Microfacies and diagenetic alteration in a semi-deep to deep lacustrine shale: The Yanchang Formation in the Ordos Basin, China

The mineralogical development and diagenetic sequence of lacustrine shales in the Chang 7 Member of the Yanchang Formation in the Ordos Basin are detailed studied.A model of their depositional system and a diagenetic diagram are proposed in this study.Through detailed petrographic,mineralogical,and elemental analyses,four distinct shale types are identified:argillaceous shale,siliceous shale,calcareous shale,and carbonate,clay,and silt-bearing shale.The main diagenetic process in argillaceous shale is the transformation of illite to smectite,negatively impacting shale porosity.Siliceous shale undergoes carbonate cementation and quartz dissolution,contributing to increased porosity,particularly in mesopores.Calcareous shale experiences diagenesis characterised by carbonate formation and dissolution,with a prevalence of siderite.In carbonate,clay,and silt-bearing shale,the dissolution of K-feldspar contributes to illitization of kaolinite.Argillaceous shale,characterised by more clay minerals and lower mesopore volume,is identified as a potential hydrocarbon seal.Siliceous shale,with the highest pore volume and abundant inter-mineral pores,emerges as a promising shale oil reservoir.These findings contribute to a comprehensive understanding of shale properties,aiding in the prediction of shale oil exploration potential in the studied area.

The Geoscience Frontier of Gulong Shale Oil:Revealing the Role of Continental Shale from Oil Generation to Production

The clay mineral content of Daqing Gulong shale is in the range of about 35%–45%,with particle sizes less than 0.0039 mm.The horizontal fluidity of oil in Gulong shale is poor,with near-zero vertical flowability.As a result,Gulong shale has been considered to lack commercial value.In recent years,however,interdisciplinary research in geoscience,percolation mechanics,thermodynamics,and surface mechanics has demonstrated that Gulong shale oil has a high degree of maturity and a high residual hydrocarbon content.The expulsion efficiency of Gulong shale in the high mature stage is 32%–48%.Favorable storage spaces in Gulong shale include connecting pores and lamellar fractures developed between and within organic matter and clay mineral complexes.The shale oil mainly occurs in micro-and nano-pores,bedding fractures,and lamellar fractures,with a high gas–oil ratio and medium–high movable oil saturation.Gulong shale has the characteristics of high hardness,a high elastic modulus,and high fracture toughness.This study achieves breakthroughs in the exploration and development of Gulong shale,including the theories of hydrocarbon generation and accumulation,the technologies of mobility and fracturing,and recoverability.It confirms the major transition of Gulong shale from oil generation to oil production,which has extremely significant scientific value and application potential for China’s petroleum industry.

Interventional therapy for acute hemorrhage in gastrointestinal tract

AIM： To evaluate the diagnostic angiography and therapy for acute massive hemorrhage in gastrointestinal tract. METHODS： Twenty-five cases of acute hemorrhage in gastrointestinal tract admitted between April 2002 and September 2004 were reviewed and analyzed by angiography and embolotherapyo RESULTS： Fifteen patients were men and ten patients were women. The Seldinger technique and method of coaxial duct were used to get access to the bleeding region. PVA particles, gelfoam, and coils were used for embolism. All bleeding sites could be confirmed and were successfully embolized. Hemostasis was achieved in all the patients without bleeding again. The cure rate was 100%. CONCLUSION： Interventional therapy can not only ascertain the bleeding site, but also stop the bleeding .The method is simple and the effect is certain.

Physical property and hydrocarbon enrichment characteristics of tight oil reservoir in Chang 7 division of Yanchang Formation,Xin’anbian oilfield,Ordos Basin,China

