This study aimed to gain more high-quality rice with less water and im- prove the level of national food security. Based on the optimized planting density of rice with drip irrigation, direct sowing technology for pla...This study aimed to gain more high-quality rice with less water and im- prove the level of national food security. Based on the optimized planting density of rice with drip irrigation, direct sowing technology for plastic-film-covered rice cultiva- tion with drip irrigation was proposed. Furthermore, sowing planter for plastic-film- covered drip-irrigation rice cultivation was developed in accordance with the require- ments for the combination of agricultural technique and agricultural machinery. Ac- cording to the large-scale field production evaluation, the film-punching direct-sowing technology for dry cultivation of rice can greatly reduce the labor consumption and results in neat emergence of seedlings. Productive practice shows that using the developed sowing planter for plastic-film-covered rice cultivation with drip irrigation leads to vacancy rate ≤3%, pass rate of grain number ≥85%, soil-covering rate ≥ 95%, and hole number per acre of 31 000-33 000. In addition, the sowing planter can adapt to the agronomic technical requirements for high-density cultivation of rice and provide technical support for the rice production in arid regions of China. Key words Fargesia murielae; Nutrition mechanism; Age grade; Nutrient distribution展开更多
The Aral Sea was one of the largest lakes in the world before it started to shrink in the 1960s due to water withdrawal for agricultural irrigation. Precipitation decreased from 9.4 kmin 1960 to 3.2 km3 in 2009, and a...The Aral Sea was one of the largest lakes in the world before it started to shrink in the 1960s due to water withdrawal for agricultural irrigation. Precipitation decreased from 9.4 kmin 1960 to 3.2 km3 in 2009, and annual river inflow into the Aral Sea decreased from 31.5 km3 in 1998 to 5.2 km3 in 2009. Comparison on the hydrological data of the Aral Sea between 1960 and 2009 showed the evaporation, water surface area, and water volume decreased by 90%, 80%, and 88%, respectively. This study employs the observed values of water volume, precipitation, runoff, evaporation, and salinity to estimate water volume and salinity from 1960 to 2009, and the efficiency coefficients for predicted water volume and salinity are o.975 and 0.974, respectively. Regression equations calculated from the observed data are used to predict precipitation, runoff, evaporation, and salinity from 20lO to 2021, and the results are then applied in the estimation of water volume and salinity Our estimates suggest that salinity will increase to around 200 g/L and water volume will decrease to around 83 km3 in 2021.展开更多
The scheme and construction measurement of reinforcement and blocking against water for winder chamber after destroyed by mining influence have been introduced in this paper. The basic principle and advantages of bolt...The scheme and construction measurement of reinforcement and blocking against water for winder chamber after destroyed by mining influence have been introduced in this paper. The basic principle and advantages of bolting and grouting lining have been also listed. Bolting and grouting lining can increase the integrity and load-carrying capacity of supporting framework and it can assure the stability of supporting framework. It possesses not only the flexible and yielding capacity of bolting and shotcrete lining, but also the effect of rigid support such as metal support and brickwork, forming many kinds of support system, maintaining the stability of roadway together.展开更多
[Objective] The study is aimed to timely grasp the growth and develop- ment process of summer maize and comprehensively evaluate the impact of envi- ronmental factors on the growth and development of maize in north Hu...[Objective] The study is aimed to timely grasp the growth and develop- ment process of summer maize and comprehensively evaluate the impact of envi- ronmental factors on the growth and development of maize in north Huanguaihai re- gion. [Method] The phenophase, leaf unfolding rate, grain filling rate and yield char- acteristics of Zhengdan 958 and Xianyu 335 were analyzed at N 37°53′, E115°42′. [Result] The summer corn Zhengdan 958 and Xianyu335 emerged in 6 days after sowing with the growing period of 111 d, grain-filling stage lasting 66 days, and the leaf unfolding rate and grain filling rate were accelerated with the increase of tem- perature. In the last 6 d before harvest （October 5-11）, Zhengdan 958 and Xi- anyu335 contributed to the yield by 6.61% and 4.20%, respectively. The two crops a year cropping system made it hard for the summer maize to achieve maturing harvest in north Huanghuaihai region. [Conclusion] The maize production could be significantly improved through selecting early maturing varieties, early sowing, timely late harvest, ensuring maize effective accumulated temperature and sufficient grout- ing time after pollination.展开更多
The subsidence prediction theory under the condition of grouting into bedseparated was developed. Reducing ground subsidence by grouting was carried out on eight fully-mechanized top-coal caving faces, by using the co...The subsidence prediction theory under the condition of grouting into bedseparated was developed. Reducing ground subsidence by grouting was carried out on eight fully-mechanized top-coal caving faces, by using the continuous grouting in multiple-layer to obtain experiment results of reducing subsidence under fully mining. The similar material model that can be dismantled under the condition of constant temperature and constant humidity was developed. The model was used to simulate the evolution of overburden bed-separated under such constraints of temperature and humidity, at the same time, and to test the hardening process of similar materials.展开更多
