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Freshwater crabs play essential roles in the well-functioning of the inland aquatic ecosystems. However, due to the lack of sufficient molecular resources, the study of freshwater crabs has been greatly hindered. In this study, the mitochondrial genome of Huananpotamon koatenense, a freshwater crab endemic to China, was sequenced for the first time. This mitogenome sequence is 15,528 bp long, and contains 13 protein-coding genes, 2 rRNA genes and 22 tRNA genes. Phylogenetic analyses based on 25 mitogenomes showed that H. koatenense was clustered with the known congeneric species of H. lichuanense. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal CrystEngComm, which focuses on the design and understanding of solid-state and crystalline materials. The contents list includes various articles and papers on topics such as lithium-ion battery cathodes, crystal distribution during cooling crystallization, and the synthesis and optical properties of metal oxalates. The journal is published by The Royal Society of Chemistry, a leading chemistry community. The document also mentions approved training courses offered by the society. [Extracted from the article]

Nanoflake-assembled ZnWO4 yolk–shell microspheres (NFYM-ZnWO4) with a diameter of 1.5–2 μm and a wall thickness of about 300 nm have been rationally designed and prepared by a facile one-pot method, were composed of numerous nanoflakes (NFs) with a thickness of 10–15 nm and possessed large specific surface areas. The controlled experiments demonstrated that the novel NFYM-ZnWO4 were induced by the synergistic effects of ligands (L -aspartic acid, L -Asp) and mixed solvents (ethylene glycol, EG). Combined with the morphological evolution process, a rational mechanism was proposed to describe the nucleation, self-assembly and Ostwald ripening associated with the formation of NFYM-ZnWO4. Benefiting from yolk–shell features and large specific surface areas, the as-synthesized NFYM-ZnWO4 were evaluated as adsorbents. With a maximum adsorption capacity of 321.2 mg g−1, NFYM-ZnWO4 exhibited a high efficiency for Pb2+ removal in aqueous solution, which was over 5 times higher than the nanoparticle-assembled ZnWO4 yolk–shell microspheres (NPYM-ZnWO4). [ABSTRACT FROM AUTHOR]

AbstractCurrent study presents state of the art approach to risk and reliability assessment for multivariate nonlinear dynamic systems. Specifically, novel hypersurface Gaidai risks evaluation methodology has been presented for evaluating offshore structural risks. Advocated approach being particularly suitable for offshore engineering multidimensional dynamic systems, possessing large number of critical components, that have either been physically observed/measured, or numerically modeled over a representative timelapse. Advocated Gaidai hypersurface structural risks evaluation methodology is applicable for a wide range of engineering and industrial systems. This study demonstrates that given in situ environmental conditions, it is well possible to assess accurately risks of system’s failures, damages or hazards, caused by excessive structural dynamics. Multivariate dynamic systems, possessing nonlinear cross-correlations between critical system’s components often present design challenges, when utilizing classic structural risks evaluation approaches, as those are mostly only univariate or bivariate. Dynamic offshore Jacket hot spot stresses have been utilized as an example in this reliability investigation. Modeling system’s excessive dynamics is challenging because of the non-stationarity of the system and the intricacy of fluid-structural dynamic interactions, arising from in situ wave-induced loads, influencing Jacket’s structural dynamics. Nonlinearities greatly affect structural dynamics, e.g., 2nd, 3rd, higher order effects within fluid-structural interactions. Methodology presented in this work offers a straightforward, effective, yet precise means of assessing the risks of failure or hazard for multivariate, non-stationary, non-linear dynamic offshore systems. For bivariate case, verification note has been added. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Heterogeneous image change detection is a very practical and challenging task because the data in the original image have a large distribution difference and the labeled samples of the remote sensing image are usually very few. In this study, we focus on solving the issue of comparing heterogeneous images without supervision. This paper first designs a self-paced multi-scale joint feature mapper (SMJFM) for the mapping of heterogeneous data to similar feature spaces for comparison and incorporates a self-paced learning strategy to weaken the mapper's capture of non-consistent information. Then, the difference information in the output of the mapper is evaluated from two perspectives, namely noise robustness and detail preservation effectiveness; then, the change detection problem is modeled as a multi-objective optimization problem. We decompose this multi-objective optimization problem into several scalar optimization subproblems with different weights, and use particle swarm optimization to optimize these subproblems. Finally, the robust evaluation strategy is used to fuse the multi-scale change information to obtain a high-precision binary change map. Compared with previous methods, the proposed SMJFM framework has the following three main advantages: First, the unsupervised design alleviates the dilemma of few labels in remote sensing images. Secondly, the introduction of self-paced learning enhances SMJFM's capture of the unchanged region mapping relationship between heterogeneous images. Finally, the multi-scale change information fusion strategy enhances the robustness of the framework to outliers in the original data. [ABSTRACT FROM AUTHOR]

