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The water-shale interaction affect the shale structure, leading to wellbore instability and increasing drilling costs. The extent of structural changes within the shale can be determined non-destructively by analyzing its acoustic characteristics. Experiments were conducted to investigate the acoustic properties of shale from the Yanchang Formation in the Ordos Basin before and after exposure to brines of varying types, soaking times, and salinities. The study investigated the effects of brine type, soaking time, and salinity on shale’s acoustic properties, including changes in acoustic wave propagation speed, P/S wave velocity ratio, and both time-domain and frequency-domain amplitudes. The results indicate that although the type of brine has a limited impact on the water-shale interaction, KCl exhibits a significant inhibitory effect. However, the soaking time and the brine salinity have a significant impact on the acoustic properties of shale. As the soaking time increases, the decrease in wave velocity increases, the P/S wave velocity ratio increases, and the decrease in time-domain amplitude increases. The amplitude of the main frequency in the frequency domain signal also decreases with the increase of reaction time, which is consistent with the analysis results of the time domain signal. As the salinity of brine increases, the decrease in wave velocity decreases, the P/S wave velocity ratio decreases, and the decrease in time-domain amplitude decreases. The amplitude of the main frequency in the frequency domain signal also decreases with the increase of brine salinity, which is consistent with the analysis results of the time domain signal. This work establishes the relationship between water-shale interaction and acoustic characteristics, which can quantitatively evaluate the degree of interaction between water and shale without damaging shale. Furthermore, this research provides new insights and guidance for predicting drilling collapse cycles and optimizing drilling fluid compositions.

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An ac-fed PMSM drive system with reduced dc-link capacitance easily suffers from fluctuations of dc-link voltage, which may aggravate modulation error and severe current ripple at low frequency. The occurrence and impact of the dc-link voltage fluctuations are discussed first. Then, a current ripple suppression method is proposed by the adoption of the improved modulation strategy, where the digital delay of dc-link voltage is compensated by the enhanced voltage observer (EVO). The EVO predicts the voltage two-switching-period ahead to eliminate the digital delay in the measured dc-link voltage. The accuracy and design of EVO are analyzed. The modulation index is updated based on the predicted average voltage of the EVO, which prevents the motor currents from voltage fluctuations and suppresses undesired current ripples. Finally, the proposed method is validated by simulation and experimental results. The proposed method could suppress the current ripples obviously under reduced dc-link capacitance, which consequently improves the power density of PMSM drives.

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PTP1B, a promising target for insulin sensitizers in type 2 diabetes treatment, can be effectively degraded using proteolysis-targeting chimera (PROTAC). This approach offers potential for long-acting antidiabetic agents. We report potent bifunctional PROTACs targeting PTP1B through the E3 ubiquitin ligase cereblon. Western blot analysis showed significant PTP1B degradation by PROTACs at concentrations from 5 nM to 5 µM after 48 h. Evaluation of five highly potent PROTACs revealed compound 75with a longer PEG linker (23 atoms), displaying remarkable degradation activity after 48 and 72 h, with DC50values of 250 nM and 50 nM, respectively. Compound 75induced selective degradation of PTP1B, requiring engagement with both the target protein and CRBN E3 ligase, in a ubiquitination and proteasome-dependent manner. It significantly reduced blood glucose AUC0–2hto 29% in an oral glucose tolerance test and activated the IRS-1/PI3K/Akt signaling pathway in HepG2 cells, showing promise for long-term antidiabetic therapy.

Carbon-based printable mesoscopic perovskite solar cells (MPSCs) have promising commercial development due to the use of easily scalable printing processes and low-cost carbon material electrodes. Simplifying the preparation process of MPSCs will undoubtedly contribute to their practical application. Here, we demonstrate that efficient and stable MPSCs can be prepared at room temperature without annealing by using low boiling point 2-methoxyethanol (2-ME) and strongly coordinated N-methyl-2-pyrrolidone (NMP) as a novel mixed solvent under the synergistic effect of ammonium chloride (NH4Cl). The results show that the 2-ME/NMP mixed solvent can generate an optimized coordination environment so that uniform nucleation and crystallization of perovskites in mesopores can be achieved at room temperature without annealing by forming uniform small-sized colloids in the precursor solution. Moreover, our work for the first time introduces NH4Cl as a crystallization modulator during a room-temperature annealing-free process, effectively regulating the crystallization behavior of perovskite in mesopores and obtaining high-quality perovskites. Finally, MPSCs prepared synergistically by a room-temperature annealing-free process based on a low boiling point 2-ME/NMP mixed solvent and NH4Cl modulator achieved a champion power conversion efficiency of 17.34% while demonstrating excellent long-term air stability for over half a year. This work provides a new approach to simplifying the preparation process of MPSCs and preparing efficient and stable MPSCs through a room-temperature annealing-free process.

Hemispherical resonator gyro (HRG) is a high-precision gyro developed on the traditional mechanical gyro and optical gyro. The precise assembly of the resonator and the electrode base is a key technology to ensure the working performance of the HRG. In this article, a method for identifying the assembly pose error of HRG with flat electrode is proposed. First, the specific definition and quantitative description of the assembly pose error of the resonator were given, and the mathematical model between the assembly pose error and the equivalent capacitance was established. Then, a finite-element simulation model between assembly pose error and equivalent capacitance was established in COMSOL multiphysics, which verified the mathematical model. In addition, on the basis of the mathematical model, the influence of the assembly error on the equivalent capacitance was explored, and the sensitivity of the assembly movement error and rotation error to the equivalent capacitance was analyzed. Finally, the nonlinear relationship between the equivalent capacitance and the assembly pose error is established based on the support vector regression (SVR) model; therefore, the assembly pose error identification was efficiently and reliably realized. The method establishes the quantitative relationship between the assembly pose error and the equivalent capacitance and realizes the accurate and rapid identification of the assembly pose error, which provides a theoretical basis and realization method for the precise assembly process of the high-precision HRG.

