Search

The importance of information and communication technology in rural areas has gradually become prominent, and rural e-commerce has emerged as a crucial driver for promoting agricultural and rural development. This paper takes the comprehensive demonstration policy for e-commerce in rural areas as a quasi-natural experiment. It is based on five-period panel data from the China Family Panel Studies (CFPS) and employs the staggered difference-in-differences method to examine the impact of e-commerce on rural women entrepreneurship and its mechanisms. The research results indicate that the implementation of the comprehensive demonstration policy for e-commerce in rural areas significantly increases the probability of rural women engaging in entrepreneurship by 1.6 %. The entrepreneurial promotion effect of this demonstration policy is more pronounced for rural women in the central and western regions and those with lower educational levels, demonstrating the inclusiveness of e-commerce in rural development. Additionally, this promotion effect is also significantly influenced by marital heterogeneity. Mechanism analysis results suggest that the comprehensive demonstration policy for e-commerce in rural areas can stimulate the use of information and communication technology by rural women, leverage the crucial role of non-traditional education in skill development, alleviate financial and social capital constraints for rural women, and inspire a wave of rural women entrepreneurship. The paper argues that the construction of rural e-commerce has the potential to empower rural women entrepreneurship.

• The ultrahigh piezoelectric coefficient (d 33 , 1264 pC/N) reaches in the composition with x = 0.55 near the tetragonal-pseudocubic (T-PC) phase boundary. • On a local scale, electric fields do not induce phase transitions, suggesting that the exceptional piezoelectric performance in PNN-PZT stems from polarization extension near the T-PC boundary. • Both the relative permittivity and planar electromechanical coupling coefficient experience a sharp rise in the temperature range of −25 °C to 25 °C. The heightened piezoelectric performance observed in most explored perovskite systems is typically attributed to the electric-field-induced phase transition near the morphotropic phase boundary (MPB) or polymorphic phase boundary (PPB). This study, however, unveils a distinct piezoelectric enhancement mechanism in the x Pb(Nb 2/3 Ni 1/3)O 3 -(1– x)Pb(Zr 0.3 Ti 0.7)O 3 (PNN-PZT) system, diverging from the MPB/PPB-centered piezoelectric systems. Notably, the composition with x = 0.55, positioned close to the tetragonal-pseudocubic (T-PC) phase boundary, achieves an unprecedented piezoelectric coefficient (d 33) of 1264 pC/N, while retaining a tetragonal local structure. Importantly, on a local scale, electric fields do not incite phase transitions, suggesting that the exceptional piezoelectric performance in PNN-PZT stems from polarization extension near the T-PC boundary. Distinct from other mechanisms, the relative permittivity significantly increases post-poling due to this particular enhancement process. The dielectric behavior in poled specimens does not exhibit a conspicuous change at the ferroelectric-relaxor transition temperature. However, both the relative permittivity and planar electromechanical coupling coefficient experience a sharp rise in the temperature range of −25 °C to 25 °C. This investigation underscores the pivotal role of designing compositionally-driven T-PC phase boundaries, presenting a promising avenue for enhancing piezoelectric properties in ferroelectric ceramics. [Display omitted] [ABSTRACT FROM AUTHOR]

The joint inversion of gravity and magnetic data can reduce the nonuniqueness problem of potential field data inversion. We propose a gravity and magnetic joint inversion method based on deep learning (DL) combined with measurement data constraint. The framework obtains the gravity and magnetic dataset required for network training by randomly generating the underground structural consistency model and then inputs the dataset into the network for training. Moreover, we add constraints to the measurement data in the training of the network, that is, fitting the data anomalies obtained by the inversion model through forward calculation with the real anomalies, which makes the network more consistent with geophysical theory. In the test phase, the trained network can obtain the inversion results rapidly, and the inversion results of the testing dataset show that this method can obtain better results when applied to the joint inversion of gravity and magnetic fields than the conventional regularized inversion and cross-gradient joint inversion methods. In addition, our method can also distinguish the anomaly conditions in the case of structural inconsistency. Furthermore, we apply this method to actual gravity and magnetic data of Gonghe Basin, Qinghai Province, China, and predict the distribution of dry hot rock related to geothermal resources.

