Relationship between rooting ability and endogenous phytohormone changes in successive continuous generation cuttings of Buxus sinica var. parvifolia, an endangered woody species in China

The objectives of this study were to investigate the effects of successive continuous generation （SCG） cuttings of Buxus sinica var. parvifolia on the rejuvenation of ortets at the hormone level, detect levels of indoleacetic acid （IAA）, abscisic acid （ABA）, isopentenyladenosine （iPA）, zeatin riboside （ZR） and gibberellin4 （GA4） during the rooting process of different generations by means of enzyme-linked immunosorbent assay （ELISA） technology and statistically analyze the rooting characteristics of cuttings. The results show that, the root systems of subsequent generations （generation 1998, 2000） developed satisfactorily, only a few initial generation （generation 1990, 1994） cuttings rooted and the root growth was inhibited. Around the period of callus formation and root projection through the epidermis, there was a marked, regular variation in the levels of IAA, ABA and GA4 between the initial generations and subsequent generations.

Polyoxometalates for continuous power generation by atmospheric humidity

Atmospheric humidity is a sustainable low-value energy widely existing in natural environment,which is a promising candidate to solve the noncontinuous and low efficiency of low-value energy power generation.Here the mono-substituted Dawson-type polyoxometalates are constructed to be highly dispersed organic ammonium-polyoxoanion clusters and are assembled into thin films power generators with micropores,working in atmospheric humidity.The optimal polyoxometalates generator with the thickness of 7.2μm and the area of 0.36 cm^(2) produces a voltage of 0.68 V and a current density of 19.5μA·cm^(-2) under simulated natural environment,and works continuously and stably under almost all-natural environments(humidity 10%–90%).The highly dispersed polyoxometalate nanoclusters can form microporous in polyoxometalate films to effectively absorb atmospheric humidity and spontaneously form distribution gradient of water,which is the structural basis of power generation.The continuous power generation may be maintained by the effective adsorption and utilization of H_(2)O,the huge electrostatic field of organic ammonium-polyoxoanion clusters,and the reasonably designed polyoxometalates containing inorganic small ions with high mobility.It is the first humidity generator designed with polyoxometalates,which may provide a new research direction for polyoxometalates in sustainable utilization of low-value energy.

Accumulation conditions and key technologies for exploration and development in Sebei gas field in Qaidam Basin,NW China

The Sebei gas field,located in the northern slope of the Sanhu depression in the eastern Qaidam Basin,is the largest inland biogas producing area in China.It is a typical Quaternary biogenetic gas reservoir composed of multiple layers of unconsolidated sandstone.Through systematic study of gas generating mechanism of source rock,reservoir-caprock combination and trap evolution,the unique biogas accumulation model characterized by“continuous hydrocarbon generation and dynamic accumulation”is established.Its uniqueness is reflected in the biogas generation mechanism under dual effect of lowtemperature thermodynamics and microbial degradation,source-reservoir one body,self generation and self storage,dynamic source-reservoir-caprock assemblages and anticline trap formation mechanism of multi-factor mutual promotion.This understanding reveals the intrinsic factors for formation of largescale biogas field under frigid climate,high salinity and low organic matter abundance.A number of exploration and development technologies have been worked out during the exploration and development of the Sebei gas field.Among them,the low-amplitude structure identification technique,multiparameter gas-bearing detection technique,sand control and comprehensive water control technique for unconsolidated sandstone are well applied in discovering the gas field,increasing reserve,and increasing and maintaining gas production.The above understandings and key technologies have great reference significance and demonstration effect for biogas exploration and development in China and the world.