Background: Augmented reality (AR) has emerged as a transformative technology in medical education, particularly in training basic laparoscopic skills. Despite its growing applications, the effectiveness of AR in this specific domain remains underexplored, with a lack of standardized assessment frameworks and inconsistent methodologies across studies. This systematic review and meta-analysis aimed to evaluate the effectiveness of AR in laparoscopic basic skills training for medical students and junior physicians. Methods: We conducted a systematic review and meta-analysis following PRISMA guidelines. Databases searched included PubMed, Embase, Cochrane Library, Web of Science, and ClinicalTrials.gov. Studies were selected based on their focus on AR applications in laparoscopic training, involving both randomized controlled trials and non-randomized studies. Inclusion criteria focused on medical students and novice surgeons, assessing educational outcomes such as Global Operative Assessment of Laparoscopic Skills (GOALS) Global, Objective Structured Assessment of Technical Skills (OSATS) Global, OSATS Specific, Training Time, and Subjective Workload. Results: A total of 12 studies involving 434 participants met the inclusion criteria. The analysis revealed that AR technology significantly improved educational outcomes, with participants achieving higher GOALS and OSATS scores. Specifically, the mean difference for GOALS scores was 2.40 points (95% CI [1.30, 3.50], p< 0.001) and for OSATS scores, 7.71 points (95% CI [3.39, 12.03], p< 0.001). Additionally, AR-assisted training showed a reduction in subjective workload, with a mean decrease of 2.95 points (95% CI [− 4.95, − 0.95], p= 0.003). Conclusions: The findings indicate that AR significantly enhances laparoscopic training outcomes, facilitating improved technical skills, efficiency, and learner independence. However, variability in study designs and outcomes limits generalizability. Future research should focus on standardize AR training protocols and evaluate long-term effectiveness to fully leverage AR's potential in surgical education.

With the continuous development of manufacturing technology, precision instruments are increasingly moving towards miniaturization, precision, and integration. The assembly accuracy of the product has become a critical factor that limits the performance of the product. Assembly alignment is a significant part of the assembly process, and the accuracy of alignment detection has a significant effect on the final assembly accuracy of the product. Currently, the mainstream technology is to recognize and detect the final image of two parts using microscopic visual inspection technology. However, this method struggles to achieve sub-micron level alignment detection accuracy. In this paper, we presented a sub-micron alignment detection system based on optical diffraction, and the factors influencing the detection accuracy are analysed. Based on this, an experimental assembly alignment detection system was designed based on piezoelectric ceramic drive, laser confocal sensor monitoring feedback, and the mapping relationship between the nanoscale moving position of the diffraction aperture and the diffraction result to achieve sub-micron displacement detection. In addition, experimental tests have been carried out to verify the feasibility of this program. The experimental results indicate that the developed alignment detection method and system can achieve sub-micron alignment detection accuracy, providing a novel device and development concept for high-precision assembly alignment detection.

The Cassegrain telescope is widely used in aerospace exploration equipment, characterized by compact structure, complex optical path, and high imaging quality. However, due to the difficulty in establishing an accurate correspondence between the relative pose and imaging quality of a multi mirror group with real machining errors, the current Cassegrain telescope assembly process is very difficult, with blind operation, time-consuming, and low accuracy. This article proposes a high-precision adaptive alignment method for Cassegrain dual mirror optical systems based on machine learning algorisms, and an experimental adaptive alignment system with uncoupled degrees of freedom is developed. Firstly, the overall architecture of the adaptive alignment method is proposed consists of detection, calculation and alignment modules. In the detection module, the Zernike polynomial coefficient of wavefront aberration of the optical system is detected online through the interferometer, meanwhile the pose coordinates of the secondary mirror is accurately fed back through a 6-DOF nanoscale micro mechanism. In the calculation module, machine learning algorithm is applied to build a nonlinear mapping model between the Zernike coefficient and the pose coordinates of the secondary mirror. In the alignment module, the pose coordinates of the secondary mirror can be forced to adjust to the target position. Then, during the real alignment process, the Zernike coefficient test data of the optical system alignment process is monitored in real time, and the nonlinear mapping model is employed to calculate the pose coordinates and then the misalignment of the secondary mirror. Finally, the alignment module is driven to execute the pose correction according to the calculated misalignment value, realizing a high-precision adjustment of the Cassegrain dual mirror optical system. Experimental results shows that the average alignment time cost can be dramatically reduced from around 7 days using the current manual alignment method to just 30 minutes using the proposed adaptive alignment method for achieving a current standard alignment accuracy of wavefront aberration root mean square (RMS) less than 0.1λ, which greatly improves the assembly efficiency. This study proposes a new method for high-precision and efficient alignment of optical systems based on artificial intelligence and contributes to the efficiency improvement for optical assembly.

In order to adapt to the rapid development of deep space exploration, pulsar navigation and space astronomical observation technology, the development of high-efficiency and high-performance X-ray space telescopes has become one of the hotspots for research in the fields of autonomous spacecraft navigation and astronomical observation. Since the X-ray multilayer nested mirror shells are thin-walled and deformable cylindrical structures with high requirements for surface shape accuracy, a slight change in the position or surface shape will lead to a reduction in the focusing imaging quality, so it is necessary to develop a high-precision assembly and adjustment system based on closed-loop real-time monitoring. In this paper, a multi-layer nested space ray telescope assembly and adjustment system with online monitoring feedback is developed, and a method for precision assembly and adjustment of multi-layer nested mirror shells based on online real-time detection and feedback is proposed, which specifically includes key innovative assembly technologies such as three-dimensional face shape measurement, flexible vacuum adsorption, precision adjustment that have been broken through in the process, and the imaging quality of the focused spot of the mirror shells is evaluated and analyzed in the end. The results of the experiment indicate that the assembly and adjustment of the multilayer nested mirror shells can effectively complete the high-precision assembly, and the relevant results can provide a certain reference significance for the further enhancement of the assembly and adjustment performance of the multilayer nested mirror shells.

Precision microstructures are the core devices of electromechanical products, and their accuracy directly affects the product’s overall performance. Laterally thin-walled structures such as precision tooth plates and silicon arms are the most common types of precision microstructures. Due to the characteristics of their tiny size and complex shape, the laterally thin-walled surface is challenging to measure and model, which in turn makes it impossible to realize the accurate prediction and quantitative control of its assembly accuracy. To address this problem, this paper proposes a geometric digital twin modeling method considering the laterally distributed error of thin-walled microstructures. A geometric digital twin model that accurately represents the geometric distributed error of the structure’s lateral surfaces is built by applying an image measuring instrument to measure the point clouds of the upper and lower surface profiles, followed by point cloud filtering and merging based on a common datum, and finally surface reconstruction and integration with an ideal 3D model. The method is effectively validated on the silicon arm, a vital component of the thermal mechanical package. Its geometric modeling error is less than 1/10 of its tolerance, and the relative error between the model-based stiffness simulation calculation results and the experimental data is less than 10%. The method can effectively analyze the influence of the manufacturing errors of thin-walled lateral surfaces on the assembly accuracy and provides an adequate model basis for the control of the geometrical and physical performances of precision microstructures.

