方捆打捆机连杆断裂问题改进探讨

指出了活塞部件是打捆机中的重要组成部分,其故障率一直处于一个相对较高的水平。结合市场上打捆机活塞的主要故障形式,从打捆机活塞故障的主要来源、活塞质量改进的角度进行了分析和研究。通过对活塞运动轨迹、阻力、焊合件材料的选用的分析,确定了活塞适用焊合材料、轴承要求、秸杆作业湿度等条件,提出了"选用新焊合材料、活塞轴承、增加活塞刮板,对打捆机连杆断裂故障率大幅度降低"的解决方案,并且通过试验验证了方案的可行性。     

基于小波变换的三江平原井灌区主汛期降水序列多时间尺度分析

近些年来,由于水田面积迅速增加,导致三江平原井灌水稻区地下水位普遍下降,吊泵、局部超采现象时有发生,因此,三江平原的地下水资源平衡急需恢复。为解决上述问题,以853农场为例,应用小波理论,对853农场实测主汛期降水时间序列的多时间尺度变化特征及突变特征进行分析,并与实测年降水序列变化特征进行了对比分析。结果表明:853农场主汛期降水序列具有3 a,6 a,29 a以及13 a左右4个主周期,同时,主汛期降水序列与年降水序列的主周期具有较好的一致性。该研究结果为853农场乃至整个三江平原充分利用天然降水、地下水资源的恢复及可持续利用提供了科学依据。     

政策激励对稻农重金属污染治理意愿的影响——基于中国南方水稻主产省耕地地力保护补贴的考察

为探究政策激励对稻农重金属污染治理意愿的影响,基于南方重金属污染典型地区的调研数据,利用二元选择模型和中介效应模型,对中国南方水稻主产省稻农的重金属污染治理意愿进行研究。结果表明:1)耕地地力保护补贴的政策激励对于稻农的重金属污染治理意愿具有显著促进作用,补贴资金可以直接改善稻农的预算约束;2)耕地地力保护补贴的主观规范可以改变稻农的收入预期,进而影响稻农的重金属污染治理意愿;3)耕地地力补贴政策的激励效果因农户类型而异,纯农户更容易受到耕地地力保护补贴金额的影响,兼业户更容易受到政策主观规范的影响。据此,提出以下对策建议,首先,完善补贴的推广模式和增强补贴力度;其次,根据群体特点差异化实施耕地地力保护补贴政策;最后,创造条件促进稻农治理意愿向行为转化。     

生态城市园林建设中雨水资源的合理利用

针对我国城市大部分缺水,绿化面积又不断扩大,需要大量水进行养护,城市雨水又大量流失的现状,提出了城市绿地应低于硬化地面、建设渗水沟、渗水井、池塘等措施,把雨水滞留在市内.以图文的形式,揭示了改进后的绿地能充分利用雨水资源的可行性,是一项缓解城市水危机,搞好城市园林绿化,造福子孙后代的有效举措.     

Evaluation of infiltration measurements under olive trees in Córdoba

Field experiments were conducted at the Alameda del Obispo Experiment Station of the Andalusian Autonomous Government, Córdoba, Spain, to compare the field-saturated hydraulic conductivity (K_fs) measured by four different techniques: constant-head well permeameter (CP), falling-head lined borehole permeameter (FP), twin-rings (TR) and disk infiltrometer (DI). For each technique, measurements under and outside the olive-canopy were compared in order to detect differences in K_fs. All techniques gave higher K_fs values under the canopy, but significantly higher only for FP and TR. Outside the canopy K_fs values obtained with CP and TR were significantly higher than those obtained with the FP and the DI methods, but the FP and the DI as well as the CP and the TR K_fs values were statistically the same. Under the canopy, K_fs values obtained with the TR method were significantly higher than those obtained with the other three techniques. Estimates of K_fs, however, are most comparable for DI and FP.     

农业资源可持续利用与综合管理基础研究刍论

阐述了资源、农业资源的概念与价值及其对社会经济发展的重要意义。依据人与自然协调发展原理,探讨了农业资源可持续利用与管理的基础理论及其实现途径。     

春小麦子粒蛋白质积累和产量形成规律及施氮的调节作用

以春小麦不同品质类型为材料,研究子粒蛋白质和干物质积累规律。结果表明,春小麦灌浆期子粒蛋白质百分含量总的趋势均呈“Ｖ”型变化。但不同品质类型存在差异。高蛋白类型灌浆前期蛋白质含量下降缓慢,曲线波动小,高产类型则相反,高产高蛋白类型虽前期下降快,但后期回升速度也快,最终有较高的蛋白质含量。粒重在整个灌浆过程中均呈上升趋势,并在接近成熟时趋于稳定。等量氮肥分期施用,生育前期施氮有利于产量的形成,开花期叶面喷氮,在提高蛋白质含量的同时具有增加粒重的双重作用。不同品质类型小麦光合产物的生产和分配方向不同,高产高蛋白品种光合能力强,光合产物多,能够兼顾产量和蛋白质的同时增加。后期保持高光合速率和叶面积持续过程是高产、高蛋白类型的重要生理特性。     

巨柏种子活力与濒危的关系

鉴于巨柏目前的濒危状况,通过对巨柏天然分布的3个居群(雅鲁藏布江朗县段、米林县、林芝县)进行野外观察和测量以及TTC法种子活力测定,研究了巨柏结实状况、种子形态特征、种实受害和种子活力、出芽率等与濒危的关系,结果表明:巨柏成熟个体有70%～80%不结实或结实极少,健康球果平均含种子58粒;树体大多受樵采危害,种实受病虫、鸟鼠危害严重,是导致巨柏濒危的主要外因;种子活力最高只有39.8%,平均只达到34.6%,远远低于红松、杉木等的种子活力;种子发芽率较低,平均只达到32.67%,是导致巨柏濒危的主要内因;种子品质和其所处生境的温湿条件不利于巨柏个体繁殖和种群扩散。     

Quantifying subjective human dimensions of recreational fishing: does good health come to those who bait?

Recreational fishing is a popular sport and leisure activity in many countries worldwide. There has been growing interest by recreational fishing groups and researchers in the perceived physical and psychological health and social (or ‘biopsychosocial’) benefits of recreational fishing. However, quantifying the key subjective ‘human dimensions’ of fishing that satisfy both the needs of recreational fishing groups and fishery managers is a major obstacle. We propose the use of psychometrically valid health‐related quality of life (HRQOL) measures widely used in the medical and health sciences – namely the Short‐Form Health Survey (SF‐36) – as rapid, reliable and cost‐effective instruments for quantifying HRQOL of recreational fishers. The widespread use of SF‐36 and availability of population normative data allows comparisons of the HRQOL of recreational fishers across multiple temporal and spatial scales, with participants of other activities, and the general population. The use of such measures in periodic surveys allows the biopsychosocial status of a recreational fishery's participants to be assessed using a modified Kobe plot, a graphical format that is easily interpretable and consistent with existing reporting formats used in fisheries stock assessment. Future biopsychosocial research in recreational fisheries can further benefit from interdisciplinary collaboration to develop a suite of standardized psychometrically valid and reliable instruments for assessing specific issues that commonly affect recreational fisheries from regional to international scales, such as drivers of fisher motivation, behaviour and satisfaction.     

自贡黑山羊生后期生长发育规律的研究

对自贡黑山羊生后期的生长发育规律进行了研究,得出自贡黑山羊公羊8月龄前、母羊6月龄前的体尺、体重变化极显著,说明自贡黑山羊早期生长发育快、成熟早,具有典型的肉用山羊品种特征。