Model-constrained and data-driven double-supervision acoustic impedance inversion

Seismic impedance inversion is an important technique for structure identification and reservoir prediction.Model-based and data-driven impedance inversion are the commonly used inversion methods.In practice,the geophysical inversion problem is essentially an ill-posedness problem,which means that there are many solutions corresponding to the same seismic data.Therefore,regularization schemes,which can provide stable and unique inversion results to some extent,have been introduced into the objective function as constrain terms.Among them,given a low-frequency initial impedance model is the most commonly used regularization method,which can provide a smooth and stable solution.However,this model-based inversion method relies heavily on the initial model and the inversion result is band limited to the effective frequency bandwidth of seismic data,which cannot effectively improve the seismic vertical resolution and is difficult to be applied to complex structural regions.Therefore,we propose a data-driven approach for high-resolution impedance inversion based on the bidirectional long short-term memory recurrent neural network,which regards seismic data as time-series rather than image-like patches.Compared with the model-based inversion method,the data-driven approach provides higher resolution inversion results,which demonstrates the effectiveness of the data-driven method for recovering the high-frequency components.However,judging from the inversion results for characterization the spatial distribution of thin-layer sands,the accuracy of high-frequency components is difficult to guarantee.Therefore,we add the model constraint to the objective function to overcome the shortages of relying only on the data-driven schemes.First,constructing the supervisor1 based on the bidirectional long short-term memory recurrent neural network,which provides the predicted impedance with higher resolution.Then,convolution constraint as supervisor2 is introduced into the objective function to guarantee the reliability and accuracy of the inversion results,which makes the synthetic seismic data obtained from the inversion result consistent with the input data.Finally,we test the proposed scheme based on the synthetic and field seismic data.Compared to model-based and purely data-driven impedance inversion methods,the proposed approach provides more accurate and reliable inversion results while with higher vertical resolution and better spatial continuity.The inversion results accurately characterize the spatial distribution relationship of thin sands.The model tests demonstrate that the model-constrained and data-driven impedance inversion scheme can effectively improve the thin-layer structure characterization based on the seismic data.Moreover,tests on the oil field data indicate the practicality and adaptability of the proposed method.

钙钛矿晶体的电荷复合动力学研究

本文利用紫外吸收光谱和稳态荧光光谱技术结合理论模型,研究了钙钛矿材料CH3NH3PbI3晶体在光激发过程中的电荷复合动力学行为,进而获得晶体的扩散长度.电荷载体的扩散长度是判断光电材料的重要参数.研究通过合成两种不同缺陷态浓度的CH3NH3PbI3晶体,测量这两种晶体在0.019~4.268μJ/cm2的激光激发下的时间分辨荧光光谱,利用动力学模型对光谱进行拟合,可以获得每个晶体的掺杂浓度,空穴浓度以及电荷复合参数.将这些参数结合已有公式,最终可获得每个晶体的电荷载体的扩散长度.

OCS分子在207 nm的光解动力学研究:S(1D2)+CO(X^1∑^+)产物通道

利用直流时间切片离子成像技术对OCS分子在紫外波段207nm的光解产物S(1D2)进行了偏振实验研究.通过在两种不同的共振增强多光子电离中间态,1F3和1P1,以及四种不同的泵浦-探测激光偏振几何构型下探测了光碎片S(1D2)的角动量极化特性.使用分子坐标系极化模型和实验室坐标系各向异性模型提取和分析出对应产物CO(X^1∑^+)的角分布.观测到的总平动能释放谱表明解离过程存在三种解离通道,分别对应于低、中、高平动能解离通道.低、中平动能通道的来源与光解波长在较长波长下得到的双峰分布来源一致.高平动能通道是一种新的解离通道,它来自于单重排斥态A(2^1A’)的直接解离.

Spatially resolved micron-scale wrinkle structures at asphaltene films induced by mild thermal treatment and its impact on emulsion stability

Mild thermal treatment is an important partial upgrading technique to enable bitumen pipeline transportation,but no attention has been paid to the impact of mild thermal treatment on the emulsification behavior of emerging partially upgraded bitumen.Asphaltene compounds are active emulsion stabilizers in bitumen oil.The emulsion stabilizing capacity of bitumen asphaltenes was investigated,before and after a mild thermal treatment at 400℃.The structural morphology and mechanical property of the asphaltene interfacial films were analyzed by using a combination of cryo-SEM,Langmuir trough,and Brewster angle microscopy.The thermal treatment significantly enhanced the emulsion stabilizing capacity of bitumen asphaltenes;the interfacial films formed by the thermally treated asphaltene samples appeared to be rougher and thicker with more abundant micron-scale wrinkle structures.The interfacial corrugation may intensify the mechanical stability/flexibility of the asphaltene films and consequently strengthen the stability of emulsion droplet.

Imaging the [1+1] Two-Photon Dissociation Dynamics of Br2 + in a Cold Ion Beam

The [1+1] two-photon dissociation dynamics of mass-selected 79Br2 + has been studied in a cold ion beam using a cryogenic cylindrical ion trap velocity map imaging spectrometer. The quartet 14Σ- u;3=2 state of 79Br2 + is employed as an intermediate state to initiate resonance enhanced two-photon excitation to high-lying dissociative states in the 4.0-5.0 eV energy region above the ground rovibronic state. Total kinetic energy release (TKER) and the twodimensional recoiling velocity distributions of fragmented 79Br+ ions are measured using the technique of DC-slice velocity map imaging. Branching ratios for individual state-resolved product channels are determined from the TKER spectra. The measured photofragment angular distributions indicate that the dissociation of 79Br2 + occurs in dissociative Ω=3/2 state via ΔΩ=0 parallel transition from the 14Σ-u;3=2 intermediate state. Due to the considerable spin-orbit coupling effects in the excited states of 79Br2 +, higher-lying dissociative quartet states are likely responsible for the observed photodissociation processes.

