Effect of Horizontal Resolution on the Representation of the Global Monsoon Annual Cycle in AGCMs

The sensitivity of the representation of the global monsoon annual cycle to horizontal resolution is compared in three AGCMs： the Met Office Unified Model-Global Atmosphere 3.0; the Meteorological Research Institute AGCM3; and the Global High Resolution AGCM from the Geophysical Fluid Dynamics Laboratory. For each model, we use two horizon- tal resolution configurations for the period 1998-2008. Increasing resolution consistently improves simulated precipitation and low-level circulation of the annual mean and the first two annual cycle modes, as measured by the pattern correla- tion coefficient and equitable threat score. Improvements in simulating the summer monsoon onset and withdrawal are region-dependent. No consistent response to resolution is found in simulating summer monsoon retreat. Regionally, in- creased resolution reduces the positive bias in simulated annual mean precipitation, the two annual-cycle modes over the West African monsoon and Northwestern Pacific monsoon. An overestimation of the solstitial mode and an underestimation of the equinoctial asymmetric mode of the East Asian monsoon axe reduced in all high-resolution configurations. Systematic errors exist in lower-resolution models for simulating the onset and withdrawal of the summer monsoon. Higher resolution models consistently improve the early summer monsoon onset over East Asia and West Africa, but substantial differences exist in the responses over the Indian monsoon region, where biases differ across the three low-resolution AGCMs. This study demonstrates the importance of a multi-model comparison when examining the added value of resolution and the importance of model physical parameterizations for simulation of the Indian monsoon.

Devonian Frasnian-Famennian Transitional Milankovitch Cycles and High-Resolution Stratigraphic Correlation

Four hierarchical cyclothems, superbundlesets, bundlesets, bundles and laminae, have been identified from the Devonian Frasnian-Famennian carbonate strata in Guangxi, South China. Their hierarchical structures, ratio relationships and sequence in conodont zones are continuous and stable and can be traced across different facies zones and sedimentary basins. Our data show that hierarchically organized superbundlesets, bundlesets, bundles and laminae correspond to the long eccentricity, eccentricity, obliquity or precession and sub-Milankovitch cycles respectively. Their periods were 400,000, 100,000, 33,333, 16,667 and 8,000–17,000 a, respectively. The ratios of long eccentricity to eccentricity, eccentricity to obliquity, and eccentricity to precession in the Devonian are 1:4, 1:3 and 1:6 respectively. Using these hierarchical Milankovitch cyclothems, chronostratigraphical division and correlation can be realized at a resolution of 100 ka or 10 ka at the Frasnian-Famennian transition. The time intervals of the Upper rhenana Zone, linguiformis Zone, and the Lower, Middle and Upper triangularis Zone are 0.6, 0.8, 0.3, 0.3 and 0.3 Ma, respectively. Sea-level changes of the Frasnian-Famennian transition were not coherent and synchronous at the resolution of 100 ka or 10 ka in the basin-slope carbonate sequences of Guangxi, South China.

On the analysis of the high-resolution sequence stratigraphy and coal accumulating law of jurassic in Ordos Basin

The strata of Jurassic was divided into three tectonic sequences and eight se- quences of third rank,according to the developing feature of the tectonic inconformity and the transforming feature of the depositional system tracts.Also the identification and the division of the base-level cycle of different period were carried through.Therefore three cycles of super period,eight cycles of long period,twenty-four cycles of middle period and some cycles of short period were identified.From the overall character of the coal-accu- mulation in the Mesozoic,we can see that the Yan'an formation is of the best nature of coal bearing.When the coal bearing systems of Jurassic were depositing,the Ordos area is the coal accumulating basin of terrene of large scale and located in the same tectonic unit.But the local structure of different part and the paleolandform are different in the basin which resulted in the difference of the depositional environment.So the layer number and the distribution of the thickness of the coal beds are different in the different part of the ba- sin.The coal-accumulating action migrated regularly along with the development,evolve- ment and migration of the depositional systems.The layer numbers of the coal beds, which can be mined,are more in the north and west fringe of the basin,whose distributing area is extensive,and they are more steady in the landscape orientation,also the total thickness is great.Therefore the nature of coal bearing and the coal-accumulating action of different part changed obviously in the space in Ordos area.

