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In order to clarify the suction characteristics of unsaturated clay under different conditions of water and salt, taking soil in western Jilin province, China as the research object, the suctions (matrix suction and osmotic suction) of samples with different water content, salt type, and salt content were determined by filter paper method. The results indicate that salt type and content have insignificant influence on the matrix suction. With the increase of water content, the matrix suction decreases at different rates in different suction regimes. When water content is constant, the osmotic suction increases with the increase of salt content, and under the condition of a constant salt content, the osmotic suction first increases and then decreases with the increase of ion concentration of the pore water, and can reach tens of MPa. The concept of suction equilibrium water content is proposed. When water content of sample is higher than this value, the magnitude of osmotic suction will always be greater than that of matrix suction. This indicates the necessity to consider osmotic suction in the presence or change of salt in soil. The applicability of the traditional models of matrix suction and osmotic suction in the full suction range of clay is discussed, and it is found that the traditional models cannot make a full explanation to the variation in suction. Based on the experimental data, an improved van Genuchten matrix suction model and an osmotic suction model, transformed by the Planck blackbody radiation formula, are proposed. [ABSTRACT FROM AUTHOR]

The aims of this paper is to illustrate the importance of grain production in China's food security strategy based on the three Northeastern provinces (NEP) in the new period, which quantitative assessment of climate change under the background of the loss caused by meteorological disasters of regional food production is clarify. In this paper, using grain planting area, yield and agricultural disaster statistics from 1981 to 2020, comparison analysis grain production and disaster characteristics between NEP and the whole country respectively. The disaster-yield assessment model was used to estimate the disaster-yield loss and final yield of the NEP by inputting disaster data in recent 10 years, and the sensitivity and stability of the disaster-yield assessment model were re-tested. The results showed that :(1) from 1981 to 2020, the grain planting area and total output in NEP increased significantly, and the proportion of the total output of NEP increased steadily, and the proportion of the total output of the three northeast provinces reached 1/5 of the total output of the whole country by 2020. (2) The disaster situation in NEP showed a significant trend of first increasing and then decreasing. The incrasing of average grain yield during the past 40 years was 65.96kg⋅ha-1 and 252.5kg⋅ha-1 per year for NEP and the whole country, while the incrasing of average grain yield during the past 10 years was 52.6kg⋅ha-1 per year for NEP significantly. (3) From 2011 to 2020, the average affected area and affected area in China were 23704.5x10³ha and 11204.7x10³ha, respectively, and 3899.1x10³disasters of the whole country and the three northeastern provinces were significantly lower than those of the previous three years, making it the decade with the least severe disasters in 40 years. (4) The simulation accuracy of the disaster-yield assessment model was high. The linear regression coefficients (R²) of simulated grain yield and measured grain yield in Heilongjiang, Jilin and Liaoning provinces were 0.98, 0.90 and 0.88, respectively. The slopes were 1.05, 1.02 and 0.98 (P < 0.01), respectively. The loss rate of grain yield due to agro-disaster was 10.4%, 17.9% and 18.0% respectively in the three province, while which was more than 8.0%, 17.0% and 16.0% for 20a.years. (5) The model slightly overestimated the grain yield of Jilin and Liaoning in recent 10 years due to the overall light disaster situation. Based on the data from 1981 to 2010, the regional grain disaster loss assessment model was proved to be able to evaluate the loss of grain yield caused by meteorological disasters well, and had the performance of predicting grain yield, and has the feasibility of operational application. The impact of meteorological disasters on the grain output in northeast China is higher than the average level of disasters in the whole country. Considering that the grain output in Northeast China accounts for a high proportion of the national grain output, preventing the risk of agro-meteorological disasters in Northeast China in the new period is of great importance to guarantee the national food security. [ABSTRACT FROM AUTHOR]

Based on the theories of mass conservation and coalbed methane (CBM) adsorption/desorption, this paper first establishes a novel reservoir pressure model for CBM production, following which, the CBM concentration and production models are also proposed. Then, these models are programmed and solved by means of the finite element method. Taking the Hunchun CBM field in Jilin province, China, as an example, the reservoir pressure, gas concentration, and production characteristics under different hydraulic fracture forms are simulated and investigated. In conclusion, the reservoir pressure decreases very rapidly in a small region near the fracture tip, which we called the "reservoir pressure singularity". The existence of a hydraulic fracture greatly reduces the reservoir pressure in the process of CBM exploitation. The permeability sensitivity coefficient of reservoir pressure, Rpk, is defined to quantitatively describe the influence of coal seam permeability on the evolution of reservoir pressure. Rpk decreases logarithmically as the distance from the CBM extraction well increases. The reservoir pressure and CBM recovery rate characteristics in the presence of multiple hydraulic fractures are also investigated. We believe these results could contribute to the design of hydraulic fracturing wells and the evaluation of gas production in a CBM reservoir. [ABSTRACT FROM AUTHOR]

