUlizer〉P fertilizer. Besides, on equation aralysls, it was proposed the optimal fertilizer quantities included N fertilizer （N） of 270 kg, P fertilizer （PUs） of 165 kg and K fertilizer （K20） of 225 kg for achieving ideal yield of 2 500 kg/hm2 of luffa in Foshan. Key words Foshan; Luffa; Index system of fertilization; Efficiency analysis展开更多
The volume of highway traffic in the United States continues to increase. In the face of this there is a concomitant need to improve and repair transportation infrastructure. Construction frequently requires a reducti...The volume of highway traffic in the United States continues to increase. In the face of this there is a concomitant need to improve and repair transportation infrastructure. Construction frequently requires a reduction in capacity during construction activity; consequently road users as well as adjacent businesses must endure the delays and inconveniences associated with transportation construction. Recognizing the problems that construction can produce, state highway agencies （SHAs） have continually sought ways to minimize the negative impact from their construction operations. Incentive contracting has played an important role in this effort to improve project performance. The Florida Department of Transportation （FDOT） is one of the leading SHAs using such innovative contracting methods as Incentive/Disincentive （I/D）, A＋B （cost plus time bidding） combined with I/D, No Excuse Bonus, and Liquidated Savings. This paper analyzes the traffic impact on incentive project time performance using highway construction projects recently completed in Florida. Project data obtained from FDOT were evaluated using time performance indices. A survey of traffic impact on project work types was performed in Florida in order to evaluate the relationship between construction project types and road traffic influence during construction. Based on the survey results, the 38 most frequently used work types in Florida during the study period were categorized into three traffic impact levels： （1） high traffic impact, （2） medium traffic impact, and （3） low traffic impact. Statistical analysis was performed. The results show that there are significant differences on project time performance between low and high impact levels as well as low and medium impact levels.展开更多
The kinetics of water absorption in water-borne anticorrosive urethane/epoxy coatings, which were actually introduced in the industrial field, are studied. It is found that the high water affinity of a water-borne coa...The kinetics of water absorption in water-borne anticorrosive urethane/epoxy coatings, which were actually introduced in the industrial field, are studied. It is found that the high water affinity of a water-borne coating supports a higher saturated water content, Mχ, and helps to facilitate absorption D. The three parameters of stretched exponential function called the William-Watt equation, Eo, τ, and β, are determined to fit the degraded stress relaxation behavior in the water absorption process because this function quantitatively describes the relaxing ability and has been successfully used by a number of researchers. An increasing in the water content is shown to correlate strongly with a decrease in Eo and fl early in the absorption process between Mt/M（χ） = 0 and Mt/Mχ≈ 0.5. The adhesive characteristics of the coatings are correlated with water content, and shown to exhibit higher cohesive failure in coating epoxies under saturated conditions. This suggests that water interferes with the intermolecular bonding between polymer chains which degrades the bulk materials ability to diffuse stress concentrations and reduces its overall strength.展开更多
基金Supported by High-efficient Cultivation Technology System Construction Project of Characteristic Vegetable in Foshan([2015]12)Special Fund of Minstry of Agriculture(201503106)~~
文摘On basis of “3414” experiment, regression analysis was conducted on rel- ative yield and fertilizer quant;.ty, and a regression equation was established, as fol- lows： Y=I 699,09 ＋52.89N -3i82P ＋59.27K-1.17N2 -0.11 p2 ＋0.06K2 ＋2.02NP-2.16NK- 1.97PK （FF=0,98）. The results of regression analysis showed F〉F0.05, indicating that fertilizer quantity is of significant regression relationship with yield. It was analyzed that yield-increasing range of N fertilizer was directly proportional to fertilizer quanti- ty, and negative yield even occurs if excessive P fertilizer is applied. In general, fertilizer effects from high to low were N fertilizer〉K ferUlizer〉P fertilizer. Besides, on equation aralysls, it was proposed the optimal fertilizer quantities included N fertilizer （N） of 270 kg, P fertilizer （PUs） of 165 kg and K fertilizer （K20） of 225 kg for achieving ideal yield of 2 500 kg/hm2 of luffa in Foshan. Key words Foshan; Luffa; Index system of fertilization; Efficiency analysis
文摘The volume of highway traffic in the United States continues to increase. In the face of this there is a concomitant need to improve and repair transportation infrastructure. Construction frequently requires a reduction in capacity during construction activity; consequently road users as well as adjacent businesses must endure the delays and inconveniences associated with transportation construction. Recognizing the problems that construction can produce, state highway agencies （SHAs） have continually sought ways to minimize the negative impact from their construction operations. Incentive contracting has played an important role in this effort to improve project performance. The Florida Department of Transportation （FDOT） is one of the leading SHAs using such innovative contracting methods as Incentive/Disincentive （I/D）, A＋B （cost plus time bidding） combined with I/D, No Excuse Bonus, and Liquidated Savings. This paper analyzes the traffic impact on incentive project time performance using highway construction projects recently completed in Florida. Project data obtained from FDOT were evaluated using time performance indices. A survey of traffic impact on project work types was performed in Florida in order to evaluate the relationship between construction project types and road traffic influence during construction. Based on the survey results, the 38 most frequently used work types in Florida during the study period were categorized into three traffic impact levels： （1） high traffic impact, （2） medium traffic impact, and （3） low traffic impact. Statistical analysis was performed. The results show that there are significant differences on project time performance between low and high impact levels as well as low and medium impact levels.
文摘The kinetics of water absorption in water-borne anticorrosive urethane/epoxy coatings, which were actually introduced in the industrial field, are studied. It is found that the high water affinity of a water-borne coating supports a higher saturated water content, Mχ, and helps to facilitate absorption D. The three parameters of stretched exponential function called the William-Watt equation, Eo, τ, and β, are determined to fit the degraded stress relaxation behavior in the water absorption process because this function quantitatively describes the relaxing ability and has been successfully used by a number of researchers. An increasing in the water content is shown to correlate strongly with a decrease in Eo and fl early in the absorption process between Mt/M（χ） = 0 and Mt/Mχ≈ 0.5. The adhesive characteristics of the coatings are correlated with water content, and shown to exhibit higher cohesive failure in coating epoxies under saturated conditions. This suggests that water interferes with the intermolecular bonding between polymer chains which degrades the bulk materials ability to diffuse stress concentrations and reduces its overall strength.
