水肥一体化智能调控设备智能液位开关设计

在对设施蔬菜生产中使用的水肥一体化设备进行智能灌溉控制设计中,监测混肥罐和回液桶中液位高低是非常必要的。现有液位检测普遍采用机械开关式液位浮子,工程实践中发现当进出水口与浮子过近,或者水纹波动显著时,浮子上下剧烈抖动会导致水泵随浮子的抖动而经常启停,对于启动电流较大的泵容易造成损伤。本文在软硬件设计中采用了计数器数字滤波电路以及单片机定时器中断,设计了一种替代简单液位浮子的实用智能液位开关。为了检验该设计的性能,在同等条件下,进行了不同液面、不同压力和水流量的对比试验。试验结果表明,计数脉冲发生电路中充电电阻和放电电阻为4.7 kΩ时,滤波后的输出信号比现场实际的数控信号时间迟延了2.11 s,经数字电路滤波后的输出信号已经完全消除了宽度小于2 s的所有干扰信号,并且具有很高的稳定性。迟延时间与计数电路、计数脉冲发生电路有关,通过电路设计调整滤波脉宽可使输出信号有效地滤除干扰成分。同时,利用该方法也可以根据不同工况,如不同功率的水泵设定不同参数滤除干扰信号,提高智能液位开关适用性。     

博尔塔拉蒙古自治州水资源承载力评价

随着人口的快速增长和社会经济的发展,水资源承载力的大小已经成为制约一个地区和国家发展的重要因素之一,以博尔塔拉蒙古自治州为研究区,选取该地区生产总值GDP、人口自然增长率、人均水资源量等16个指标建立评价指标体系,采用主成分分析法PCA得到影响博尔塔拉蒙古自治州水资源承载力的三大主成分,并对博尔塔拉蒙古自治州水资源承载力状况进行综合评价。结果表明:1对水资源承载力影响起主导作用的有人均用水量、地表水资源量、单位面积水资源量,累积贡献率达到了94%。2第一主成分与人均水资源占有量X12和地表水资源量X9等较大正相关,认为第一主成分主要代表该地区的水资源利用;第二主成分与地区生产总值GDP X1和人均GDP X4等具有较大正相关,认为第二主成分主要代表该地区经济与人口的发展水平;第三主成分与人口自然增长率X6和地区人口X2具有较大正相关,可以认为第三主成分主要代表该地区人口的变化情况。因此,对博尔塔拉蒙古自治州水资源承载力进行分析和评价,可以为博州水资源规划及其合理开发利用提供参考依据。     

征地过程中的新不和谐现象及对策分析——基于对菏泽市XX行政村的实地调研

其于对山东省菏泽市XX行政村的实地调查研究,指出当前在征地过程中出现的新不和谐现象。按照征地方面的相关法律规定和学者关于这方面的研究,提出破解这些不和谐现象的可行性的对策建议。特别提出,要解决当前征地过程中出现的矛盾,政策制定者和基层工作人员要深刻领会包容性增长的内涵,并将其应用到工作当中,目的是让被征地农民共享经济发展的成果。     

中晚熟大白菜新品种天白80的选育

天白80是以雄性不育系C441和自交不亲和系T01配制而成的中晚熟直筒型大白菜一代杂种,生长期75d(天)左右,株型直立,株高51cm,开展度58.5cm,外叶浅绿色,叶面少茸毛,中肋白色;叶球长筒形,顶部舒心,球色浅绿,结球紧实,内叶浅黄色,球高46.4cm,球径11.2cm,球形指数4.1;叶球质量2.8kg左右,净菜率75.4%。抗病性强,高抗病毒病和霜霉病,抗黑腐病。平均每667m2产量7200kg左右,适宜我国华北及西北地区作为中晚熟秋大白菜种植。     

Relationship between polymorphism of angiotensin converting enzyme gene and different traditional Chinese medicine syndrome in patients with essential hypertension