Xin’anbian Oilfield of the Ordos Basin is the large tight oilfield to be first exploration discovery in china.The production of tight oil increased significantly in recent years.It shows great exploration potential of Chang 7 tight oil.But the physical property and hydrocarbon enrichment characteristics of Chang 7 tight oil reservoirs were rarely studied,The forming conditions of tight oil reservoirs are systematically summarized and analyzed through the study of hydrocarbon generation,sedimentary reservoirs and hydrocarbon migration and accumulation based on production and core experimental data.The result shows that,The porosity of the Chang 7_(2)reservoir mainly distributed in 5.0-11.0%,average at 7.9%,The permeability mainly distributed in 0.04-0.18×10^(-3)μm^(2),average at 0.12×10^(-3)μm^(2),The pore diameters of the tight oil reservoir distributed in 2-8μm.The high-quality Chang 7_(3)source rocks and the micropsammite of Chang 7_(2)subaqueous distributary channel were widely distributed in the study area.The lenticular or banded sand bodies are distributed among mudstone or hydrocarbon source rocks and have the advantage of migration distance for hydrocarbon accumulation.The reservoir space is composed of micro-nanometer pores and throat,that is formed in the process of increasing pressure during hydrocarbon generation and hydrocarbon accumulation.The Chang 7 tight oil was generated in the early Cretaceous and injected into the sand of the subaqueous distributary channel driven by continuous hydrocarbon generation supercharging.The formation and accumulation of tight oil reservoirs are mainly controlled by source rocks,sedimentary microfacies and reservoirs of good quality.

Identification of QTL for adult-plant resistance to powdery mildew in Chinese wheat landrace Pingyuan 50

Powdery mildew caused by Blumeria graminis f. sp. tritici is one of the major wheat diseases worldwide. The Chinese wheat landrace Pingyuan 50 has shown adult-plant resistance(APR)to powdery mildew in the field for over 60 years. To dissect the genetic basis of APR to powdery mildew in this cultivar, a mapping population of 137 double haploid(DH) lines derived from Pingyuan 50/Mingxian 169 was evaluated in replicated field trials for two years in Beijing(2009–2010 and 2010–2011) and one year in Anyang(2009–2010). A total of 540 polymorphic SSR markers were genotyped on the entire population for construction of a linkage map and QTL analysis. Three QTL were mapped on chromosomes 2BS(QPm.caas-2BS.2), 3BS(QPm.caas-3BS),and 5AL(QPm.caas-5AL) with the resistance alleles contributed by Pingyuan 50 explaining 5.3%,10.2%, and 9.1% of the phenotypic variances, respectively, and one QTL on chromosome 3BL(QPm.caas-3BL) derived from Mingxian 169 accounting for 18.1% of the phenotypic variance.QPm.caas-3BS, QPm.caas-3BL, and QPm.caas-5AL appear to be new powdery mildew APR loci.QPm.caas-2BS.2 and QPm.caas-5AL are possibly pleiotropic or closely linked resistance loci to stripe rust resistance QTL. Pingyuan 50 could be a potential genetic resource to facilitate breeding for improved APR to both powdery mildew and stripe rust.

支气管镜肺泡灌洗术早期介入治疗对艾滋病合并重症肺炎的作用

目的探讨支气管镜肺泡灌洗术的早期介入治疗对艾滋病并发重症肺炎患者的作用。方法选取2018年1月至2021年6月在昆明市第三人民医院重症医学科住院且需有创机械通气支持的成人艾滋病并发重症肺炎患者(44例),分为观察组和对照组,每组分别为22例。观察组除采取常规治疗外早期进行支气管镜肺泡灌洗术,对照组采取常规治疗。对比分析2组患者治疗前后的感染指标、动脉血氧饱和度(SaO_(2))、动脉氧分压(PaO_(2))和氧结合指数(PaO_(2)/FiO_(2))、急性生理和慢性健康评分II(APACHEII)、ICU住院天数、28 d的病死率、机械通气时间和体温恢复正常时间。结果(1)观察组在治疗1周后的降钙素原和C反应蛋白指标明显低于对照组(P<0.05);(2)观察组在治疗1周后的SaO_(2)、PaO_(2)、PaO_(2)/FiO_(2)比对照组高,差异有统计学意义(P<0.05);(3)观察组在治疗1周后,APACHEII评分明显低于对照组,差异有统计学意义(P<0.05);观察组机械通气时间、体温恢复时间均短于对照组,差异有统计学意义(P<0.05);观察组28 d病死率明显低于对照组,但差异无统计学意义(P>0.05);2组患者ICU的住院时间比较差异无统计学意义(P>0.05)。结论早期介入支气管镜肺泡灌洗术治疗艾滋病并发重症肺炎患者,可有效地降低感染指标,减轻机体的炎症性反应,改善氧合,减少有创机械通气时间,对改善预后、提升临床救治效能有重要的意义,值得在临床上应用和普及。