Nowadays, research on temporal membership queries is indispensable. Generally, temporal membership queries exist in two modalities: fixed windows and sliding windows, the latter having obvious advantages. The first sketch that implements temporal membership queries is the persistent Bloom filter (PBF). PBF has two shortcomings: it does not support sliding windows nor frequency queries. Here, we propose HoppingSketch to promote the original PBF. It is the first sketch that implements temporal membership queries for sliding windows. HoppingSketch is a general and efficient data stream processing framework, able to implement different tasks thanks to different atomic sketches. When the atomic sketches are Bloom filters and we apply them to PBF, HoppingSketch can achieve significantly higher temporal membership query accuracy than the original PBF. When the atomic sketches are sketches of Count-Min, Conservative Update, and Count, HoppingSketch can achieve more accurate frequency query than by applying PBF on the corresponding sketches. Our experimental results demonstrate the advantages of HoppingSketch compared with the state-of-the-art.

Three-dimensional gravity inversion is an effective method for restoring underground density distribution from gravity anomaly data. Conventional regularization inversion has good data fitting, but its inversion model has insufficient model fitting capabilities due to its low-depth resolution. Although data-driven deep learning (DL)-based gravity inversion results significantly improve depth resolution and physical property distribution, it is difficult to ensure the data fitting of the inversion results. Accordingly, this study proposes a 3-D gravity data inversion based on enhanced dual U-Net (EdU-Net) framework to solve the above problems, making the inversion results have good model and data fitting performance. The proposed EdU-Net consists of two parts: first, training a large generalization pretrained network Net I and then quickly generating an enhanced Net II for the target data through fine-tuning. Additionally, this study adds forward-fitting constraints in the framework’s loss function to reduce the problem of large data-fitting errors in traditional data-driven DL inversion. The trained Net II inversion result has better model and data fitting accuracy than Net I. Moreover, by comparing the inversion results of synthetic models, this study demonstrates that the EdU-Net method performs better than the traditional DL. Finally, this method is applied to the measured data of the Gonghe Basin in Qinghai Province, China, and provides a reasonable explanation for the distribution of hot dry rocks.

Reversible solid oxide cells (rSOCs) offer the prospect of long term bulk energy storage using hydrogen or methane fuel. Whilst less mature than alkaline and PEM fuel cell/electrolysis technology, solid oxide cells offer superior efficiency: as high as 80–90%LHVat system level. Furthermore, the possibility of using the cells reversibly means that separate ‘power-to-gas’ and ‘gas-to-power’ components are not needed. Here, we consider the suitability of a hydrogen energy storage system (HESS) using rSOCs for a solar-powered residential microgrid. Battery energy storage (BESS) is considered as a competing (or complementary) energy storage technology. Since the electrification of transport is likely to be a major aspect of the transformation of domestic energy consumption, electric cars are also included in the microgrid model. The performance of the microgrid is evaluated in terms of its grid independence (self-sufficiency ratio, SSR) and economics (simple payback time and net present value). Optimisation is used to select and size the microgrid’s components under different scenarios. Optimisation results suggest that battery storage is often preferred to HESS. However, two factors in particular can cause the selection of HESS to be favoured: (i) a requirement for high SSR and (ii) a lower constraint (6 kW) on the PV capacity per household. The economics for such systems remain very challenging.

The increasing penetration of Decentralised Energy Resources (DERs) into the residential sector along with a reduction in their subsidy in many countries requires innovative approaches to ensure economic viability. Whilst applications of Household Energy Storage (HES) have been widely investigated and deployed, in recent years communities have been identified as a key scale for energy systems, particularly for energy storage. Community Energy Storage (CES) is therefore a promising alternative deployment model to assist the roll-out of DERs. The power and energy demand may vary significantly with the demographic composition of community; therefore, it is important to evaluate the operation of HES and CES for different communities and hence to assign suitable energy storage options to corresponding objectives. In this work, an Agent Based Model (ABM) is developed that includes household demand heterogeneities, as well as HES and CES, and photovoltaic (PV) systems. The single household models can be aggregated to a community, and hence it is able to simulate the interaction between households in a local, grid connected, energy system. A battery degradation model is also included in order to reproduce the capacity fade of a Li-ion battery over time. The impact on battery performance of the heterogeneous demand within communities is explored using typical performance indicators, such as Self-Consumption Rate (SCR), Self-Sufficiency Rate (SSR) and battery cycle counts.

