我国粮食安全根本出路探讨

在对我国历年粮食总产变化趋势进行研判的前提下,分析了增加粮食数量的宏观路径,表明确保我国粮食安全的根本出路在于提高粮食单位面积产量,提出了提高粮食单产的综合农业措施,并讨论了3大支撑体系的相关问题。     

稀土转光农膜的光色效应研究

将铕有机配合物添加到聚乙烯树脂中,制得聚乙烯荧光农膜。它具有将紫外光转换成红光的功能。与普通聚乙烯农膜相比,它可提高棚内透光率和温度,还可促进光合作用,提高 产量和品质 。     

Soil water content and freezing temperature affect freeze–thaw related N2O production in organic soil

An organic agricultural soil was exposed to freeze–thaw cycles (FTC) using either intact soil cores or cores packed with homogenized soil. The cores were first exposed to two mild FTCs (–1.5°C/+4°C) with soil water content being 56–85% of the water-filled pore space (WFPS). Both intact and packed soil cores showed high N₂O emissions when the soil was thawing and had high WFPS. The second freeze–thaw cycle induced lower N₂O emission than the first. After the mild FTCs, a deep frost (–15°C) was applied. This greatly increased the N₂O emissions when the soil was thawing. Freezing–thawing had a smaller effect on CO₂ than on N₂O release. The results show that both soil moisture and the severity of frost modify the N₂O burst after thawing, and N₂O release (denitrification) was favoured more by FTC than heterotrophic microbial activity (CO₂ production) in general. The possible reason for this difference is discussed.     

Child bystanding: A risk factor for injury and identifying its’ determinants on midwestern agricultural operations

Background

Agriculture is considered among the most dangerous occupations and has consistently ranked among the top three. Production processes, associated with this occupation, place at risk not only workers but also others who live on the operations. We evaluated the incidence and determinants of associated bystander injuries in the Regional Rural Injury Study-II (RRIS-II).

Methods

The RRIS-II followed 32,601 people (∼85% of eligible) from rural communities in the Midwest for 1999 and 2001, using six-month recall periods, and identified their injury events. Demographic, injury, and exposure data were collected through comprehensive and case-control computer-assisted telephone interviews. Multivariate logistic regression analyses were used to estimate the risk of child bystanding and agricultural injury, while controlling for potentially confounding variables.

Results

Nearly 60% of all 425-child injury cases (<20 years) responded to sometimes/frequently bystanding in six out of seven different agricultural environments (e.g., workshops, animal areas, etc.) Multivariate regression analyses, with odds ratios and 95% confidence intervals, showed increased odds of injury for bystanding near used (1.5; 1.1, 1.9) or stored (1.4; 1.1, 1.8) machinery, and near fields and barnyards (1.4; 1.0, 1.9). Further, multivariate analyses revealed increased odds of bystanding for parental beliefs, such as: child age (1.4; 1.0, 2.0) near stored equipment. Parental levels of strictness were also evaluated and showed decreased odds of bystanding when the parents were not strict about the child's wearing a seatbelt near used equipment (0.5; 0.3, 1.0). Households with only one child had decreased odds of bystanding for five of the exposures while there was an increased odds of bystanding near animals for households with five or more children.

Conclusions

Although parents cannot child-proof their operations, it is important for them to understand the apparent odds of and risks associated with bystanding. Children can have injury odds similar to adults in this environment; therefore, it is necessary to examine parental factors that may be associated with children's likelihood of bystanding in high-risk work environments.     

泡沫钻进在宁夏宁南山区找水工程中的应用

介绍了泡沫作为循环介质打井钻进在宁夏的野外试验工作，给出了课题组获取的深井泡沫钻进的第一手资料，为今后西部干旱地区找水工作提供了极为重要的科学依据。     

Performance Risk Analysis for Fukuoka Water Supply System

In this study, simulation is used to evaluate the performance of the municipal water system in Fukuoka city. In combination with daily simulation model, a kind of risk model incorporating water demand prediction is presented. This model applies five risk indices: reliability, resiliency, vulnerability, drought risk index (DRI) and drought damage index (DDI). They aid in the identification of operation policies for the municipal water system, and the planning and operational policies obtained are aimed at achieving minimum risk for a given scenario of operation. In this paper, the performance risk of the municipal water system is investigated under three alternatives: (1) the existing system operation when available supply from the Chikugo river is decreased; (2) water restrictions for different percentages of reduction are implemented; and (3) available water supply increases when desalination of sea water is implemented. The results obtained show that savings of between 5 and 12% of water consumption from May 1, or increasing of daily desalination of sea water about 30 000 m³ or more, may efficiently decrease the performance risk of the Fukuoka water supply system. Potentials also exist for further increase of reservoir storage by more rational operation. The measure that more attention should be paid to increasing the water supply from stable sources is recommended as well.     

