Influences of clean fracturing fluid viscosity and horizontal in-situ stress difference on hydraulic fracture propagation and morphology in coal seam

The viscosity of fracturing fluid and in-situ stress difference are the two important factors that affect the hydraulic fracturing pressure and propagation morphology. In this study, raw coal was used to prepare coal samples for experiments, and clean fracturing fluid samples were prepared using CTAB surfactant. A series of hydraulic fracturing tests were conducted with an in-house developed triaxial hydraulic fracturing simulator and the fracturing process was monitored with an acoustic emission instrument to analyze the influences of fracturing fluid viscosity and horizontal in-situ stress difference on coal fracture propagation. The results show that the number of branched fractures decreased, the fracture pattern became simpler, the fractures width increased obviously, and the distribution of AE event points was concentrated with the increase of the fracturing fluid viscosity or the horizontal in-situ stress difference. The acoustic emission energy decreases with the increase of fracturing fluid viscosity and increases with the increase of horizontal in situ stress difference. The low viscosity clean fracturing fluid has strong elasticity and is easy to be compressed into the tip of fractures, resulting in complex fractures. The high viscosity clean fracturing fluids are the opposite. Our experimental results provide a reference and scientific basis for the design and optimization of field hydraulic fracturing parameters.

Focus control of wide-angle metalens based on digitally encoded metasurface

Based on the principle of super-symmetric lens with quadratic phase gradient transformation, combined with the principle of digital coding of metasurface, we propose a wide-angle coded metalens for focusing control in two-dimensional space. This metalens achieves focus shift in the x-direction by changing the oblique incidence angle of the incident wave,and focus control in the y-direction by combining with the convolution principle of the digitally coded metasurface to achieve flexible control of light focusing in the two-dimensional plane. The metasurface unit is mainly composed of threelayer of metal structure and two layers of medium, and the transmission phase is obtained by changing the middle layer of metal structure, which in turn obtains the required phase distribution of the metalens. The design of the metalens realizes the function of the lens with a large viewing angle at the x-polarized incidence, and realizes two-dimensional focus control. Experimentally, we prepared the designed coding metalens and tested the focus control function of the wide-angle coding metalens. The experimental results are in good agreement with the design results.

Compliance to Medication Management and Mental Health Status of Elderly Hypertensive Patients: Basis of Educational Health Program

Objective:The study aimed to assess medication management compliance and mental health in elderly patients with hypertension.Method:The study evaluated medication compliance and mental health status of elderly hypertensive patients in China using simple random sampling.Data was collected using the Morisky Medication Compliance Questionnaire,Hospital Anxiety and Depression Scale,and a checklist.Ethical practices were strictly observed.Results:A study of 100 elderly hypertensive patients found poor drug management compliance,with female patients showing worse compliance.Female patients were more vulnerable to anxiety and depression.The study also found no significant association between gender,age,education level,marital status,living standards,and medication compliance.Barriers to medication management included food and daily necessities,lack of awareness about the importance of drug treatment,and basic family needs.The lowest-ranked barriers were lack of support from government health clinics,low income,and lack of family support.Conclusion:Based on the results,the study proposes an educational plan for elderly hypertensive patients and their families,to be evaluated and implemented by the hospital and township community service center.The plan aims to improve medication management and lifestyle modification compliance,encourage active participation,and provide access to medical and mental health clinics,support groups,and counseling services.