The majority of heat in the UK comes from the combustion of natural gas, and heat is responsible for 37% of the nation’s carbon emissions. Thus the decarbonisation of heat is a major challenge. Electrification is one possible approach to decarbonisation; however, huge increases in the electrical grid’s generation and transmission capacity would be needed to meet the peaks in space heat demand during cold winter weather. Thermal energy storage (TES) may have a role to play in alleviating this problem, by shifting heat demand by hours or longer periods, enabling peaks to be shaved.

Peptide-based supramolecular hydrogels are an attractive class of soft materials for biomedical applications when biocompatibility is a key requirement as they exploit the physical self-assembly of short self-assembling peptides avoiding the need for chemical cross-linking. Based on the knowledge developed through our previous work, we designed two novel peptides, E(FKFE)2and K(FEFK)2, that form transparent hydrogels at pH 7. We characterized the phase behavior of these peptides and showed the clear link that exists between the charge carried by the peptides and the physical state of the samples. We subsequently demonstrate the cytocompatibility of the hydrogel and its suitability for 3D cell culture using 3T3 fibroblasts and human mesenchymal stem cells. We then loaded the hydrogels with two polymers, poly-l-lysine and dextran. When polymer and peptide fibers carry opposite charges, the size of the elemental fibril formed decreases, while the overall level of fiber aggregation and fiber bundle formation increases. This overall network topology change, and increase in cross-link stability and density, leads to an overall increase in the hydrogel mechanical properties and stability, i.e., resistance to swelling when placed in excess media. Finally, we investigate the diffusion of the polymers out of the hydrogels and show how electrostatic interactions can be used to control the release of large molecules. The work clearly shows how polymers can be used to tailor the properties of peptide hydrogels through guided intermolecular interactions and demonstrates the potential of these new soft hydrogels for use in the biomedical field in particular for delivery or large molecular payloads and cells as well as scaffolds for 3D cell culture.

Electrochemically converting carbon dioxide (CO2) into valuable fuels and renewable chemical feedstocks is considered a highly promising approach to achieve carbon neutrality. In this work, a robust interfacial built-in electric field (BEF) has been successfully designed and created in Bi/Bi2Te3nanowires (NWs). The Bi/Bi2Te3NWs consistently maintain over 90% Faradaic efficiency (FE) within a wide potential range (−0.8 to −1.2 V), with HCOOH selectivity reaching 97.2% at −1.0 V. Moreover, the FEHCOOHof Bi/Bi2Te3NWs can still reach 94.3% at a current density of 100 mA cm–2when it is used as a cathode electrocatalyst in a flow-cell system. Detailed in situexperiments confirm that the presence of interfacial BEF between Bi and Bi/Bi2Te3promotes the formation of *OHCO intermediates, thus facilitating the production of HCOOH species. DFT calculations show that Bi/Bi2Te3NWs increase the formation energies of H* and *COOH while reducing the energy barrier for *OCHO formation, thus achieving a bidirectional optimization of intermediate adsorption. This work provides a feasible scheme for exploring electrocatalytic reaction intermediates by using the BEF strategy.

To evaluate the association between embryo transfer technique and pregnancy outcome.

A compact filtering Wilkinson power divider with harmonic suppression based on lumped components is presented in this paper. The new divider uses two 5th-order elliptic-function low-pass filters to replace the quarter wavelength microstrip lines of the conventional Wilkinson power divider. The structure combines the power divider and the filter into a complete device. By integrating elliptic low-pass filters with the power divider, the proposed structure can suppress harmonics due to the filter’s band-notched characteristic. The power divider demonstrates a measured suppression of 37.1 dB for the second harmonic, 36.6 dB for the third harmonic, 38.6 dB for the fourth harmonic respectively. The harmonic suppression is higher than 20 dB from 2.75 to 7.035 GHz. Furthermore, lumped components are utilized to achieve improvement on size reduction. Compared with the conventional divider, the proposed structure effectively reduces the size by 77 %. The insertion loss is 3.2 dB at the center frequency (1.45GHz).