How hydrothermal factors and CO 2 concentration affect the vegetation carbon sink over time and across elevation gradients is crucial for carbon sequestration and enhancement, which remains unclear. Here, the temporal changes of the interannual relationship of net primary productivity (NPP) with hydrothermal factors and CO 2 concentration over elevation were revealed using ensemble empirical mode decomposition (EEMD) method and moving window-based multiple regression analysis during 1981–2018, in a case study of six provinces along the 'Maritime Silk Road' of China. We found that: (1) except for low-elevation farmland, the interannual relationship of vegetation NPP with CO 2 (R NPP-CO2), precipitation accumulation (R NPP-PA), soil moisture (R NPP-SM), downward surface shortwave radiation (R NPP-SR) and minimum temperature (R NPP-TMN) is mainly positive, while the relationship with maximum temperature (TMAX, R NPP-TMX) and vapor pressure deficit (VPD, R NPP-VPD) is mainly negative, indicating that most hydrothermal factors can increase NPP except TMAX and VPD. Most of the interannual relationship is strengthening, especially for thermal factor, indicating the strengthened impacts of hydrothermal factors and CO 2, while the weakening relationship with hydrological factors accounted for large areas, which cannot be ignored. (2) With increasing elevation, the positive R NPP-CO2 diminished, while the positive R NPP-SM and the negative R NPP-VPD amplified, indicating the positive impacts from CO 2 decreased, while those from SM and VPD increased. Meanwhile, R NPP-SR , R NPP-TMN , and R NPP-PA reversed from positive to negative, while R NPP-TMX reversals from negative to positive, indicating reversed impacts. (3) With increasing elevation, the temporal changes of positive R NPP-CO2 and R NPP-SM varied from weakening to strengthening and from strengthening to weakening, respectively, while those of R NPP-SR and R NPP-TMN together with R NPP-PA varied from strengthening positive to strengthening negative and weakening negative, respectively. Meanwhile, the strengthening negative of R NPP-TMX , and R NPP-VPD , changed to weakening positive and weakening negative, respectively. Our study highlights the importance of the divergent trends of the interannual relationship of NPP with hydrothermal factors and CO 2 concentration across elevation for accurate prediction of future carbon sink potential under global change. [Display omitted] • Interannual relationships between environmental factors and NPP were mostly positive. • Interannual relationship are strengthening, especially for thermal factors. • Elevation has significant effects on the temporal trends below 200m and above 1000m. • The relationship showed divergent trends across elevation. [ABSTRACT FROM AUTHOR]

Data mining technology is the process of extracting hidden knowledge and potentially useful information from a large number of incomplete, noisy, and random practical application data. The clustering algorithm based on multi-objective evolution has obvious advantages compared with the traditional single-objective method. In order to further improve the performance of evolutionary multi-objective clustering algorithms, this paper proposes a multi-objective automatic clustering model based on evolutionary multi-task optimization. Based on the multi-objective clustering algorithm that automatically determines the value of k, evolutionary multi-task optimization is introduced to deal with multiple clustering tasks simultaneously. A set of non-dominated solutions for clustering results is obtained by concurrently optimizing the overall deviation and connectivity index. Multi-task adjacency coding based on a locus adjacency graph was designed to encode the clustered data. Additionally, an evolutionary operator based on relevance learning was designed to facilitate the evolution of individuals within the population. It also facilitates information transfer between individuals with different tasks, effectively avoiding negative transfer. Finally, the proposed algorithm was applied to both artificial datasets and UCI datasets for testing. It was then compared with traditional clustering algorithms and other multi-objective clustering algorithms. The results verify the advantages of the proposed algorithm in clustering accuracy and algorithm convergence. [ABSTRACT FROM AUTHOR]