Experimental Investigation on Hydrophobic Behavior of Carbon Spheres Coated Surface Made from Microplastics

In this paper,a simple method to plate a hydrophobic coating on the inner surface of a small-scaled tube was proposed,where the coating consisted of carbon microspheres.Three common plastics polystyrene,polycarbonate and polyethylene were used as the feedstocks to be processed in supercritical water in a quartz tubular reactor.After reaction,the contact angle of droplet on the inner surface of the quartz tube was turned out to be over 100°,significantly larger than that of the blank tube 54°.When processing polystyrene in the 750℃ supercritical water for 10 min,the largest contact angle was obtained,up to 145°.Besides,in this sample,the size of carbon spheres was smallest,about 2.09μm diameter on average.When comparing among different types of plastics under the same condition,the contact angle of surface made from PC took the dominant position over that of PS and PE,124°,100°and 90°,respectively.In the sample made from PC,carbon spheres adhered into a mountainlike shape,producing a binary geometric structure.Furthermore,this research could be helpful in the discussion of plastic waste management and carbon spheres fabrication with low cost.

Ab initio study of dynamical properties of U-Nb alloy melt

The U-Nb alloy,as a kind of nuclear material with good corrosion resistance and mechanical properties,plays an important role in the nuclear industry.However,the experimental measurements and theoretical calculations of many parameters which are essential in describing the dynamical properties of this alloy melt,including density,diffusivity,and viscosity,have not been carried out yet.The lack of data on the dynamical properties of nuclear materials seriously hinders the high-performance nuclear materials from being developed and applied.In this work,the dynamical properties of the U-Nb alloy melt are systematically studied by means of ab initio molecular dynamics simulations and their corresponding mathematical models are established,thereby being able to rapidly calculate the densities,diffusion coefficients,viscosities,and their activation energies in the whole U-Nb liquid region.This work provides a new idea for investigating the dynamical properties of binary alloy melts,thereby promoting the development of melt research.

Optimal Operation of Electric Vehicles and Distributed Generation Resources in Smart Grid Considering Load Management

Technology advancement and the global tendency to use renewable energy in distributed generation units in the distribution network have been proposed as sources of energy supply.Despite the complexity of their protection,as well as the operation of distributed generation resources in the distribution network,factors such as improving reliability,increasing production capacity of the distribution network,stabilizing the voltage of the distribution network,reducing peak clipping losses,as well as economic and environmental considerations,have expanded the influence of distributed generation(DG)resources in the distribution network.The location of DG sources and their capacity are the key factors in the effectiveness of distributed generation in the voltage stability of distribution systems.Nowadays,along with the scattered production sources of electric vehicles with the ability to connect to the network,due to having an energy storage system,they are known as valuable resources that can provide various services to the power system.These vehicles can empower the grid or be used as a storage supply source when parked and connected to the grid.This paper introduces and studies a two-stage planning framework for the concurrent management of many electric vehicles and distributed generation resources with private ownership.In the first stage,the aim is to increase the profit of electric vehicles and distributed generation sources;finally,the purpose is to reduce operating costs.The proposed scheduling framework is tested on a distribution network connected to bus 5 of the RBTS sample network.Besides distributed generation sources and electric vehicles,we integrate time-consistent load management into the system.Due to distributed generation sources such as photovoltaic systems and wind turbines and the studied design in the modeling,we use the Taguchi TOAT algorithm to generate and reduce the scenario to ensure the uncertainty in renewable energy.MATLAB software is used to solve the problem and select the optimal answer.

Optimal scheduling of flexible grid-side resources and auxiliary service cost allocation model considering renewable-energy penetration

Renewable energy has penetrated power grid enterprises on a large scale.Due to the intermittency and volatility of renewable energy generation,it is necessary to build new flexible grid-side resources to ensure the safe and stable operation of the power grid,which will cause great pressure on cost allocation for power grid enterprises.This article considers four types of flexible grid-side resources and constructs a dual-level configuration optimization model for flexible grid-side resources under the penetration of renewable energy.Based on the configuration results,the cost scale of flexible grid-side resources is estimated and an improved ancillary service cost allocation model based on the Shapley value method is proposed to smooth the allocation of ancillary service costs in the cost of flexible grid-side resources between the two main bodies of renewable energy and load.The calculation results show that,when the penetration rate of renewable-energy power is 30%and 35%,respectively,the cost of flexible grid-side resources is 9.606 billion yuan and 21.518 billion yuan,respectively.The proportion of ancillary service costs allocated to load is relatively high-about five times that of the ancillary service costs allocated to renewable energy-and the higher the penetration rate of renewable energy,the higher the proportion of ancillary service costs allocated to renewable energy.

