不同施氮方式及施氮量对砂生槐生长及生根的影响

以1年生砂生槐播种苗为研究对象,通过设置两种施氮方式(平均施肥和指数施肥)和5个氮素水平(CK、200、400、800 mg/株、平均施肥400 mg/株),分析苗木生长和生根对不同施氮方式及施氮量的响应。结果表明:不同施氮方式处理下,指数施肥(200 mg/株)处理下苗高、地径、比叶质量及生物量均达到最大值且高于平均施肥(400 mg/株);指数施肥(200、400、800 mg/株)时,根系的生物量、总长度、表面积和体积均高于平均施肥(400 mg/株)处理;指数施肥(200 mg/株)的根系组织密度最大(0.51 g/cm_(3))且高于平均施肥(400 mg/株)。不同施氮量处理下,指数施肥(200 mg/株)处理的苗高、地径、比叶质量及生物量均达到最大值,根系生物量、总长度、体积和组织密度表现最好,平均施肥(400 mg/株)处理表现较差。指数施肥(200、400 mg/株)处理的根表面积较大,而对照、平均施肥(400 mg/株)处理的表现欠佳。

干旱胁迫对西藏半干旱河谷区典型灌木生理特性和解剖结构的影响

以西藏干旱半干旱区5种典型灌木为研究对象,进行不同干旱下的盆栽试验,通过对比5种灌木叶片中的生理特性及解剖结构的变化,对其进行抗旱性能分析与评价。设充分供水(CK,土壤含水量为田间持水量的90%~95%),轻度干旱(LS,70%~75%),中度干旱(MS,50%~55%为),重度干旱(HS,30%~35%)。结果表明:①各树种生理特性对不同水分梯度的响应各异,其中各水分条件下砂生槐叶片过氧化物酶(POD)活性均显著高于其他树种(P<0.05),中度干旱时其分别是香柏、醉鱼草、江孜沙棘和细叶小红柳的3.1、5.3、6.0、10.5倍;细叶小红柳和香柏的叶绿素质量分数较另外3个树种较低,醉鱼草在中度干旱时叶绿素质量分数达到1.95 mg/g,显著高于其他处理(P<0.05);中、重度干旱会增加细叶小红柳、江孜沙棘、砂生槐及醉鱼草丙二醛质量摩尔浓度。②不同水分条件下各灌木树种气孔密度存在差异,细叶小红柳气孔密度在轻度干旱下最大;江孜沙棘气孔密度在充分供水、轻度干旱和中度干旱时较大,重度干旱时显著小于其余3个水分条件(P<0.05);香柏气孔密度在轻度干旱时最大;砂生槐气孔密度在轻度干旱和中度干旱时显著大于充分供水和重度干旱条件(P<0.05);醉鱼草气孔密度在充分供水和轻度干旱时较大。③随干旱加剧,细叶小红柳和醉鱼草叶片厚度和海绵组织厚度均逐渐减小,砂生槐栅栏组织厚度在各水分条件下均显著大于其他树种,且其在各水分梯度下差异不显著;组织紧密度砂生槐远大于其余树种,醉鱼草和江孜沙棘次之,香柏最小,组织疏松度香柏最大,其次为砂生槐,其余3个数种差异不显著。主成分分析结果表明5种灌木树种中砂生槐的抗旱性最强,香柏最弱,抗旱性由大到小表现为砂生槐、江孜沙棘、醉鱼草、细叶小红柳、香柏。

容器类型和规格对砂生槐幼苗生长的影响

通过对比不同容器类型和容器规格条件下一年生砂生槐幼苗生长及根系发育状况,筛选出适宜砂生槐容器苗培育的容器类型和规格,为砂生槐的壮苗培育和成功造林提供理论依据。结果表明:1)不同容器对砂生槐幼苗的生长影响显著。幼苗的苗高、生物量以及质量指数在容器Ⅱ处理下达到最大值。2)幼苗叶绿素含量和根系活力在容器Ⅱ处理下达到最大值且与另外两组处理间差异显著(P<0.05),但容器Ⅱ处理显著降低了幼苗的丙二醛、超氧化物歧化酶、过氧化物酶和脯氨酸的含量。3)较小规格的育苗容器明显限制了砂生槐幼苗的根系伸展。幼苗的根系长度、根系表面积、根系体积和根系生物量均在容器Ⅱ处理时达到最大值,且与另外两组处理间差异显著(P<0.05)。但根系组织密度在容器Ⅰ处理下最大,表现为:容器Ⅰ>容器Ⅲ>容器Ⅱ。结合苗木质量及苗木生产的经济成本,在生产实践中为获得优质壮苗,砂生槐容器苗培育时优先选择12 cm×16 cm规格的无纺布育苗袋。

论公共图书馆少儿阅读推广的服务发展趋势——以苏州为例

公共图书馆少儿阅读推广服务需要根据不同年龄段儿童的生理、心理、行为习惯和认知方面的差异,在阅读推广对象、阅读推广主体、阅读推广客体和阅读推广方式等方面组织开展不同的阅读活动,更加注重人文关怀,充分重视阅读活动的评估。

