氮磷钾对马铃薯产量和品质影响的研究进展

为了进一步提高马铃薯的产量和品质,简要综述了氮磷钾对马铃薯生长发育过程及产量和品质形成的影响以及马铃薯对其吸收、积累和分配的规律,并总结了影响氮磷钾提高马铃薯产量和品质的因素及肥料类型、合理配比与施肥时期。     

贵州烟草商业信息化现状及对策研究

信息化是提高企业经济效益和增强竞争力的重要手段。本文首先分析贵州烟草商业信息化建设现状,然后在此基础上总结贵州烟草商业信息化建设存在的主要问题,最后结合贵州烟草企业的战略发展需要,给出贵州烟草商业未来解决信息化问题的思路及对策。     

微生物脱氮作用及对中间产物的抑制

开展了 pH及好氧 厌氧转换对微生物脱氮作用影响的研究 ,结果表明 ,在 pH7.5时 ,经过 3次好氧与厌氧条件转换后 ,混合微生物的脱氮作用能顺利进行 ,N2产量持续稳定 ,NO2- 、N2O和NO产量很少 ;在 pH =6.8时 ,中间产物NO2- 、N2O等大量出现 ,脱氮菌的细胞干重急速下降并被洗出 ,脱氮能力受到抑制     

中央和地方政府水利投融资的演化博弈分析

在我国水利建设资金配置中,存在着中央和地方两级政府作为投资的主体,在兴建水利工程上进行着是否投资的利益博弈.基于演化博弈视角,分析了中央政府与地方政府在不同收益考量下长期博弈中形成的演化稳定策略,并揭示出由于存在“智猪博弈心态”,双方共同投资水利工程始终是不稳定策略组合,揭示了当前政府主导型的水利资金配置机制僵化现象.     

基于贵州省土地变化的碳储量演变及其脆弱性特征分析

[目的]分析贵州省生态系统碳储量时空分布格局、演变特征及其对土地利用转移的响应,研究各县域生态系统碳储量服务的脆弱性,为贵州省区域土地利用管理决策及“双碳”目标的实现提供科学依据和参考。[方法]运用InVEST模型和潜在影响指数(PI)分析贵州省2000—2020年碳储量变化特征和生态系统碳储存服务的脆弱性。[结果](1)近20 a间贵州省土地利用结构发生显著变化,前10 a和后10 a分别有14.10%,17.29%的土地发生转移,耕地是建设用地扩张的主要来源。(2)贵州省20 a间生态系统碳储量减少2.40×10⁷ t,林地的缩减和建设用地的扩张是碳储量减少的主要原因。(3)贵州省碳储量Moran’s I指数均大于0,空间分布具有显著的空间正相关性和集聚性。冷热点分析显示碳储量热点分布较为分散,冷点分布集中稳定。(4)贵州省前10 a和后10 a PI指数分别为-1.27和-0.15,脆弱性有所改善。县域间脆弱性存在空间差异,边缘县域负向影响显著,20 a间81.82%的县脆弱性降低。[结论]贵州省林地的转出和建设用地的扩张对碳储量和碳储量服务脆弱性影响显著,...     

望谟县特大山洪泥石流灾后重建分区与功能定位

贵州省黔西南自治州望谟县灾后重建关系到灾区群众的切身利益和长远发展,必须全面贯彻落实科学发展观,坚持以人为本,尊重自然,科学规划,合理布局,要立足灾区实际,做好重建分区与功能定位.在灾区范围内根据流域的生态环境背景,通过对其资源环境承载能力进行综合评价,充分考虑其国土开发强度、产业发展方向以及人口集聚和城镇建设的适宜程度,对其指标体系进行分层聚类,以定量为主,定性为辅进行生态环境建设分区,同时兼顾行政单元的完整性,将灾区范围国土空间分为生态保护区(面积376.07 km2)、适度重建区(面积716.06 km2)、适宜发展区(面积407.47 km2),分析其功能定位,使管制原则与城镇建设更趋于合理,为灾后重建的规划布局工作提供理论支撑.     

从三个层面突破"最后一公里"

社会的进步,知识经济的初现端倪,使人们开始注意到了传统经济增长理论的一个缺陷.过去的经济增长理论只是将土地、人和资本作为生产要素,而将知识作为一个外在余值.由于知识包含了人类对自然和社会的所有认知和适应,是真正意义上的生产要素.离开知识就不会有经济增长,而经济增长的过程实质上就是一个知识增长的过程.科技部提供的一组数据,也直观地说明了科技对促进农业生产的作用：“十五”前3年,新培育出农作物新品种800多个,平均增产10%以上;粮食超高产栽培技术取得重大突破,三熟地区试验田667m^2产量已接近1 900 kg;重大动植物病虫害防治技术有效增强了对突发性动植物病虫害的防控能力,每年可挽回粮食损失2 500万t.     

