长春市精明增长测评研究     

王光灿  刘兆顺  李淑杰  何有富  解小雨  于丽丽 《安徽农业科学》2014,(30):10738-10742

“精明增长”是由西方国家针对城市蔓延提出的一种全新的城市发展理念,它倡导高效、集约、紧凑的城市发展模式,对于解决我国城市化进程中面临的诸多问题具有现实意义.该研究从城市增长的数量、强度、效益、循环和建设水平5个方面选取了8个指标建立城市精明增长现状测评体系,对长春市的精明增长现状进行测评.结果表明,长春市城市扩展速度较快,土地利用的集约度与强度均有待提高,但就城市经济发展、道路和公共交通现状来说,符合精明增长的发展方向.  相似文献   

庐江地区不同栽培方式对油菜产量及经济效益影响     

杭宇航 《现代农业科技》2023,(21)

探索庐江地区不同栽培方式对油菜产量与经济效益的影响，在相同茬口条件下，以陕油28为试验材料，研究人工育苗移栽、机条播和无人机飞播等三种栽培方式对油菜生育特性、产量构成及经济效益等影响。结果表明，人工移栽产量最高，机条播经济效益最好，亦是目前农户主要栽培方式。作为规模生产主体，由于劳动力等因素，选择机条播为最佳。  相似文献   

Effects of dietary lipid-to-carbohydrate ratio on growth and carbohydrate metabolism in juvenile cobia (Rachycentron canadum)     

《动物营养（英文）》2020,6(1):80-84

This experiment was conducted to investigate the effects of dietary lipid-to-carbohydrate ratio on growth and carbohydrate metabolism in juvenile cobia (Rachycentron canadum). Six isonitrogenous diets were prepared to vary in lipid-to-carbohydrate ratio (g/g) as follows: D1, 2.26; D2, 1.31; D3, 0.78; D4, 0.47; D5, 0.34; and D6, 0.23. Cobias were fed to satiety for 8 weeks. The weight gain and protein efficiency ratio in D1 group were significantly lower than those in other groups (P < 0.05), accompanied by a lower level of feed conversion ratio (P < 0.05). Protein retention efficiency in D4 and D6 and whole body protein in D4 and D5 were significantly higher than those in D1 group (P < 0.05). Survival rate in D4 group was the highest among all groups and was significantly higher than that in D1, D2 and D5 (P < 0.05). In terms of serum triglyceride, D1 and D2 were significantly higher than D6 (P < 0.05). Hepatosomatic index in D3 and D4 was significantly lower than that in D1 (P < 0.05). Fructose-1,6-diphosphatase in D4 was significantly higher than that in D1 and D3 (P < 0.05). Phosphofructokinase in D3 and D4 and malic enzyme in D4 and D5 were significantly higher than those in other groups (P < 0.05). Results indicate that cobia utilizes carbohydrates as energy source more efficiently than it utilizes lipids. The optimal lipid-to-carbohydrate ratio in juvenile cobia diets is 0.47.  相似文献   

花生黄曲霉生长预测模型的研究   总被引：1，自引：1，他引：0  

房保海  王波  刘会梅  雷质文  张艺兵  门爱军  祝素珍  李正义  唐静 《山东农业科学》2011,(5):29-32

通过对分离自花生的黄曲霉LYYSS03-3在不同温度(15-35℃)、不同相对湿度(水活度分别为0.5,0.7,0.9)下的菌落生长特性进行检测,采用Boltzmann和Logistic 模型对黄曲霉的生长曲线进行拟合,结果表明,在适宜温湿度阶段,花生黄曲霉的生长曲线更适合用Boltzmann模型拟合.  相似文献   

生防菌+恶霉灵最优组合的筛选及对苦瓜枯萎病的防治效果研究     

王炎峰  田叶韩  魏滟洁  高克祥 《中国蔬菜》2019,1(7):67-73

苦瓜枯萎病是由尖孢镰孢菌苦瓜专化型（Fusarium oxysporum f. sp. momordicae）侵染引起的一种土传病害，目前市场上缺乏防治效果较好的农药或生防菌剂。为了更好地防治苦瓜枯萎病，通过盆栽试验筛选出绿针假单胞菌（Pseudomonas chlororaphis）G5 与恶霉灵复配施用的最优组合，并在苦瓜枯萎病发病样地对盆栽试验筛选出的最优组合进行防效验证。试验结果表明：菌药组合B+0.75Hym（1×10⁹ cfu · mL^-1 G5 菌悬液+187.5 mg · L-¹ 恶霉灵）处理对盆栽苦瓜枯萎病的防病效果为81.60%，明显高于其他处理；同时该组合对苦瓜幼苗的促生作用最为明显。接种苦瓜枯萎病菌后，菌药组合B+0.75Hym的苦瓜叶片中PAL、PPO、POD 防御酶活性较高。田间防效验证试验中苦瓜苗移栽30、60 d 后菌药组合B+0.75Hym 对苦瓜枯萎病的防治效果较高，分别达到了52.59%、32.13%，且苦瓜产量也高于其他处理。表明盆栽试验筛选出的菌药最优组合B+0.75Hym 不仅能够降低农药的使用量，而且能够有效防治苦瓜枯萎病，提高苦瓜产量，有一定的生产实用价值。  相似文献   

