Development characteristics and controlling factors of fractures in lacustrine shale and their geological significance for evaluating shale oil sweet spots in the third member of the Shahejie Formation in the Qikou Sag, Bohai Bay Basin

Natural fractures are critical for shale oil and gas enrichment and development. Due to the extremely high heterogeneity of shale, the factors controlling the formation of internal fractures, especially horizontal fractures, remain controversial. In this study, we integrate thin section analysis and microcomputed tomography(CT) data from several lacustrine shale samples from the third member(Es3) of the Shahejie Formation, Qikou Sag, Bohai Bay Basin, to assess the fractures in detail. The goal is to reveal the development characteristics, controlling factors, and geological significance for evaluating sweet spots in a shale oil play. The fractures in the Es3contain high-angle structural and horizontal bed-parallel fractures that are mostly shear and extensional. Various factors influence fracture development,including lithofacies, mineral composition, organic matter content, and the number of laminae. Structural fractures occur predominantly in siltstone, whereas bed-parallel fractures are abundant in laminated shale and layered mudstone. A higher quartz content results in higher shale brittleness, causing fractures, whereas the transformation between clay minerals contributes to the development of bedparallel fractures. Excess pore pressure due to hydrocarbon generation and expulsion during thermal advance can cause the formation of bed-parallel fractures. The density of the bed-parallel and structural fractures increases with the lamina density, and the bed-parallel fractures are more sensitive to the number of laminae. The fractures are critical storage spaces and flow conduits and are indicative of sweet spots. The laminated shale in the Es3with a high organic matter content contains natural fractures and is an organic-rich, liquid-rich, self-sourced shale play. Conversely, the siltstone, massive mudstone, and argillaceous carbonate lithofacies contain lower amounts of organic matter and do not have bed-parallel fractures. However, good reservoirs can form in these areas when structural fractures are present and the source, and storage spaces are separated.

Morphological characteristics,developmental dynamics,and gene temporal expressions across various development stages of Aphis gossypii sexual female

Background Aphis gossypii(Hemiptera:Aphididae)is a worldwide polyphagous phloem-feeding agricultural pest,and it can produce offspring by sexual or asexual reproduction.Compared with dozens of generations by parthenogenesis,sexual reproduction is performed in only one generation within one year,and little is known about the sexual reproduction of A.gossypii.In this study,sexual females of A.gossypii were successfully obtained through a previously established induction platform,and the morphological characteristics,developmental dynamics,and temporal gene expression were examined.Subsequently,signaling pathways potentially involved in regulating the growth,development,and reproduction of sexual females were investigated.Results The morphological observation showed that from the 1st instar nymph to adult,sexual females exhibited a gradually deepened body color,an enlarged body size,longer antennae with a blackened end,and obviously protruding cauda(in adulthood).The anatomy found that the ovaries of sexual females developed rapidly from the 2^(nd)instar nymph,and the embedded oocytes matured in adulthood.In addition,time-course transcriptome analysis revealed that gene expression profiles across the development of sexual females fell into 9 clusters with distinct patterns,in which gene expression levels in clusters 1,5,and 8 peaked at the 2^(nd)instar nymphal stage with the largest number of up-regulated genes,suggesting that the 2^(nd)instar nymph was an important ovary development period.Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis revealed that a large number of genes in the sexual female adult were enriched in the TGF-beta signaling pathway and Forkhead box O(FoxO)signaling pathway,highlighting their important role in sexual female adult development and reproduction.Conclusion The morphological changes of the sexual female at each developmental stage were revealed for the first time.In addition,time-course transcriptomic analyses suggest genes enriched in the TGF-beta signaling pathway and FoxO signaling pathway probably contribute to regulating the development and oocyte maturation of sexual females.Overall,these findings will facilitate the regulating mechanism research in the growth and development of sexual females by providing candidate genes.