The reflective optical mirror group is the core component of precision optical instruments, and their assembly accuracy will directly impact the imaging of optical instruments. In recent years, with the rapid development of digital twin technology in the field of assembly, the application of digital twin to assembly process optimization is currently a research hotspot. This paper proposes an assembly process optimization method for a reflective optical mirror group based on an accurate digital twin model. By accurately simulating the geometrically distributed errors generated by machining and the physical properties of the assembled parts of the reflective optical mirror group during assembly and use, an accurate digital twin model is established to accurately characterize the geometrical and physical properties of the reflective optical mirror group. Using the accurate digital twin modeling method, the mirror deformation and stress distribution of a reflective optical mirror group are accurately predicted, and the main process parameters in the assembly process are optimized according to the prediction results, so that the target value of the imaging phase of the mirror group after assembly is improved by 24%, and the encircled energy is improved by 15.1%. The optimization calculation method proposed in this paper can obtain the optimized assembly process parameters more accurately, and the research results provide effective support for improving the assembly accuracy and performance of optical mirrors and precision digital twin modeling research.

This article proposes a novel fault-tolerant strategy for the operation of modular multilevel converters after submodule (SM) faults, which combines dc injection, neutral shift (NS), and balanced zero-sequence voltage injection (BZVI). A new method to calculate the injected zero-sequence voltage is proposed, which greatly simplifies the calculation of the dc injection and enables the combination of BZVI with NS. The resulted strategy has stronger fault-tolerant capability than previous ones: First, it increases the maximum redundancy limit of SM faults under which it is unnecessary to decrease the line voltages. Second, it can achieve higher, balanced line voltages when faulty SMs exceed the above maximum redundancy limit. The proposed strategy also has the advantages of online implementation, optimal three-phase balance ability, and self-limiting of the phase with maximum phase output capacity.

Electrospinning has drawn wide attention for its powerful capacity to produce ultrafine nanofibers (UNFs) from various materials. These UNFs demonstrated significantly enhanced performance, such as ultra-high surface area, more porosity and stronger mechanical properties. Here, we comprehensively review their basic principles, state-of-the-art methods and preponderant applications. We begin with a brief introduction to the refinement theory of polymer jets, followed by discussion of factors affecting fiber refinement. We then discuss the refining strategies from the aspects of solution properties, spinning parameters, auxiliary force and post-treatment. Afterward, we highlight the most relevant and recent applications associated with the remarkable features of UNFs, including filtration materials, supercapacitors, biomedical materials and other applications. At the end, we offer perspectives on the challenges, opportunities, and new directions for future development of electrospun UNFs.

Hole conductor-free printable mesoscopic perovskite solar cells (p-MPSCs), comprising m-TiO2/m-ZrO2/C triple mesoscopic layers, have emerged as a promising photovoltaic technology for commercial applications because of their low cost, easy operation, and outstanding stability. However, p-MPSCs suffer from a considerable open-circuit voltage (VOC) loss compared with traditional PSCs, resulting in a discernible disparity in power conversion efficiency (PCE) between p-MPSCs and traditional PSCs. In this article, we present a novel approach employing 5-amino-4-carboxamide imidazole hydrochloride (AICA) to enhance VOCof p-MPSCs. AICA demonstrates a dual function, encompassing the regulation of the work function of the perovskite film and effective passivation of the uncoordinated Pb2+and I−defects within the perovskites. Consequently, the introduction of AICA stabilizes the structure of the perovskites, leading to the formation of high-quality perovskite films and effectively inhibiting defect-induced nonradiative recombination. Owing to the incorporation of AICA, notable improvements in the photovoltaic performance of p-MPSCs are observed, with a considerable increase in PCE from 14.21% to 16.68% and a corresponding rise in VOCfrom 0.88 to 0.98 V.

The power converters integrated with active power decoupling (APD) may handle the ripple power in dc link and then reduce the volume of the filter capacitor dramatically. Generally, voltage and current signals of the LC branch are required for the closed-loop APD control. However, sensor failures could degrade the control performance and even lead to the breakdown of the converter system. This article proposes a detection method for sensor failures in the APD circuit of the single-phase converter. The voltage and current of the LC branch in the APD circuit are estimated by a dual sliding mode observer (SMO). The residuals of the estimated and measured signals are calculated, and they have high sensitivity to specific sensor faults, namely, the current residual is sensitive to the fault of the current sensor and the voltage residual is sensitive to the fault of the voltage sensor, which could be employed to locate the faulty sensors. Finally, the effectiveness of the proposed method is verified by the simulation and experimental results.

In this study, La(OH)3/g-C3N4photocatalyst was designed for degradation of tetracycline hydrochloride (TCH) under visible light. The impact of different operational factors (dosage, initial TCH concentration, photocatalytic time, temperature, and competing anions and organic matter) on the removal of TCH was analyzed. La(OH)3/g-C3N4exhibits a narrowed bandgap (2.90 eV) and enhanced visible-light absorption, leading to efficient TCH degradation (90.1%) and excellent reuse potential. The degradation intermediates were analyzed by liquid chromatography-mass spectrometry (LC-MS) to deduce the plausible degradation pathways. Quantitative structure activity relationship (QSAR) assessment indicated that the toxicity of the degradation products was greatly reduced. Furthermore, La(OH)3/g-C3N4can simultaneously remove TCH, COD and PO43−from real wastewater by 56.31%, 69.63% and 89.9% respectively, demonstrating its robust potential in water and wastewater engineering and science.

As one of those natural carbon-based non-toxic and non-metallic materials, g-C3N4has exhibited excellent electronic and structural properties that make it versatile as an efficient photocatalyst, which was widely mentioned in applications of photocatalytic oxidation reactions. Recently, a gradually increased number of research efforts have been focused on the development of novel g-C3N4-based composite catalysts for better photocatalytic biomass valorization. In this context, this paper aims to retrospect the progress of the g-C3N4-driven photocatalytic oxidation of biomass-derived alcohols represented by 5-hydroxymethylfurfural (HMF) and benzyl alcohol (BA). The core concerns are discussed to elaborate the effects of structural regulating approaches of g-C3N4-based photocatalysts on biomass-derived alcohol oxidation performance, involving intrinsic structure optimization, dye sensitization, and heterojunction construction. Also, influences of key external condition parameters, including the light source, oxygen source, and solvent, on the g-C3N4-based photocatalytic system are discussed. The viewpoints proposed in this paper may contribute to the design, synthesis, and modification of novel g-C3N4-based photocatalytic materials, thus providing potential opportunities to enhance the photocatalytic selective oxidation performance of biomass-derived alcohols for a better sustainable biomass refining system.