不同生长素对藏川杨生长扦插繁殖的影响

为培育优质的藏川杨苗木,本文探讨了不同生长素处理对藏川杨插穗生根的影响。以藏川杨枝条为试验材料,以清水作为对照,设置了不同类型的生根粉(ABT1号、2号、3号)及不同浓度的2,4-D(100、200、300、400、500 mg/L),测定其插穗苗高、地径、总根数、最长根长及生物量等指标。不同生根粉对藏川杨后期的成活株数表现依次为:ABT1号>ABT2号>ABT3号;较低浓度的2,4-D(100、200 mg/L)处理下藏川杨后期的成活率、苗高、地径、总根数均表现较好。对比不同类型的生根粉和不同浓度的2,4-D后发现,适宜浓度的生长素处理对藏川杨扦插苗根系发生和发育具有促进的作用。在生产中,为了提高藏川杨的成活率,可以选用ABT1号和较低浓度的2,4-D(100、200 mg/L)。

Study of Treating HAPE with HBO in Situ at the Altitude of 4636m

Study Objective: To evaluate the treatment effect of HAPE with HBO in situ at an extreme altitude of 4636 m. To investigate the relationship between pulmonary hypertension (PH) and HAPE. To emphasize the importance of the treatment in situ.Methods: The 32 patients from the plateau of 4636～5130 m (the barometric pressure: 57.41～53.28 kPa/431.6～400.6 mmHg(1 mmHg=133.3224 Pa), the partial pressure of oxygen: 12.0～11.6 kPa/90.0～87.0 mmHg) were treated in situ of 4636 m altitude with HBO. Before and after the treatment, the clinical symptoms / signs, radiographic evidence, SaO2, and MPAP were compared.Results: The clinical symptoms/signs, and all the targets of the patients were improved dramatically (p<0.001).Conclusions: Treating HAPE with HBO is the most effective method among various therapies in situ at an extreme altitude. The pulmonary -artery pressure was significantly decreased. All cases showed improved immediately. Among the subjects, 11 cases (34.3%) were cured at once. The therapy made it possible for patients to get further treatment at a lower altitude area with prospective good results. We suggested that treating HAPE with HBO should be the first choice in situ. There must be PH in the patients of HAPE, but the reverse is not the true. The PH is a mechanism of normal compensation of the body exposing in the hypoxic environment. It is very necessary for us to explore the threshold of PH when a HAPE happens.

The Difference of the Pulmonary-Artery Pressure of the Migrantsfrom Difference Elevation at the 4636～4907 m Altitude

Study Objective: To compare and analyze the changes of the pulmonary-artery pressure of the migrants coming from different elevation in the hypoxic environment of 4636～4907 m extreme altitude. To explore the susceptibility to hypoxic pulmonary-artery hypertension (PH) in the subjects from different altitude and profession.Methods: By using Color Doppler Ultrasonography (CDU), measuring the pulmonary-artery pressure of 207 healthy men, who had continuously being lived and worked at the extreme altitude for more than six months, and then were divided into three groups according to their profession and the altitude of original living place. Results: There was a significant difference in the outcomes of pulmonary-artery pressure from the 3 groups. Conclusions: Altitude of original living place, labor intensity are some of factors that impact the pulmonary-artery pressure of the people who exposure to a hypoxic environment. The pulmonary-artery pressure of person without strenuously physical work experience was more sensitive to hypoxic surroundings than that of labor workers. It was not always the fact at an extreme altitude that the moderate altitude mountaineers were superior to other migrants from a lower altitude or plain. The higher PH was found in the groups of the moderate altitude mountaineers and labor workers. It is unlikely certain that one with PH would surfer from HAPE.

保水剂对砂生槐幼苗生长及生理的影响

以砂生槐一年生播种苗为试材,设置5个保水剂用量(CK、T1、T2、T3、T4),研究了不同浓度保水剂对砂生槐幼苗生长、生理和生根指标的影响,以期为砂生槐的最佳节水模式及水分高效利用提供参考依据。结果表明:保水剂施用量的增加可以提高砂生槐幼苗的苗高、地径和生物量;幼苗的苗高、地径及生物量在T2处理下达到最大值且均随着保水剂浓度的增加呈先增后减的趋势。施用保水剂提高了砂生槐叶绿素含量和根系活力,在T2处理时幼苗叶绿素含量和根系活力最大;施用保水剂降低了丙二醛和脯氨酸含量,降低了超氧化物歧化酶、过氧化物酶活性。砂生槐幼苗根系生物量、总长度、表面积和体积在T2处理下达到最大值且均随着保水剂浓度的增加呈先增后减的趋势。在适宜添加量范围内,施用保水剂能提高砂生槐幼苗生长,而当施用量过大时将阻碍砂生槐幼苗正常生长,以T2(0.2%)的保水剂用量作用效果最佳。