In recent years, China's pig industry has gradually shifted to the northeast. Compared with the rich feed resources and land resources in Northeast China, the cold environment reduces the feed conversion efficiency and the production performance of pigs. In the winter of northern China, pig producers often face a huge problem of heat preservation when they control the environment of piggery. The aim of this study is to explore the heat preservation of piggeries in Northeast China. According to the investigation, there were four types of piggeries in Jilin Province, which were brick wall piggery, concrete wall piggery, color steel wall piggery and greenhouse piggery. The simulated piggeries with brick wall, concrete wall and color steel wall were based on the experimental piggery of Jilin Agricultural University, the simulated piggery with greenhouse was based on a piggery in a pig farm, and the simulated pig farm area was based on a pig farm area. Based on Ecotect software, this paper took a typical piggery in a large pig farm in Jilin Province as an object, and studied the light and heat environment of piggery, and the light environment of pig farm production area. The daylight factor of different heights in the piggery and the lighting situation in the production area of the pig farm were studied. The thermal insulation performances of 4 kinds of piggeries with different walls were analyzed. The results were as follows: The daylight factor of each research height of the experimental piggery was higher than 2%, which met the green building standard. The production area of the pig farm had good daylight, and the solar radiation in Great Cold Day could reach 5.38 MJ/(m²·d), and the sunshine was sufficient. The building spacing of the pig farm met the epidemic prevention standard, and there was no shelter problem. By comparing the monthly energy consumption values of 4 kinds of piggeries with different building materials, the best insulation performance of piggeries was as follow: Clay porous brick piggery, foam concrete pig piggery, color steel piggery with phenolic sandwich board, low density polyethylene film greenhouse piggery. After considering the cost, it was recommended to use cinder brick masonry piggery, fly ash aerated block piggery, polyphenylene sandwich board color steel piggery and low density polyethylene film greenhouse piggery. The daily energy consumption of empty piggery in December was tested and verified. The relative error range was 0.74%-8.62% after data comparison, which verified the reliability of the model. The simulation values of energy consumption were in good agreement with the measured values. On the one hand, it verified the correctness and rationality of setting parameters in the software. On the other hand, it showed that Ecotect software was feasible in piggery building. This paper can provide theoretical basis for exploring the light and heat environment of the northern piggery, and provide more ideas for architects to optimize the design before the implementation of the plan. [ABSTRACT FROM AUTHOR]

Summary Electric heating is perceived as an effective way to tackle heavy wind curtailment and severe smog in northern China, wherein distributed electric heating (DEH) accounts for a significant proportion. However, more research is required with regard to its thermal characteristic. This paper presents the multiperiod heating storage control for a DEH load to reduce wind curtailment. To cope with intermittent wind power, a novel multi‐objective and layered optimization method is proposed by decomposing the integrated electricity and heating optimization problem into the electricity optimization subproblem and the heating optimization subproblem. Additionally, the influence of solar radiation on the thermal characteristic of the DEH load is considered in the building thermal process model when creating the day‐ahead schedule of the DEH load control, and this is also regarded as the basis for grouping DEH users. Last, the simulation and economic feasibility analysis based on the data measured by the DEH system of Jilin Province, China, are carried out. The results show that this proposal can reduce the electricity cost for DEH users by 25%, and the critical feasible price for curtailed wind power is varying between 86.1 and 115.3 yuan/MWh according to different subsidy methods. [ABSTRACT FROM AUTHOR]

In recent years, China and Japan are cooperating in the destruction of the Japanese army abandoned chemical weapons in China (JACWs). During the long-term burial of JACWs, As-containing agents leaked into the environment due to the corrosion of the shell, resulting in soil As pollution. This paper studied the fraction, speciation, and composition of As in the soil polluted by the As-containing agent in Jilin, China. The results showed that As was mainly distributed in the forest soil in the study area, with the highest concentration of 110 mg/kg, and had the trend of migration to the downhill farmland soil. As mainly accumulated in the amorphous Fe/Al oxides bounded fraction and residual states, the proportion of potentially risky fractions in the soil of downhill farmland is higher than that of uphill farmland. The speciation of As in the soil is mainly As(V), with an average content of 25.02 mg/kg. The transformation behavior of As in the horizontal migration of topsoil is mainly the oxidation of As (III). The residual organic As in soil mainly includes 2-chlorovinylarsonic acid, triphenylarsine, phenylarsine oxide, and diphenylarsonic acid. Similar to the influence factors of As, both speciation and organic compounds of As are significantly affected by Fe/Al/Mn-oxides, and degradation and transformation reactions such as redox occur during migration. • As mainly existed in amorphous Fe/Al oxide bound fraction and residual fraction. • The organic-As in soil mainly includes CVAOA, TPA, PAO, and DPAA. • DPAA showed a significant negative correlation with TP, Ca and Mn. [ABSTRACT FROM AUTHOR]

