To make clear the emission characteristics of soil N20 from typical green- house vegetable fields in North China, an experiment was conducted in greenhouse tomato field in Shouguang city, Shandong province, China's ...To make clear the emission characteristics of soil N20 from typical green- house vegetable fields in North China, an experiment was conducted in greenhouse tomato field in Shouguang city, Shandong province, China's "Home of Vegetables". The N2O fluxes were observed in four experimental treatments, as follows: none N fertilizer (CK), single organic fertilizer (OM), conventional fertilization (FP) and opti- mized and reduced nitrogen fertilization (OPT), by a close chamber-gas chromato- graph method. The effects of different fertilization treatments on N2O emission and tomato yield were analyzed. The results showed that following the fertilization and ir- rigation, the pulsed emissions of N2O were measured. The N2O emission peak ap- peared after basal fertilizer application and irrigation and could be maintained for about 20 days. While the N2O emission peak caused by topdressing was smaller and last only 3-5 days. The statistical analysis showed that the N2O fluxes were affected by air temperature, soil temperature and WFPS at soil depth of 3 cm. The total contents of soil N2O fluxes had significant differences among experimental groups. The total content orderly was FP of 14. 77 kg/hm^2, OPT of 9. 73 kg/hm^2, OM of 6.84 kg/hm^2 and CK of 2.37 kg/hm^2. The N~:~ emission coefficient ranged from 0.83%-1.10%,which was close to or more than the recommended value (1.0%) by IPCC. Compared with the FP treatment, the tomato yield in OPT treatment, whose application rate of chemical N fertilizer decreased by about 60%, increased by 2.2%. Under the current management measures, the reasonable reduction on ap- plicaUon rate of organic manure and chemical nitrogen fertilizer could effectively re- duce the N=O emissions in greenhouse vegetable fields.展开更多
Based on the UCG(underground coal gasification) theory, the “three zones” which are oxidization zone, reduction zone, and drying zone, were divided; physical and chemical properties of each zone were analyzed. Facto...Based on the UCG(underground coal gasification) theory, the “three zones” which are oxidization zone, reduction zone, and drying zone, were divided; physical and chemical properties of each zone were analyzed. Factors, such as temperature, rate of water pouring, quantity of air blast, thickness of coal seam, and the operation pressure were discussed. Among the influencing factors, the temperature is the most important one.展开更多
Nowadays,many steganographic tools have been developed,and secret messages can be imperceptibly transmitted through public networks.This paper concentrates on steganalysis against spatial least significant bit(LSB) ma...Nowadays,many steganographic tools have been developed,and secret messages can be imperceptibly transmitted through public networks.This paper concentrates on steganalysis against spatial least significant bit(LSB) matching,which is the prototype of many advanced information hiding methods.Many existing algorithms deal with steganalysis problems by using the dependencies between adjacent pixels.From another aspect,this paper calculates the differences among pixel pairs and proves that the histogram of difference values will be smoothed by stego noises.We calculate the difference histogram characteristic function(DHCF) and deduce that the moment of DHCFs(DHCFM) will be diminished after stego bits are hidden in the image.Accordingly,we compute the DHCFMs as the discriminative features.We calibrate the features by decreasing the influence of image content on them and train support vector machine classifiers based on the calibrated features.Experimental results demonstrate that the DHCFMs calculated with nonadjacent pixels are helpful to detect stego messages hidden by LSB matching.展开更多
In the basic concepts of mathematic culture, mathematics was given a broad meaning. Mathematics is not only a scientific language, a system of knowledge, but also a way of thinking, a kind of art has aesthetic feature...In the basic concepts of mathematic culture, mathematics was given a broad meaning. Mathematics is not only a scientific language, a system of knowledge, but also a way of thinking, a kind of art has aesthetic features. On this basis, the meaning of mathematical quality should have a new exposition, the essence of mathematical quality is integration of mathematic cultural values, knowledge, abilities, psychological, while the key to the quality of mathematics education is to fully embody the essence of mathematics culture, let the concepts of mathematic cultm'e integrated to the whole process of mathematics education.展开更多
Let f(z) be a holomorphic cusp form of weight κ with respect to the full modular group SL2(Z). Let L(s, f) be the automorphic L-function associated with f(z) and χ be a Dirichlet character modulo q. In this ...Let f(z) be a holomorphic cusp form of weight κ with respect to the full modular group SL2(Z). Let L(s, f) be the automorphic L-function associated with f(z) and χ be a Dirichlet character modulo q. In this paper, the authors prove that unconditionally for k =1/n with n ∈ N,Mk(q,f)=∑χ(mod q)χ≠χ0|L(1/2,f χ)|^2k〈〈 kФ(q)(log q)^k^2, and the result also holds for any real number 0 〈 k 〈 1 under the GRH for L(s, f χ).The authors also prove that under the GRH for L(s, f χ),for any real number k 〉 0 and any large prime q.展开更多
This paper presents a criterion for testing the irreducibility of a polynomial over an algebraicextension field.Using this criterion and the characteristic set method,the authors give a criterion fortesting whether ce...This paper presents a criterion for testing the irreducibility of a polynomial over an algebraicextension field.Using this criterion and the characteristic set method,the authors give a criterion fortesting whether certain difference ascending chains are strong irreducible,and as a consequence,whetherthe saturation ideals of these ascending chains are prime ideals.展开更多
