裸地直播下播期对德棉16号产量和品质的影响

为了防治棉田地膜污染,探讨春季裸地直播栽培条件下,德棉16号在山东德州地区的适宜播期,以德棉16号为材料,设置3个播期处理,分析了裸地栽培条件下不同播期对棉花农艺性状、植株干物质积累、产量和纤维品质的影响。结果表明,裸地直播条件下播期显著影响德棉16号的果枝数、花期株高、铃期株高、子指和断裂比强度,对其他性状的影响则无显著差异;德棉16号在该地区裸地直播最适播期为5月6日,过早或过晚播种均比覆膜棉花降低产量10%以上。通过优化栽培措施可以降低无膜棉对产量的损失,该研究结果可为鲁西北棉区绿色植棉提供参考。

增密减氮对棉花干物质和氮素积累分配及产量的影响

为了探讨种植密度和施氮量对棉花干物质与氮素积累分配及产量的影响。本研究以聊棉6号为试验材料,设置5.25、6.75和8.25万株hm^-2(D5.25、D6.75、D8.25)3个种植密度,0、105、210、315和420 kg hm^-2(N0、N105、N210、N315、N420)5个施氮量,研究增密减氮对棉花干物质积累与分配、氮素积累与分配、产量及其构成因素的影响。结果表明,与D5.25相比,D6.75、D8.25条件下棉花干物质积累量显著升高,2016年提高了17.6%、28.7%,2017年提高了12.6%、20.9%。与N0相比,施氮肥后干物质积累量随施氮量的增加显著升高,2016年各施氮处理分别提高了4.5%、11.1%、13.7%、16.3%,2017年提高了3.6%、13.5%、15.3%、19.8%。棉花氮素吸收与干物质积累动态曲线均符合Logistic模型,2年间棉株氮素最大累积量(Ym)均在D8.25N420处理下获得,与平均值相比,棉株氮素最大累积量分别提高了17.3%和23.8%、快速累积持续时间(T)延长了5.2%和9.9%、最大累积速率(Vm)提升11.5%和13.8%,氮素快速积累期起始时期(t1)比干物质积累分别提早了4.1 d和6.4 d。2016年D5.25N315、D6.75N210、D6.75N105和2017年D5.25N315、D6.75N210处理的棉花产量显著高于其他处理。种植密度和施氮量的互作效应对棉花产量的影响显著,增密减氮可以获得高产,推荐本地区棉花种植密度从常规的5.25万株hm^-2增加到6.75万株hm^-2,施氮量从常规的300 kg hm^-2第一年减少为105 kg hm^-2,第二年减少为210 kg hm^-2。

Effects of plant density and nitrogen rate on cotton yield and nitrogen use in cotton stubble retaining fields

Increasing nitrogen(N)rate could accelerate the decomposition of crop residues,and then improve crop yield by increasing N availability of soil and N uptake of crops.However,it is not clear whether N rate and plant density should be modified after a long period of cotton stubble return with high N rate.This study seeks to assess the effects of N rate and plant density on cotton yield,N use efficiency,leaf senescence,soil inorganic N,and apparent N balance in cotton stubble return fields in Liaocheng,China,in 2016 and 2017.Three plant densities 5.25(D_(5.25)),6.75(D_(6.75))and 8.25(D_(8.25))plants m^(-2) and five N rates 0(N_(0)),105(N_(105)),210(N_(210)),315(N315),and 420(N420)kg ha^(-1) were investigated.Compared to the combination used by local farmers(D_(5.25)N_(315)),a 33.3%N reduction and a 28.6%increase in plant density(D_(6.75)N_(210))can maintain high cotton yield,while a 66.7%N reduction at 6.75 plants m^(-2)(D_(6.75)N_(105))can only achieve high yield in the first year.Biological yield increased with the increase of N rate and plant density,and the highest yield was obtained under 420 kg N ha^(-1) at 8.25 plants m^(-2)(D_(8.25)N_(420))across the two years under investigation.Compared to D5.25N315,N agronomic efficiency(NAE)and N recovery efficiency(NRE)in D_(6.75)N_(210) increased by 30.2 and 54.1%,respectively,and NAE and NRE in D6.75N105 increased by 104.8 and 88.1%,respectively.Soil inorganic N decreased sharply under 105 kg N ha^(-1),but no change was found under 210 kg N ha^(-1) at 6.75 plants m^(-2).N deficit occurred under 105 kg N ha^(-1),but it did not occurr under 210 kg N ha^(-1) at 6.75 plants m^(-2).Net photosynthetic rate and N concentration of leaves under N rate ranging from 210 to 420 kg ha^(-1) were higher than those under N rate of 0 or 105 kg N ha^(-1) at all three densities.The findings suggest that D6.75N210 is a superior combination in cotton stubble retaining fields in the Yellow River Valley and other areas with similar ecologies.

博来霉素病灶内注射在皮肤科的临床应用

博来霉素族抗生素属于氨基糖肽类的一个亚家族,是一种抗肿瘤抗生素。现阶段博来霉素族抗生素临床上容易获得且最常用的是博来霉素。博来霉素的主要作用机制是DNA链切割。博来霉素在皮肤科的应用主要包括难治性跖疣和甲周疣、瘢痕疙瘩和增生性疤痕、婴儿血管瘤、非黑色素瘤皮肤癌、皮肤转移瘤角化棘皮瘤等。博来霉素注射后的皮肤反应包括疼痛、红斑、水肿、发黑、焦痂形成、色素改变。偶尔报告的不良反应是坏疽、甲癣、雷诺现象、硬皮病和鞭挞样红斑。

伟大民族精神是决胜全面建成小康社会的强大精神力量

决胜全面建成小康社会离不开强大的精神力量的支撑和推动,人民群众中蕴藏着决胜全面建成小康社会的强大精神力量。决胜全面建成小康社会需要坚持以人民为中心,弘扬人民群众的伟大创造精神、伟大奋斗精神、伟大团结精神和伟大梦想精神。