Irrigation and drainage in the new millennium

Presented at the 2000 USCID international conference, Challenges facing irrigation and drainage in the new millennium on June 20-24 in Fort Collins, Colorado.Includes bibliographical references.Cross-boundary issues in water resources development and management are very popular throughout the world. One of the most notable cross-boundary issues facing irrigation is water resources allocation between urban and rural areas, and typically industrial and agricultural uses. In many areas in the world, agricultural water resources (typically irrigation) is severely impacted by urbanization, which has been one of the crucial restricting factors to sustainable agriculture of the world, especially that of developing countries. This paper presents the impact of urbanization on agricultural water resources. The general impact in China is briefly described. Some special solutions to the impact are recommended which include raising the design standards of irrigation projects, bestowing priority on farmland irrigation, and stipulating an upper limit to the water available per capita. More attention should be paid to the comprehensive solutions: to set up a water-saving society, to strengthen water pollution prevention and water resources protection, and to speed up capacity building. A strategic framework for sustainable water resources development and management for the new millennium is proposed for central Shaanxi, one of China's typical regions suffering from severe water shortage. Based on the analysis of basic demand for sustainable development and probable water resources available, an amount of 500 cubic meters of water per capita per year on average might be an upper limit to this region. A rough allocation of the water to agricultural, industrial, residential and environmental for the year 2020 is suggested based on the objective of self-sufficient food supply, continuous development of industry, persistent improvement of life quality, and safe environment These solutions may also be appropriate for most developing countries and other countries with similar issues

HEIGHTENING URBAN WATER SUPPLY CAPACITY AND RELIABILITY THROUGH RECONSTRUCTING INTEGRATED REGIONAL WATER RESOURCES SYSTEMS

ABSTRACT This paper presents essential concept of reconstruction of integrated regional water resources systems (IRWRS), basic status of urban water supply in China, and a case study of solving urban water issues induced by unitary water source through reconstructing IRWRS. Integrated regional water resources systems are defined as water resources systems that consist of water source subsystems, water project subsystems, water utilization subsystems, water management subsystems and the environment of the systems. Lack of enough water sources with sufficient quantity and proper quality is recognized to be one of the most crucial stresses to urban water security. Integrated regional water resources systems with multiple water sources are regarded as an important solution to unitary water source induced urban water scarcity and pertinent issues. The results from the Xi'an Water Resources System show that urban water supply capacity and reliability is capable of being significantly improved through reconstructing IRWRS. KEYWORDS Integrated regional water resources system (IRWRS); multiple water sources; water scarcity; water supply capacity and reliability; unitary water source, urbanization

A randomized controlled trial to evaluate the impact of a geo-specific poster compared to a general poster for effecting change in perceived threat and intention to avoid drowning \u27hotspots\u27 among children of migrant workers: evidence from Ningbo, China

Background Drowning among children of migrant workers is a major, though neglected public health issue in China. Methods A randomised controlled trial was used to examine the potential impact of viewing a preventive health poster with/without geo-located drowning events on perceptions of drowning risk among Chinese migrant children. A total of 752 children from three schools in Jiangbei district were selected by multi-stage sampling and randomly assigned to the intervention (n = 380) or control (n = 372). Multilevel models were used to analyse changes in responses to the following questions after viewing the assigned poster for 10 min: (1) “Do you believe that drowning is a serious health problem in Ningbo city?”; (2) “Do you believe that there are lots of drowning-risk waters around you?”; (3) “Do you believe that the likelihood of your accessing a drowning-risk water is great?”; and (4) “Would you intend to avoid accessing to those drowning-risk waters when being exposed?” Results At baseline there were no significant differences between the intervention and control groups in perceptions of drowning risk or covariates. Following the intervention, participants that viewed the geo-specific poster were more likely to respond more favourably to the first three questions (p \u3c 0.001) than those who viewed the standard poster. However, there was no substantive difference between the geo-specific or standard poster in terms of changing intentions to avoid drowning hotspots (p = 0.214). Conclusions Use of ‘geo-located’ information added value to the effectiveness of a drowning prevention poster for enhancing awareness of drowning hotspots among children of migrant workers

A Hyper Heuristic Algorithm Based Genetic Programming for Steel Production Scheduling of Cyber-Physical System-ORIENTED