早期胃癌浸润深度的主要影响因素分析及预测模型的构建

目的:探讨影响早期胃癌(early gastric cancer,EGC)浸润深度的相关因素,构建列线图预测模型,并评估其预测性能。方法:选取西安交通大学第二附属医院2011年1月至2019年12月行内镜黏膜下剥离术(endoscopic submucosal dissection,ESD)或外科手术,且病理诊断为EGC的451例患者为研究对象。比较黏膜层组和黏膜下层组的临床病理特征,采用多因素Logistic回归分析选择变量构建预测模型,并进行内部检验评价该模型的可行性和准确性。结果:研究共纳入EGC患者409例,其中局限于黏膜层组240例,黏膜下层组169例。多因素Logistic回归分析显示:病变长径>20 mm、病变边缘隆起、溃疡、非肠化以及组织学混合型、未分化型都是病变黏膜下层浸润的独立危险因素。相比分化程度,以组织学特征联合其他危险因素构建的模型预测性能较好。在此基础上建立的预测EGC浸润深度的列线图模型,经Bootstrap法进行内部验证,其一致性指数为0.776,校正曲线显示预测的浸润深度与实际浸润深度的相关性良好。结论:以病变大小、组织学、边缘隆起、肠化、溃疡为基础建立的相关列线图预测模型对EGC的浸润深度有较好的预测性能,具有一定的临床参考价值。

无机纳米材料在骨代谢调控中的应用

与有机和高分子纳米材料相比,无机纳米材料具有化学性质稳定、力学性能优良、生物相容性和骨诱导性良好等优势,是用于骨代谢调控的主要材料。文章分别从细胞、分子及动物水平总结了羟基磷灰石、稀土纳米材料、金纳米颗粒、碳纳米管等无机纳米材料在骨代谢调控中的作用及其机制,并对无机纳米材料在骨代谢调控中面临的挑战进行了展望。

Petrogenesis and tectonic significance of the early Paleozoic Delenuoer ophiolite in the Central Qilian Shan, northeastern Tibetan Plateau

The newly discovered early Paleozoic Delenuoer ophiolite,in the western margin of the Central Qilian Shan,is composed of serpentinized peridotite,cumulate gabbro,diabase,massive basalt,and pillow basalt.This study presents geochronological and geochemical data for the cumulate gabbro and basalt.LA-ICP-MS U-Pb dating of zircons from the cumulate gabbro yielded a magmatic crystallization age of 472±4 Ma.The basalts have normal mid-ocean ridge basalt(N-MORB)compositions and a narrow range ofεNd(t)values(+4.5 to+5.3),which indicates they were derived from a depleted mantle source.On the basis of regional geological constraints,it is proposed that the Delenuoer ophiolite is a westward extension of the South Ophiolite Belt(Yushigou-Youhulugou-Donggou-Dongcaohe Ophiolite Belt)in the North Qilian Shan.The Delenuoer ophiolite,along with the Gulangxia-Delenuoer fault,defines the westernmost part of the tectonic boundary between the North and Central Qilian Shan.This ophiolite may have formed during southward subduction of the Qilian Ocean slab during the early Paleozoic.

Effect of K1, K2 Anti-Bacterial Agents on Tobacco Ralstonia Solanacearum

The tobacco Ralstonia Solanacearum were both cultured on nutrient agar plates and inoculated in seedling stage of tobacco, then treated with K1 and K2, two anti-bacterial agents, at a serial con-centrations to study their inhibitory efficiency. The result indicated that K1 can inhibit R. Solanacearum growth entirely, at the concentration range from 1/50 to 1/5000. K2 can reach the same result at the concentration range from 1/50 to 1/50000. Compared with the control plates, K1, at the concentration 1/50000, had no significant differences, and the average number of colony per plate was 112-115. The immature tobacco shown wilt as soon as inoculated with R. Solanacearum, and recovered gradually after using K1, K2. The densities of microbial suspension, handled by K1, K2 within 10 hs, were both significantly lower than the controlled ones. The optical microscopy also shown that handled microbial body differed from the controlled, whose body was regular short, rod shape as opposed to the handled ones with irregular rod shape and damaged body. All the results indicated that K1 and K2 both had inhibitory effects on tobacco R. Solanacearum, and K2 was more efficient than K1.