Analysis and Monitoring of Indoor Radon Concentrations of 37 Kindergartens — Beijing Municipality, China, 2023

Introduction:Radon(222Rn or 222radon)is a radioactive gas emitted from building materials,foundations,and soil.Children are especially susceptible to radon exposure,underscoring the need to assess indoor radon levels in kindergartens.This study monitored radon concentrations in 37 Beijing kindergartens from June to October 2023.Methods:A random sample of 37 kindergartens was selected from 18 administrative districts in Beijing.The indoor radon concentration was measured using the solid track accumulation method,with radon detectors continuously monitored over a 3-month period.Results:The mean indoor radon level in 37 kindergartens,observed at 252 monitoring points,was 84.3 Bq/m^(3),with values varying from 12.9 to 263.5 Bq/m^(3).About 20.2%of points showed radon levels between 100.0 and 200.0 Bq/m^(3),while 2.4%exceeded 200.0 Bq/m^(3).Notably,radon levels were significantly elevated on the ground floor compared to the upper floors.Conclusion:Indoor radon levels in 37 kindergartens remained below the national standard limit of 300.0 Bq/m^(3) for buildings(GB/T 16146-2015).Nonetheless,18.9%of the kindergartens exceeded the 100.0 Bq/m^(3) limit set for new constructions.It is advised to improve radon monitoring in kindergartens and consider developing a national standard for maximum permissible radon levels in such facilities.

Theory, Technology and Practice of Unconventional Petroleum Geology

0 INTRODUCTION The breakthroughs in unconventional petroleum have a great impact on world petroleum industry and innovation in petroleum geology(Dou et al,2022;Jia,2017;Zou et al.,2015b,2014a;Yerkin,2012;Pollastro,2007;Schmoker,1995).The exploration and development evolution from conventional petroleum to unconventional petroleum and more and more frequent industrial activities of exploring petroleum inside sources kitchen have deepened theoretical understanding of unconventional petroleum geology and promoted technical research and development(Jia et al.,2021,2017;Jin et al.,2021;Zhao W Z et al.,2020;Ma Y S et al.,2018,2012;Zou et al.,2018b,2016,2009;Dai et al.,2012).We have introduced and extended the theory of continuous hydrocarbon accumulation since 2008 and published several papers/books(in Chinese and English)with respect to unconventional petroleum geology since 2009,basically forming the theoretical framework for this discipline(Yang et al.,2022a,2021a,2019a,,2015a;Zou et al.,2019c,2017b,2014a,,2013a).In this paper,we present the background of unconventional petroleum geology,review the latest theoretical and technological progress in unconventional petroleum geology,introduce relevant thinking and practices in China,and explore the pathway of unconventional petroleum revolution and multi-energy coordinated development in super energy basins,hopefully to promote the unconventional petroleum geology and industry development.

二十世纪30年代上海渔轮捕捞与渔业现代化研究

在近代上海渔业生产中,渔轮捕捞是非常重要的捕捞方式。20世纪30年代出版发行的《渔况》《统计月刊》和《上海市水产经济月刊》等期刊中记载了大量涉及上海渔轮捕捞的数据。数据分析显示,1930年至1937年上海港渔轮捕捞数量和价值基本呈上升趋势,但并没有明显的季节性集聚现象;捕捞海产品种类呈现出明显的集聚现象,鱏鱼、小黄鱼、鮸鱼、鞋底鱼为主要捕捞海产品,但除小黄以外的各主要海产品捕捞季节性特征并不明显。种种特点,无疑显示出渔轮捕捞相比传统捕捞方式的优势所在。渔轮捕捞积极推动降低渔业捕捞成本、增强渔业抗风险能力和改进渔业管理,但对于维护海洋权益和抵制日本侵渔则作用甚少。整体而言,作为现代渔业的开端,上海渔轮捕捞引领中国渔业现代化的方向。

A Chromosome-level Reference Genome of African Oil Palm Provides Insights into Its Divergence and Stress Adaptation

