bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrospun Poly(lactic acid) and Silk Fibroin Based Nanofibrous Scaffold for Meniscus Tissue Engineering
Authors: Promnil Siripanyo , Ruksakulpiwat Chaiwat , Numpaisal Piya-on , Ruksakulpiwat Yupaporn
Published: June 2022

Biopolymer based scaffolds are commonly considered as suitable materials for medical application. Poly(lactic acid) (PLA) is one of the most popular polymers that has been used as a bioscaffold, but it has poor cell adhesion and slowly degrades in an in vitro environment. In this study, silk fibroin (SF) was selected to improve cell adhesion and degradability of electrospun PLA. In order to fabricate a PLA/SF scaffold that offered both biological and mechanical properties, related parameters such as solution viscosity and SF content were studied. By varying the concentration and molecular weight of PLA, the solution viscosity significantly changed. The effect of solution viscosity on the fiber forming ability and fiber morphology was elucidated. In addition, commercial (l-lactide, d-lactide PLA) and medical grade PLA (pure PLLA) were both investigated. Mechanical properties, thermal properties, biodegradability, wettability, cell viability, and gene expression of electrospun PLA and PLA/SF based nanofibrous scaffolds were examined. The results demonstrated that medical grade PLA electrospun scaffolds offered superior mechanical property, degradability, and cellular induction for meniscus tissue regeneration. However, for commercial non-medical grade PLA used in this study, it was not recommended to be used for medical application because of its toxicity. With the addition of SF in PLA based scaffolds, the in vitro degradability and hydrophilicity were improved. PLAmed50:SF50 scaffold has the potential to be used as biomimetic meniscus scaffold for scaffold augmented suture based on mechanical properties, cell viability, gene expression, surface wettability, and in vitro degradation.
Physical Properties of Glass-Fibre-Reinforced Polymer Filled with Alumina Trihydrate and Calcium Carbonate
Authors: Setyanto Djoko , Jayatun Yohanes Agus , Basoeki Prita Dewi , De Fretes Anthon
Published: June 2022

Gutters made of glass-fibre-reinforced polymer (GFRP) are usually produced with a three-millimetre thickness. The fillers are mixed into unsaturated polyester (UP) resin, which is intended to make the composite material more affordable. This study aims to examine the effects of the addition of alumina trihydrate (ATH), calcium carbonate (CC), and a mixture of ATH and CC of 15 and 30 parts per hundredweight of resins (PHR) on the material properties of the three-millimetre-thick three-layered GFRP composites. The properties observed included physical properties, namely, specific gravity and water absorption, chemical properties such as burning rate, and mechanical properties such as hardness, flexural strength, and toughness. The effects of the fillers on the voids and interfacial bond between the reinforcing fibre and matrix were analysed using the flexural fracture observation through scanning electron microscopy (SEM). The results showed that the addition of fillers into the UP resin led to an increase in the density, hardness, flexural strength, modulus of elasticity, and toughness but a decrease in water absorption and burning rate in a horizontal position. This information can be helpful for manufacturers of gutters made of GFRP in selecting the appropriate constituent materials while considering the technical and economic properties.
Enhanced Silk Fibroin/Sericin Composite Film: Preparation, Mechanical Properties and Mineralization Activity
Authors: Li Meng , Tian Wei , Zhang Yao , Song Hui , Yu Yangxiao , Chen Xiangshang , Yong Nan , Li Xiuzhen , Yin Yin , Fan Qingmin , Wang Jiannan
Published: June 2022

The periosteum plays an important role in bone formation and reconstruction. One of the reasons for the high failure rate of bone transplantation is the absence of the periosteum. Silk fibroin (SF) and silk sericin (SS) have excellent biocompatibility and physicochemical properties, which have amazing application prospects in bone tissue engineering, but lacked mechanical properties. We developed a series of SF/SS composite films with improved mechanical properties using boiling water degumming, which caused little damage to SF molecular chains to retain larger molecules. The Fourier transform infrared spectroscopy and X-ray diffraction results showed that there were more β-sheets in SF/SS films than in Na2CO3 degummed SF film, resulting in significantly improved breaking strength and toughness of the composite films, which were increased by approximately 1.3 and 1.7 times, respectively. The mineralization results showed that the hydroxyapatite (HAp) deposition rate on SF/SS composite films was faster than that on SF film. The SF/SS composite films effectively regulated the nucleation, growth and aggregation of HAp-like minerals, and the presence of SS accelerated the early mineralization of SF-based materials. These composite films may be promising biomaterials in the repair and regeneration of periosteum.
Performance and Structure Evaluation of Gln-Lys Isopeptide Bond Crosslinked USYK-SPI Bioplastic Film Derived from Discarded Yak Hair
Authors: Wang Ruirui
Published: June 2022