Gap Structure of 12442-Type KCa2(Fe1-xCox)4As4F2(x=0,0.1)Revealed by Temperature Dependence of Lower Critical Field

We report an in-depth investigation on the out-of-plane lower critical field Hc1 of the KCa2(Fe1-xCox)4As4F2(12442-type,x=0,0.1).The multi-gap feature is revealed by the kink in the temperature-dependent Hc1(T)curve for the two samples with different doping levels.Based on a simplified two-gap model,the magnitudes of the two gaps are determined to beΔ1=1.2 meV andΔ2=5.0 meV for the sample with x=0,Δ1=0.86 meV andΔ2=2.8 meV for that with x=0.1.With the cobalt doping,the ratio of energy gap to critical transition temperature(Δ/kBTc)remains almost unchanged for the smaller gap and is suppressed by 20%for the larger gap.For the undoped KCa2Fe4As4F2,the obtained gap sizes are generally consistent with the results of angle-resolved photoemission spectroscopy experiments.

Cross-heterogeneous Domain Authentication Scheme Based on Blockchain

With the rising popularity of the Internet and the development of big data technology,an increasing number of organizations are opting to cooperate across domains to maximize their benefits.Most organizations use public key infrastructure to ensure security in accessing their data and applications.However,with the continuous development of identity-based encryption(IBE)technology,small-and medium-sized enterprises are increasingly using IBE to deploy internal authentication systems.To solve the problems that arise when crossing heterogeneous authentication domains and to guarantee the security of the certification process,we propose using blockchain technology to establish a reliable cross-domain authentication scheme.Using the distributed and tamper-resistant characteristics of the blockchain,we design a cross-domain authentication model based on blockchain to guarantee the security of the heterogeneous authentication process and present a cross-domain authentication protocol based on blockchain.This model does not change the internal trust structure of each authentication domain and is highly scalable.Furthermore,on the premise of ensuring security,the process of verifying the signature of the root certificate in the traditional cross-domain authentication protocol is improved to verify the hash value of the root certificate,thereby improving the authentication efficiency.The developed prototype exhibits generality and simplicity compared to previous methods.

Data-driven Based Uncertainty Set Modeling Method for Microgrid Robust Optimization with Correlated Wind Power

Microgrid is considered an important part of the future zero carbon energy systems.However,the uncertainty caused by renewable energy source brings huge challenges to the scheduling of MG and restricts its ability of carbon emission reduction.In this paper,a novel improved multi-ellipsoidal uncertainty set modeling method is proposed to better depict the uncertainty of wind power and reduce the conservativeness of traditional robust optimization.Probabilistic information from historical data is utilized to capture the temporal correlation of forecast error of wind power,as well as the conditional correlation of forecast error with forecast value,making the uncertainty set more data-adaptive to variation of forecast results and more accurate for uncertainty description.A two-stage robust optimization model of a grid-connected microgrid is established based on the proposed uncertainty set and solved by column and constraint generation algorithm.Simulation results based on actual data illustrate the average unbalanced power of microgrid between day-ahead trading and real-time power exchange with utility grid is dropped by nearly 11.16%compared with a deterministic optimization method,11.86%with traditional box uncertainty set-based robust optimization method,and 2.89%with stochastic optimization method.

AAZ2 induces mitochondrial-dependent apoptosis by targeting PDK1 in gastric cancer

Drastic surges in intracellular reactive oxygen species(ROS)induce cell apoptosis,while most chemotherapy drugs lead to the accumulation of ROS.Here,we constructed an organic compound,arsenical N-(4-(1,3,2-dithiarsinan-2-yl)phenyl)acrylamide(AAZ2),which could prompt the ROS to trigger mitochondrial-dependent apoptosis in gastric cancer(GC).Mechanistically,by targeting pyruvate dehydrogenase kinase 1(PDK1),AAZ2 caused metabolism alteration and the imbalance of redox homeostasis,followed by the inhibition of phosphoinositide-3-kinase(PI3K)/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)pathway and leading to the activation of B-cell lymphoma 2(Bcl2)/Bcl2-associated X(Bax)/caspase-9(Cas9)/Cas3 cascades.Importantly,our in vivo data demonstrated that AAZ2 could inhibit the growth of GC xenograft.Overall,our data suggested that AAZ2 could contribute to metabolic abnormalities,leading to mitochondrial-dependent apoptosis by targeting PDK1 in GC.