The palm family(Arecaceae),consisting of2600 species,is the third most economically important family of plants.The African oil palm(Elaeis guineensis)is one of the most important palms.However,the genome sequences of palms that are currently available are still limited and fragmented.Here,we report a high-quality chromosome-level reference genome of an oil palm,Dura,assembled by integrating long reads with150 genome coverage.The assembled genome was 1.7 Gb in size,covering 94.5%of the estimated genome,of which 91.6%was assigned into 16 pseudochromosomes and 73.7%was repetitive sequences.Relying on the conserved synteny with oil palm,the existing draft genome sequences of both date palm and coconut were further assembled into chromosomal level.Transposon burst,particularly long terminal repeat retrotransposons,following the last whole-genome duplication,likely explains the genome size variation across palms.Sequence analysis of the VIRESCENS gene in palms suggests that DNA variations in this gene are related to fruit colors.Recent duplications of highly tandemly repeated pathogenesis-related proteins from the same tandem arrays play an important role in defense responses to Ganoderma.Whole-genome resequencing of both ancestral African and introduced oil palms in Southeast Asia reveals that genes under putative selection are notably associated with stress responses,suggesting adaptation to stresses in the new habitat.The genomic resources and insights gained in this study could be exploited for accelerating genetic improvement and understanding the evolution of palms.

Shale oil resource evaluation with an improved understanding of free hydrocarbons:Insights from three-step hydrocarbon thermal desorption

The pyrolysis parameter S1,which indicates the amount of free hydrocarbons present in shale,is often underestimated due to hydrocarbon loss during sample handling and measurement processes.To remedy this issue,we strongly recommend an immediate three-step hydrocarbon thermal desorption(HTD)approach to be conducted on oil shale at the drilling site.This approach measures S_(g),S_(O),and S_(1)^(*),which refer to gaseous,light,and free hydrocarbons,respectively.The new shale oil content value,calculated from the total of these three parameters,is far more precise and reliable than traditional pyrolysis S1.Moreover,we thoroughly investigated the components and microscopic occurrence features of hydrocarbons thermally desorbed at three temperature stages using gas chromatography(GC)and X-ray microcomputed tomography(CT).For example,we selected Chang 7_(3)mud shale.Our experimental results irrefutably indicate that the ultimate shale oil content of poor resource rocks is significantly impacted by evaporative loss,with this effect being greater when the total organic carbon(TOC)is lower.Additionally,C_(1-5)and C_(1-7)hydrocarbons constitute almost all of S_(g)and S_(O),respectively.S_(g)and S_(O)are predominantly composed of C_(1-3)gaseous hydrocarbons,with a maximum proportion of 42.93%.In contrast,S_(1)^(*)contains a substantial amount of C_(16-31)hydrocarbons.A three-dimensional reconstruction model of an X-ray micro-CT scan shows that while the amount of shale organic matter greatly decreases from the frozen state to 300℃,the pore volume significantly increases,particularly between 90 and 300℃.The increased pore volume is mainly due to macropores and fractures.It is imperative to note that the shale oil triple-division boundaries must be adjusted based on more accurate oil content,although this would not affect the resource zones to which the samples already belong(ineffective,low-efficient,and enriched resources).In conclusion,we strongly advise conducting an immediate well-site analysis or utilizing preservation procedures,such as deep freezing or plastic film wrapping followed by core waxing,to minimize volatile loss.

Measurement and analysis on distribution of radiation field dose inside thetreatment room of TaiChi Pro multimodal integrated digitalradiotherapy system