Gas barrier films with water-vapor-permeability have exhibited broad application prospects in gas separation and dehumidification. Herein, multilayer films comprised of layered double hydroxides (LDH) nanosheets and carboxymethyl cellulose sodium (CMC) were fabricated via layer-by-layer assembly. The resulting (LDH/CMC)nfilms show excellent gas barrier properties, which are ascribed to the significantly increased pathway for gas permeation originating from the large aspect ratio and high orientation of two-dimensional LDH nanosheets. Unlike traditional gas barrier films with nonselective blocking effect for various gases (including water vapor), the (LDH/CMC)nfilms exhibit an unusual moisture permselective property. The moisture-permeable property was related to the hygroscopicity of CMC and hydrophilicity of LDH, which can enrich the water molecules from the surroundings and aggrandize the osmotic pressure for water vapor, resulting in an uncommon improvement of water vapor transmission. It is interesting to find that the (LDH/CMC)nfilms exhibit enhanced gas (O2, CO2, CH4, and N2) barrier properties upon treatment in a humid environment, due to the formation of hydrogen bonds between the infiltrated water molecules and hydrophilic groups in CMC, thus padding the interstitial space of the CMC molecular chains and increasing the gas transmission path. The reduction of free volume and extension of the gas transmission path further enhance the gas barrier properties of (LDH/CMC)nfilms. Moreover, the (LDH/CMC)nfilms represent the water vapor permselective property in mixed gas (including O2, CO2, CH4, N2, and water vapor), while maintaining the barrier for other gases, which can be potentially applied in air dehydration and dehumidification of natural gas.

ABSTRACTObjectives: Hyperhomocysteinemia (Hhcy) is a known cardiovascular disease (CVD) risk factor. Observational studies had supported the role of lifestyle factors such as physical activity, diet and alcohol consumption in CVD prevention. Our study aimed to determine the relationship between Hhcy and lifestyle factors in general Chinese population.Methods: In this cross-sectional study, a total of 7135 adults (3320 men and 3815 women) aged 35 years or older were recruited from the rural Northeast China. Data on lifestyle factors, such as physical activities, sleep duration, current smoking and drinking status, dietary habits and familial factors were collected in interviews and laboratory examinations were performed by well-trained personnel.Results: Plasma total homocysteine (tHcy) level was higher in men than in women, and greater in the elderly than in other age groups. Subjects with Hhcy were more likely to be current smokers (men: OR 1.328, 95% CI 1.143–1.543, p<0.001; women: OR 1.465, 95% CI 1.214–1.767, p<0.001). Separately, men with Hhcy were more likely to have an education of primary school or below (OR 1.251, 95% CI 1.068–1.465, p=0.006) and less likely to eat more vegetables (OR 0.927, 95% CI 0.863–0.996, p=0.037) than the normal-tHcy participants. In women, participants with Hhcy were more likely to have longer sleeping time (>9h/d) (OR 1.677, 95% CI 1.292–2.177, p<0.001), low physical activity (OR 1.721, 95% CI 1.197–2.475, p=0.044) and increased diet score (OR 1.126, 95% CI 1.007–1.259, p=0.037) and less likely to be current drinkers (OR 0.488, 95% CI 0.297–0.802, p=0.005) than the normal-tHcy participants.Conclusion: Our study revealed that physical activity and current drinking status were not significantly associated with Hhcy in males, but inversely associated in females. In both genders, current smoking status and dietary habits were significantly associated with Hhcy. Our study supports existing recommendations for Chinese to maintain a physically active behaviors and healthy lifestyle habits.