To reduce the dependence on fossil energy, the use of photocatalytic technology value-added conversion of biomass platform molecules has been widely studied. Photocatalytic materials with high photogenerated carrier separation and migration efficiency are key to realizing the molecular value-added conversion of biomass platforms. In this study, a simple and effective method prepared the 2D–3D heterojunction structure of black phosphorus/CdIn2S4for biomass value-added conversion. The use of this catalyst for the photocatalytic oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran gave excellent performance under ambient conditions without any additives. Compared with pure CdIn2S4, the black phosphorus/CdIn2S4heterojunction has higher photocatalytic selective oxidation activity. The photocatalytic mechanism of S-type heterojunctions with high photogenerated carrier separation and migration efficiency is proposed based on the relevant characterization and DFT simulations. Through a capture agent experiment and electron paramagnetic resonance (EPR) spectroscopy, the main intermediates in the reaction were determined to be holes (h+) and the superoxide radical (O2−), and the reaction pathway of HMF photocatalytic conversion to DFF was further determined. This paper provides new ideas for S-type heterostructure construction and photocatalytic conversion of biomass platform molecules.

Selective photocatalytic oxidation rather than mineralisation is essential for the catalytic valorisation of biomass, which requires precise control of the generation of reactive oxygen species viathe rational construction of heterogeneous junctions. In this paper, CdIn2S4/g-C3N4(CIS/CNNS) heterojunctions were constructed by a microwave-assisted method and used for selective photocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF), a key intermediate for fine chemical synthesis and an important furan-based polymer monomer. According to the electron transfer mechanism of the heterojunctions, the effective separation of charges and holes led to a significant enhancement of the utilization efficiency of photogenerated electrons (PGEs). Specifically, the valence band (VB) potential of the constructed heterojunctions did not reach the oxidation potential of OH/OH−, which avoided the massive generation of strongly oxidizing active species OH and thus increased the reaction selectivity. Under visible light irradiation, 65.2% HMF conversion and 91.5% DFF selectivity could be achieved over CIS/CNNS, with a product yield 3.26 times higher than monomeric CdlIn2S4and 4.2 times higher than monomeric CNNS. The radical quenching experiments verified that O2−was the predominant active species in the reaction process, and the O2−signal of the composite was significantly enhanced in the ESR characterization, achieving highly selective conversion of HMF to DFF.

AimsTo characterise the influence of primary open-angle glaucoma (POAG) and high myopia (HM) on the macular and choroidal capillary density (CD).MethodsTwo hundred and seven eyes were enrolled, including 80 POAG without HM, 50 POAG with HM, 31 HM without POAG and 46 normal controls. A fovea-centred 6×6 mm optical coherence tomography angiography scan was performed to obtain the CD of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris. Macular and choroidal CDs were compared among the groups and the association of CDs with visual field mean deviation (MD) was determined using linear regression models.ResultsCompared with normal eyes, SCP CD was decreased in the POAG without HM group (p<0.05), while DCP CD was significantly decreased in the HM without POAG group (p<0.05). Both SCP and DCP CDs were significantly decreased in the POAG with HM group (p<0.05). CD reduction occurred mainly in the outer rather than inner ring of the 6×6 mm scan size. In multivariate regression analysis, worse MD was associated with lower CD in the outer ring of the SCP in all the HM eyes (p<0.05).ConclusionsPOAG and HM reduced macular CD in different layers of the retinal capillary plexus and both particularly in the outer ring of the 6×6 mm scans. Furthermore, assessment of the CD in the outer ring of the SCP may facilitate the diagnosis of glaucoma in eyes with HM.

Lasers differ from other light sources in that they are coherent, and their coherence makes them indispensable to both fundamental research and practical application. In optomechanical cavities, photon and phonon lasing is facilitated by the ability of photons and phonons to interact intensively and excite one another coherently. The lasing linewidths of both phonons and photons are critical for practical application. This study investigates the lasing linewidths of photons and phonons from the underlying dynamics in an optomechanical cavity. We find that the linewidths can be accounted for by two distinct physical mechanisms in two regimes, namely the normal regime and the reversed regime, where the intrinsic optical decay rate is either larger or smaller than the intrinsic mechanical decay rate. In the normal regime, an ultra-narrow spectral linewidth of 5.4 kHz for phonon lasing at 6.22 GHz can be achieved regardless of the linewidth of the pump light, while these results are counterintuitively unattainable for photon lasing in the reversed regime. These results pave the way towards harnessing the coherence of both photons and phonons in silicon photonic devices and reshaping their spectra, potentially opening up new technologies in sensing, metrology, spectroscopy, and signal processing, as well as in applications requiring sources that offer an ultra-high degree of coherence.

Despite the current demand for shale gas development, there is no means to evaluate nanoscale microfracture plugging technologies for ultra-low permeability formations. In this paper, we expand upon previous research and develop new means to create artificial fractures in model mud cake. By controlling the mud cake quality and strength, we developed mud cake with permeability that approached that of real mud shale. Low-permeability mud cake was prepared from barite powder, calcium carbonate, polyacrylamide, sodium polyacrylate, water, silica, a polycarboxylate comb macromolecule, a double sparse inhibitor, a film-forming agent and a mud cake curing agent. The mud cake permeability reached 5.9 × 10–4mD and increased with soaking time to 1.3 × 10–3mD (240 h). The equivalent opening of a single fracture did not change greatly and remained in the range from 3.93 × 10–5m to 4.93 × 10–5m. Plugging performance was evaluated by simulating microfractures and low-permeability environment of the formation. This method provides very important guidelines for the selection and development of nanoscale and microscale plugging agents and the evaluation of the plugging effect. It is also applicable to the evaluation of plugging performance in other fractured formations.

The development of saltiness or saltiness enhancement peptides is important to decrease the dietary risk factor of high sodium. Taste peptides in the yeast extract were separated by ultrafiltration and subsequently identified by UPLC-Q-TOF-MS/MS. The 377 identified peptides were placed into the umami receptor T1R1/T1R3. The results showed that eight taste peptides with higher binding energies were screened by molecular virtual docking, and the results revealed that Asp218, Ser276, and Asn150 of T1R1 play key roles in umami docking of peptides. The taste characteristic description and saltiness enhancement effect results suggested that PKLLLLPKP (sourness and umami, 0.18 mM), GGISTGNLN (sourness, 0.59 mM), LVKGGLIP (umami, 0.28 mM), and SSAVK (umami, 0.35 mM) had higher saltiness enhancement effects. The sigmoid curve analysis further confirmed that the taste detection threshold of the GGISTGNLN in the peptide and salt model (157.47 mg/L) was lower than 320.99 mg/L and exhibited a synergistic effect on saltiness perception, whereas SSAVK, PKLLLLPKP, and LVKGGLIP exhibited additive effects on the saltiness perception. This work also corroborated previous research, which indicated that the sourness and umami taste attributes could enhance the saltiness perception.