To reduce the waste from yak hair and introduce resource recycling into the yak-related industry, an eco-friendly yak keratin-based bioplastic film was developed. We employed yak keratin (USYK) from yak hair, soy protein isolate (SPI) from soybean meal as a film-forming agent, transglutaminase (EC 2.3.2.13, TGase) as a catalytic crosslinker, and glycerol as a plasticizer for USYK-SPI bioplastic film production. The structures of the USYK-SPI bioplastic film were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and X-Ray diffraction (XRD). The mechanical properties, the thermal behavior, light transmittance performance, and water vapor permeability (WVP) were measured. The results revealed that the added SPI possibly acted as a reinforcement. The formation of Gln-Lys isopeptide bonds and hydrophobic interactions led to a stable crosslinking structure of USYK-SPI bioplastic film. The thermal and the mechanical behaviors of the USYK-SPI bioplastic film were improved. The enhanced dispersion and formation of co-continuous protein matrices possibly produced denser networks that limited the diffusion of water vapor and volatile compounds in the USYK-SPI bioplastic films. Moreover, the introduction of SPI prompted the relocation of hydrophobic groups on USYK molecules, which gave the USYK-SPI bioplastic film stronger surface hydrophobicity. The SPI and USYK molecules possess aromatic amino residuals (tyrosine, phenylalanine, tryptophan), which can absorb ultraviolet radiation. Thus, the USYK-SPI bioplastic films were shown to have an excellent UV barrier. The synergy effect between USYK and SPI is not only able to improve rigidity and the application performance of keratin-based composite film but can also reduce the cost of the keratin-based composite film through the low-cost of the SPI alternative which partially replaces the high-cost of keratin. The data obtained from this research can provide basic information for further research and practical applications of USYK-SPI bioplastic films. There is an increasing demand for the novel USYK-SPI bioplastic film in exploit packaging material, biomedical materials, eco-friendly wearable electronics, and humidity sensors.
Electrical Conductivities of Narrow-Bandgap Polymers with Two Types of π-Conjugated Post-Crosslinking
Authors: Guo Hao-xuan , Takahara Hiroshi , Imai Yusuke , Aota Hiroyuki
Published: June 2022

Bandgap energy is one of the most important properties for developing electronic devices because of its influence on the electrical conductivity of substances. Many methods have been developed to control bandgap, one of which is the realization of conducting polymers using narrow-bandgap polymers; however, the preparation of these polymers is complex. In this study, water-soluble, narrow-bandgap polymers with reactive groups were prepared by the addition–condensation reaction of pyrrole (Pyr), benzaldehyde-2-sulfonic acid sodium salt (BS), and aldehyde-containing reactive groups (aldehyde and pyridine) for post-crosslinking. Two types of reactions, aldehyde with p-phenylenediamine and pyridine with 1,2-dibromoethylene, were carried out for the π-conjugated post-crosslinking between polymers. The polymers were characterized by proton nuclear magnetic resonance (1H-NMR), thermogravimetric/differential thermal analysis (TG/DTA), UltraViolet-Visible-Near InfraRed spectroscopy (UV-Vis-NIR), and other analyses. The bandgaps of the polymers, calculated from their absorption, were less than 0.5 eV. Post-crosslinking prevents resolubility and develops electron-conducting routes between the polymer chains for π-conjugated systems. Moreover, the post-crosslinked polymers maintain their narrow bandgaps. The electrical conductivities of the as-prepared polymers were two orders of magnitude higher than those before the crosslinking.
Octenyl Succinic Anhydride Modified Pearl Millet Starches: An Approach for Development of Films/Coatings
Authors: Siroha Anil Kumar , Bangar Sneh Punia , Sandhu Kawaljit Singh , Lorenzo Jose Manuel , Trif Monica
Published: June 2022

Pearl millet starches were modified at pH 8.0 using 3.0% octenyl succinic anhydride (OSA), and their pasting, rheological properties, and in vitro digestibility were analyzed. The degree of substitution (D.C.) of OSA-modified starches varied from 0.010 to 0.025. The amylose content decreased after modification, while the reverse was observed for swelling power. After OSA modification, the pasting viscosities (peak, trough, setback (cP)) of the modified starches increased compared to their native counterparts. G′ (storage modulus) and G″ (loss modulus) decreased significantly (p < 0.05) compared to their native counterparts during heating. Yield stress (σo), consistency (K), and flow behavior index (n) varied from 9.8 to 87.2 Pa, 30.4 to 91.0 Pa.s., and 0.25 to 0.47, respectively. For starch pastes, steady shear properties showed n < 1, indicating shear-thinning and pseudoplastic behavior. The readily digestible starch (RDS) and slowly digestible starch (SDS) contents decreased, while the resistant starch (R.S.) content increased. After OSA treatment, the solubility power of the starches increased; this property of OSA starches speeds up the biodegradability process for the films, and it helps to maintain a healthy environment.
An Efficiency Improvement Driver for Master Oscillator Power Amplifier Pulsed Laser Systems
Authors: Chen Fu-Zen , Song Yu-Cheng , Ho Fu-Shun
Published: June 2022

The master oscillator power amplifier (MOPA) pulsed laser, one of the popular topologies for high-power fiber laser systems, is widely applied in industrial machining laser systems. In MOPA, the low-power pulsed laser, stimulated from a seed laser diode, is amplified by the high- power optical energy from pump laser diodes via the gain fiber. Generally, the high-power pump laser diodes are driven by lossy linear current drivers. The switched mode current drivers boost the driver efficiency but suffer from pulse energy consistency due to the current switching ripple. In this paper, a laser driver system that varies the switching frequency of current source to synchronize with pulsed laser repetition rate is analyzed and implemented. Experimental results are demonstrated using a 20 W pulsed fiber laser system.
A Review of the Preparation, Machining Performance, and Application of Fe-Based Amorphous Alloys
Authors: Huo Zexuan , Zhang Guoqing , Han Junhong , Wang Jianpeng , Ma Shuai , Wang Haitao
Published: June 2022