ABSTRACTObjectives: This cross-sectional study aimed to determine the prevalence of elevated alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in Chinese type 2 diabetic patients and identify contributing risk factors.Methods: This cross-sectional study was conducted in rural areas of China, and 1,198 type 2 diabetic patients with complete data were recruited. Elevated ALT and AST levels were defined as >40 U/L. Prevalence of abnormal liver enzymes was analyzed and multivariable analysis was used to identify independent risk factors.Results: 10.3% and 6.1% diabetic patients had elevated ALT and elevated AST, respectively. The prevalence of elevated liver enzymes was gender-related; it was 13.8% in men and 7.5% in women for elevated ALT, and 7.4% in men and 3.1% in women for elevated AST. High triglyceride was positively associated with both elevated ALT (OR 1.80, 95% CI 1.08–3.01, p = 0.024) and elevated AST (OR 2.24, 95%CI 1.08–4.65, p = 0.031), while taking anti-diabetes medicine was inversely related to both elevated ALT (OR 0.48, 95% CI 0.29–0.80, p = 0.005) and elevated AST (OR 0.37, 95% CI 0.17–0.82, p = 0.014). The risk of elevated ALT in diabetic patients increased with the presence of obesity (OR 2.54, 95% CI 1.07–6.01, p = 0.034), and was lower in women (OR 0.37, 95% CI 0.19–0.72, p = 0.003). Hypertension (OR 4.33, 95% CI 1.41–13.30, p = 0.011), current drinking status (OR 2.90, 95% CI 1.21–6.96, p = 0.017) and national minority (OR 3.26, 95%CI 1.31–8.12, p = 0.011) were risk factors for elevated AST.Conclusion: A relatively high prevalence of abnormal serum liver enzymes in diabetic patients was demonstrated in China, especially in males. More attention should be paid to preventing liver injuries in diabetic patients.

Structured illumination technique enhances the lateral resolution by projecting non-uniform intensity patterns on a sample. In a typical implementation, three lateral phase shifts (0, 2π/3, 4π/3) are needed for each orientation of the sinusoidal pattern, and 3 different orientations are needed to double the bandwidth isotopically in the Fourier domain. To this end, 9 incoherent images are needed in the acquisition process. In this paper, we discuss an imaging strategy for the structured illumination technique and demonstrate the use of a modified incoherent Fourier ptychographic procedure for reducing the number of acquisitions. In the first implementation, we used complementary sinusoidal patterns for sample illumination. We show that, the number of lateral phase shifts can be reduced from 3 to 2 for each orientation of the sinusoidal pattern and the total number of image acquisitions can be reduced to 6 with 3 orientations. In the second implementation, we further reduce the number of image acquisitions to 4. We also show that, the resolution-doubled image can be recovered even with unknown phases of the sinusoidal patterns. We validate the proposed imaging procedure with non-fluorescence samples. The reported approach may shorten the acquisition time of super-resolution imaging and reduce phototoxicity of biological samples.

Progressive tissue fibrosis is a cause of major morbidity and mortality. Pulmonary fibrosis is an epithelial-mesenchymal disorder in which TGF-β1 plays a central role in pathogenesis. Here we show that follistatin-like 1 (FSTL1) differentially regulates TGF-β and bone morphogenetic protein signaling, leading to epithelial injury and fibroblast activation. Haplodeletion of Fstl1 in mice or blockage of FSTL1 with a neutralizing antibody in mice reduced bleomycin-induced fibrosis in vivo. Fstl1 is induced in response to lung injury and promotes the accumulation of myofibroblasts and subsequent fibrosis. These data suggest that Fstl1 may serve as a novel therapeutic target for treatment of progressive lung fibrosis.

Illumination engineering is critical for obtaining high-resolution, high-quality images in microscope settings. In a typical microscope, the condenser lens provides sample illumination that is uniform and free from glare. The associated condenser diaphragm can be manually adjusted to obtain the optimal illumination numerical aperture. In this paper, we report a programmable condenser lens for active illumination control. In our prototype setup, we used a $15 liquid crystal display as a transparent spatial light modulator and placed it at the back focal plane of the condenser lens. By setting different binary patterns on the display, we can actively control the illumination and the spatial coherence of the microscope platform. We demonstrated the use of such a simple scheme for multimodal imaging, including bright-field microscopy, darkfield microscopy, phase-contrast microscopy, polarization microscopy, 3D tomographic imaging, and super-resolution Fourier ptychographic imaging. The reported illumination engineering scheme is cost-effective and compatible with most existing platforms. It enables a turnkey solution with high flexibility for researchers in various communities. From the engineering point-of-view, the reported illumination scheme may also provide new insights for the development of multimodal microscopy and Fourier ptychographic imaging.