Forestry is a fundamental industry of national economy. In social development of human beings, forestry plays an essential role in expanding employment, realizing rural prosperity and safeguarding ecological safety. This paper firstly introduced current development situations of forestry in Jilin Province. Then, it analyzed influence of factor input on forestry economic growth of Jilin Province by linear regression analysis method. Finally, it came up with pertinent recommendations. [ABSTRACT FROM AUTHOR]

Mastering the lodging risk of planting environment is of great significance to the optimal layout of maize varieties and the breeding of lodging resistant varieties. However, the existing lodging risk models are still at the stage of single or multi-factors independent analysis, and lack of assessment for different lodging types. To address this issue, based on the mechanism of different lodging types, the Archimedean copula function was used to describe the joint probability distribution of wind speed and precipitation, and the lodging risk assessment model of maize was established. By comparing the goodness of fit, when the rank correlation coefficient of these two is positive and negative, the corresponding optimal joint probability distribution functions are the Gumbel copula and Frank copula. According to the spatial distribution of lodging risk, the area from Liaodong Bay northward to Tongyu, Jilin province in the Northeast and the North China Plain has a high frequency of lodging, in which the probability of stalk lodging is two to four times that of root lodging. Finally, we discussed how to apply the lodging risk distribution results to optimize the maize variety test sites to improve the efficiency and reliability of the existing test system. The method proposed in this paper comprehensively considers the synergistic effect of multiple factors and can provide technical support for other risk assessment. [ABSTRACT FROM AUTHOR]

• IQI-NLS index performed better than other soil quality model in BSZJLC. • The determined MDS for BSZJLC included BD, CEC, SOM, AN, TK, ACu, and AFe. • The soil quality in study area was dominated by moderate grades. • Effects of environmental factors on soil quality has local characteristic. Soil quality assessment is an effective way to improve understanding of the heterogeneity of soil quality and to encourage the adoption of proper agricultural practices. The object of this paper is to select the most effective soil quality indices and the minimum data set (MDS) for the black soil zone of Jilin Province, China, and analyze the association between soil quality and the environmental control. Taking the croplands of the black soil zone of Jilin Province, China, as the study area, different combinations of scoring methods, indices, and data set methods were compared. A minimum data set, based on the integrated quality index derived from non-linear scoring methods (MDS IQI-NLS index), was then selected via principal components analysis to assess the soil quality of the study area. The determined minimum data set for the study area included bulk density, cation exchange capacity, soil organic matter, alkali-dissolvable N, total K, extractable Cu, and extractable Fe. The results showed that the soil quality in the study area was of dominantly moderate grades (grades II, III and IV), accounting for approximately 90% of the total as well as the minimum data set, and the soil quality index increased from the northwest to the southeast. Group analysis was applied because different combinations of environmental factors play different roles in different sub-regions. The analysis results showed that the most important factors affecting soil quality in group 1 (in decreasing order of importance) were: mean annual temperature, DEM, amount of straw return, parent material, and topographic wetness index. For group 2 they were: parent material, annual precipitation, mean annual temperature, chemical fertilizer, DEM, amount of straw return. This analysis proves to be an effective way to determine the factors that affect the spatial distribution of soil quality. [ABSTRACT FROM AUTHOR]

Examining the effects of climate change on spring maize, and its suitability under dynamic cultivation patterns, will aid strategic decision-making for future agricultural adaptation. This paper investigates the climate suitability of spring maize, based on daily data from 50 meteorological stations, and statistics on maize yield and area at the county level in Jilin Province, China, between 1986 and 2015. Based on a significant correlation between the cultivation patterns indicator ≥10 °C accumulated temperature (AAT10) and the average yield (R2 = 0.503), the yield data are used to determine suitable thresholds for meteorological factors under the dynamic cultivation pattern, and a fuzzy fitness approach is used to evaluate the climate suitability. The results showed a good agreement between suitability estimates and scaled observed yields (average d = 0.705). Moreover, good consistency between cultivation patterns, climate suitability and yield show that the late-maturing varieties of maize have gradually moved northward and eastward, and the areas of high suitability and high yield have gradually expanded eastward. In addition, drought and chilling hazard factors limit the suitability of climate resources, especially in the eastern and western regions. [ABSTRACT FROM AUTHOR]