Intelligent manufacturing is the trend of the steel industry. A cyber-physical system oriented steel production scheduling system framework is proposed. To make up for the difficulty of dynamic scheduling of steel production in a complex environment and provide an idea for developing steel production to intelligent manufacturing. The dynamic steel production scheduling model characteristics are studied, and an ontology-based steel cyber-physical system production scheduling knowledge model and its ontology attribute knowledge representation method are proposed. For the dynamic scheduling, the heuristic scheduling rules were established. With the method, a hyper-heuristic algorithm based on genetic programming is presented. The learning-based high-level selection strategy method was adopted to manage the low-level heuristic. An automatic scheduling rule generation framework based on genetic programming is designed to manage and generate excellent heuristic rules and solve scheduling problems based on different production disturbances. Finally, the performance of the algorithm is verified by a simulation case

Irrigation and Nitrogen Regimes Promote the Use of Soil Water and Nitrate Nitrogen from Deep Soil Layers by Regulating Root Growth in Wheat

Unreasonably high irrigation levels and excessive nitrogen (N) supplementation are common occurrences in the North China Plain that affect winter wheat production. Therefore, a 6-yr-long stationary field experiment was conducted to investigate the effects of irrigation and N regimes on root development and their relationship with soil water and N use in different soil layers. Compared to the non-irrigated treatment (W0), a single irrigation at jointing (W1) significantly increased yield by 3.6–45.6%. With increases in water (W2, a second irrigation at flowering), grain yield was significantly improved by 14.1–45.3% compared to the W1 treatments during the drier growing seasons (2010–2011, 2012–2013, and 2015–2016). However, under sufficient pre-sowing soil moisture conditions, grain yield was not increased, and water use efficiency (WUE) decreased significantly in the W2 treatments during normal precipitation seasons (2011–2012, 2013–2014, and 2014–2015). Irrigating the soil twice inhibited root growth into the deeper soil depth profiles and thus weakened the utilization of soil water and NO3-N from the deep soil layers. N applications increased yield by 19.1–64.5%, with a corresponding increase in WUE of 66.9–83.9% compared to the no-N treatment (N0). However, there was no further increase in grain yield and the WUE response when N rates exceeded 240 and 180 kg N ha−1, respectively. A N application rate of 240 kg ha−1 facilitated root growth in the deep soil layers, which was conducive to utilization of soil water and NO3-N and also in reducing the residual NO3-N. Correlation analysis indicated that the grain yield was significantly positively correlated with soil water storage (SWS) and nitrate nitrogen accumulation (SNA) prior to sowing. Therefore, N rates of 180–240 kg ha−1 with two irrigations can reduce the risk of yield loss that occurs due to reduced precipitation during the wheat growing seasons, while under better soil moisture conditions, a single irrigation at jointing was effective and more economical

A randomized controlled trial to evaluate the impact of a geo-specific poster compared to a general poster for effecting change in perceived threat and intention to avoid drowning ‘hotspots’ among children of migrant workers: evidence from Ningbo, China

Abstract Background Drowning among children of migrant workers is a major, though neglected public health issue in China. Methods A randomised controlled trial was used to examine the potential impact of viewing a preventive health poster with/without geo-located drowning events on perceptions of drowning risk among Chinese migrant children. A total of 752 children from three schools in Jiangbei district were selected by multi-stage sampling and randomly assigned to the intervention (n = 380) or control (n = 372). Multilevel models were used to analyse changes in responses to the following questions after viewing the assigned poster for 10 min: (1) “Do you believe that drowning is a serious health problem in Ningbo city?”; (2) “Do you believe that there are lots of drowning-risk waters around you?”; (3) “Do you believe that the likelihood of your accessing a drowning-risk water is great?”; and (4) “Would you intend to avoid accessing to those drowning-risk waters when being exposed?” Results At baseline there were no significant differences between the intervention and control groups in perceptions of drowning risk or covariates. Following the intervention, participants that viewed the geo-specific poster were more likely to respond more favourably to the first three questions (p < 0.001) than those who viewed the standard poster. However, there was no substantive difference between the geo-specific or standard poster in terms of changing intentions to avoid drowning hotspots (p = 0.214). Conclusions Use of ‘geo-located’ information added value to the effectiveness of a drowning prevention poster for enhancing awareness of drowning hotspots among children of migrant workers. Trial registration Chinese Clinical Trial Registry ChiCTR-IOR-16008979 (Retrospectively registered) (The date of trial registration: Aug 5, 2016, the date of enrolment of the first participant: Nov 10, 2015)

