Although the quality of organic crops has been intensively studied for over three decades, there is still a lack of conclusive data that can prove the superiority of organic crops over conventional ones. There is no d...Although the quality of organic crops has been intensively studied for over three decades, there is still a lack of conclusive data that can prove the superiority of organic crops over conventional ones. There is no doubt that the organic food is safer due to the lack of pesticide residues;however, it is still not entirely sure whether vegetables and fruits produced in this way are better in the context of nutritional values. The study of commonly used vegetables in the European diet was performed to evaluate the difference in concentration of macro nutrients such as Ca, Mg, Na, N, K and P between organic and conventional crops. Additionally, the soil analysis was performed on the material from two growing systems. The results showed that organically cultivated vegetables had generally a higher level of macro nutrients. Also, soil samples showed higher content of these elements in the organically treated soil. From all vegetables, the highest concentrations of macro elements were found in parsley leaves and celery roots.展开更多
Model B-I for marco rectangular element is presented for the first time in this paper. To establish the influence surf ace for resultant R of bending plates, a number of generalized distributive loads q are defined. I...Model B-I for marco rectangular element is presented for the first time in this paper. To establish the influence surf ace for resultant R of bending plates, a number of generalized distributive loads q are defined. It is shown by numerical examples that Model B-I and the formula for the generalized distributive loads advanced in this paper are featured by high accuracy, low memory space and flexibility in practical application, and that they are especially effective for plate structures subject to moving loads, such as the two-dimensional continuous plates of highway bridges and the flat stabs in piled jetty engineering.展开更多
The discretization size is limited by the sampling theorem, and the limit is one half of the wavelength of the highest frequency of the problem. However, one half of the wavelength is an ideal value. In general, the d...The discretization size is limited by the sampling theorem, and the limit is one half of the wavelength of the highest frequency of the problem. However, one half of the wavelength is an ideal value. In general, the discretization size that can ensure the accuracy of the simulation is much smaller than this value in the traditional finite element method. The possible reason of this phenomenon is analyzed in this paper, and an efficient method is given to improve the simulation accuracy.展开更多
Content of macro- and microelements in plant and soil was studied after biochar, compost, digestate, lignite, and lignohumate application. Pot experiments were carried out in Phytotron CLF Plant Master （Wertingen, Ge...Content of macro- and microelements in plant and soil was studied after biochar, compost, digestate, lignite, and lignohumate application. Pot experiments were carried out in Phytotron CLF Plant Master （Wertingen, Germany）. As tested plant lettuce （Lactucasativa） was used. Elemental composition was determined by AAS and XRF spectroscopy. Macronutrients content （Ca, Mg, K, and P） was determined by Mehlich III. Total content of carbon and nitrogen were determined by LECO TruSpec CN analyser. Results showed that different exogenous organic amendments statistically significantly influenced macro and micronutrients content in soil and plant. Satisfactory C/N ratio for soil microorganisms was measured only after compost and digestate application. As concerns hazardous elements, no legislation limits were overstepped after application of the tested organic amendments. Bioavailability and their uptake by plants followed the order： Cd 〉 Mn 〉 Zn 〉 Fe.展开更多
文摘Although the quality of organic crops has been intensively studied for over three decades, there is still a lack of conclusive data that can prove the superiority of organic crops over conventional ones. There is no doubt that the organic food is safer due to the lack of pesticide residues;however, it is still not entirely sure whether vegetables and fruits produced in this way are better in the context of nutritional values. The study of commonly used vegetables in the European diet was performed to evaluate the difference in concentration of macro nutrients such as Ca, Mg, Na, N, K and P between organic and conventional crops. Additionally, the soil analysis was performed on the material from two growing systems. The results showed that organically cultivated vegetables had generally a higher level of macro nutrients. Also, soil samples showed higher content of these elements in the organically treated soil. From all vegetables, the highest concentrations of macro elements were found in parsley leaves and celery roots.
文摘Model B-I for marco rectangular element is presented for the first time in this paper. To establish the influence surf ace for resultant R of bending plates, a number of generalized distributive loads q are defined. It is shown by numerical examples that Model B-I and the formula for the generalized distributive loads advanced in this paper are featured by high accuracy, low memory space and flexibility in practical application, and that they are especially effective for plate structures subject to moving loads, such as the two-dimensional continuous plates of highway bridges and the flat stabs in piled jetty engineering.
文摘The discretization size is limited by the sampling theorem, and the limit is one half of the wavelength of the highest frequency of the problem. However, one half of the wavelength is an ideal value. In general, the discretization size that can ensure the accuracy of the simulation is much smaller than this value in the traditional finite element method. The possible reason of this phenomenon is analyzed in this paper, and an efficient method is given to improve the simulation accuracy.
文摘Content of macro- and microelements in plant and soil was studied after biochar, compost, digestate, lignite, and lignohumate application. Pot experiments were carried out in Phytotron CLF Plant Master （Wertingen, Germany）. As tested plant lettuce （Lactucasativa） was used. Elemental composition was determined by AAS and XRF spectroscopy. Macronutrients content （Ca, Mg, K, and P） was determined by Mehlich III. Total content of carbon and nitrogen were determined by LECO TruSpec CN analyser. Results showed that different exogenous organic amendments statistically significantly influenced macro and micronutrients content in soil and plant. Satisfactory C/N ratio for soil microorganisms was measured only after compost and digestate application. As concerns hazardous elements, no legislation limits were overstepped after application of the tested organic amendments. Bioavailability and their uptake by plants followed the order： Cd 〉 Mn 〉 Zn 〉 Fe.