Amorphous alloy is an emerging metal material, and its unique atomic arrangement brings it the excellent properties of high strength and high hardness, and, therefore, have attracted extensive attention in the fields of electronic information and cutting-edge products. Their applications involve machining and forming, make the machining performance of amorphous alloys being a research hotspot. However, the present research on amorphous alloys and their machining performance is widely focused, especially for Fe-based amorphous alloys, and there lacks a systematic review. Therefore, in the present research, based on the properties of amorphous alloys and Fe-based amorphous alloys, the fundamental reason and improvement method of the difficult-to-machine properties of Fe-based amorphous alloys are reviewed and analyzed. Firstly, the properties of amorphous alloys are summarized, and it is found that crystallization and high temperature in machining are the main reasons for difficult-to-machine properties. Then, the unique properties, preparation and application of Fe-based amorphous alloys are reviewed. The review found that the machining of Fe-based amorphous alloys is also deteriorated by extremely high hardness and chemical tool wear. Tool-assisted machining, low-temperature lubrication assisted machining, and magnetic field-assisted machining can effectively improve the machining performance of Fe-based amorphous alloys. The combination of assisted machining methods is the development trend in machining Fe-based amorphous alloys, and even amorphous alloys in the future. The present research provides a systematic summary for the machining of Fe-based amorphous alloys, which would serve as a reference for relevant research.
Blockchain Development Services Provider Assessment Model for a Logistics Organizations
Authors: Thanh Nguyen Van
Published: June 2022

As the global market develops along with technological advances, especially the opening of markets in developing and underdeveloped countries, the logistics industry is considered by managers to be a useful tool to link different functions of corporate strategy. Logistics is the process of planning, implementing and controlling the movement of goods or information that are related to raw materials (inputs) and final products (outputs) from the point of origin to the point of consumption in order to meet customer requirements. The logistics industry brings about many positive effects, not only for the national economy but also for creating equal business opportunities for businesses of all economic sectors. However, large companies in the logistics industry still depend on EDI or APIS to exchange secure authentication data, which increase the security of operations within the industry, but this is the cause of a lot of confusion with serious consequences on the supply chain when it is too dependent on these systems. To minimize the risks and optimize the problems mentioned above, blockchain technology could help the logistics industry to operate optimally. In an era when everything is digitized, from personal information to financial transactions, choosing a system with high reliability and security becomes extremely important. Currently, there are many blockchain development services providers and it is essential to choose the investment in this technology that suits the characteristics and purposes of the logistics organization in question. This study aimed to propose a two-stage fuzzy multicriteria decision-making model for the assessment of blockchain development services providers for logistics organizations. The hybrid MCDM model was evaluated through a real-world case study at a logistics organization. The contribution of this work is the provision of useful guidelines for the evaluation and selection of blockchain technology services providers for logistics companies.
A Value-Added Utilization Method of Sugar Production By-Products from Rice Straw: Extraction of Lignin and Evaluation of Its Antioxidant Activity
Authors: Zhang Shengming , Ma Liangfei , Gao Shushan , Zhu Chonghao , Yan Yehong , Liu Xiaohan , Li Longhai , Chen Haitao
Published: June 2022

To value-added utilization of the rice straw, two types of lignin were extracted from the by-products of sugar production. The ether-extracted lignin with a purity of 98.7% was extracted from the pretreatment filtrate with two times the concentrated filtrate volume of ether, where the lignin yield was 6.62 mg/g of the rice straw. The ball-milled lignin with a purity of 99.6% was extracted from the milled enzymatic hydrolysis residue with a 1,4-dioxane solution, where the revolution speed and grinding time were 300 rpm and 12 h, respectively. The yield of ball-milled lignin was 34.52 mg/g of the rice straw, which was 421.5% higher than that extracted from extract-free rice straw. In the process of rice straw pretreatment and lignin extraction, 76.43% by mass of phosphotungstic acid catalyst and approximately 98% by volume of 1,4-dioxane solution could be recycled and reused. Compared with the soda lignin extracted from papermaking black liquor, the scavenging rates of DPPH radical and ABTS+ radical of ether-extracted lignin increased by 36.26% and 41.18%, respectively, while the above scavenging rates of ball-milled lignin increased by 30.22% and 37.75%, respectively. Moreover, the reducing power of the two extracted lignins was also stronger than that of soda lignin. The ether-extracted lignin and ball-milled lignin have the potential to be developed as natural macromolecular antioxidants.
Just War and Anti-War: Two Stances of the Japanese Methodist Church toward the Russo-Japanese War
Authors: Park Eun-young , Kim Do-hyung
Published: June 2022