A Review of Prosthetic Hand Control Signal Source

Human limbs systemic function is complicated and the feedback is very abundant. How to make sure hands signal source becomes a very complicated conundrum with the push of development. After the theory of control is proposed, researchers spend much time on doing research. With the development of science technology, the requirement of prosthetic hands’ multi-perceived information feedback is higher and higher in biomedical field and ammunition industry. Research on signal source about hand prostheses become a hotpot for long time. Nowadays, control signal sources are used to control prosthetic hand include mechanical movement, voice, reconstructed fingers, EMG, EEG, MEG and so on. This passage displayed a comparative analysis on the hand prostheses field in recent decade and introduced the theory of hand prostheses control. Whats more, researches on hand prostheses signal sources are surveyed. At last, hand prostheses control signals are under the comparison. Some further research and developing trend of prosthetic hand signal sources are indicated

Evolution of Char Structure During In-Situ Biomass Tar Reforming: Importance of the Coupling Effect Among the Physical-Chemical Structure of Char-Based Catalysts

In order to illustrate the importance of a coupling effect in the physical-chemical structure of char-based catalysts on in-situ biomass tar reforming, three typical char-based catalysts (graphite, Zhundong coal char, and sawdust biochar) were studied in the fixed-bed/fluidized-bed reactor. The physical-chemical properties of carbon-based catalysts associated with their catalytic abilities were characterized by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), Raman, X-ray photoelectron spectroscopy (XPS), scanning electron microscope&ndash;energy dispersive spectrometer (SEM-EDS) and N2 adsorption. The relationship between the specific reactivity and tar reforming ability of carbon-based catalysts was discussed through a micro fluidized bed reaction analyzer (MFBRA&ndash;MR). The results indicate that the char-based catalyst has a certain removal ability for in-situ biomass tar of corn straw in an inert atmosphere, which is as follows: sawdust biochar &gt; Zhundong (ZD) coal char &gt; graphite. During the in-situ tar reforming, the alkali and alkaline earth metal species (AAEMs) act as adsorption/reaction sites, affecting the evolution of the aromatic ring structure and oxygen-containing functional groups of the char-based catalyst, and also its pore structure. AAEM species on the surface of char-based catalysts are the active sites for tar reforming, which promotes the increase of active intermediates (C-O bond and C-O-AAEMs), and enhances the interactions between char-based catalysts and biomass tar. The abundant AAEMs may lead to the conversion of O=C&ndash;O and C=O to C&ndash;O. For tar reforming, the internal pore structure of char-based catalysts is little changed, mainly with the carbon deposit forming on the surface pore structure. The carbon deposit from the reformation of straw tar on the char surface has better reactivity than the inherent carbon structure of ZD coal char and sawdust biochar. There is a positive relationship between the MFBRA&ndash;MR specific reactivity and tar catalytic reforming ability of char-based catalysts (decided by the coupling effect in their physical-chemical structure), which can be used to determine the catalytic ability of char-based catalysts on tar reforming directly

Unraveling the effects of Cr interface segregation on precipitation mechanism and mechanical properties of MC carbides in high carbon chromium bearing steels

This study explored the influence of Cr interfacial segregation on the precipitation mechanism and mechanical properties of MC carbides in high-carbon chromium bearing steels. The precipitation of Cr-doped MC carbides at different concentrations was investigated using microscopic morphological characterization (SEM, EDS and HR-TEM) alongside first principles calculations. The results indicated that both the austenite matrix and MC carbides exhibited, FCC structures, and the following orientation relationships of crystal planes in high-carbon chromium bearing steels were as follows: MC (010)//FCC-Fe (100) and MC (111)//FCC-Fe (111). Initially, Cr atoms adsorbed on the Fe-top site of the MC carbide (010) crystal plane, maintaining a distance of 2.5 Å from the Fe atom. Notably, when the Cr atom doping amount was 0.5, the Cr–Fe metallic bond exhibited a long bond length, large bond angle and low bond strength in the MC transition state (TS), resulting in a reduced, reaction barrier (908.08 kcal/mol), thus promoting the precipitation of MC carbide in bearing steel. However, at a Cr atom doping amount level of 1, the shorter bond length, small bond angle, and higher bonding strength of the Cr–Fe metallic bond in the MC TS, elevated the reaction barrier (49709.72 kcal/mol), inhibiting the precipitation of MC carbide in bearing steel. Additionally, this study quantitatively analyzed the effect of Cr atom content on the brittle plastic properties and hardness of MC carbides. At Cr atom contents of 0.23 and 1, the MC carbide hardness reached a minimum value of 3.0 GPa and a maximum value of 17.1 GPa, respectively. This investigation not only elucidated the atomic scale effects of Cr interfacial segregation on the precipitation mechanism and mechanical properties of MC carbides but also provided new ideas for controlling carbide precipitation in high-carbon chromium bearing steels