Application of multi-resolution analysis in sonar image denoising

Sonar images have complex background, low contrast, and deteriorative edges; these characteristics make it difficult for researchers to dispose the sonar objects. The multi-resolution analysis represents the signals in different scales efficiently, which is widely used in image processing. Wavelets are successful in disposing point discontinuities in one dimension, but not in two dimensions. The finite Ridgelet transform （FRIT） deals efficiently with the singularity in high dimension. It presents three improved denoising approaches, which are based on FRIT and used in the sonar image disposal technique. By experiment and comparison with traditional methods, these approaches not only suppress the artifacts, but also obtain good effect in edge keeping and SNR of the sonar image denoising.

A SIMPLE METHOD FOR QUANTITATIVE ANALYSESOF REVERSIBLE KINETIC RESOLUTIONS

Objectics A convenient method was developed for the determination of the enantioselectivity ofreversible kinetic resolutions with the new equation deduced by us. Methods By using the data of extent ofconversions at t1, 2t1, and the equilibrium constant K measured by usual method, the enantiomeric ratio E can beeasily calculated by the newly developed equation. Results We have successfully applied our method to theanalyses of enantioselectivity of three lipasic resolutions. The results are in good agreement with those of otherexperiments. Conclusion The method is simple and practical, and plays an important role in the determination ofkinetic data of reversible resolution.

Application of WRF 3DVar to a high-resolution model over Beijing area

To improve the weather forecasting over the Beijing area for the 2008 Olympic Games,a triple-nested(27/9/3km) WRFVar/WRF system with 3-h update cycle was established.Experiments have been done for a convective event that occurred on August 1,2006.The results showed that the high-resolution rapid update cycle gave a good precipitation forecast;the tunings of background error statistics(BES) and observation-error statistics in WRFVar improved the skill of the precipitation forecast;the BES for the fine domain(3 km) obtained by interpolation from its parent domain(9 km) can be used in 3 km WRFVar as a reasonable approximation.The user can now save a great deal of work related to the derivation of the fine mesh BES from the forecast over a period of time;the rapid update cycle with 3-h frequency has satisfied the forecast,and the update cycle with 1-h frequency was not necessary.

Performing High Resolution Seismic Reflection for Mapping Bauxite Layers

The seismic method is able to produce highly accurate images of the Earth's subsurface. Having such detail is not only an important factor in mining, but also in civil engineering. Bauxite exploration attracts both government and industrialists to invest in it because of the high percentage of aluminum present. The economic importance of extracting aluminum from bauxite encouraged us to take this challenge;to image bauxite layers by using a high-resolution seismic reflection method at Al Qassim, Saudi Arabia. Since the subsurface structure of the area is complex, this high-resolution reflection method was carried out along a 2D line with geophone and source interval, with settings at 5 m. The result for the seismic section shows that the depth and thickness of the bauxite layer varied from 20 to 34 m, and 3 to 7 m respectively. In addition, the bauxite layer was sandwiched between clay layers. In order to achieve an even more precise depth than presented by seismic section alone, we tied the drilled wells to the seismic data and we accomplished a well match with an approximation error of 1 - 2 m, which may have been caused by the upper clay layer or by very shallow loose subsurface material. The seismic method thus applied shows the ability to detect significant details within the near surface of the earth, and considers more cost-effective than only drilled wells.

Entransy analyses of heat–work conversion systems with inner irreversible thermodynamic cycles

In this paper, we try to use the entransy theory to analyze the heat–work conversion systems with inner irreversible thermodynamic cycles. First, the inner irreversible thermodynamic cycles are analyzed. The influences of different inner irreversible factors on entransy loss are discussed. We find that the concept of entransy loss can be used to analyze the inner irreversible thermodynamic cycles. Then, we analyze the common heat–work conversion systems with inner irreversible thermodynamic cycles. As an example, the heat–work conversion system in which the working fluid of the thermodynamic cycles is heated and cooled by streams is analyzed. Our analyses show that larger entransy loss leads to larger output work when the total heat flow from the high temperature heat source and the corresponding equivalent temperature are fixed.Some numerical cases are presented, and the results verify the theoretical analyses. On the other hand, it is also found that larger entransy loss does not always lead to larger output work when the preconditions are not satisfied.