Dynamic Development Characteristics and Driving Factors of High Quality Development Level in China’s Five Major Urban Agglomerations

High-quality development is the primary task of comprehensively building a socialist,modern country,as well as the primary task of building urban agglomerations in China.Based on the five development concepts,this paper used the entropy method to measure the High Quality Development Index(HQDI)of the five major urban agglomerations.The results showed that the HQDI of the five major urban agglomerations shows a fluctuating upward trend.First,using the Dagum Gini coefficient to explore the sources of HQDI development differences in urban agglomerations,we found that the main source of HQDI differences in urban agglomerations was inter-regional differences,while intra-regional differences were not important.Second,kernel density estimation was used to test the dynamic evolution trend of HQDI within urban agglomerations.There was a polarisation phenomenon in the HQDI of urban agglomerations,such as the Pearl River Delta urban agglomeration and the Chengdu-Chongqing urban agglomeration.But overall,the degree of imbalance had decreased.Third,using geographic detectors to examine the driving factors of HQDI in urban agglomerations,we found that the main driving forces for improving HQDI in urban agglomerations were economic growth,artificial intelligence technology and fiscal decentralisation.All the interaction factors had greater explanatory power for the spatial differentiation of HQDI,which can be divided into two types:two-factor improvement and non-linear improvement.This study is conducive to improving and enriching the theoretical system for evaluating the high quality development of urban agglomerations,and provides policy references for promoting the high quality development of urban agglomerations.

Research on the Relationship between the School-Running Characteristics of Private Colleges and Universities and the Development Objectives of the Government

The development objectives of the Chinese government have a guiding effect on the school-running characteristics of private colleges and universities.This paper explores the relationship between the characteristics of private colleges and universities and the development objectives of the provincial government,using Jiangsu Province as a case study.All the schools have the consciousness of fully considering the development objectives of Jiangsu Province when formulating the school-running characteristics.Their characteristics all contain some training methods,training courses,or institutional construction aiming at the development objectives.Most universities can support the government’s objectives on employment and innovation.Only a third of the schools provide government support for science research.Private colleges and universities should make full use of the free and flexible advantages of private education,combine them with the continuous changes of policies and markets,and create clear,scientific,and dynamic school-running characteristics,in order to achieve long-term development.

Phase Transitions and Seepage Characteristics during the Depletion Development of Deep Condensate Gas Reservoirs

Deep condensate gas reservoirs exhibit highly complex and variable phase behaviors,making it crucial to understand the relationship between fluid phase states and flow patterns.This study conducts a comprehensive analysis of the actual production process of the deep condensate gas well A1 in a certain oilfield in China.Combining phase behavior analysis and CMG software simulations,the study systematically investigates phase transitions,viscosity,and density changes in the gas and liquid phases under different pressure conditions,with a reservoir temperature of 165°C.The research covers three crucial depletion stages of the reservoir:single-phase flow,two-phase transition,and two-phase flow.The findings indicate that retrograde condensation occurs when the pressure falls below the dew point pressure,reachingmaximum condensate liquid production at around 25MPa.As pressure decreases,gas phase density and viscosity gradually decrease,while liquid phase density and viscosity show an increasing trend.In the initial single-phase flow stage,maintaining a consistent gas-oil ratio is observed when both bottom-hole and reservoir pressures are higher than the dew point pressure.However,a sudden drop in bottom-hole pressure below the dew point triggers the production of condensate oil,significantly reducing subsequent gas and oil production.In the transitional two-phase flow stage,as the bottom-hole pressure further decreases,the reservoir exhibits a complex flow regime with coexisting areas of gas and liquid.In the subsequent two-phase flow stage,when both bottom-hole and reservoir pressures are below the dew point pressure,a significant increase in the gas-oil ratio is observed.The reservoir manifests a two-phase flow regime,devoid of single-phase gas flow areas.For lowpressure conditions in deep condensate gas reservoirs,considerations include gas injection,gas lift,and cyclic gas injection and production in surrounding wells.Additionally,techniques such as hot nitrogen or CO_(2) injection can be employed to mitigate retrograde condensation damage.The implications of this study are crucial for developing targeted development strategies and enhancing the overall development of deep condensate gas reservoirs.

Coupling and Long-term Change Characteristics of Forest Carbon Sink and Forestry Economic Development in China