Integration of interlayer surface enhancement technologies into metal additive manufacturing:A review

Additive manufacturing(AM)has the advantages of rapid prototyping,high design freedom,and flexible manufacturing,while the mechanical properties of additively manufactured products are not uniform due to inherent defects and residual stresses.Integration of interlayer surface enhancement(SE)technologies into AM is a potential solution to improve the microstructure,close defects,residual stress state,mechanical properties,and chemical properties of formed materials.This paper reviews the current literature on hybrid AM process through the combination of SE and AM,and proves the possibility of integrating SE technologies into AM from the technical level.Then the improvement effects of SE processes on AM parts are introduced in terms of microstructure,defects,residual stress,mechanical properties,and chemical properties.Finally,considering the commonly used directed energy deposition(DED)process and ultrasonic impact treatment(UIT),a closed-loop quality control framework for integration of interlayer UIT into the DED process is proposed.Future research directions to the hybrid AM and interlayer SE are pointed out.

Highly efficient Ag-modified copper phyllosilicate nanotube:Preparation by co-ammonia evaporation hydrothermal method and application in the selective hydrogenation of carbonate

Rapidly deactivation of Cu/SiO2 catalysts at high liquid hour space velocity(LHSV) has been an important obstacle for scale-up application.Herein,silver modified copper phyllosilicate nanotubes were fabricated by different strategies,and implemented to the selective hydrogenation of ethylene carbonate(EC) to methanol and ethylene glycol(EG) as alternative route for the indirect utilization of CO2.The CuPs Ag-copre catalyst synthesized by the co-ammonia evaporation hydrothermal process achieved79% methanol and 99% EG yield within various ranges of EC LHSV,which was attributed to the balanced Cu+/CuO ratio and the enhanced H2 dissociation ability.Inlaid silver species over copper phyllosilicate promoted the interaction between the metal and the support,which substantially regulated the reducibility and dispersion of copper species,meanwhile,increased the stability for long-term running of the catalyst.

Locational Marginal Pricing Mechanism for Uncertainty Management Based on Improved Multi-ellipsoidal Uncertainty Set

The large-scale integration of renewable energy sources (RESs) brings huge challenges to the power system. A cost-effective reserve deployment and uncertainty pricing mechanism are critical to deal with the uncertainty and variability of RES. To this end, this paper proposes a novel locational marginal pricing mechanism in day-ahead market for managing uncertainties from RES. Firstly, an improved multi-ellipsoidal uncertainty set (IMEUS) considering the temporal correlation and conditional correlation of wind power forecasting is formulated to better capture the uncertainty of wind power. The dimension of each ellipsoidal subset is optimized based on a comprehensive evaluation index to reduce the invalid region without large loss of modeling accuracy, so as to reduce the conservatism. Then, an IMEUS-based robust unit commitment (RUC) model and a robust economic dispatch (RED) model are established for the day-ahead market clearing. Both the reserve cost and ramping constraints are considered in the overall dispatch process. Furthermore, based on the Langrangian function of the RED model, a new locational marginal pricing mechanism is developed. The uncertainty locational marginal price (ULMP) is introduced to charge the RES for its uncertainties and reward the generators who provide reserve to mitigate uncertainties. The new pricing mechanism can provide effective price signals to incentivize the uncertainty management in the day-ahead market. Finally, the effectiveness of the proposed mechanism is verified via numerous simulations on the PJM 5-bus system and IEEE 118-bus system.

Active and passive compliant force control of ultrasonic surface rolling process on a curved surface

Ultrasonic surface rolling process(USRP)is one of the effective mechanical surface enhancement techniques.During the USRP,unstable static force will easily do harm to the surface quality.In order to achieve a higher surface quality on the part with a curved surface,an active and passive compliant USRP system has been developed.The compliant USRP tool can produce the natural obedience deformation along the part surface.Force control based on the fuzzy Proportional-integral-derivative(PID)method is then designed to maintain the static force during the USRP.Experiments have been performed on a real aero-engine blade with curved surface.It is proved that the deigned active and passive compliant USRP system can significantly reduce the force variation from 42.2 N to 4.2 N,and achieve a uniform surface quality after processing.