If the Christian Church prioritizes its existence and expansion, it will turn to the entity that approves of it and protects it. When the Modern Japanese emperor’s state approached the church as his grace, the Japanese Christian Church showed its gratitude and pledged its allegiance to the emperor. In the Sino-Japanese War, which assisted modern Japan in becoming an imperial-ist country, the Japanese Christian community was in favor of a war under the pretext of a “righteous war” to maintain a lasting peace in the East. However, during the Russo-Japanese War, when most of the Christians were actively in favor of the war, there were a few anti-war voices among small groups of Christians that had not been heard during the Sino-Japanese War. There was a tension that could not be easily resolved in the Japanese Christian Church. In particular, Gokyō, a Christian journal published by the Japanese Methodist Church, one of the major Protestant denominations, simultaneously presented two interesting and conflicting stances regarding the Russo-Japanese War (just war vs. anti-war). In this paper, we examine the diverging perspectives presented in Gokyō and explore various patterns of religion–war relations. Through this, we can see an example of two opposing arguments of just war and anti-war that coexisted and competed on the grounds of Christianity.
Sexual Complexity: A Comparison between Men and Women in a Sexual Minority Sample of Members of the Church of Jesus Christ of Latter-day Saints
Authors: Bradshaw William S. , Dehlin John P. , Galliher Renee V.
Published: June 2022

We report here some of the results from an online survey of 1612 LGBTQ members and former members of the Church of Jesus Christ of Latter-day Saints (CJCLDS, Mormon). The data permitted an exploration of diversity—individual similarities and differences within and between the sexes. Men and women were compared with respect to sexual identity self-labeling and behavior (i.e., identity development, disclosure, activity), orientation change efforts, marital relationships, and psychosocial health—these variables in the context of their religious lives. More women than men self-identified in the bisexual range of the sexual attraction continuum. Both men and women had engaged in extensive effort to change their sexual orientation. Only about 4% of the respondents claimed that those efforts had been successful, and the claims were for outcomes other than an alteration in erotic feeling. In general, only those who identified as bisexual reported success in maintaining a mixed-orientation marriage and continuing activity in the church. For both men and women, measures of psychosocial and sexual health were higher for those in same-sex relationships and those disaffiliated from the church.
Diffusion Approximations of the Ruin Probability for the Insurer–Reinsurer Model Driven by a Renewal Process
Authors: Burnecki Krzysztof , Teuerle Marek A. , Wilkowska Aleksandra
Published: June 2022

We introduce here a diffusion-type approximation of the ruin probability both in finite and infinite time for a two-dimensional risk process, where claims and premiums are shared with a predetermined proportion. This type of process is often called the insurer–reinsurer model. We assume that the flow of claims is governed by a general renewal process. A simple ruin probability formula for the model is known only in infinite time for the special case of the Poisson process and exponentially distributed claims. Therefore, there is a need for simple analytical approximations. In the literature, in the infinite-time case, for the Poisson process, a De Vylder-type approximation has already been introduced. The idea of the diffusion approximation presented here is based on the weak convergence of stochastic processes, which enables one to replace the original risk process with a Brownian motion with drift. By applying this idea to the insurer–reinsurer model, we obtain simple ruin probability approximations for both finite and infinite time. We check the usefulness of the approximations by studying several claim amount distributions and comparing the results with the De Vylder-type approximation and Monte Carlo simulations. All the results show that the proposed approximations are promising and often yield small relative errors.
Recent Changes in Glaciers in the Northern Tien Shan, Central Asia
Authors: Zhang Qifei , Chen Yaning , Li Zhi , Xiang Yanyun , Li Yupeng , Sun Congjian
Published: June 2022

The Tien Shan is regarded as the “Water tower of Central Asia,” being a solid reservoir of freshwater resources and also a natural and early warning indicator of climate change. Research on glaciers is important for the sustainable development and management of water resources in Central Asia. This study investigated the spatiotemporal dynamics of glaciers in the northern Tien Shan from 1990 to 2015 using multi-source remote sensing and meteorological data. The results showed that the total area and volume of glaciers in the northern Tien Shan exhibited negative trends, decreasing by 456.43 km2 (16.08%) and 26.14 km3 (16.38%), respectively. The reduction in the total glacier area exhibited an accelerating trend, decreasing by 0.60%/a before 2000, but by 0.71%/a after 2000. Glaciers in the outer northern Tien Shan region, with areas < 2 km2 showed the greatest shrinkage, especially those in the northeastern and southwestern regions. All aspects in the northern Tien Shan exhibited negative trends in the glacier area, especially in the east–west aspects (shrinkage of 24.74–38.37%). Regarding altitude, the termini of glaciers rose continuously from 1990 to 2015, particularly for glaciers below 3700 m, with a total area decrease of 30.37%, and the lower altitude of the glaciers showed a higher area decrease.
Landslide Detection Based on ResU-Net with Transformer and CBAM Embedded: Two Examples with Geologically Different Environments
Authors: Yang Zhiqiang , Xu Chong , Li Lei
Published: June 2022

An efficient method of landslide detection can provide basic scientific data for emergency command and landslide susceptibility mapping. Compared to a traditional landslide detection approach, convolutional neural networks (CNN) have been proven to have powerful capabilities in reducing the time consumed for selecting the appropriate features for landslides. Currently, the success of transformers in natural language processing (NLP) demonstrates the strength of self-attention in global semantic information acquisition. How to effectively integrate transformers into CNN, alleviate the limitation of the receptive field, and improve the model generation are hot topics in remote sensing image processing based on deep learning (DL). Inspired by the vision transformer (ViT), this paper first attempts to integrate a transformer into ResU-Net for landslide detection tasks with small datasets, aiming to enhance the network ability in modelling the global context of feature maps and drive the model to recognize landslides with a small dataset. Besides, a spatial and channel attention module was introduced into the decoder to effectually suppress the noise in the feature maps from the convolution and transformer. By selecting two landslide datasets with different geological characteristics, the feasibility of the proposed model was validated. Finally, the standard ResU-Net was chosen as the benchmark to evaluate the proposed model rationality. The results indicated that the proposed model obtained the highest mIoU and F1-score in both datasets, demonstrating that the ResU-Net with a transformer embedded can be used as a robust landslide detection method and thus realize the generation of accurate regional landslide inventory and emergency rescue.
Hydrological Characteristics Change of Hala Lake and Its Response to Climate Change, 1987–2018
Authors: Jiang Zhiyong , Wang Jianru , Cai Xiaobin , Zhao Junli , Zhang Huawei , Zhang Yi , Wang Chongshan
Published: June 2022