In this paper, the pore structure characteristics of shales and its controlling factors were analyzed by means of total organic carbon (TOC) analysis, X-ray diffraction (XRD) analysis, field emission scanning electron microscopy (FE-SEM) and low-pressure N2adsorption (LPNA) analysis. Based on the grey relational analysis, the controlling factors of pore structure parameters were discussed. The results showed that the TOC contents range from 2.98 to 4.97%, the main minerals of shales are quartz and clay minerals with an average of 41.62 and 30.98%, respectively. The organic matter pores, the interparticle pores, the intraparticle pores, and the micro-fractures are the main pore types determined by the FE-SEM observation. The pore volume of shales is between 0.0637 and 0.1053 cm3/g, the specific surface area ranges from 16.44 to 37.61 m2/g, the average pore size is between 11.20 and 15.50 nm. The organic matter and the quartz have a positive influence on the specific surface area and total pore volume, whereas the clay minerals have a negative impact. The shales have a wide range of pore size, and the mesopores and macropores are the dominant contributor to the total pore volume while the mesoporous contribute the main specific surface area. The TOC contents and quartz contents have the most significant effect on the total pore volume and specific surface area, and the average pore size is mainly controlled by the quartz contents.

In this work, inexpensive, easily available and typical waste activated sludge (generated by anaerobic/anoxic/oxic (A2/O) and cyclic activated sludge system (CASS) processes) was investigated as an adsorbent for the defluoridation of geothermal water using both batch and column adsorption systems. Initially, the defluoridation efficiency was optimized in batch experiments according to sludge type, contact time, initial F–concentration and adsorbent dose. Fluoride removal efficiency of A2/O was superior to that of CASS. An optimum 86% fluoride removal efficiency occurred at an adsorbent dose of 60 g/L within 180 min. The adsorption behaviors were fitted well by the pseudo-first-order model and Freundlich model. Moreover, the thermodynamic parameters illustrated that the adsorption process of fluoride on activated sludge was spontaneous and endothermic. The mechanism of fluoride adsorption was exchange with hydroxyls on the activated sludge. The release of OH−due to fluoride adsorption was confirmed by the observed pH values. Finally, a homemade column was used to systematically evaluate the defluoridation performance for real F-containing geothermal water. The dynamic adsorption capacity was 0.55 mg/g. The results demonstrated that this simple, economic and efficient sludge adsorbent has potential for application and can be developed into a feasible defluoridation technology for F–removal from geothermal water.

Klotho is a life extension factor that has the ability to regulate the function of GluN2B-containing N-methyl-d-aspartate receptors (NMDARs), whose dysfunction in the nucleus accumbens (NAc) underlies critical aspects of the pathophysiology of major depression. Here, we study the functional relevance of klotho in the pathogenesis of depression. A chronic social defeat stress paradigm, in which mice are categorized as either susceptible or unsusceptible based on their performance in a social interaction test, was used in this study. We found that the expression of klotho was largely decreased in the NAc of susceptible mice compared to control or unsusceptible mice. Genetic knockdown of klotho in the NAc induced behavioral alterations relevant to depression in naive mice, while overexpression of klotho produced an antidepressive effect in normal mice and ameliorated the behavioral responses to stress in susceptible mice. Molecularly, knockdown of klotho in the NAc resulted in selective decreases in total and synaptic GluN2B expression that were identical to those in susceptible mice. Elevation of klotho in the NAc reversed the reductions in GluN2B expressions and altered synaptic transmission and spine density in the NAc of susceptible mice. Furthermore, blockade of GluN2B with a specific antagonist abolished the beneficial effects of klotho elevation in susceptible mice. Collectively, we demonstrated that klotho in the NAc modulates behavioral responses to stress by regulating the function of GluN2B-containing NMDARs. These results reveal a novel role for klotho in the pathogenesis of depression, providing new insights into the molecular basis of major depression.

AbstractAccurate sex estimation is crucial to determine the identity of human skeletal remains effectively. Here, we developed convolutional neural network (CNN) models for sex estimation on virtual hemi-pelvic regions, including the ventral pubis (VP), dorsal pubis (DP), greater sciatic notch (GSN), pelvic inlet (PI), ischium, and acetabulum from the Han population and compared these models with two experienced forensic anthropologists using morphological methods. A Computed Tomography (CT) dataset of 862 individuals was divided into the subgroups of training, validation, and testing, respectively. The CT-based virtual hemi-pelvises from the training and validation groups were used to calibrate sex estimation models; and then a testing dataset was used to evaluate the performance of the trained models and two human experts on the sex estimation of specific pelvic regions in terms of overall accuracy, sensitivity, specificity, F1 score, and receiver operating characteristic (ROC) curve. Except for the ischium and acetabulum, the CNN models trained with the VP, DP, GSN, and PI images achieved excellent results with all the prediction metrics over 0.9. All accuracies were superior to those of the two forensic anthropologists in the independent testing. Notably, the heatmap results confirmed that the trained CNN models were focused on traditional sexual anatomic traits for sex classification. This study demonstrates the potential of AI techniques based on the radiological dataset in sex estimation of virtual pelvic models. The excellent sex estimation performance obtained by the CNN models indicates that this method is valuable to proceed with in prospective forensic trials.Key pointsDeep learning can be a promising alternative for sex estimation based on the pelvis in forensic anthropology.The deep learning convolutional neural network models outperformed two forensic anthropologists using classical morphological methods.The heatmaps indicated that the most known sex-related anatomic traits contributed to correct sex determination.

The presence of ripple power in a converter system has a negative influence on both control performance and reliability. Active power decoupling (APD) is a practical technique to deal with such problems. However, the APD method requires extra sensors on the LC branch, which increases the complexity and cost of the control system. This paper puts forward a new APD method to handle undesirable ripple power for H-bridge PWM converters. When compared with previous APD methods, the proposed APD method eliminates the current and voltage sensors on the LC branch by utilizing a ripple voltage control loop. Then, both the cost and reliability of the converter system are improved. To improve the control performance, an APD method that only has a voltage sensor in the LC branch is also discussed. Simulation results show that the DC-link voltage ripples can be decreased due to the application of the proposed APD method. Finally, the effectiveness of the proposed method is verified by the experimental results.