Geochemistry, Geophysics, Geosystems (G‐Cubed) is a respected Earth science journal that publishes research papers, methods, and coding applications. In 2023, the journal received 485 manuscripts and published 244 of them. The journal credits its success to the voluntary contributions of over 764 reviewers who provided more than 937 reviews. The journal expresses gratitude to the reviewers for their time and expertise, as their efforts ensure that the published papers meet the high standards expected by the research community. The journal welcomes feedback on its peer review process and anticipates exciting advancements in the field. Additionally, the document is a list of names of individuals who have contributed to a report or study, organized alphabetically. The purpose of the document is to acknowledge the participation of these individuals, who come from diverse fields, in the research or study. [Extracted from the article]

Copyright of Carsologica Sinica is the property of Institute of Karst Geology, CAGS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Carsologica Sinica is the property of Institute of Karst Geology, CAGS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: Acral melanoma (AM) is the most common subtype of malignant melanoma in China, with a very poor prognosis. Despite the frequent reporting of trauma events in AM cases, the precise etiology of AM remains elusive. Methods: A retrospective analysis was conducted on a cohort of 303 AM patients at Nanjing Drum Tower Hospital. The patients were categorized into four distinct groups based on different patterns of disease onset: trauma type (Type 1), pigmented nevus type (Type 2), pigmented nevi with trauma (Type 3), and pigmented nevi with natural ulceration (Type 4). Differences in clinicopathological features, genetic alterations, and tumor immune microenvironment (TIME) were analyzed. Results: Traumatic events accounted for a large proportion of AM cases. Among these categories, Type 1 patients displayed the least favorable pathological traits and an immunosuppressive TIME. Common copy number variations (CNVs) were observed in CCND1, RB1, FGF19, and IL7R, while CNVs in CDK4 and TERT occurred less frequently in patients with a history of trauma (Type 1 and Type 3). Type 2 patients exhibited the most favorable pathological characteristics and genetic profiles, and demonstrated the lowest incidence of CCDN1 and RB1 CNVs but had the highest CDK4 CNVs. In contrast, the pathological behavior of Type 3 and Type 4 patients was in between Type 1 and Type 2. And patients in Type 3 and Type 4 displayed a more favorable overall microenvironment. Conclusion: This study provides a clinical classification of Chinese AM based on diverse clinical onset characteristics and highlights the important role of trauma in AM. These findings may help to guide the diagnosis, treatment, and prognosis of AM patients. Further investigations are imperative to elucidate the underlying mechanisms governing the association between trauma and AM. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ecological Science is the property of Ecological Science Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Arctic sea ice is broadly regarded as an indicator and amplifier of global climate change. The rapid changes in Arctic sea ice have been widely concerned. However, the spatiotemporal changes in the horizontal and vertical dimensions of Arctic sea ice and its asymmetry during the melt and freeze seasons are rarely quantified simultaneously based on multiple sources of the same long time series. In this study, the spatiotemporal variation and freeze-thaw asymmetry of Arctic sea ice were investigated from both the horizontal and vertical dimensions during 1979–2020 based on remote sensing and assimilation data. The results indicated that Arctic sea ice was declining at a remarkably high rate of −5.4 × 104 km2/a in sea ice area (SIA) and −2.2 cm/a in sea ice thickness (SIT) during 1979 to 2020, and the reduction of SIA and SIT was the largest in summer and the smallest in winter. Spatially, compared with other sub-regions, SIA showed a sharper declining trend in the Barents Sea, Kara Sea, and East Siberian Sea, while SIT presented a larger downward trend in the northern Canadian Archipelago, northern Greenland, and the East Siberian Sea. Regarding to the seasonal trend of sea ice on sub-region scale, the reduction rate of SIA exhibited an apparent spatial heterogeneity among seasons, especially in summer and winter, i.e., the sub-regions linked to the open ocean exhibited a higher decline rate in winter; however, the other sub-regions blocked by the coastlines presented a greater decline rate in summer. For SIT, the sub-regions such as the Beaufort Sea, East Siberian Sea, Chukchi Sea, Central Arctic, and Canadian Archipelago always showed a higher downward rate in all seasons. Furthermore, a striking freeze-thaw asymmetry of Arctic sea ice was also detected. Comparing sea ice changes in different dimensions, sea ice over most regions in the Arctic showed an early retreat and rapid advance in the horizontal dimension but late melting and gradual freezing in the vertical dimension. The amount of sea ice melting and freezing was disequilibrium in the Arctic during the considered period, and the rate of sea ice melting was 0.3 × 104 km2/a and 0.01 cm/a higher than that of freezing in the horizontal and vertical dimensions, respectively. Moreover, there were notable shifts in the melting and freezing of Arctic sea ice in 1997/2003 and 2000/2004, respectively, in the horizontal/vertical dimension. [ABSTRACT FROM AUTHOR]