2003年旱情紧急情况下黄河水量调度工作综述

2003年1～7月,黄河主要来水区来水严重偏枯,水资源供需缺口大,黄河水量调度面临着自1999年实施全河水量统一调度以来最为严峻的考验。根据我国《水法》的有关规定,黄委编制了《2003年旱情紧急情况下黄河水量调度预案》,并经国务院同意,由水利部印发沿黄有关省区和有关枢纽管理单位实施。经过有关单位、部门的共同努力和采取综合有效措施,调度期内,在确保黄河不断流的前提下,较好地协调了沿黄地区城乡人民生活及工农业生产用水。为了今后水调工作的顺利开展,建议：黄河水量调度实行行政首长负责制和断面流量控制责任制;黄河干流重要水利枢纽进行统一管理调度：《黄河水量统一调度条例》和《黄河水量调度规程》等法律法规尽快出台。     

Treatment and Disposal of Sewage Sludge in the Mid-1990s

The paper reviews the current methods of sludge technology, and compares them with those discussed by Ashton in 1904. The paper also plots the development of some of the current technology over the last century, particularly those methods of treatment which were mentioned by Ashton but were not in existence at the time.
The 1990s have been a most interesting era, and have probably seen more changes in sludge technology than any other decade this century. The most significant impact will be due to the cessation of the sea disposal route which, at the beginning of the 1990s, was used for about 30% of the total sludge production in England and Wales and approximately 76% of the total sludge produced in Scotland.     

汉江上游干旱恢复期间气象-水文干旱特征响应概率研究

探究干旱恢复期的气象-水文干旱特征响应规律,对干旱恢复及水资源管理具有重要的参考意义。选用标准化降水蒸散发指数（Standardized Precipitation-Evapotranspiration Index,SPEI）、标准化径流指数（Standardized Runoff Index,SRI）分别表征1961—2019年汉江上游流域气象、水文干旱,首先利用Pearson相关系数法计算气象-水文干旱响应时间,采用时间重叠法对气象、水文干旱事件进行匹配,进一步得出干旱恢复期气象-水文干旱特征,最后建立基于Copula函数耦合贝叶斯网络的气象-水文干旱恢复响应概率模型,探究干旱恢复期气象-水文干旱特征之间的联系。结果表明：①在6—11月期间,流域水文干旱对气象干旱的响应时间最短,仅为2个月,1月份的响应时间最长,达到了8个月,4、5、12月份的响应时间大约为5个月左右;②干旱恢复期气象、水文干旱历时的响应概率最优边缘分布均为LogL分布,烈度则分别为Kernel和LogL分布,且历时和烈度的最优联合分布函数均为Gumbel Copula函数;③随着气象干旱恢复特征值的增加,水文干旱恢复特征的响应概率也随之增加,如,当气象干旱恢复历时分别大于2、3、4、5、6个月的时候,水文干旱恢复历时大于4个月水文干旱的概率分别为34.8%、38.5%、42.8%、47.0%、50.7%。同时,水文干旱恢复特征的响应概率变化速率随着气象干旱恢复特征的增大而加快。研究成果可为深入理解汉江上游干旱恢复机制及干旱防治预警提供重要参考。     

GRACE卫星数据在干旱研究中的应用综述

干旱是全球范围内普遍存在的自然灾害,对环境、生态、经济和社会等多个方面产生深远影响。GRACE（Gravity Recovery and Climate Experiment）重力卫星通过测量地球重力场变化数据可动态监测陆地水储量变化。应用GRACE获得的水储量时空分布信息,可监测干旱,以研究干旱事件的发生、发展与演变过程。采用文献计量法分析总结了GRACE卫星数据在地下水储量变化、气象与水文干旱演变规律与响应、干旱预警等方面的应用现状及存在数据验证与数据插补重建方面的问题,并展望了变化环境下水储量变化、构建更适合干旱监测的干旱指数、提高GRACE数据精度、提升GRACE数据时空分辨率、干旱预警和决策支持以及区域水循环和生态系统响应等研究方向,可为后续的相关应用研究提供一定参考价值。