岩溶碳汇原理、过程与计量

岩溶生态系统碳循环由陆地生物碳循环(植物光合作用驱动)和岩溶碳循环(碳酸盐岩溶解风化驱动)两部分组成。岩溶碳循环与陆地生物碳循环存在协同作用,岩溶碳循环过程对陆地淡水生态系统产生显著影响。岩溶碳汇主要发生在岩溶和生物紧密联系的植物根系土壤岩石相互融合的表层岩溶带,在快速交互的地下水系统和地表水系统中发生迁移转化过程。当前流域岩溶碳汇计量存在至少3个方面的问题:(1)全岩溶流域中来源于碳酸盐岩的碳和来源于大气/土壤中的碳比例不清;(2)部分岩溶流域碳酸盐岩和硅酸盐岩风化溶解产生碳汇的量如何区分;(3)水生植物光合作用生产的内源有机碳与陆地生态系统的外源有机碳的贡献大小如何。建议岩溶碳汇计算要以流域为单元,通过确定流域边界,查明地质结构,分析土地覆被配置,揭示岩溶碳循环及碳汇效应影响的主控因子,建立反演和正演模型,估算流域岩溶和生物碳汇的贡献,填补岩溶碳汇服务价值评估的空白。

高含水油田“二三结合”转换时机优化

针对现有转换时机研究方法无法满足高含水期老油田“二三结合”转换时机优化设计需要的问题,在综合分析三次采油转换时机和技术经济评价方法的基础上,考虑工程技术可行性和经济效益可行性,提出综合考虑技术、经济、社会价值的“二三结合”全生命周期开发价值链理念,建立高含水期老油田“二三结合”全生命周期效益稳产开发价值链模型,并实例分析“二三结合”转换时机对油藏最终采收率和生命周期的敏感性。结果表明,稳产、效益、生命周期是“二三结合”全生命周期效益稳产开发的主要考虑因素,转换时机对效益和稳产的影响是相对立的。

客户数字化转型与企业营运资金管理效率——基于竞争侵占与约束防御的双重视角

无论在企业管理实践中,还是从已有文献来看,客户数字化转型对企业营运资金管理效率表现出促进还是抑制,仍未形成一致结论。文章采用中国深沪A股上市企业披露的前五大客户数据,探讨客户数字化转型对企业营运资金管理效率的溢出效应与作用机理。基准检验发现,客户数字化转型降低了企业营运资金管理效率,说明数字溢出存在负外部性。作用渠道检验发现,竞争侵占与约束防御是客户数字化转型影响企业营运资金管理效率的两大渠道,即客户数字化转型催生的数字溢出通过降低企业相对议价能力、降低企业应收账款回收率、加剧企业专用资产套牢风险、加大企业商业信用供给以及扩大企业存货储备规模进而降低了企业营运资金管理效率,说明数字溢出具有竞争约束特征。异质性检验发现,当客户集中度较低、企业规模较大、企业风险承担能力较强时,数字溢出的竞争约束特征得到缓解。研究结论解释了客户数字化转型是否能够提升企业营运资金管理效率的争议,发现了客户数字化转型引致的数字溢出具有竞争约束特征,并提供了企业克服数字溢出负外部性的理论指导,具有理论价值和现实意义。

基于实数化的均匀圆阵矩阵重构方法

为了减小低快拍数和低信噪比下采样协方差矩阵误差,并降低其运算复杂度,提出了一种基于实数化的均匀圆阵采样协方差矩阵重构方法。针对均匀圆阵的特点,通过组建特殊的基向量,构成特殊的重构矩阵。通过将采样协方差矩阵实数化,进一步降低了重构矩阵的复杂度。考虑到多通道不一致性对重构矩阵的影响,引入0位校正算法,提高了重构方法的稳健性。最后应用重构后的协方差矩阵进行子空间类波达方向估计(direction of arrival,DOA)。实验仿真证明,该特殊重构矩阵在实数化下与原矩阵重构能力相同;当快拍数为100、信噪比为0 dB时,双信源分辨力较重构前由74%提高到95%以上;理论重构运算复杂度降低到原来的53.99%。