The large consumer market has made cellphone lens modules available at low-cost and in high-quality. In a conventional cellphone camera, the lens module is used to demagnify the scene onto the image plane of the camera, where image sensor is located. In this work, we report a 3D-printed high-resolution Fourier ptychographic microscope, termed FPscope, which uses a cellphone lens in a reverse manner. In our platform, we replace the image sensor with sample specimens, and use the cellphone lens to project the magnified image to the detector. To supersede the diffraction limit of the lens module, we use an LED array to illuminate the sample from different incident angles and synthesize the acquired images using the Fourier ptychographic algorithm. As a demonstration, we use the reported platform to acquire high-resolution images of resolution target and biological specimens, with a maximum synthetic numerical aperture (NA) of 0.5. We also show that, the depth-of-focus of the reported platform is about 0.1 mm, orders of magnitude longer than that of a conventional microscope objective with a similar NA. The reported platform may enable healthcare accesses in low-resource settings. It can also be used to demonstrate the concept of computational optics for educational purposes.

Information multiplexing is important for biomedical imaging and chemical sensing. In this paper, we report a microscopy imaging technique, termed state-multiplexed Fourier ptychography (FP), for information multiplexing and coherent-state decomposition. Similar to a typical Fourier ptychographic setting, we use an array of light sources to illuminate the sample from different incident angles and acquire corresponding low-resolution images using a monochromatic camera. In the reported technique, however, multiple light sources are lit up simultaneously for information multiplexing, and the acquired images thus represent incoherent summations of the sample transmission profiles corresponding to different coherent states. We show that, by using the state-multiplexed FP recovery routine, we can decompose the incoherent mixture of the FP acquisitions to recover a high-resolution sample image. We also show that, color-multiplexed imaging can be performed by simultaneously turning on R/G/B LEDs for data acquisition. The reported technique may provide a solution for handling the partially coherent effect of light sources used in Fourier ptychographic imaging platforms. It can also be used to replace spectral filter, gratings or other optical components for spectral multiplexing and demultiplexing. With the availability of cost-effective broadband LEDs, the reported technique may open up exciting opportunities for computational multispectral imaging.

•Techno-enviro-economic analysis of community energy storage system (CES) in the UK and Germany presented.•Solar generation, costs of technologies and subsidies critical to system feasibility.•A locational-specific approach essential to system planning.•More financial and legislative support needed in the UK.

It is of great significance to develop multifunctional biomaterials to effectively deliver anticancer drug to tumor cells for cancer therapy. Here, inspired by the specific tumor microenvironment (TME) cues, a unique multistage pH/redox‐responsive polyprodrug composed of amphiphilic pH‐sensitive diblock copolymer poly(ethylene glycol) methyl ether‐b‐poly(β‐amino esters) conjugated with doxorubicin (DOX) via redox‐sensitive disulfide bonds (mPEG‐b‐PAE‐ss‐DOX) is designed and developed. This polyprodrug can self‐assemble into micelles (DOX‐ss@PMs) at low concentration with high serum stability, indicating that DOX‐ss@PMs have prolonged circulation time. The dual pH/redox‐responsiveness of the multistage platform is thoroughly evaluated. In vitro results demonstrate that DOX‐ss@PMs can highly accumulate at tumor site, followed by responding to the acidity for disassembly and effectively penetrating into the tumor cells. DOX is released from the platform due to the cleavage of disulfide bonds induced by high glutathione (GSH) concentration, thereby inducing the apoptosis of tumor cells. In vivo studies further reveal that multistage DOX‐ss@PMs can more efficiently inhibit the growth of tumors and improve the survival of tumor‐bearing mice in comparison to the free drug and control. These results imply that multistage delivery system might be a potential and effective strategy for drug delivery and DOX‐ss@PMs could be a promising nanomedicine for cancer chemotherapy. A multistage pH/redox‐responsive polyprodrugcomposed of amphiphilic pH‐sensitive diblock copolymer poly(ethylene glycol) methyl ether‐b‐poly(β‐amino esters) conjugated with doxorubicin (DOX) via redox‐sensitive disulfide bonds (mPEG‐b‐PAE‐ss‐DOX) which can self‐assemble into polyprodrug micelles (DOX‐ss@PMs) is developed. The DOX‐ss@PMs can sequentially respond to low pH and high glutathione concentration for multistaged delivery of DOX for improving cancer therapeutic efficiency.