Lakes on the Tibetan Plateau (TP) are an indicator of global climate change. The study on the factors driving lake change on the TP can help us understand its response to climate change. In this study, Landsat and ICESat data were used to obtain the variations of area, water level, and storage of Hala Lake and the area of glaciers in the Hala Lake Basin during 1987–2018. Combined with meteorological data, climate change trends and the factors driving Hala Lake change in the last 30 years were analyzed. The contribution of glacier mass loss to lake recharge was estimated by the water balance of Hala Lake. The results showed that Hala Lake has experienced three stages: slight expansion (1987–1994), shrinkage (1995–2001) and rapid expansion (2002–2018) during the study period. The rate of glacial melting continued to decline during the study period. Precipitation was the main factor that drove the hydrological characteristic changes in Hala Lake. The step change points of annual precipitation and temperature occurred in 2001, almost the same time that Hala Lake began expanding rapidly.
A Mid- and Long-Term Arctic Sea Ice Concentration Prediction Model Based on Deep Learning Technology
Authors: Zheng Qingyu , Li Wei , Shao Qi , Han Guijun , Wang Xuan
Published: June 2022

Mid- and long-term predictions of Arctic sea ice concentration (SIC) are important for the safety and security of the Arctic waterways. To date, SIC predictions mainly rely on numerical models, which have the disadvantages of a short prediction time and high computational complexity. Another common forecasting approach is based on a data-driven model, which is generally based on traditional statistical analysis or simple machine learning models, and achieves prediction by learning the relationships between data. Although the prediction performance of such methods has been improved in recent years, it is still difficult to find a balance between unstable model structures and complex spatio-temporal data. In this study, a classical statistical method and a deep learning model are combined to construct a data-driven rolling forecast model of SIC in the Arctic, named the EOF–LSTM–DNN (abbreviated as ELD) model. This model uses the empirical orthogonal function (EOF) method to extract the temporal and spatial features of the Arctic SIC, then the long short-term memory (LSTM) network is served as a feature extraction tool to effectively encode the time series, and, finally, the feature decoding is realized by the deep neural network (DNN). Comparisons of the model with climatology results, persistence predictions, other data-driven model results, and the hybrid coordinate ocean model (HYCOM) forecasts show that the ELD model has good prediction performance for the Arctic SIC on mid- and long-term time scales. When the forecast time is 100 days, the forecast root-mean-square error (RMSE), Pearson correlation coefficient (PCC), and anomaly correlation coefficient (ACC) of the ELD model are 0.2, 0.77, and 0.74, respectively.
Long-Term and Bimonthly Estimation of Lake Water Extent Using Google Earth Engine and Landsat Data
Authors: Zhang Tao , Wang Hongxing , Hu Shanshan , You Shucheng , Yang Xiaomei
Published: June 2022

Lakes are one of the most important parts of the terrestrial hydrosphere. The long-term series of lake area dynamic data with high spatial-temporal resolution is of great significance to the study of global change of the water environment. Satellite observations (such as Landsat) have provided images since the 1970s, but there were challenges for the construction of long-term sequences of lake area on a monthly temporal scale. We proposed a temporal-spatial interpolation and rule-based (TSIRB) approach on the Google Earth Engine, which aims to achieve automatic water extraction and bimonthly sequence construction of lake area. There are three main steps of this method which include bimonthly image sequence construction, automatic water extraction, and anomaly rectification. We applied the TSIRB method to five typical lakes (covering salt lakes, river lagoons, and plateau alpine lakes), and constructed the bimonthly surface water dataset (BSWD) from 1987 to 2020. The accuracy assessment that was based on a confusion matrix and random sampling showed that the average overall accuracy (OA) of water extraction was 96.6%, and the average Kappa was 0.90. The BSWD sequence was compared with the lake water level observation data, and the results show that the BSWD data is closely correlated with the water level observation sequence, with correlation coefficient greater than 0.87. The BSWD improves the hollows in the global surface water (GSW) monthly data and has advantages in the temporal continuity of surface water data. The BSWD can provide a 30-m-scale and bimonthly series of surface water for more than 30 years, which shows good value for the long-term dynamic monitoring of lakes, especially in areas that are lacking in situ surveying data.
Landslide Deformation Extraction from Terrestrial Laser Scanning Data with Weighted Least Squares Regularization Iteration Solution
Authors: Zhao Lidu , Ma Xiaping , Xiang Zhongfu , Zhang Shuangcheng , Hu Chuan , Zhou Yin , Chen Guicheng
Published: June 2022