In-situ monitoring of cell-secreted lactate by electrochemiluminescence sensing under biomimetic microfluidic confinement

Cell migration proceeds in 3D matrices in vivo,which can naturally switch to distinct phenotypes for bet-ter invasion in confined microenvironments.The studies of important metabolites under confinement are extremely meaningful for comprehensive insights into cancer metastasis.The integration of cell confine-ment device and analytical techniques is a key point for in-situ analysis of significant metabolites in vitro.Herein,an electrochemiluminescence(ECL)sensing platform was designed for in-situ monitoring of cell-secreted lactate in highly confined microenvironments.The 3-μm confiner was exactly fabricated via mi-crofabrication and microfluidics technique,and cells in high confinement and low adhesion tended to be round with contractile blebs on cell margins.Significantly,in-situ monitoring of lactate was successfully achieved on the ECL platform with the catalysis of lactate oxidase,in which the levels in different time intervals were acquired in the luminol-hydrogen peroxide system.Furthermore,the results were verified by the liquid chromatography-tandem mass spectrometry(LC-MS/MS)technology,which showed similar fluctuations with the ECL platform.This system offered an available avenue for metabolites analysis in highly confined microenvironments,which may advance deeper insights into metabolic mechanisms of cancer metastasis.

Gendered Narrative and Feminine Modernity:Free Indirect Discourse in Lin Huiyin’s“In Ninety-Nine Degrees of Heat”

In the modern Chinese literary scene,Lin Huiyin(1904-55)was a prominent woman writer who applied free indirect discourse(FID),a“new”narrative device,into her creative writing.In some of her works,FID is not only a new way in which to realize a modern narrative style but also a discreet way to provide her own voice.The existence of slippage between the narrator and character-focalizer deliberately destabilizes the reader,somehow swaying between the narrators authoritative and the character's initial characteristics.In this way,this narrative strategy allows Lin to establish a kind of private space for herself within which to query authority,thereby escaping the material world dominated by male writers at that time.For instance,in her well-known short story,aln Ninety-Nine Degrees of Heat^(Jiushijiu du zhong),Lin Huiyin employed this typical narrative strategy,illustrating the modernity of her creative writing and revealing some meanings of social and gendered narratives.

The effects of parental relationships,and gender and grade differences on depressive disorder in Chinese adolescents:the evidence from multiple cross-sectional surveys(1999-2016)

This study aims to investigate the impacts of parental relationships,gender,and grade differences on depressive disorder among Chinese adolescents over a time period of nearly 20 years.The first survey took place in 1999 and involved 852 stu-dents;subsequent follow-up surveys took place in 2006,2009 and 2016,with 3345 students involved in total.Depressive disorder was measured by SCL-90-R(Chi-nese version).The surveys also collected social-demographic information about the respondents.Three indicators of parental relationships were examined-parental quarrels,parental disharmony and parental divorce.The results show that gender was significantly associated with adolescents’depressive disorder and that there was a higher prevalence of depressive disorder among senior middle school students than among junior middle school students,except in 1999.Troubled parental rela-tionships were associated with high risks of depressive disorder.Coefficients and 95%CI were adjusted for the survey years(1999,2006,2009,2016),school grades(junior or senior middle school students),gender(girls/boys),parental quarrels(yes/no),parental disharmony(yes/no),and parental divorce(yes/no).Logistic regres-sion indicated that parental divorce and gender were the two strongest predictors of the presence of depressive disorder.In summary,there was a higher prevalence of depressive disorder among girls and senior middle school students.Adolescents are vulnerable to depressive disorder in cases of parental divorce.Therefore,good parental relationships may be considered an important and necessary factor that affects the susceptibility of Chinese adolescents to depressive disorder.