To explore the influences of gravel characteristics on hydraulic fracture propagation in conglomerate formations, the real rock fracture process analysis software was used under specific stress conditions: including gravel particle size, gravel volume content, and gravel strength. Based on the numerical simulation results, the fracture propagation process under different conditions was investigated and the type and evolution of fractures were described. The results showed that larger gravel particle sizes led to stronger shielding and induction effects on the fractures. With the increasing gravel particle size, the propagation model of the fractures changes gradually from by passing gravel to passing through gravel or embedding in gravel particles. When the gravel particle sizes are constant, with increasing gravel volume content, the conglomerate reservoir becomes more heterogeneous and the fractures become more easily shielded and inducted by the gravel particles. Therefore, the fractures become more dispersed and the fracture propagation laws become more complex, which allows the formation of a hydraulic fracture network. The greater the difference in the ratio of the strength parameters of the gravel to the strength parameters of the matrix, the more strongly the fractures are blocked by the gravels and the propagation model of fractures changes from passing through gravel to by passing gravel.

The issue of water body eutrophication induced by phosphorus is escalating, and there is an urgent need for materials that can control phosphate in water bodies. Biochar is often used as an adsorption material for phosphate removal from water bodies because of its high efficiency, strong stability, and low cost. However, the phosphate adsorption capacity of pristine biochar is limited, and iron and its compounds are often loaded to overcome this limitation and improve the adsorption effect. The current status of the use of nanoscale zero-valent iron (nZVI) and other iron-modified biochar in the treatment of eutrophic water is summarized. The preparation process of nanoscale zero-valent iron-modified biochar was introduced. The adsorption mechanism of nZVI and other iron-modified biochar in phosphorus removal from water was explained (mainly related to the roles of electrostatic, precipitation, complexation, ion exchange, etc.); the effects of factors such as dosage, pH value, and initial phosphate concentration on the adsorption of phosphate by iron-modified biochar were analyzed; and the possibility of reusing iron-modified biochar after adsorbing phosphate was pointed out. Based on the above research, the problems and future development directions of nZVI and other iron-modified biochars were proposed. This study provides a theoretical basis for the treatment of eutrophication in water bodies and the utilization of solid waste resources.

This paper presents an improved timing compensation scheme to enhance the performance of multi-level VSB receivers. Long and short ghosts may cause both timing-offsets and carrier phase offsets in the multi-level VSB receivers. Consequently, they may induce errors to search the frame headers. The timing method using the Nyquist sidebands can be used to efficiently acquire the sampling frequency offset. However, the timing loop may also suffer from the carrier phase offsets. In this paper, the square-sum of both components of the channel correlation output is adopted to find the frame headers; and it also be used to compensate the residual timing-offsets. The proposed compensation scheme is free from the carrier phase offset. Simulations show the performance of the VSB receivers has been improved in poorly fading multi-path channels. Index Terms--Nyquist sidebands, PN sequence, Timing synchronization, VSB receivers.

In this paper, according to the multi-channel model of the fractionally spaced linear equalizers, the symbol-spaced adaptive decision feedback equalizers (ADFE) are extended to the fractionally spaced adaptive decision feedback equalizers (FSADFE) naturally. We applied FSADFE to the ATSC DTV receivers. The ADFE converges very slowly when the channel presents severe characteristic, which results in the poor performance. FSADFE can make up this weakness of ADFE, and the gain of performance between them is considerable. This gain benefits the DTV receivers, especially in some severe channels. Index Terms--Adaptive equalizer, ATSC, DTV, Decision feedback equalizer, Fractionally spaced linear equalizer

The wettability behaviors of nanoscale pores in shales from Longmaxi Formation in the Sichuan Basin of South China, which contain quartz pores, illite pores, and organic matter pores, were investigated using the molecular dynamics simulation and experimental methods, and the organic matter surface was approximated by grafting oxygenated functional groups onto a graphite surface. The distribution characteristics of a water–methane system in organic matter pores were studied. The results indicate that the organic matter pore network and the inorganic pore network in shales show cross-distribution characteristics. The speed of spontaneous imbibition of oil is less than that of water, and the spontaneous imbibition mass of oil increases with increasing the total organic carbon (TOC) contents. The surfaces of illite and quartz mineral are hydrophilic. With the increase in oxygen-containing functional groups, the interaction energy between the organic matter surface and water molecules decreases, resulting in an increase in the wetting contact angle of the organic matter surface. With increasing temperature, the interaction energy between the organic matter surface and water molecules increases, resulting in a decrease in the wetting contact angle. In symmetrical graphite pore models with different C/O ratios, water molecules are symmetrically spread near the oxygen-functionalized graphite wall, and with a decrease in the C/O ratio, the relative concentration of water molecules increases and the diffusion coefficient decreases. In contrast, methane molecules are gathered and distributed in the center of the pore. In an asymmetric graphite pore model with different C/O ratios, water molecules are asymmetrically spread near the oxygen-functionalized graphite wall, whereas methane molecules are concentrated and spread in the pore center. The side with a lower C/O ratio has stronger hydrophilicity and a higher relative concentration of water molecules, whereas the side with a higher C/O ratio has stronger hydrophobicity and a lower relative concentration of water molecules.