The extraction of landslide deformation using terrestrial laser scanning (TLS) has many important applications. The landslide deformation can be extracted based on a digital terrain model (DTM). However, such methods usually suffer from the ill-posed problem of a multiplicative error model as illustrated in previous studies. Moreover, the edge drift of commonly used spherical targets for point cloud registration (PCR) is ignored in the existing method, which will result in the unstable precision of the PCR. In response to these problems, we propose a method for extracting landslide deformations from TLS data. To archive the PCR of different period point clouds, a new triangular pyramid target is designed to eliminate the edge drift. If a fixed target is inconvenient, we also propose a PCR method based on total station orientation. Then, the use of the Tikhonov regularization method to derive the weighted least squares regularization solution is presented. Finally, the landslide deformation is extracted by DTM deference. The experiments are conducted on two datasets with more than 1.5 billion points. The first dataset takes Lashagou NO. 3 landslide in Gansu Province, China, as the research object; the point cloud data were collected on 26 February 2021 and 3 May 2021. The registration accuracy was 0.003 m based on the permanent triangular pyramid target and 0.005 m based on the total station orientation. The landslide deforms within 3 cm due to the ablation of the frozen soil. The second dataset is TLS data from the Lihua landslide in Chongqing, China, collected on 20 April 2021 and 1 May 2021. The overall deformation of the Lihua landslide is small, with a maximum value of 0.011 m. The result shows that the proposed method achieves a better performance than previous sphere-based registration and that the weighted least square regularization iterative solution can effectively reduce the ill-condition of the model.
A Novel Method for Long Time Series Passive Microwave Soil Moisture Downscaling over Central Tibet Plateau
Authors: Jiang Hongtao , Chen Sanxiong , Li Xinghua , Wu Jingan , Zhang Jing , Wu Longfeng
Published: June 2022

The coarse scale of passive microwave surface soil moisture (SSM) is not suitable for regional agricultural and hydrological applications such as drought monitoring and irrigation management. The optical/thermal infrared (OTI) data-based passive microwave SSM downscaling method can effectively improve its spatial resolution to fine scale for regional applications. However, the estimation capability of SSM with long time series is limited by OTI data, which are heavily polluted by clouds. To reduce the dependence of the method on OTI data, an SSM retrieval and spatio-temporal fusion model (SMRFM) is proposed in the study. Specifically, a model coupling in situ data, MODerate-resolution Imaging Spectro-radiometer (MODIS) OTI data, and topographic information is developed to retrieve MODIS SSM (1 km) using the least squares method. Then the retrieved MODIS SSM and the spatio-temporal fusion model are employed to downscale the passive microwave SSM from coarse scale to 1 km. The proposed SMRFM is implemented in a grassland dominated area over Naqu, central Tibet Plateau, for Advanced Microwave Scanning Radiometer—Earth Observing System sensor (AMSR-E) SSM downscaling in unfrozen period. The in situ SSM and Noah land surface model 0.01° SSM are used to validate the estimated MODIS SSM with long time series. The evaluations show that the estimated MODIS SSM has the same temporal resolution with AMSR-E and obtains significantly improved detailed spatial information. Moreover, the temporal accuracy of estimated MODIS SSM against in situ data (r = 0.673, μbRMSE = 0.070 m3/m3) is better than the AMSR-E (r = 0.661, μbRMSE = 0.111 m3/m3). In addition, the temporal r of estimated MODIS SSM is obviously higher than that of Noah data. Therefore, this suggests that the SMRFM can be used to estimate MODIS SSM with long time series by AMSR-E SSM downscaling in the study. Overall, the study can provide help for the development and application of microwave SSM-related scientific research at the regional scale.
Spatiotemporal Variations of Forest Vegetation Phenology and Its Response to Climate Change in Northeast China
Authors: Zheng Wenrui , Liu Yuqi , Yang Xiguang , Fan Wenyi
Published: June 2022

Vegetation phenology is an important indicator of vegetation dynamics. The boreal forest ecosystem is the main part of terrestrial ecosystem in the Northern Hemisphere and plays an important role in global carbon balance. In this study, the dynamic threshold method combined with the ground-based phenology observation data was applied to extract the forest phenological parameters from MODIS NDVI time-series. Then, the spatiotemporal variation of forest phenology is discussed and the relationship between phenological change and climatic factors was concluded in the northeast China from 2011 to 2020. The results indicated that the distribution of the optimal extraction threshold has spatial heterogeneity, and the changing rate was 3% and 2% with 1° increase in latitude for SOS (the start of the growing season) and EOS (the end of the growing season). This research also notes that the SOS had an advanced trend at a rate of 0.29 d/a while the EOS was delayed by 0.47 d/a. This variation of phenology varied from different forest types. We also found that the preseason temperature played a major role in effecting the forest phenology. The temperature in winter of the previous year had a significant effect on SOS in current year. Temperature in autumn of the current year had a significant effect on EOS.
A Framework for Assessing the Dynamic Coastlines Induced by Urbanization Using Remote Sensing Data: A Case Study in Fujian, China
Authors: Wu Wenting , Gao Yiwei , Chen Chunpeng , Sun Yu , Su Hua
Published: June 2022