Objective:To examine the leakage radiation dose from the accelerator module's primary beam self-shielding,aswell as stray radiation levels and distribution in the treatment room across various planes for the innovative X/γmultimodal radiotherapy system,TaiChi Pro,which is the world's first digitally integrated system that combines alinear accelerator,multi-source rotational focused gamma knife,and multi-modal image guidance,in order toformulate treatment room safety strategies and estimate additional radiation doses to patients.Methods:The TaiChi Pro multi-mode integrated radiotherapy system was utilized with a 6 MV X-ray accelerator inthe flatten-filter free(FFF)treatment mode.The system has a primary radiation beam self-shielding,and anisocenter dose rate of 800 cGy/min.For detection points in various planes,an x,y,z coordinate system wasestablished with the isocenter as the origin.To simulate the situation of patient,water-equivalent phantom wasemployed.The ambient dose equivalent and ambient dose equivalent rate at detection points in the radiation fieldwere measured using thermoluminescence dosimeters.Results:The self-shielding area achieved a maximum dose of 114.0 mGy at 1 m distance from the target point after3 min of cumulative irradiation.The leakage radiation ratios at all points remained below 0.5%,fulfilling the selfshielding design requirements.Regarding the couch,the highest radiation was observed in the opposite directionof the beam at the target point.The stray radiation on the treatment bed plane resulted in an ambient doseequivalent that did not exceed 0.5%of the ambient dose equivalent at the central point.Conclusion:The levels and distribution patterns of stray and leakage radiation inside the TaiChi Pro treatmentroom meet the requirements of the relevant national standard.The measured values of indoor radiation levels anddistribution are very useful for room shielding design and personnel protection.

A Deep Learning Method for Statistical Downscaling of CLDAS Relative Humidity with Different Sources of Data:Sensitivity Analysis

High-resolution relative humidity(RH)data are essential in studies of climate change and in numerical meteorological forecasting.However,because high-resolution meteorological grid data require a large number of stations,the sparse distribution of ground meteorological stations in China before 2008 has limited the development of long-term and high-resolution RH products in the China Meteorological Administration’s Land Assimilation System(CLDAS)dataset.To retrieve high-quality and high-resolution RH data before 2008,we propose a statistical downscaling model(SDM)based on a generative adversarial network(GAN)to transform the original RH data from a resolution of0.05°to 0.01°.The GAN-based SDM(GSDM)is trained with the RH of the CLDAS(0.05°)dataset after 2008 as its input,and the RH of the high-resolution CLDAS(HRCLDAS,0.01°)dataset after 2008 as its target for training.The2-m air temperature data from the HRCLDAS dataset are also included in the input,and the station observations of RH are incorporated in the target for training.To select the optimum data combination for the model,we compared three methods:(1)incorporating without auxiliary data(GSDM),(2)incorporating air temperature as an additional input(GSDM_T),and(3)incorporating air temperature as an additional input and the RH data at stations as an additional target for training(GSDM_TO).Taking the Beijing–Tianjin–Hebei region as an example,we trained the GSDM by using data from 2018 and tested the model performance in 2019.The experimental results showed that the GSDM_TO algorithm achieved the lowest root-mean-square error(3.85%),followed by the GSDM_T(4.01%)and GSDM(4.95%)algorithms.The proposed models showed a competitive performance and captured more local details of the RH fields than other deep learning models and traditional bilinear interpolation.In general,the GSDM_TO algorithm using a combination of different sources of data(air temperature and observed RH)achieved the best results among the various deep learning approaches,indicating that more auxiliary data and more accurate observations are beneficial in downscaling.This may be helpful for the statistical downscaling of other meteorological data.

20世纪初期浙海关进出口问题研究

作为晚清以来最早设立的新式海关之一,浙海关的进出口管理是非常成熟的。基于对《申报》等报刊文献的整理与分析,20世纪初期浙海关的进出口管理由货物监管、商船监管和海关缉私三部分组成。由此可以看出,浙海关职能的完善仍延续了传统海关的政策路径,并顺应海洋贸易发展的新要求。

明清时期宁波海洋渔业文化研究

宁波拥有丰富的海洋渔业资源和历史悠久的捕捞渔业。明清时期宁波地方文献对于宁波海洋渔业的记载主要包括海洋渔业资源的开发、海洋渔业加工与流通、海洋渔业税收等三个方面。通过文献梳理和沿海区域比较可以看到,宁波海洋渔业文化最明显的特征就是海洋渔业捕捞方式和捕捞产业的分工。

余姚洪勋与《游历瑞典那威闻见录》

中国与瑞典的交往可以上溯到400年前,而官方的外交往来则要到晚清以后。1888年,余姚洪勋一行对瑞典进行了长达四个月的考察,并形成著作《游历瑞典那威闻见录》。洪勋的著作对1888年瑞典的政治、经济、社会和文化做了全方位的论述,是研究近代瑞典史及中瑞关系史的重要著作。洪勋的欧洲之行体现了晚清政府开始主动了解西方的意愿,但其回国后的经历也说明国家变革的缓慢。