文摘This study aimed to gain more high-quality rice with less water and im- prove the level of national food security. Based on the optimized planting density of rice with drip irrigation, direct sowing technology for plastic-film-covered rice cultiva- tion with drip irrigation was proposed. Furthermore, sowing planter for plastic-film- covered drip-irrigation rice cultivation was developed in accordance with the require- ments for the combination of agricultural technique and agricultural machinery. Ac- cording to the large-scale field production evaluation, the film-punching direct-sowing technology for dry cultivation of rice can greatly reduce the labor consumption and results in neat emergence of seedlings. Productive practice shows that using the developed sowing planter for plastic-film-covered rice cultivation with drip irrigation leads to vacancy rate ≤3%, pass rate of grain number ≥85%, soil-covering rate ≥ 95%, and hole number per acre of 31 000-33 000. In addition, the sowing planter can adapt to the agronomic technical requirements for high-density cultivation of rice and provide technical support for the rice production in arid regions of China. Key words Fargesia murielae; Nutrition mechanism; Age grade; Nutrient distribution
文摘The Aral Sea was one of the largest lakes in the world before it started to shrink in the 1960s due to water withdrawal for agricultural irrigation. Precipitation decreased from 9.4 kmin 1960 to 3.2 km3 in 2009, and annual river inflow into the Aral Sea decreased from 31.5 km3 in 1998 to 5.2 km3 in 2009. Comparison on the hydrological data of the Aral Sea between 1960 and 2009 showed the evaporation, water surface area, and water volume decreased by 90%, 80%, and 88%, respectively. This study employs the observed values of water volume, precipitation, runoff, evaporation, and salinity to estimate water volume and salinity from 1960 to 2009, and the efficiency coefficients for predicted water volume and salinity are o.975 and 0.974, respectively. Regression equations calculated from the observed data are used to predict precipitation, runoff, evaporation, and salinity from 20lO to 2021, and the results are then applied in the estimation of water volume and salinity Our estimates suggest that salinity will increase to around 200 g/L and water volume will decrease to around 83 km3 in 2021.
文摘The scheme and construction measurement of reinforcement and blocking against water for winder chamber after destroyed by mining influence have been introduced in this paper. The basic principle and advantages of bolting and grouting lining have been also listed. Bolting and grouting lining can increase the integrity and load-carrying capacity of supporting framework and it can assure the stability of supporting framework. It possesses not only the flexible and yielding capacity of bolting and shotcrete lining, but also the effect of rigid support such as metal support and brickwork, forming many kinds of support system, maintaining the stability of roadway together.
基金Supported by the Foundation of China Agricultural Research System for Maize Industry(CARS-02-48)~~
文摘[Objective] The study is aimed to timely grasp the growth and develop- ment process of summer maize and comprehensively evaluate the impact of envi- ronmental factors on the growth and development of maize in north Huanguaihai re- gion. [Method] The phenophase, leaf unfolding rate, grain filling rate and yield char- acteristics of Zhengdan 958 and Xianyu 335 were analyzed at N 37°53′, E115°42′. [Result] The summer corn Zhengdan 958 and Xianyu335 emerged in 6 days after sowing with the growing period of 111 d, grain-filling stage lasting 66 days, and the leaf unfolding rate and grain filling rate were accelerated with the increase of tem- perature. In the last 6 d before harvest （October 5-11）, Zhengdan 958 and Xi- anyu335 contributed to the yield by 6.61% and 4.20%, respectively. The two crops a year cropping system made it hard for the summer maize to achieve maturing harvest in north Huanghuaihai region. [Conclusion] The maize production could be significantly improved through selecting early maturing varieties, early sowing, timely late harvest, ensuring maize effective accumulated temperature and sufficient grout- ing time after pollination.
基金Supported by National Natural Science Foundation of China（50174035） National Key Project of Scientific and Technical Supporting Programs（2006BAB16B00） National.＂973＂ Program（2006CB202200）
文摘The subsidence prediction theory under the condition of grouting into bedseparated was developed. Reducing ground subsidence by grouting was carried out on eight fully-mechanized top-coal caving faces, by using the continuous grouting in multiple-layer to obtain experiment results of reducing subsidence under fully mining. The similar material model that can be dismantled under the condition of constant temperature and constant humidity was developed. The model was used to simulate the evolution of overburden bed-separated under such constraints of temperature and humidity, at the same time, and to test the hardening process of similar materials.