Effects of insecticide acetamiprid on photosystem II (PSII) activity of Synechocystis sp. (FACHB-898)

Effects of insecticide acetamiprid on photosystem II (PSII) activity of Synechocystis sp. were investigated by a variety of in vivo chlorophyll fluorescence tests. Acetamiprid exposure increased the proportion of inactivated PSII reactive centers (PSII_X) and led to loss of active centers (PSII_A). High concentration (1.0 mM) acetamiprid decreased amplitude of the fast phase and increased the slow phase of fluorescence decay during reoxidation. The electron transport after Q_A was hindered by high concentration acetamiprid and more Q_A had to be reoxidized through S₂(Q_AQ_B)⁻ charge recombination. Acetamiprid decreased the density of the active reaction centers, electron transport flux per cross section and the performance of PSII activity but had little effect on dissipated energy flux per reaction center, antenna size and the maximum quantum yield for primary photochemistry (F_v/F_m). The target site of acetamiprid toxicity to the PSII of Synechocystis sp. was electron transfer on the acceptor side.     

Protective effect of heat-shock pretreatment on rat ischemia-reperfusion myocardium

AIM:To investigate the changes of expression of P-selectin (Ps) in ischemia-reperfusion myocardium and to observe the effects of heat shock protein (HSP) on the expression of Ps and apoptosis. METHODS:Mature female Wistar rats (n=40) were divided into three groups at random. Under general anesthesia, the rats in heat-shock group were subjected to whole-body hyperthermia, and those in the other two groups were treated with anesthetic alone. Twenty-four hours later, the animals in heat-shock group and in control group were subjected to surgical operative ligation of coronary left anterior descending branch (LAD) for 1 h, then accepted reperfusion for 2 h. Those in sham operation group were also performed surgical operation without LAD ligation for 3 h. After operation, the CK-MB in blood serum, infarct size of left ventricles, HSP70, Bax, Bcl-2, Ps and apoptosis cells were measured. RESULTS:The amount of HSP70 in heat-shock group was significant higher than that in control group and in sham operation group (P<0.05). There was no difference between control group and sham operation group (P>0.05). Compared with control group, the infarct size, CK-MB, apoptosis cells, Bax and Ps in heat-shock group were significantly reduced (P<0.05). However, expression of Bcl-2 was similar (P>0.05). No expression of Ps in sham operation group was detected. CONCLUSIONS:HSP70 may reduce myocardial apoptosis during ischemia-reperfusion. One of the mechanisms is that HSP70 restraines the expression of Bax and Bax/Bcl-2. Ps plays an injurious role in ischemia-reperfusion myocardium. HSP70 is likely to restrain Ps from expression, which may be one of the mechanisms by which heat-shock pretreatment plays a protective role in ischemia- reperfusion myocardium.     

灵芝和菌糠降低鸡蛋胆固醇的试验研究

选取48周龄海兰褐商品蛋鸡120羽,随机分成3组,试验期为4周,对照组Ⅰ组喂基础日粮,试验Ⅱ组添加2.5g/kg灵芝,试验Ⅲ组添加2.5g/kg菌糠,在一致的背景下,探讨灵芝、菌糠对鸡蛋胆固醇的影响。结果表明:Ⅱ、Ⅲ组可降低蛋鸡血液甘油三酯(TG)、总胆固醇(TC)含量,增高血清高密度脂蛋白胆固醇(HDL-C)含量;3组之间料蛋比差异显著,Ⅱ、Ⅲ组料蛋比分别比对照组低6.4%(P<0.05)、11.0%(P<0.05)。Ⅱ、Ⅲ组平均产蛋率分别比对照组提高5.38%(P<0.05)和3.29%(P<0.05)。试验4周,Ⅱ、Ⅲ组鸡蛋胆固醇含量分别降低15.3%(P<0.05)和10.4%(P<0.05),且两组间差异显著(P<0.05),研究表明灵芝及菌糠均能提高蛋鸡生产性能,降低鸡蛋胆固醇含量。相比之下,灵芝是降低鸡蛋胆固醇较为理想的添加剂。