Reinvestigate the C^2Π-X^2Π(0,0)Band of AgO

The C^2Π-X^2Π(0,0)band of AgO has been reinvestigated by laser induced fluorescence spectroscopy with a spectral resolution of ~0.02 cm^−1.The AgO molecules are produced by discharging a gas mixture of O2/Ar with silver needle electrodes in a supersonic jet expansion.By employing a home-made narrowband single longitude mode optical parametric oscillator(SLM-OPO)as the laser source,high-resolution spectra of the C^2Π-X^2Π(0,0)band have been recorded for both 107Ag16O and 109Ag16O isotopologues.The spectroscopic constants of the C^2Π state are consequently determined,with the 109Ag16O one being reported for the first time.The nature of the spin-orbit coupling effect in the C^2Π state is proposed to be due to state mixing with the nearby repulsive 4Σ− and 4Π states.

New Insights into the Molecular Basis of Kidney Governing Bone Theory

Kidney governing bone theory plays an important role in treating bone metabolic disease such as osteoporosis, and many tonifying kidney prescriptions/herbs are widely used in Traditional Chinese Medicine(TCM). However, the exact biological basis of kidney governing bone theory in the context of new advances in biology is still not fully established. In this paper, the content of kidney governing bone theory in biology has been fully demonstrated from different aspects. We first propose that bone and kidney mutually affect each other in pathology and physiology, particularly through homeostasis of calcium, phosphorus and fibroblast growth factor-23(FGF-23). Next, we identify that tonifying kidney prescriptions/herbs exert bone protective effects, thus treating osteoporosis by regulating bone formation and bone resorption.Furthermore, the exact molecular mechanisms of tonifying kidney prescriptions, herbs and their effective components in treating osteoporosis have been systematically reviewed. Finally, we come into the conclusion that kidney regulating bone mineral homeostasis, bone protective effects of tonifying kidney herbs and regulatory effects on bone homeostasis are all the manifestations of kidney governing bone theory.Therefore, the new insights into kidney governing bone theory in biology will promote the development of clinical practices, and drugs discovery in treating osteoporosis.

Tonifying Shen-Yin and-Yang Principles in Treating Osteoporosis: All Roads Lead to Rome

Tonifying Shen strategy works as an important alternative and complementary method that is widely used to treat osteoporosis in Traditional Chinese Medicine(TCM) based on the proper identification of Zheng. Shen deficiency Zheng is one of the main types of osteoporosis while Shen-Yin and-Yang deficiencies represent two basic principles/types of Shen deficiency. Currently, Tonifying Shen strategy, in particular, the Tonifying Shen-Yin and-Yang principles, has been demonstrated to exert osteoprotective effects. However, the mechanisms by which Tonifying Shen strategy and/or Tonifying Shen-Yin and-Yang principles function in treating osteoporosis are still not clearly understood. Here we first briefly explore current understanding of Tonifying Shen strategy, such as Tonifying Shen prescriptions, herbs, and effective components, in treating osteoporosis. Furthermore, the mechanism of Tonifying Shen-Yang principle in treating osteoporosis is reviewed from the clinic experience, animal, and mechanistic investigation. Moreover, the mechanisms by which Tonifying Shen-Yin principle in treating osteoporosis are established. Finally, we compare the similarity and difference between Tonifying Shen-Yang and-Yin principles in treating osteoporosis.Our findings indicate that both principles exert bone-protective effects in treating osteoporosis by simultaneously stimulating the differentiation of mesenchymal stem cells(MSCs) into osteoblast and the differentiation of hematopoietic stem cells(HSCs) into osteoclast. However,Tonifying Shen-Yin principle is in favor of increasing bone mineral density(BMD) while Tonifying Shen-Yang principle is in favor of osteoporosis-related syndromes. Our findings indicate that Tonifying Shen-Yin and-Yang principles not only share some similarity but also obtain some difference in treating osteoporosis.

From Osteoblast to Osteoclast: New Insights of Yin-Yang Theory in Bone Remodeling

Yin-Yang theory plays critical role in traditional Chinese medicine(TCM) science. However, there are many competing interpretations of YinYang theory in the context with the development in biology, and no consensus has been established. Here we first propose that osteoblast should be regarded as Yin, while osteoclast should be considered as Yang in bone remodeling compartment(BRC). Our conceptions are consistent with the following key findings: 1)osteoblast and osteoclast both derive from the embryonic ectoderm; 2)osteoblast and osteoclast work collaboratively in BRC to maintain bone homeostasis; 3)the activities of osteoblast and osteoclast are coupled to remain dynamic balance;4)osteoblast and osteoclast exert their function in ceaseless successions. Moreover, we argue that Yin-Yang relationships exist between osteoblast and osteoclast: osteoblast secretes the receptor activator for nuclear factor-κB ligand(RANKL) and the monocyte/macrophage colony-stimulating factor(M-CSF) and osteoprotegerin(OPG) to positively or negatively regulate osteoclast differentiation and function.Meanwile, osteoclast and bone resorption in turn release cytokines, such as transforming growth factor-β(TGF-β), insulin-like growth factor-1(IGF-1) from bone matrix, to regulate osteoblast differentiation and function. Next, the unlimited division of Yin-Yang can be applied to divide sublevel of Yin-Yang inside osteoblast or osteoclast. Finally, Yin-Yang relationship of osteoblast and osteoclast is relative. Therefore, we come into the conclusion that the relationships between osteoblast and osteoclast as established in contemporary biology reflect the classic Yin-Yang in bone remodeling. The new Yin-Yang concepts of osteoblast and osteoclast may strengthen basic theory and clinical practice in TCM.