[Objectives]To analyze the changes in of forest carbon sink and forestry economic development,provide reference for relevant management decisions,ecological governance and resource and environment management,and promote the development of green low-carbon economy in China.[Methods]Based on the data of six forest resource inventories from 1989 to 2018 and related studies,the comprehensive evaluation model of forest carbon sink and forestry economic development,the coupling degree model of forest carbon sink and forestry economic development,and the coupling coordination degree model of forest carbon sink and forestry economic development were adopted.The coupling degree of forest carbon sink and forestry economic development from 1992 to 2018 was analyzed.Stepwise regression and ARIMA model were used to analyze the influencing factors and lagging characteristics of forest carbon sink.The coupling degree between forest carbon sink and forestry economic development in China from 2019 to 2030 was predicted by autoregression and ADF test.The coupling between forest carbon sink and forestry economic development in China and its long-term change characteristics were also discussed in this study.[Results](i)The investment of ecological construction and protection,the actual investment of forestry key ecological projects,GDP and the import of forest products had a significant impact on forest resources carbon stock.The total output value of forestry industry,the actually completed investment of forestry key ecological projects and the export volume of forest products had a significant impact on the forest carbon sink,and the actually completed investment of forestry key ecological projects has the greatest impact on the two.(ii)The impact of actually completed investment of forestry key ecological projects had a lag of 2 years on the forest resources carbon stock and a lag of 1 year on the forest carbon sink.When investing in forest carbon sink,it is necessary to make a good plan in advance,and do a good job in forest resources management and time optimization.(iii)From 1992 to 2018,the coupling degree of forest resources carbon stock,forest carbon sink and long-term development of forestry economy in China was gradually increasing.Although there were some fluctuations in the middle time,the coupling degree of forest resources carbon stock and the long-term development of forestry economy increased by 9.24%annually,and the degree of coupling coordination increased from"serious imbalance"in 1992 to"high-quality coordination"in 2018.From 1993 to 2018,the coupling degree of forest carbon sink and long-term development of forestry economy increased by 9.63%annually,slightly faster than the coupling coordination degree of forest resources carbon stock and long-term development of forestry economy.The coordination level also rose from level 2 in 1993 to level 10 in 2018.(iv)The prediction shows that the coupling coordination degree of forest resources carbon stock,forest carbon sink and the long-term development of forestry economy would increase from 2019 to 2030.The coupling coordination degree(D)values of both were close to 1,the coordination level was also 10 for a long time,and the degree of coupling coordination was also maintained at the"high-quality coordination"level for a long time.[Conclusions]Forest has multiple benefits of society,economy and ecology,and forest carbon sink is only a benefit output.The long-term coupling analysis of forest carbon sink and forestry economic development is a key point to multiple benefit analysis.The analysis shows that the spillover effect and co-evolution effect of forest carbon sink in China are significant.From 1992 to 2018,the coupling coordination degree of forest carbon sink and forestry economic development was gradually rising.The prediction analysis also indicate that the coupling coordination degree between the forest carbon sink and the long-term development of forestry economy will remain at the level of"high-quality coordination"for a long time from 2019 to 2030.Therefore,improving the level of forest management and maintaining the current trend of increasing forest resources are the key to achieving the goal of carbon peaking and carbon neutrality in China.

New aspects of a small GTPase RAB35 in brain development and function

In eukaryotic cells,organelles in the secretory,lysosomal,and endocytic pathways actively exchange biological materials with each other through intracellular membrane trafficking,which is the process of transporting the cargo of proteins,lipids,and other molecules to appropriate compartments via transport vesicles or intermediates.These processes are strictly regulated by various small GTPases such as the RAS-like in rat brain(RAB)protein family,which is the largest subfamily of the RAS superfamily.Dysfunction of membrane trafficking affects tissue homeostasis and leads to a wide range of diseases,including neurological disorders and neurodegenerative diseases.Therefore,it is important to understand the physiological and pathological roles of RAB proteins in brain function.RAB35,a member of the RAB family,is an evolutionarily conserved protein in metazoans.A wide range of studies using cultured mammalian cells and model organisms have revealed that RAB35 mediates various processes such as cytokinesis,endocytic recycling,actin bundling,and cell migration.RAB35 is also involved in neurite outgrowth and turnover of synaptic vesicles.We generated brain-specific Rab35 knockout mice to study the physiological roles of RAB35 in brain development and function.These mice exhibited defects in anxiety-related behaviors and spatial memory.Strikingly,RAB35 is required for the precise positioning of pyramidal neurons during hippocampal development,and thereby for normal hippocampal lamination.In contrast,layer formation in the cerebral cortex occurred superficially,even in the absence of RAB35,suggesting a predominant role for RAB35 in hippocampal development rather than in cerebral cortex development.Recent studies have suggested an association between RAB35 and neurodegenerative diseases,including Parkinson's disease and Alzheimer's disease.In this review,we provide an overview of the current understanding of subcellular functions of RAB35.We also provide insights into the physiological role of RAB35 in mammalian brain development and function,and discuss the involvement of RAB35 dysfunction in neurodegenerative diseases.