Effects of Different Substrate Composition on Growth of Gesneriaceae Plants     

ZhijingQIU  ;ChunqingZOU  ;ZhengjunSHI  ;YaoliangDAI  ;RuixingXIE 《农业科学与技术》2014,(8):1335-1338

The cultivation experiment was carried out to investigate the effects of different proportions of peat soil, perlite, vermiculite and yellow mud on growth of Gesneriaceae species(Chirita gueilinensis, Sinningia speciosa, Lysionotus pauciflorus, Hemiboea henryi, Aeschynanthus acuminatus, Saintpaulia ionantha). The growth traits of each plant growing in 7 different matrix materials were investigated.The plant height, crown width and chlorophyll content of each plant were measured. The results showed that the best substrate ratio was peat soil∶vermiculite=2∶1for C. gueilinensis, L. pauciflorus and H. henryi; peat soil∶perlite∶vermiculite = 2∶1∶1for S. ionantha; peat soil∶vermiculite∶yellow mud=2∶1∶1 for S. speciosa; peat soil∶perlite∶vermiculite∶yellow mud=2∶1∶1∶1 for A. acuminatus.  相似文献   

修剪方式对广玉兰大树移植成活率及生长的影响     

罗贵斌  张建军 《西北农业学报》2016,25(6):875-881

为提高大树移植成活率及探索修剪方式与大树移植成活生长的关系,以20a以上生广玉兰为试材,以全冠移植为对照(CK),分别采用剪去1/3枝叶量的轻度修剪(QX)、剪去2/3枝叶量的中度修剪(ZX)和不留枝叶的截干回缩修剪(JX)3种方式修剪后移植,经过3a连续试验观察,研究不同修剪方式对广玉兰大树移植成活率和生长的影响。结果表明,与CK相比,3种修剪方式极显著提高广玉兰移植后的成活率和新生叶片数、第2年(2013年)和第3年(2014年)的侧梢数、侧梢长度和底径以及第1年(2012年)和第3年(2014年)冠幅生长;与其他2种修剪方式相比,JX显著提高广玉兰移植成活率、第2年(2013年)和第3年(2014年)的侧梢数、顶梢长度、侧梢长度及冠幅生长以及第3年(2014年)的新生叶片数;显著提高第2年(2013年)和第3年(2014年)的侧梢底径。表明截干回缩修剪更有利于广玉兰大树移植的成活和复壮生长。  相似文献   

加强生长育肥猪的饲养管理减少疾病的发生     

吴正明  邱丙姗  程娜  李志勋  赵桂英 《猪业科学》2020,37(9):59-61

在整个养猪生产中,育肥是养猪的最后一个生产环节,是检测猪种选择是否正确,营养饲料是否适合,饲养技术是否过硬,疫病防控是否完善的关键,不仅关系到市场供应,而且对猪场经济效益有着重要影响,也是发展养猪生产的最终目的。  相似文献   

不同海拔对幼年牦牛生长发育的观察     

刘更寿 《青海畜牧兽医杂志》2014,(3):18-19

对幼年牦牛断乳后分别在海拔3200m和4229m地区饲养,结果高海拔饲养的牦牛的体重和各项体尺均显著高于低海拔饲养的牦牛。  相似文献   

Demographic trends in Claremont California’s street tree population     

《Urban Forestry & Urban Greening》2018

The aim of this study was to quantify street tree population dynamics in the city of Claremont, CA. A repeated measures survey (2000 and 2014) based on a stratified random sampling approach across size classes and for the most abundant 21 species was analyzed to calculate removal, growth, and replacement planting rates. Demographic rates were estimated using a hierarchical Bayesian framework. The community-level (all species) median growth rate was 1.41% per year (95% CI: 1.21–1.65%) with Pinus brutia and Pistacia chinensis growing significantly faster than the community-level median. The community-level median removal rate was 1.03% per year (95% CI: 0.66–1.68%), with no significant differences between species and the community-level medium. Once removed, only 7.2% (95% CI: 4.4–12.9%) were replaced annually. Presence of overhead utility lines influenced tree removal rates while age, diameter-at-breast-height, and prior tree condition influenced tree growth. Overall live aboveground biomass in sampled sites was 713.29 Mg in 2000 and increased to 877.36 Mg by 2014. Biomass gain from growth outweighed loss from removals nearly three-fold; replacement contributed 0.5% of the total biomass gain. We conclude that to increase the resilience of the street tree population will require 1) an increase in percent of full stocking or biomass stock and 2) a shift in the species palette to favor species less vulnerable to pests and expected disturbance from climate change and 3) ongoing monitoring to detect departures from baseline demographic rates.  相似文献