AIM: To study the distribution of angiotensin converting enzyme (ACE) gene I/D polymorphism and its relationship with various traditional Chinese medicine (TCM ) syndromes in patients with essential hypertension.METHODS: 120 individuals with essential hypertension were involved and classified into liver-fire hyperactivity(LFH) syndrome,yin-deficiency and yang-hyperactivity(YDYH) syndrome, yin-yang deficiency(YYD) syndrome and sputum-dampness retention(SDR) syndrome based on the syndrome differentiation of TCM, while 30 normal individuals served as the control group.The polymerase chain reaction (PCR) was used to test ACE I/D polymorphism.RESULTS: The ACE gene DD genotype in yin-deficiency and yang-hyperactivity syndrome was markedly higher than that in control group(P＜0.05).There was no significant difference in ACE gene II, ID genotypes and alleles between patients with hypertension and normal controls(P>0.05).There was no difference in ACE genotype and allele among different TCM syndromes in patients with essential hypertension(P>0.05).CONCLUSION: The DD genotype of ACE polymorphism is associated with yin-deficiency and yang-hyperactivity syndrome in patients with essential hypertension.     

养殖环境生物应激因素对鸡免疫功能和生产性能的影响

为了认识不同养殖环境对肉鸡免疫功能和生产性能的影响,本实验选用1日龄健康AA(Arbor Acres)肉鸡320只,随机分为试验组和对照组,每组设4个重复。在不同的鸡舍环境卫生管理条件下,定期测定环境参数气载需氧菌、气载真菌和气载内毒素的浓度,与此同时再对鸡只的新城疫抗体水平、免疫器官指数、生产性能、胴体性状和外观步态进行测定。结果表明,鸡舍环境质量差,使微生物气溶胶含量增高,对鸡的免疫功能和生产性能均有一定程度的负面影响。所以,保持良好的饲养环境清洁卫生条件,是健康养殖的重要措施之一。     

内向型投资阻滞了越南畜牧养殖业发展

<正>越南人已经战胜了几个世纪以来来自于美国、法国强加给他们的外来干涉。最近几年来,该国的社会主义政府实行"Doi Moi"政策,即开放和创新的政策,为其赢得了赞赏。现在,繁华的大都市胡志明市已经成为曼谷和新加坡的竞争对手。早在2000年,比尔·克林顿总统访问胡志明市的     

Effects of High Fluoride and Low Iodine on Thyroid Function in Offspring Rats

Thirty-two Wistar rats were divided randomly into four groups of eight with six females and two males in each group. The rats were exposed to high fluoride drinking water (45 mg F- L-1 from 100 mg NaF L-1), low dietary iodine (0.0855 mg kg-1), or both together in order to assess the effects of these three regimens on the thyroid function of the offspring rats. After the animal model was established, the offspring rats were bred and 10-, 20-, 30-, 60-, and 90-d-old rats were used for the experiment. The treatments for the offspring rats were the same as those of their parents. In comparison with control rats, the relative thyroid glands were changed by three regimens, but the mean values of thyroid weight in the experimental groups saw no marked difference. Serum TT3 levels were increased in all stages in the low iodine (LI) group. In the high fluoride (HiF) group, increase in TT3 levels was observed except in 20-d-old rats. Decrease in TT3 at 20- and 90-d and increase in TT3 at 30- and 60-d were found in HiF+LI group. Serum TT4 levels first saw an increase, and then dropped in the LI and HiF+LI group. However, an increase in TT4 was found in the HiF group. The levels of TSH in serum rocketed at d 20, and then dropped in the next stages in experimental groups. The results suggested that thyroid disorder could be induced by high flroride in drinking water, low iodine diet, or both of them. Exposure time to fluoride or low iodine diet was one of the important factors that fluoride can induce the development of thyroid dyfunction.     

园林工程项目施工进度管理研究

分析园林工程施工特点,总结施工进度影响因素,提出园林工程施工进度管理目标和内容,指出为保证施工进度管理目标顺利实现,必须做好事前计划、事中控制、事后补救,采取有效的进度管理方法。     

咏梅楹联鉴赏

主要从风景名胜、题赠、挽逝、谐趣等几个方面,对我国历史上的部分咏梅楹联进行了分析、释义和鉴赏。