Near-infrared brain functional characteristics of mild cognitive impairment with sleep disorders

BACKGROUND Mild cognitive impairment(MCI)has a high risk of progression to Alzheimer’s disease.The disease is often accompanied by sleep disorders,and whether sleep disorders have an effect on brain function in patients with MCI is unclear.AIM To explore the near-infrared brain function characteristics of MCI with sleep disorders.METHODS A total of 120 patients with MCI(MCI group)and 50 healthy subjects(control group)were selected.All subjects underwent the functional near-infrared spec-troscopy test.Collect baseline data,Mini-Mental State Examination,Montreal Cognitive Assessment scale,fatigue severity scale(FSS)score,sleep parameter,and oxyhemoglobin(Oxy-Hb)concentration and peak time of functional near-infrared spectroscopy test during the task period.The relationship between Oxy-RESULTS Compared with the control group,the FSS score of the MCI group was higher(t=11.310),and the scores of Pittsburgh sleep quality index,sleep time,sleep efficiency,nocturnal sleep disturbance,and daytime dysfunction were higher(Z=-10.518,-10.368,-9.035,-10.661,-10.088).Subjective sleep quality and total sleep time scores were lower(Z=-11.592,-9.924).The sleep efficiency of the MCI group was lower,and the awakening frequency,rem sleep latency period,total sleep time,and oxygen desaturation index were higher(t=5.969,5.829,2.887,3.003,5.937).The Oxy-Hb concentration at T0,T1,and T2 in the MCI group was lower(t=14.940,11.280,5.721),and the peak time was higher(t=18.800,13.350,9.827).In MCI patients,the concentration of Oxy-Hb during T0 was negatively correlated with the scores of Pittsburgh sleep quality index,sleep time,total sleep time,and sleep efficiency(r=-0.611,-0.388,-0.563,-0.356).It was positively correlated with sleep efficiency and total sleep time(r=0.754,0.650),and negatively correlated with oxygen desaturation index(r=-0.561)and FSS score(r=-0.526).All comparisons were P<0.05.CONCLUSION Patients with MCI and sleep disorders have lower near-infrared brain function than normal people,which is related to sleep quality.Clinically,a comprehensive assessment of the near-infrared brain function of patients should be carried out to guide targeted treatment and improve curative effect.

Establishment of human cerebral organoid systems to model early neural development and assess the central neurotoxicity of environmental toxins

Human brain development is a complex process,and animal models often have significant limitations.To address this,researchers have developed pluripotent stem cell-derived three-dimensional structures,known as brain-like organoids,to more accurately model early human brain development and disease.To enable more consistent and intuitive reproduction of early brain development,in this study,we incorporated forebrain organoid culture technology into the traditional unguided method of brain organoid culture.This involved embedding organoids in matrigel for only 7 days during the rapid expansion phase of the neural epithelium and then removing them from the matrigel for further cultivation,resulting in a new type of human brain organoid system.This cerebral organoid system replicated the temporospatial characteristics of early human brain development,including neuroepithelium derivation,neural progenitor cell production and maintenance,neuron differentiation and migration,and cortical layer patterning and formation,providing more consistent and reproducible organoids for developmental modeling and toxicology testing.As a proof of concept,we applied the heavy metal cadmium to this newly improved organoid system to test whether it could be used to evaluate the neurotoxicity of environmental toxins.Brain organoids exposed to cadmium for 7 or 14 days manifested severe damage and abnormalities in their neurodevelopmental patterns,including bursts of cortical cell death and premature differentiation.Cadmium exposure caused progressive depletion of neural progenitor cells and loss of organoid integrity,accompanied by compensatory cell proliferation at ectopic locations.The convenience,flexibility,and controllability of this newly developed organoid platform make it a powerful and affordable alternative to animal models for use in neurodevelopmental,neurological,and neurotoxicological studies.

Postnatal development of rat retina:a continuous observation and comparison between the organotypic retinal explant model and in vivo development

The organotypic retinal explant culture has been established for more than a decade and offers a range of unique advantages compared with in vivo experiments and cell cultures.However,the lack of systematic and continuous comparison between in vivo retinal development and the organotypic retinal explant culture makes this model controversial in postnatal retinal development studies.Thus,we aimed to verify the feasibility of using this model for postnatal retinal development studies by comparing it with the in vivo retina.In this study,we showed that postnatal retinal explants undergo normal development,and exhibit a consistent structure and timeline with retinas in vivo.Initially,we used SOX2 and PAX6 immunostaining to identify retinal progenitor cells.We then examined cell proliferation and migration by immunostaining with Ki-67 and doublecortin,respectively.Ki-67-and doublecortin-positive cells decreased in both in vivo and explants during postnatal retinogenesis,and exhibited a high degree of similarity in abundance and distribution between groups.Additionally,we used Ceh-10 homeodomain-containing homolog,glutamate-ammonia ligase(glutamine synthetase),neuronal nuclei,and ionized calcium-binding adapter molecule 1 immunostaining to examine the emergence of bipolar cells,Müller glia,mature neurons,and microglia,respectively.The timing and spatial patterns of the emergence of these cell types were remarkably consistent between in vivo and explant retinas.Our study showed that the organotypic retinal explant culture model had a high degree of consistency with the progression of in vivo early postnatal retina development.The findings confirm the accuracy and credibility of this model and support its use for long-term,systematic,and continuous observation.