The coastline plays an important role in indicating the conditions of social-economic development in the coastal zone. In this study, an integrated assessment framework was proposed to address the provincial and county-level spatiotemporal dynamics of continental coastlines from the perspectives of length, position, composition, and anthropogenic utilization quantitatively, and to explore the exact impacts of urbanization on coastline changes in the Fujian Province over the period from 1985 to 2020. Results showed that the total length of coastlines decreased first and then increased due to the different patterns of economic development. The proportion of artificial coastlines and the index of coastal utilization degree increased rapidly during the same period. Moreover, the seaward movement of coastlines due to the coastal reclamation projects resulted in a considerable increment in land areas. The pressure brought by the continuous concentration of population, built-up areas, and industrial districts under the rapid urbanization was the primary factor that increased the degree of anthropogenic disturbances in the coastal zone. Furthermore, the policies issued by the local or central government can be critical tipping points for coastline changes in different periods.
Evaluasi Kapasitas Kolam Retensi Cieunteung Sebagai Upaya Mereduksi Banjir Baleendah, Kabupaten Bandung
Authors: Fitriani Asri Annisa , Pratiwi Vitta
Published: June 2022

Banjir di Baleendah, Kabupaten Bandung disebabkan oleh beberapa faktor diantaranya daerah yang berada di topografi cekung, curah hujan tinggi dan penyempitan badan sungai, sehingga dibutuhkan upaya pengendalian. Kolam retensi Cieunteung sebagai bangunan pengendali banjir dengan volume sebesar 235.092,04 mÂ³ berfungsi sebagai tampungan sementara untuk mengurangi debit banjir di kawasan ini nyatanya masih belum berfungsi secara maksimal. Penelitian ini bertujuan untuk menganalisis kondisi eksisting di lokasi penelitian dalam hal ini sungai-sungai yang berpengaruh di sekitar lokasi penelitian dan efektivitas kolam retensi Cieunteung sebagai bangunan pengendali banjir. Pada penelitian, analisis hidrologi menggunakan data curah hujan periode 15 tahun, guna mendapatkan debit banjir rencana dengan berbagai periode ulang. Analisis debit banjir rencana menggunakan metode HSS Nakayasu, Snyder dan SCS-USA. Analisis hidrolika menggunakan software HEC-RAS 5.0.7 untuk memodelkan berbagai skenario alternatif penanganan banjir.

Berdasarkan hasil analisis, efektivitas kolam retensi Cieunteung sebesar 30,18% dan mampu mereduksi banjir 11,89%. Direkomendasikan alternatif penanganan banjir yaitu Skenario 2 (kolam retensi tambahan dan normalisasi dasar sungai) untuk Sungai Cigado dengan % reduksi 62,62%. Skenario 3 (normalisasi dasar sungai, tanggul sungai dan kolam retensi baru) untuk Sungai Cisangkuy dengan % reduksi 19,51%. Skenario 2 (normalisasi dasar dan tanggul sungai) untuk Sungai Citarum dengan % reduksi 0,0012%.
ANALISIS DAERAH RAWAN KECELAKAAN DI JALAN KOLEKTOR PRIMER KABUPATEN SUKABUMI
Authors: Aulia M Donie
Published: June 2022

Banyaknya jumlah kendaraan bermotor yang meningkat dari tahun ke tahun merupakan faktor pendukung meningkatnya jumlah kecelakaan lalu lintas di Kabupaten Sukabumi. Dengan kondisi tersebut diperlukan upaya untuk mengetahui daerah rawan kecelakaan (blacksite) dan titik rawan kecelakaan (blackspot). Hasil analisis Z-Score daerah rawan kecelakaan didapat satu ruas jalan dengan kriteria rawan kecelakaan sangat tinggi, yaitu ruas jalan Cikidang dengan nilai Z-Score sebesar 1, sedangkan pada ruas jalan Surya Kencana memiliki kriteria tidak rawan kecelakaan dengan nilai Z-Score sebesar -1. Pada hasil analisis Cusum lokasi titik rawan kecelakaan terdapat blackspot dengan kriteria rawan kecelakaan sangat rendah, yaitu pada ruas jalan desa Sampora; Cijambe; Cikidang; Nangka Koneng; Pangkalan dan Cibadak
Satellite Remote Sensing of Savannas: Current Status and Emerging Opportunities
Authors: Abdi Abdulhakim M. , Brandt Martin , Abel Christin , Fensholt Rasmus
Published: June 2022

Savannas cover a wide climatic gradient across large portions of the Earth’s land surface and are an important component of the terrestrial biosphere. Savannas have been undergoing changes that alter the composition and structure of their vegetation such as the encroachment of woody vegetation and increasing land-use intensity. Monitoring the spatial and temporal dynamics of savanna ecosystem structure (e.g., partitioning woody and herbaceous vegetation) and function (e.g., aboveground biomass) is of high importance. Major challenges include misclassification of savannas as forests at the mesic end of their range, disentangling the contribution of woody and herbaceous vegetation to aboveground biomass, and quantifying and mapping fuel loads. Here, we review current (2010–present) research in the application of satellite remote sensing in savannas at regional and global scales. We identify emerging opportunities in satellite remote sensing that can help overcome existing challenges. We provide recommendations on how these opportunities can be leveraged, specifically (1) the development of a conceptual framework that leads to a consistent definition of savannas in remote sensing; (2) improving mapping of savannas to include ecologically relevant information such as soil properties and fire activity; (3) exploiting high-resolution imagery provided by nanosatellites to better understand the role of landscape structure in ecosystem functioning; and (4) using novel approaches from artificial intelligence and machine learning in combination with multisource satellite observations, e.g., multi-/hyperspectral, synthetic aperture radar (SAR), and light detection and ranging (lidar), and data on plant traits to infer potentially new relationships between biotic and abiotic components of savannas that can be either proven or disproven with targeted field experiments.
A Self-Powered Optogenetic System for Implantable Blood Glucose Control
Authors: Liu Zhuo , Zhou Yang , Qu Xuecheng , Xu Lingling , Zou Yang , Shan Yizhu , Shao Jiawei , Wang Chan , Liu Ying , Xue Jiangtao , Jiang Dongjie , Fan Yubo , Li Zhou , Ye Haifeng
Published: June 2022