多种构型超临界CO_(2)循环热力学解构分析与参数优化

新型超临界CO_(2)(S-CO_(2))循环可通过流程改良提高效率,构型复杂多样。为了直观阐明各种流程改良措施对循环效率提升的作用机制,本文将预压缩、后压缩、再压缩、间冷、再热等五种构型的S-CO_(2)循环解构为若干热功转换过程,建立各解构过程与循环效率之间的关联方程,进而开展流程参数优化。研究结果表明,预压缩、后压缩和再压缩方案均是通过增加压缩耗功,减少吸热量实现循环效率提升,其中再压缩方案效果最优,再压缩流量优化后循环效率提高5.1%;采用部分间冷方案,可有效降低压缩功耗,同时避免高品位热量贬值,间冷压力优化后循环效率提高2.2%;再热方案在不改变压缩耗功的前提下,增加透平出功,再热压力优化后循环效率提高1.9%;最后,循环联用再压缩、间冷和再热三种节能措施,可使效率提高9.3%。

沉浸美学视野下宋画山水的数字化转变

宋画的数字化美学体现在解构与重组中,主要从形式上的二维到三维的转变;叙事上的消解与转换;体验中的五感融合与沉浸这三点体现。本文以宋画中的山水画为主,从宋画与沉浸美学的关系入手,结合案例分析宋画在数字化过程中的转变与呈现,以沉浸美学的视角探究宋画本身可被活化的因素,希望能为其他中国传统绘画数字化提供参考,为文化与技术结合作出有意义的探讨。

基于不同模糊度固定产品的PPP-AR定位性能评估

基于CODE、GFZ、CNES、武汉大学PRIDE实验室和内部估计的模糊度固定产品,从收敛时间、首次固定时间及定位精度等方面进行PPP-AR固定性能的研究。实验选用2022年40个IGS测站7 d的观测数据和各模糊度固定产品配套使用的精密产品,结果表明,在置信度为95%的静态解算模式下,5种产品在解算时间为1 h时固定解较浮点解定位精度提升最明显,分别提升46.58%(3.4 cm)、41.10%(3.0 cm)、45.21%(3.3 cm)、34.25%(2.5 cm)和41.10%(3.0 cm)。仿动态解算模式下,5种产品E、N方向的定位精度都能达到mm级,U方向较浮点解精度提升较小,其中使用GBM产品的精度提升最小,E、N、U方向分别提高72.73%(2.4 cm)、47.37%(0.9 cm)、5.41%(0.2 cm);提升效果较好的是WUM和COM产品,分别为81.82%(2.7 cm)、63.16%(1.2 cm)、24.32%(1.1 cm)和81.82%(2.7 cm)、63.16%(1.2 cm)、15.58%(0.8 cm)。

High-resolution data acquisition technique in broadband seismic observation systems

The dynamic range of the currently most widely used 24-bit seismic data acquisition devices is 10–20 d B lower than that of broadband seismometers, and this can affect the completeness of seismic waveform recordings under certain conditions. However, this problem is not easy to solve because of the lack of analog to digital converter(ADC) chips with more than 24 bits in the market. In this paper, we propose a method in which an adder, an integrator, a digital to analog converter chip, a field-programmable gate array, and an existing low-resolution ADC chip are used to build a third-order 16-bit oversampling delta-sigma modulator. This modulator is equipped with a digital decimation filter, thus facilitating higher resolution and larger dynamic range seismic data acquisition. Experimental results show that, within the 0.1–40 Hz frequency range, the circuit board's dynamic range reaches 158.2 d B, its resolution reaches 25.99 bits, and its linearity error is below 2.5 ppm, which is better than what is achieved by the commercial 24-bit ADC chips ADS1281 and CS5371. This demonstrates that the proposed method may alleviate or even completely resolve the amplitude-limitation problem that so commonly occurs with broadband observation instruments during strong earthquakes.

