Calibrate complex fracture model for subsurface flow based on Bayesian formulation

In practical development of unconventional reservoirs,fracture networks are a highly conductive transport media for subsurface fluid flow.Therefore,it is crucial to clearly determine the fracture properties used in production forecast.However,it is different to calibrate the properties of fracture networks because it is an inverse problem with multi-patterns and highcomplexity of fracture distribution and inherent defect of multiplicity of solution.In this paper,in order to solve the problem,the complex fracture model is divided into two sub-systems,namely"Pattern A"and"Pattern B."In addition,the generation method is grouped into two categories.Firstly,we construct each sub-system based on the probability density function of the fracture properties.Secondly,we recombine the sub-systems into an integral complex fracture system.Based on the generation mechanism,the estimation of the complex fracture from dynamic performance and observation data can be solved as an inverse problem.In this study,the Bayesian formulation is used to quantify the uncertainty of fracture properties.To minimize observation data misfit immediately as it occurs,we optimize the updated properties by a simultaneous perturbation stochastic algorithm which requires only two measurements of the loss function.In numerical experiments,we firstly visualize that small-scale fractures significantly contribute to the flow simulation.Then,we demonstrate the suitability and effectiveness of the Bayesian formulation for calibrating the complex fracture model in the following simulation.

Evolutionary history of a desert perennial Arnebia szechenyi(Boraginaceae):Intraspecific divergence,regional expansion and asymmetric gene flow

The complex interactions of historical,geological and climatic events on plant evolution have been an important research focus for many years.However,the role of desert formation and expansion in shaping the genetic structures and demographic histories of plants occurring in arid areas has not been well explored.In the present study,we investigated the phylogeography of Arnebia szechenyi,a desert herb showing a near-circular distribution surrounding the Tengger Desert in Northwest China.We measured genetic diversity of populations using three maternally inherited chloroplast DNA(cpDNA)fragments and seven bi-paternally inherited nuclear DNA(nDNA)loci that were sequenced from individuals collected from 16 natural populations across its range and modelled current and historical potential habitats of the species.Our data indicated a considerably high level of genetic variation within A.szechenyi and noteworthy asymmetry in historical migration from the east to the west.Moreover,two nuclear genetic groups of populations were revealed,corresponding to the two geographic regions separated by the Tengger Desert.However,analysis of cpDNA data did not show significant geographic structure.The most plausible explanation for the discrepancy between our findings based on cpDNA and nDNA data is that A.szechenyi populations experienced long periods of geographic isolation followed by range expansion,which would have promoted generalized recombination of the nuclear genome.Our findings further highlight the important role that the Tengger Desert,together with the Helan Mountains,has played in the evolution of desert plants and the preservation of biodiversity in arid Northwest China.

Stable zinc anode by regulating the solvated shell and electrode-electrolyte interface with a sodium tartrate additive

Aqueous zinc-ion batteries(ZIBs)have attracted great research interest for use in large-scale energy storage devices due to their inherent safety,environmental friendliness,and low cost.Unfortunately,dendrite growth and interfacial side reactions during the plating/stripping process triggered by uneven electric field distribution on the surface of the Zn anode seriously hinder the further development of aqueous ZIBs.Here,practical and inexpensive sodium tartrate(STA)is used as an electrolyte additive to construct a stable electrode-electrolyte interface,in which STA adsorbs preferentially on the Zn metal surface,contributing to promoting homogeneous Zn deposition.Moreover,STA interacts more strongly with Zn^(2+),which takes the place of the water molecules in the solvated shell and prevents the development of side reactions.In symmetrical cells and full cells,flat Zn anodes can therefore demonstrate remarkable cycle stability,opening the door for the development of cost-effective and effective electrolyte engineering techniques.

High-pressure balloon dilation for male anterior urethral stricture:single-center experience

Objectives： We retrospectively reviewed the urethral stricture cases treated in our tertiary center, and assessed the safety and feasibility of the high-pressure balloon dilation （HPBD） technique for anterior urethral stricture Methods： From January 2009 to December 2012, a total of 31 patients with anterior urethral strictures underwent HPBD at our center, while another 25 cases were treated by direct vision internal urethrotomy （DVIU）. Patient de- mographics, stricture characteristics, surgical techniques, and operative outcomes were assessed and compared between the two groups. The Kaplan-Meier survival analysis was applied to evaluate the stricture-free rate for the two surgical techniques. Results： The operation time was much shorter for the HPBD procedure than for the DVIU （（13.19±2.68） min vs. （18.44±3.29） min, P〈0.01）. For the HPBD group, the major postoperative complications as urethral bleeding and urinary tract infection （UTI） were less frequently encountered than those in DVIU （urethral bleeding： 2/31 vs. 8/25, P=0.017; UTI： 1/31 vs. 6/25 P=0.037）. The Kaplan-Meier survival analysis showed that there was no significant difference in stricture-free rate at 36 months between the two groups （P=-0.21, hazard ratio （HR）=0.65, 95% confidence interval （CI）： 0.34 to 1.26）. However, there was a significantly higher stricture-free survival in the HPBD group at 12 months （P=-0.02, HR=0.35, 95% CI： 0.14 to 0.87）, which indicated that the stricture recurrence could be delayed by using the HPBD technique. Conclusions： HPBD was effective and safe and it could be considered as an alternative treatment modality for anterior urethral stricture disease.

Hydrogels with Dynamically Controllable Mechanics and Biochemistry for 3D Cell Culture Platforms

Many cell-matrix interaction studies have proved that dynamic changes in the extracellular matrix(ECM)are crucial to maintain cellular properties and behaviors.Thus,developing materials that can recapitulate the dynamic attributes of the ECM is highly desired for threedimensional(3 D)cell culture platforms.To this end,we sought to develop a hydrogel system that would enable dynamic and reversible turning of its mechanical and biochemical properties,thus facilitating the control of cell culture to imitate the natural ECM.Herein,a hydrogel with dynamic mechanics and a biochemistry based on an addition-fragmentation chain transfer(AFCT)reaction was constructed.Thiol-modified hyaluronic acid(HA)and allyl sulfide-modifiedε-poly-L-lysine(EPL)were synthesized to form hydrogels,which were non-swellable and biocompatible.The reversible modulus of the hydrogel was first achieved through the AFCT reaction;the modulus can also be regulated stepwise by changing the dose of UVA irradiation.Dynamic patterning of fluorescent markers in the hydrogel was also realized.Therefore,this dynamically controllable hydrogel has great potential as a 3 D cell culture platform for tissue engineering applications.