ABSTRACTMLKL (mixed lineage kinase domain like pseudokinase) is a well-known core component of necrosome that executes necroptotic cell death upon phosphorylation by RIPK3 (receptor interacting serine/threonine kinase 3). Recent studies also implicate a role of MLKL in endosomal trafficking, which is not always dependent on RIPK3. Using mouse Neuro-2a and L929 as well as human HEK293 and HT29 cells, we show here that MLKL is phosphorylated in response to serum and amino acid deprivation from the culture medium, in a manner that depends on CAMK2/CaMKII (calcium/calmodulin dependent protein kinase II) but not RIPK3. The starvation-induced increase in MLKL phosphorylation was accompanied by decreases in levels of lipidated MAP1LC3B/LC3B (microtubule associated protein 1 light chain 3 beta; LC3-II) and SQSTM1/p62 (sequestosome 1), markers of autophagosomes. These changes were prevented by disrupting either MLKL or CAMK2 by pharmacology and genetic manipulations. Moreover, disrupting MLKL or CAMK2 also inhibited the incorporation of LC3-II into autolysosomes, demonstrating a role of the CAMK2-MLKL pathway in facilitating autophagic flux during short-term starvation, in contrast to necroptosis which suppressed autophagic flux. Furthermore, unlike the necroptotic pathway, the starvation-evoked CAMK2-mediated MLKL phosphorylation protected cells from starvation-induced death. We propose that upon nutrient deprivation, MLKL is activated by CAMK2, which in turn facilitates membrane scission needed for autophagosome maturation, allowing the proper fusion of the autophagosome with lysosome and the subsequent substance degradation. This novel function is independent of RIPK3 and is not involved in necroptosis, implicating new roles for this pseudokinase in cell survival, signaling and metabolism.Abbreviations:CAMK2/CaMKII: calcium/calmodulin dependent protein kinase II; DIABLO/SMAC: direct inhibitor of apoptosis-binding protein with low pI/second mitochondria-derived activator of caspase; ECS: extracellular solution; ESCRT: endosomal sorting complexes required for transport; FBS: fetal bovine serum; GSK3B: glycogen synthase kinase 3 beta; HBSS: Hanks’ balanced salt solution; KO: knockout; LC3-II: lipidated microtubule associated protein 1 light chain 3 beta; LDH: lactate dehydrogenase; MLKL: mixed lineage kinase domain like pseudokinase; MTOR: mechanistic target of rapamycin kinase; MTORC1: MTOR complex 1; N2a: Neuro-2a neuroblastoma; Nec-1: necrostatin-1; NSA: necrosulfonamide; PBS: phosphate-buffered saline; PI: propidium iodide; PK-hLC3: pHluorin-mKate2-human LC3; RIPK1: receptor interacting serine/threonine kinase 1; RIPK3: receptor interacting serine/threonine kinase 3; ROS: reactive oxygen species; RPS6KB1/S6K: ribosomal protein S6 kinase B1; shRNA: short hairpin RNA; siRNA: small interference RNA; SQSTM1/p62: sequestosome 1; TBS: Tris-buffered saline; TNF/TNF-α: tumor necrosis factor; TSZ, treatment with TNF + DIABLO mimetics + z-VAD-FMK.

Carbon-based mesoscopic perovskite solar cells (MPSCs) are becoming one of the most competitive photovoltaic technologies owing to their lower manufacturing cost and excellent stability. In this work, methylammonium acetate (MAAc), an ionic liquid additive, is added into methylammonium lead triiodide (MAPbI3) perovskite and is used to fabricate high-performance MPSCs. Systematic and detailed studies have shown that the MAAc interacts with PbI2preferentially to form a MAPbI3–x(Ac)xintermediate phase that can effectively control the crystallization kinetics of MAPbI3in the triple-mesoscopic layer. MAPbI3films with an appropriate amount of MAAc exhibit higher crystallinity, lower defect density, and dense pore filling, which effectively reduce carrier non-radiative recombination loss in MPSCs. As a result, a champion power conversion efficiency (PCE) of 13.54% is obtained based on the optimized MAAc-engineered MPSCs. The PCE is 24% higher than 10.90% of the control devices. Moreover, unencapsulated MAAc-engineered MPSCs retain 90% of their initial PCE after being stored in the dark for 50 days under ambient atmosphere, which demonstrates much better air stability than control devices. This work provides an effective strategy for developing efficient and stable carbon-based MPSCs with an eco-friendly ionic liquid additive.

The intrinsic stability issues of the perovskite materials threaten the efficiency and stability of the devices, and stability has become the main obstacle to industrial applications. Herein, the efficient and facile passivation strategy by 2-amino-5-iodobenzoic acid (AIBA) is proposed. The impact of AIBA on the properties of the perovskite films and device performance is systemically studied. The results show that the trap states are eliminated without affecting the crystal properties of the perovskite grains, leading to the enhanced performance and stability of the perovskite solar cells (PSCs). A high power conversion efficiency (PCE) of 20.23% and lower hysteresis index (HI) of 1.49‰ are achieved, which represent one of the most excellent PCE and HI values for the inverted PSCs based on MAPbI3/[6,6]-Phenyl-C61-Butyric Acid Methyl Ester (PCBM) planar heterojunction structure. Moreover, the UV stability of the perovskite films and the thermal and moisture stability of the devices are also enhanced by the AIBA passivation. The PCE of the device with AIBA can maintain about 83.41% for 600 h (40 RH %) and 64.06% for 100 h (55–70 RH %) of its initial PCE value without any encapsulation, while the control device can maintain only about 72.91 and 45.59% of its initial PCE. Density functional theory calculations are performed to study the origins of enhanced performance. Interestingly, the results show that the surface states induced by AIBA can facilitate the photoexcited charge transfer dynamics and reduce the electron–hole recombination loss. The passivation method developed in this work provides an efficient way to enhance the stability and performance of inverted PSCs.

Cancer cachexia, characterized by muscle and fat tissue wasting, is a major determinant of cancer‐related mortality without established treatment. Recent animal data revealed that cancer cells induce muscle wasting by releasing Hsp70 and Hsp90 as surface proteins on extracellular vesicles (EVs). Here, we test a therapeutic strategy for ameliorating cancer cachexia by inhibiting the release of Hsp70 and Hsp90 using proton pump inhibitor omeprazole. Omeprazole effect on Hsp70/90 release through EVs by Lewis lung carcinoma (LLC) cells in vitro, serum levels of Hsp70/90 and Hsp70/90‐carrying EVs in LLC tumour‐bearing mice, and LLC‐induced muscle protein degradation pathways in C2C12 myotubes and mice were determined. Omeprazole effect on endolysosomal pH and Rab27b expression in LLC cells were analysed. Omeprazole treatment of LLC cells inhibited Hsp70/90 and Hsp70/90‐carrying EV release in a dose‐dependent manner (1 to 10 μM) and attenuated the catabolic activity of LLC cell‐conditioned medium on C2C12 myotubes. Systemic omeprazole administration to LLC tumour‐bearing mice (5 mg/kg/day subcutaneously) for 2 weeks blocked elevation of serum Hsp70, Hsp90, and Hsp70/90‐carrying EVs, abrogated skeletal muscle catabolism, and prevented loss of muscle function as well as muscle and epididymal fat mass without altering tumour growth. Consequently, median survival increased by 23.3%. Mechanistically, omeprazole increased cancer cell endolysosomal pH level dose‐dependently (0.1 to 1 μM) by inhibiting vacuolar H+‐ATPase. Further, omeprazole suppressed the highly elevated expression of Rab27b, a key regulator of EV release, in LLC cells. Omeprazole ameliorates cancer cachexia by inhibiting cancer cell release of Hsp70 and Hsp90.

Rechargeable potassium-ion batteries (PIBs) have great potential in the application of electrochemical energy storage devices due to the low cost, the abundant resources and the low standard reduction potential of potassium. As electrode materials are the key factors to determine the electrochemical performance of devices, relevant research is being carried out to build high-performance PIBs. In recent years, significant progress has been made in the study of the design of inorganic electrode materials. Herein, we review the cathode materials (Prussian blue and its analogues, layered oxides and polyanionic compounds) and the anode materials (antimony-based, selenium-based and bismuth-based compounds). On the basis of previous work, the structural design principles for improving the performance of electrode materials are reasonably summarized. At the same time, the problems that need to be solved in the preparation of electrode materials and the direction of future research and improvement are pointed out.

