The newly identified Jinlin crater in southern China lies on a hillside covered by a thick granite weathering crust.It appears as a slightly elliptical bowl-shaped depression with a diameter of 820-900 m.The structure...The newly identified Jinlin crater in southern China lies on a hillside covered by a thick granite weathering crust.It appears as a slightly elliptical bowl-shaped depression with a diameter of 820-900 m.The structure is a tilted impact crater,showing a maximum rim height difference of about 200 m and an apparent depth of 90 m.The crater rim is composed mainly of granite weathered soil and a small amount of granite fragments,while the bottom of the crater is filled with the same mixture of granite weathered soil and granite fragments.Planar deformation features in quartz grains from the rock fragments of the crater provide decisive evidence for its impact origin.The impact event is inferred to have taken place during the Holocene.展开更多
Tree peony is well known and sought after for its large, colorful flowers. Its propagation is via vegetative methods. Mech- nisms of the adventitious rooting and the regulation of rooting processes are the principles ...Tree peony is well known and sought after for its large, colorful flowers. Its propagation is via vegetative methods. Mech- nisms of the adventitious rooting and the regulation of rooting processes are the principles and techniques of plant propagation and improvement. Microstructures and fluctuations of phytohormones in the adventitious rooting were studied with the etiolated soft- wood shoots of Paeonia suffkuticosa ＇Yinfen Jinlin＇. There are no pre-primordia in the shoots of the cultivar. Adventitious roots are produced in five stages： shoot selection, primordium initiation, primordium growth, conducting tissue differentiation and root protru- sion. Primordia initiated in the cortex. The contents of the endogenous hormones, IAA, ABA and GA, were 5.842, 0.873 and 1.043 nmol·g^-1 FW on the bases of shoots, respectively. CTKs which included isopentenyl adenine （iPA）, zeatin riboside （ZR） and dihy- drozeatin riboside （DHZR） were 0.949, 0.695 and 2.034 nmol·g^-1 FW, respectively. DHZR is active among CTKs. The ratio of IAA to GA, CTK and ABA clearly increased at the stage of primordium initiation, while they showed low levels at the stages of primor- dium growth. The ratios were restored at the shoot levels at the stage of root protrusion. IBA provoked primordia initiation in the cortex, the vascular cambium, the pith and even in the callus induced on the base of shoots. ]AA levels in the treated shoots increased gradually to its highest level （three times of control） at the stage of conducting tissue differentiation. The ratios of IAA to GA, CTK and ABA clearly decreased at the stage of primordium initiation. The ratio of IAA to ABA is regulated at 10：1.展开更多
在对芦苇小区调查取样的基础上,利用Pearson关联分析法研究了土壤水、电导率与芦苇生长和种群分布的关系。结果表明土壤电导率空间变率明显,最大值是最小值的2倍。芦苇小区土壤电导率超过110 m S/m,且pH值大于10时,芦苇由单一种群落转...在对芦苇小区调查取样的基础上,利用Pearson关联分析法研究了土壤水、电导率与芦苇生长和种群分布的关系。结果表明土壤电导率空间变率明显,最大值是最小值的2倍。芦苇小区土壤电导率超过110 m S/m,且pH值大于10时,芦苇由单一种群落转变成伴生种群落(芦苇+碱茅)。并随着电导率和pH值的增加,碱茅所占的比例增加。土壤电导率与芦苇生长指标(覆盖度、平均株高、生物量干重、鲜重)呈显著性相关(p<0.01),说明土壤盐分是影响芦苇种群特征的重要因素。表层土壤含水量(10 cm剖面)与芦苇生长指标中的覆盖度、生物量呈显著性相关(p<0.05)。深层含水量(100 cm剖面)与芦苇生长指标均呈显著性相关(p<0.05),因此表层水和深层水对芦苇的生长具有重要作用。展开更多
基金financial support from Shanghai Key Laboratory Novel Extreme Condition Materials,China(Grant No.22dz2260800)the Shanghai Science and Technology Committee,China(Grant No.22JC1410300).
文摘The newly identified Jinlin crater in southern China lies on a hillside covered by a thick granite weathering crust.It appears as a slightly elliptical bowl-shaped depression with a diameter of 820-900 m.The structure is a tilted impact crater,showing a maximum rim height difference of about 200 m and an apparent depth of 90 m.The crater rim is composed mainly of granite weathered soil and a small amount of granite fragments,while the bottom of the crater is filled with the same mixture of granite weathered soil and granite fragments.Planar deformation features in quartz grains from the rock fragments of the crater provide decisive evidence for its impact origin.The impact event is inferred to have taken place during the Holocene.
文摘Tree peony is well known and sought after for its large, colorful flowers. Its propagation is via vegetative methods. Mech- nisms of the adventitious rooting and the regulation of rooting processes are the principles and techniques of plant propagation and improvement. Microstructures and fluctuations of phytohormones in the adventitious rooting were studied with the etiolated soft- wood shoots of Paeonia suffkuticosa ＇Yinfen Jinlin＇. There are no pre-primordia in the shoots of the cultivar. Adventitious roots are produced in five stages： shoot selection, primordium initiation, primordium growth, conducting tissue differentiation and root protru- sion. Primordia initiated in the cortex. The contents of the endogenous hormones, IAA, ABA and GA, were 5.842, 0.873 and 1.043 nmol·g^-1 FW on the bases of shoots, respectively. CTKs which included isopentenyl adenine （iPA）, zeatin riboside （ZR） and dihy- drozeatin riboside （DHZR） were 0.949, 0.695 and 2.034 nmol·g^-1 FW, respectively. DHZR is active among CTKs. The ratio of IAA to GA, CTK and ABA clearly increased at the stage of primordium initiation, while they showed low levels at the stages of primor- dium growth. The ratios were restored at the shoot levels at the stage of root protrusion. IBA provoked primordia initiation in the cortex, the vascular cambium, the pith and even in the callus induced on the base of shoots. ]AA levels in the treated shoots increased gradually to its highest level （three times of control） at the stage of conducting tissue differentiation. The ratios of IAA to GA, CTK and ABA clearly decreased at the stage of primordium initiation. The ratio of IAA to ABA is regulated at 10：1.
文摘在对芦苇小区调查取样的基础上,利用Pearson关联分析法研究了土壤水、电导率与芦苇生长和种群分布的关系。结果表明土壤电导率空间变率明显,最大值是最小值的2倍。芦苇小区土壤电导率超过110 m S/m,且pH值大于10时,芦苇由单一种群落转变成伴生种群落(芦苇+碱茅)。并随着电导率和pH值的增加,碱茅所占的比例增加。土壤电导率与芦苇生长指标(覆盖度、平均株高、生物量干重、鲜重)呈显著性相关(p<0.01),说明土壤盐分是影响芦苇种群特征的重要因素。表层土壤含水量(10 cm剖面)与芦苇生长指标中的覆盖度、生物量呈显著性相关(p<0.05)。深层含水量(100 cm剖面)与芦苇生长指标均呈显著性相关(p<0.05),因此表层水和深层水对芦苇的生长具有重要作用。