Development Characteristics and Control Measures for Semiothisa cineraria Bremer & Grey

The development characteristics of Semiothisa cinerearia Bremer ＆ Grey was summarized, and we also put forward the control measures of well completing insect surveys to provide scientific basis for the control and actively carrying out comprehensive management to control the pests damage in the economic permissible level.

Effects of Nitrogen Application Amount on Growth Characteristics,Boll Development and Lint Yield of High Quality Cotton

[Objective] This study aimed to explore an optimum application amount of nitrogen for cotton cultivation. [Method] In this study, a field experiment was conducted to investigate the effects of nitrogen application amount on the growth characteristics, boll development and lint yield of high quality cotton line FZ-1. [Result] Compared with the nitrogen level of 225 kg/hm2, the lint yield had increased by 28.46% and 18.73%, respectively, with the nitrogen application amount of 300 and 375 kg/hm2. When the nitrogen application amount had increased from 225 to 300 kg/hm2, boll number per plant, boll weight and lint yield had significantly increased. At the nitrogen level of 375 kg/hm2, however, the effects of increasing lint yield were significantly less than that at the nitrogen level of 300 kg/hm2. Compared with the nitrogen levels of 225 and 375, 300 kg/hm2 of nitrogen was the optimum application amount to improve the plant height, daily increment of plant height, number of fruit branches, number ratio of nodes to fruit branches, boll volume and seed cotton weight per boll. [Conclusion] The rational management of nitrogen is the most effective way to promote the growth and development of cotton plants, ensure high yielding ability and minimize the environmental pollution caused by the overuse of nitrogen. This study had provided a sound nitrogen application strategy for the cultivation of this high-quality cotton line in the field plantation.

Characteristics and Functions of Cooperative Economic Organizations for Water-saving Irrigation in Agricultural Development in Arid Areas

Agricultural cooperative economic organization for water-saving irrigation in arid areas is a new form of economic organization in production,operation and management during the application process of water-saving irrigation technologies.Currently,there are few researches on this cooperative economic organization.In this study,connotations of cooperative economic organizations for water-saving irrigation are specifically defined,and the characteristics and functions of this cooperative economic organization are analyzed.Based on that,several suggestions are proposed on the continuous development of cooperative economic organizations for water-saving irrigation.

Development Mode for the Characteristic Urbanization of Rural Areas in Heilongjiang Province

By analyzing the urbanization of rural areas in Heilongjiang Province,the authors pointed out the existing problems:insufficient motive power of its subjects,low construction level,less prominent functional features of townlets,low scale merits,low efficiency of resource distribution and so on.According to the classification of its townlets,the following 4 modes were given for the rural urbanization of Heilongjiang:A.Motivated by Ecological Construction.It is to solve population problems through ecological migrants,enhance infrastructure construction of townlets,strengthen their capacity of concentrating and absorbing resources;B.Motivated by featured agriculture.It is to develop featured industries on the basis of featured resources with market as the orientation,create a favorable exterior development environment for featured agriculture with the help of government;C.Based on Competitive Tourist Products.It is to coordinate the development of tourism and townlets through scientific planning,design competitive tourism projects and build famous tourism towns;D.Driven by Trade and Processing Industry.It is to promote the capacity of these towns in developing foreign trade,improve policy environment and trade facilities.All these 4 modes are proposed on the basis of actual conditions to give more choices for the characteristic urbanization of its rural areas.

Dynamic Characteristics of Growth and Development of Xiangsha Taro in Jingjiang

The growth and development of Jingjiang Taro [Colocasia esculenta（L.） Schott] were observed, laying foundation for highly-yielding cultivation technology system of Xiangsha taro. The results indicate that germination of the second taro happened from 46 d after sprouting （7-8 leaves）; the first taro began to expand, from 125 d after sprouting （12 leaves） when the the second taro was been formed; the third taro began to form from 141 to 150 d after sprouting （15-16 leaves）. The fresh weight of the second and third taros quickly increased from the time of 15 leaves to harvest. Early September is a transformation term of Xiangsha taro from vegetative body dominant to corm growth dominant.