This article summarizes the composite honeycomb structure which possess important meaning and application value on the high-precision satellite antenna reflector. The key technologies of composite material honeycomb structure are summarized, including the material selection for satellite antenna reflector, honeycomb configuration, fabrication process, mechanical properties, lightweight design, surface accuracy, thermal deformation control and other issues. The development goal of “lighter, larger, more refined and more stable” are put forward after looking forward to the manufacturing technology and functional requirement of the future satellite antenna reflector.

Psychiatric disorders impose tremendous economic burden on society and are leading causes of disability worldwide. However, only limited drugs are available for psychiatric disorders and the efficacy of most currently used drugs is poor for many patients. To identify novel therapeutic targets for psychiatric disorders, we performed genome-wide Mendelian randomization analyses by integrating brain-derived molecular quantitative trait loci (mRNA expression and protein abundance quantitative trait loci) of 1263 actionable proteins (targeted by approved drugs or drugs in clinical phase of development) and genetic findings from large-scale genome-wide association studies (GWASs). Using transcriptome data, we identified 25 potential drug targets for psychiatric disorders, including 12 genes for schizophrenia, 7 for bipolar disorder, 7 for depression, and 1 (TIE1) for attention deficit and hyperactivity. We also identified 10 actionable drug targets by using brain proteome data, including 4 (HLA-DRB1, CAMKK2, P2RX7, and MAPK3) for schizophrenia, 1 (PRKCB) for bipolar disorder, 6 (PSMB4, IMPDH2, SERPINC1, GRIA1, P2RX7 and TAOK3) for depression. Of note, MAPK3 and HLA-DRB1 were supported by both transcriptome and proteome-wide MR analyses, suggesting that these two proteins are promising therapeutic targets for schizophrenia. Our study shows the power of integrating large-scale GWAS findings and transcriptomic and proteomic data in identifying actionable drug targets. Besides, our findings prioritize actionable novel drug targets for development of new therapeutics and provide critical drug-repurposing opportunities for psychiatric disorders.

Shale gas has enormous potential and has become a hotspot in recent decades. To exploit shale gas, a variety of working fluids (drilling fluid, fracturing fluid, etc.) have to be applied in drilling and well-completion engineering. When fluid contacts with shale, spontaneous imbibition occurs, affecting wellbore stability, fracturing fluid loss, and shale gas production. In the past few years, numerous researchers conducted studies on shale spontaneous imbibition, yet the vast majority of their works are derived from conventional method based on sandstone and carbonate. One of the characteristics of shale is strong hydration, which has been widely reported. During the interaction between liquid and shale, spontaneous imbibition is accompanied by hydration. Shale hydration mainly involves two aspects, i.e., osmotic pressure and hydration structural damage. Now there is still no research on studying the hydration effect during spontaneous imbibition, and how hydration affects spontaneous imbibition is still not fully understood. Therefore, in this paper, considering osmotic pressure and hydration structural damage, spontaneous imbibition in shale formation has been investigated. Besides, according to the Hagen–Poiseuille law, a novel analytical model has been established by coupling imbibition and hydration. In comparison to experimental data of spontaneous imbibition, practicability of this spontaneous imbibition model has been verified. On the basis of this new model and spontaneous imbibition test, influences of salinity and hydration on shale spontaneous imbibition have been systematically discussed. Results indicate that salinity reduces spontaneous imbibition by lowering the driving force of imbibition and restricting hydration damage. Hydration structural damage is its major influencing mechanism for shale spontaneous imbibition. In the shale exploitation, this model can offer guidance for evaluating fracturing fluid loss and hydration damage, which are practical for drilling and hydraulic fracturing design. Besides, the outcome of this paper is beneficial for improving our understanding on spontaneous imbibition in shale formation.

The emerging carbon-based mesoscopic perovskite solar cells (MPSCs) are known as one of the most promising candidates for photovoltaic applications thanks to their screen-printing process and excellent stability. Unfortunately, they usually suffer from serious defects because it is challenging to realize sufficient mesopore filling of the perovskite precursor solution throughout the triple-mesoporous scaffold. Herein, a bifunctional additive, biuret, endowed with both carbonyl and amino groups, was designed to realize a convenient fabrication approach for controllable crystallization of the precursor solution. Owing to the strong coordination ability with perovskite components, the incorporation of biuret can not only regulate crystallization kinetics allowing for the growth of high-quality perovskite crystals but also associate with uncoordinated ions for defect passivation to enhance the overall photovoltaic performance of MPSCs. A champion power conversion efficiency (PCE) of 13.42% with an enhanced short-circuit current density of 19.49 mA cm–2and a much higher open-circuit voltage of 0.96 V was achieved for the device doped with 3 mol % biuret, which is 26% higher than that of the control device (10.66%). Moreover, the unencapsulated devices with biuret incorporation demonstrated superior stability, maintaining over 90% of the original PCE after 50 days of storage under ambient conditions. This work helps exploit bifunctional additive strategies for simultaneous defect passivation and crystallization control toward high-efficiency and long-term stability of carbon-based MPSCs.

The mode-I fracture toughness is of great significance for evaluating the fracturing ability of shale reservoirs. In this study, the mode-I fracture toughness of the shale in the Lower Silurian Longmaxi Formation, Southern Sichuan Basin was determined with the Cracked Chevron Notched Brazilian Disc (CCNBD). Based on the experimental data, the relationships among the mode-I fracture toughness, the density, the acoustic time and the clay mineral content were analyzed. The shale samples for fracture toughness test from cores were commonly limited, the investigation of fracture toughness using well logs was necessary. Therefore, a prediction model was proposed by correlating the fracture toughness with well logs responses. The results indicate that the fracture toughness of shale samples is from 0.4744 MPa·m1/2to 1.0607 MPa·m1/2with an average of 0.7817 MPa·m1/2, indicating that the anisotropy of fracture toughness of the Longmaxi Formation shale. The clay mineral content and the density have a positive effect on the fracture toughness, whereas the acoustic time plays a negative role on the fracture toughness. The clay mineral content has an important effect on the relationships among fracture toughness, acoustic time and density. The prediction model can provide continuous data of mode-I fracture toughness along the wellbore for field hydraulic fracturing operation, and it has certain guiding significance in the exploration and development of oil and gas reservoirs