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201103039)Shandong Provincial Natural Science Foundation,China(ZR2013DQ023)+1 种基金Science and Technology Development Plan Project of Shandong Province(2013GNC11204)Major Agricultural Application Technology Innovation Project of Shandong Province(Study on Environmental Regulation and Fertilizer Application Techniques for High Yield and High Efficiency Utilization of Greenhouse Tomato)~~
文摘To make clear the emission characteristics of soil N20 from typical green- house vegetable fields in North China, an experiment was conducted in greenhouse tomato field in Shouguang city, Shandong province, China's "Home of Vegetables". The N2O fluxes were observed in four experimental treatments, as follows: none N fertilizer (CK), single organic fertilizer (OM), conventional fertilization (FP) and opti- mized and reduced nitrogen fertilization (OPT), by a close chamber-gas chromato- graph method. The effects of different fertilization treatments on N2O emission and tomato yield were analyzed. The results showed that following the fertilization and ir- rigation, the pulsed emissions of N2O were measured. The N2O emission peak ap- peared after basal fertilizer application and irrigation and could be maintained for about 20 days. While the N2O emission peak caused by topdressing was smaller and last only 3-5 days. The statistical analysis showed that the N2O fluxes were affected by air temperature, soil temperature and WFPS at soil depth of 3 cm. The total contents of soil N2O fluxes had significant differences among experimental groups. The total content orderly was FP of 14. 77 kg/hm^2, OPT of 9. 73 kg/hm^2, OM of 6.84 kg/hm^2 and CK of 2.37 kg/hm^2. The N~:~ emission coefficient ranged from 0.83%-1.10%,which was close to or more than the recommended value (1.0%) by IPCC. Compared with the FP treatment, the tomato yield in OPT treatment, whose application rate of chemical N fertilizer decreased by about 60%, increased by 2.2%. Under the current management measures, the reasonable reduction on ap- plicaUon rate of organic manure and chemical nitrogen fertilizer could effectively re- duce the N=O emissions in greenhouse vegetable fields.
文摘Based on the UCG(underground coal gasification) theory, the “three zones” which are oxidization zone, reduction zone, and drying zone, were divided; physical and chemical properties of each zone were analyzed. Factors, such as temperature, rate of water pouring, quantity of air blast, thickness of coal seam, and the operation pressure were discussed. Among the influencing factors, the temperature is the most important one.
基金supported by the NSFC(61173141,61362032,U1536206, 61232016,U1405254,61373133,61502242,61572258)BK20150925+4 种基金the Natural Science Foundation of Jiangxi Province, China(20151BAB207003)the Fund of Jiangsu Engineering Center of Network Monitoring(KJR1402)the Fund of MOE Internet Innovation Platform(KJRP1403)the CICAEET fundthe PAPD fund
文摘Nowadays,many steganographic tools have been developed,and secret messages can be imperceptibly transmitted through public networks.This paper concentrates on steganalysis against spatial least significant bit(LSB) matching,which is the prototype of many advanced information hiding methods.Many existing algorithms deal with steganalysis problems by using the dependencies between adjacent pixels.From another aspect,this paper calculates the differences among pixel pairs and proves that the histogram of difference values will be smoothed by stego noises.We calculate the difference histogram characteristic function(DHCF) and deduce that the moment of DHCFs(DHCFM) will be diminished after stego bits are hidden in the image.Accordingly,we compute the DHCFMs as the discriminative features.We calibrate the features by decreasing the influence of image content on them and train support vector machine classifiers based on the calibrated features.Experimental results demonstrate that the DHCFMs calculated with nonadjacent pixels are helpful to detect stego messages hidden by LSB matching.
文摘In the basic concepts of mathematic culture, mathematics was given a broad meaning. Mathematics is not only a scientific language, a system of knowledge, but also a way of thinking, a kind of art has aesthetic features. On this basis, the meaning of mathematical quality should have a new exposition, the essence of mathematical quality is integration of mathematic cultural values, knowledge, abilities, psychological, while the key to the quality of mathematics education is to fully embody the essence of mathematics culture, let the concepts of mathematic cultm'e integrated to the whole process of mathematics education.
基金supported by the National Natural Science Foundation of China(No.11301299)the Natural Science Foundation of Shandong Province(No.ZR2012AQ001)the Specialized Research Fund for the Doctoral Program of Higher Education(New Teachers)(Nos.20110131120001,20120131120075)
文摘Let f(z) be a holomorphic cusp form of weight κ with respect to the full modular group SL2(Z). Let L(s, f) be the automorphic L-function associated with f(z) and χ be a Dirichlet character modulo q. In this paper, the authors prove that unconditionally for k =1/n with n ∈ N,Mk(q,f)=∑χ(mod q)χ≠χ0|L(1/2,f χ)|^2k〈〈 kФ(q)(log q)^k^2, and the result also holds for any real number 0 〈 k 〈 1 under the GRH for L(s, f χ).The authors also prove that under the GRH for L(s, f χ),for any real number k 〉 0 and any large prime q.
基金supported by a National Key Basic Research Project of ChinaNSFC
文摘This paper presents a criterion for testing the irreducibility of a polynomial over an algebraicextension field.Using this criterion and the characteristic set method,the authors give a criterion fortesting whether certain difference ascending chains are strong irreducible,and as a consequence,whetherthe saturation ideals of these ascending chains are prime ideals.