Flowering Biology and Fruit Development Characteristics of Apricot Cultivar ‘Kezilang' in Xinjiang

The flowering biology and fruit development characteristics of a Xinjiang apricot （Armeniaca vulgaris Lam） cultivar Kezilang were studied by measuring its flowering phenology, floral organ development, stigma receptivity, pollen quantity, pollen viability, fruit diameter, fruit fresh weight, fruit dry weight and fruit contents, with an attempt to provide a theoretical basis for the cultivation and promotion of Kezilang. The results showed that Kezilang can be popularized as an early-maturing apricot cultivar, as it had high fruit setting rate, large fruit weight, excellent taste, high sugar content and lower titratable acid content in fruit. The dynamic curves of Kezilang fruit diameters in three directions, fruit fresh weight and fruit dry weight were all S-shaped, and the rapid growth stage of dry weight was later than that of other terms. Fruit swelling was due to higher water content of flesh tissue in early stage of the rapid growth periods of fruit. Most sugar in flesh was accumulated at the second rapid growth period of fruit.

Development Characteristics and Controlling Countermeasures of Rice Stem Borer, Chilo suppressalis(Walker)

The development characteristics of rice stem border, Chilo suppressalis （Walker） was introduced, and the corresponding control ing measures were put forward, including agricultural control, physical control, biological control, chemical control.

Development Characteristics of Private P.E Economy

The regional policy in the innovation development of private P.E economy plays better role in management according to law,guidance and escort;increase the macro quality of main body of private P.E entrepreneurs and the overall staff quality,develop P.E vocational P.E to provide P.E talents for private P.E economy.

Characteristic Development Road for the New Countryside Construction ——With Laoshan District, Qingdao City as a Study Case

This study points out existing problems in the present planning for the new countryside construction of Laoshan District, Qingdao City, Shandong Province. First, local features and industrial structures are ecologically analyzed as a whole; second, specific elaborations are given from 3 angles, guiding development by exploring characteristics, enhancing development by applying various modes, protecting features by taking steps from diverse perspectives, so as to play a referential role in the construction of new countryside in this district.

Preliminary Study on Leaf Color Development and Photosynthetic Characteristics of Golden-leaf Ginkgo

[Objective]The aim of this study is to research leaf color development and photosynthetic characteristics of golden-leaf ginkgo.[Method]With one-year-old grafted seedlings of golden-leaf ginkgo as the materials,the changes of leaf color,chlorophyll content（Chl）,carotenoid（x.c）content and rate of chlorophyll and carotenoid content,as well as photosynthetic characteristics under full sunlight and overshadowing were all investigated in this study.[Result]Sprouts of golden-leaf ginkgo were pale-yellow,and changed from orange to golden in April,to light yellow-green in May,to yellow-green from June to October,to yellow in November.The chlorophyll and carotenoid contents and the rates of chlorophyll and carotenoid contents of yellow-leaf were significantly lower than that of green-leaf,while the rate of Chla/x.c and Chlb/x.c was obviously lower than the corresponding pigment content of green-leaf.During the leaf color development,Chla,Chlb and x.c content as well as the rate of Chla/x.c and Chlb/x.c of yellow-leaf ginkgo all increased.The saturation light intensity of ginkgo leaf under natural light was higher than that under overshadowing.Maximum net photosynthetic rate,light compensation point and dark respiration rate of yellow leaf were all significantly higher than that of green leaf.Chla/x.c,Chlb/x.c and Chla＋b/x.c of yellow-leaf ginkgo under overshadowing were higher than the corresponding pigment rate of leaf under natural light.[Conclusion]The best ornamental duration of golden-leaf ginkgo is April and May.The major reason for showing yellow leaf is that Chla/x.c and Chlb/x.c of yellow-leaf is obviously lower than that of green-leaf.During the leaf color development,the major reason for yellow-leaf turning to yellow-green is that the rate of Chla/x.c and Chlb/x.c increases.Chlb content of yellow-leaf under overshadowing is higher than that under natural light,which is an adaptive response to overshadowing.Chla/x.c,Chlb/x.c and Chla＋b/x.c of yellow-leaf under overshadowing are relatively higher,which is one of the reasons why yellow-leaf under overshadowing becomes yellow-green or green.