Galileo三频非组合PPP相位小数偏差估计与模糊度解算

欧洲的Galileo目前已经有28颗在轨可用卫星,具备全球精密定位能力,并且所有卫星均能够播发多频信号,多频信号融合有望进一步改善精密单点定位(precise point positioning,PPP)模糊度固定解性能.本文研究了Galileo三频非组合PPP相位小数偏差(fractional cycle bias,FCB)估计与模糊度解算(ambiguity resolution,AR)方法,并将其结果同双频非组合PPP模糊度固定解与浮点解结果进行了对比分析.结果表明:利用155个全球分布的地面跟踪站数据进行FCB估计,单个频率上的FCB估值序列标准差(standard deviation,STD)优于0.04周;双频PPP浮点解在E、N、U方向收敛时间分别为32.0 min、10.0 min、43.5 min,双频PPP固定解收敛时间分别减少到30.5 min、8.5 min、32.0 min,三频PPP固定解收敛时间分别进一步缩短到16.5 min、8.0 min、32.0 min.

吡咯基三嗪聚合框架用于固相转变硫聚物正极性能研究

针对锂硫电池存在严重穿梭效应的问题,硫物质的固相转变可有效消除多硫化锂在液相中的溶解扩散。以聚丙烯腈为代表的常规链状聚合物可通过共价结合短链硫实现固相转变,然而往往受到硫含量低、倍率性能差的限制。通过氰基三聚与吡咯自由基聚合构筑了吡咯基三嗪聚合物框架(P-CNPy),其硫含量较高,达到47%。电化学测试结果显示硫聚物正极具有优异的循环稳定性与倍率性能,0.2C循环500次平均容量衰减仅为0.03%,4C时可逆容量仍保留580mA∙h/g。该方法可为高性能二维框架结构硫聚物正极的设计应用提供指导。

Spratlies Archipelago as the Australasian Tektite Impact Crater, Details of Formation &Richard Muller’s Dust Cloud Explanation for the Mid-Pleistocene Ice Age Cycle Transition

Several significant events of a geological nature occurred approximately 800 ka before the present: (1) Australasian tektite fall (AA), (2) Brunhes-Matuyama geomagnetic reversal (BMR), (3) mid-Pleistocene changes in ice age cycles. Add to these the undated fault system (4) in the South-West (SW) of the South China Sea (SCS). Here we offer a unified cause for all four of these in (5), an impact in the SCS of a large, massive cosmic object, likely a comet, obliquely coming from the SW at an extremely shallow angle, striking the Sunda shelf yet unexploded with the shock of its compressed air bow wave, and causing the continual shelf and slope to collapse, resulting in the fault system (4), then traveling almost tangentially to the surface, exploding at impact with the sea surface, ejecting the tektites (1), creating the formation underlying the later atolls of Spratlies Archipelago (6), Nansha Islands in Chinese, & causing the BMR (2). An explanation of event (3) was Richard Muller’s hypothesis of planet Earth passing through an interplanetary dust cloud periodically due to ecliptic precession. Here we hypothesize this cloud actually is a belt of Australasian tektites ejected into space at super-orbital velocities that Earth encounters about every 100 ka.

基于改进型多斜Ⅲ技术的7位半AD转换器设计

高精度测试仪器在环境试验中扮演着重要角色,而积分型AD转换器被广泛的应用在高精度测试仪器中。针对传统型积分型AD转换器转换速率较低的问题,提出了一种提高转换速率的改进型多斜ⅢAD转换器,详细的介绍了其原理和设计思路。该转换器以单片机与CPLD一同控制积分型ADC,在积分末尾利用单片机片内ADC测量积分器的残留电压,以达到提高转换速率的目的。经理论分析该AD转换器比传统型转换速率快836倍,分辨率可达到31位,在±10V直流电压测量中可实现7位半分辨率。