Diabetes treatment and rehabilitation are usually a lifetime process. Optogenetic engineered designer cell-therapy holds great promise in regulating blood glucose homeostasis. However, portable, sustainable, and long-term energy supplementation has previously presented a challenge for the use of optogenetic stimulation
in vivo
. Herein, we purpose a self-powered optogenetic system (SOS) for implantable blood glucose control. The SOS consists of a biocompatible far-red light (FRL) source, FRL-triggered transgene-expressing cells, a power management unit, and a flexible implantable piezoelectric nanogenerator (i-PENG) to supply long-term energy by converting biomechanical energy into electricity. Our results show that this system can harvest energy from body movement and power the FRL source, which then significantly enhanced production of a short variant of human glucagon-like peptide 1 (shGLP-1)
in vitro
and
in vivo
. Indeed, diabetic mice equipped with the SOS showed rapid restoration of blood glucose homeostasis, improved glucose, and insulin tolerance. Our results suggest that the SOS is sufficiently effective in self-powering the modulation of therapeutic outputs to control glucose homeostasis and, furthermore, present a new strategy for providing energy in optogenetic-based cell therapy.
Crystal Facet-Dependent Intrinsic Charge Separation on Well-Defined Bi
4
TaO
8
Cl Nanoplate for Efficient Photocatalytic Water Oxidation
Authors: Adenle Abraham , Shi Ming , Tao Xiaoping , Zhao Yue , Zeng Bin , Ta Na , Li Rengui
Published: June 2022

The development of photocatalysts with wide spectral absorption and high charge separation efficiency has always been a pursued objective for photocatalytic solar energy conversion. Herein, we reported a wide-range visible-light-active Bi
4
TaO
8
Cl (BTOC) single crystal nanoplate with dominating {110} and {001} facets for enhancing the intrinsic charge separation efficiency.
Insitu
selective photodeposition of metals and metal oxides provides evidences of photogenerated electrons and holes spatially separated on {110} and {001} coexposed facets of BTOC, respectively. The intrinsic charge separation efficiency was demonstrated to be closely dependent on the crystal facets, which can be modulated by tuning the coexposed crystal facet ratio. Further surface modification of BTOC with suitable dual cocatalyst Ag and RuO
x
enables remarkable improvement of charge separation efficiency and photocatalytic water oxidation performance. Investigation by comparison between well-defined BTOC nanoplate and BTOC nanoparticles confirmed the significance of coexposed crystal facets for efficient spatial charge separation and the blocking of reverse reaction from Fe
2+
to Fe
3+
ions during water oxidation reaction, indicating that rational modulation of exposed crystal facets is significant for controlling the intrinsic charge separation efficiency on Bi
4
TaO
8
Cl photocatalyst for efficient photocatalytic water splitting.
Network Analysis of Traditional Word of Mouth
Authors: Alexandrov Aliosha , Tippins Michael , Sen Sandipan
Published: June 2022

Network analysis of Word of Mouth (WOM) examines how customers exchange opinions within their social networks. Compared to standard survey questions, which typically measure the likelihood to recommend, the network approach provides more metrics (e.g., average path length, clustering coefficient, density, average degree) that can be used to diagnose customer chatter. Unfortunately, traditional WOM has not benefitted from network analysis, which usually is applied to online WOM due to the availability of stored data. Despite the pervasiveness of online WOM, however, recent commercial reports reveal that traditional WOM still surpasses online WOM by a large margin. Traditional WOM also is perceived as more trustworthy and persuasive than online WOM. Considering the strong standing of traditional WOM and the advances in network analysis due to online WOM, this study fills a gap by demonstrating how a network analysis can be applied to traditional WOM. Network analysis is more demanding on the researcher and the respondents, but as the study illustrates, it also is more diagnostic than a standard survey. A preliminary study confirmed that people, indeed, are more likely to share traditional WOM then online WOM. The main study utilized network analysis by using an alter-alter survey method, which was used to map the network structures of a variety of WOM networks. Specifically, we examined the WOM networks structure as a function of product type (search, experience, and credence products) and opinion valence (positive vs. negative). The results reveal that WOM is affected primarily by product type. People are most likely to share opinions about experience products, followed by opinions about search products, and least likely to talk about credence products. The effect of opinion valence is limited. Practitioners can use these findings to manage WOM primarily based on product type by including search, experience, or credence qualities in promotional messages.  This is the first study to compare WOM networks to the existing social network, which can serve as a benchmark for evaluating WOM campaigns. The results reveal that for most products, people do not utilize all of their social connections for WOM, but there are exceptions, such as sharing a positive opinion about a movie, where WOM chatter can exceed the social network. The study discusses the WOM network metrics from a practical perspective and how they can be used to optimize WOM campaigns. Overall, the conclusion is that network analysis is a viable technique for studying traditional WOM, which brings new research directions.