Exploring the effectiveness of the pilot project on comprehensive control of rock desertification since its launch by China's government is of great significance for regional sustainable development. Jointly affected by the karst surface-underground geological structure and human activities, the natural ecological environment is fragile in southwest Guangxi, with frequent droughts and floods, severe soil erosion and rock desertification. Consequently, the socio-economic development in this region is relatively lagging behind. With the support of national policies, southwest Guangxi has been comprehensively carrying out projects of controlling rocky desertification, promoting the control of rocky desertification and poverty alleviation in a coordinated manner. According to "Thirteenth Five-Year Plan for Comprehensive Control of Rocky Desertification in Karst Areas of Guangxi Zhuang Autonomous Region", southwest Guangxi is designated as an area for the control of cluster-peak depression, in which comprehensive control of rocky desertification has been carried out in terms of building ecological barriers, protecting biodiversity, and promoting the protection and the comprehensive utilization of water and soil resources. In order to further investigate the effectiveness of controlling rocky desertification in cluster-peak depression of southwest Guangxi, this study the physical exploration. Based on the correction of the data from the borehole, the parameter of geological radar, V, is taken to be 0.060 m•ns -1 which is applicable to the study area. The study results indicate that Biyun lake belongs to the oblique tectonic basin, where leakage points and underground river pipes are mainly developed close to the axis of the Babu compound oblique, along the lithological interface of three sections of greystone and the second section of the mudstone of Jialingjiang Group. The mudstone constitutes a water separating plate of the karst leakage zone. After lake water seeps along the zone, it flows northwest, and is discharged in the end at the outlet of the Babu underground river. In addition, the leakage of Biyun lake is mainly of the karst pipeline type. The karst leakage zone is located at the measuring point of 540 m, with a 40-meter- deep of karst pipeline; therefore, the leakage section is relatively narrow, and it is feasible to plug the leakage by grouting. The drilling test results confirm the reliability of the technical method used in karst areas, which is combined by hydrogeological investigation, tracer test and physical exploration, because this method can well determine the direction of the leakage channel and the location of the leakage zone, and thus providing guidance on the leakage control of lakes or reservoirs in karst areas. [ABSTRACT FROM AUTHOR]

Yunnan is located in the center of the east-Asian karst area, one of the three largest karst areas in the world. Rocky desertification is widespread in the area, which seriously restricts the sustainable development of local social economy. In this study, we summarize the research status and achievements of rocky desertification in Yunnan mainly from three aspects, rocky desertification zoning, governance model and vegetation restoration in rocky desertification areas. The results show that rocky desertification areas in Yunnan are divided into 2 large areas and 5 small ones. After years of exploration, 23 kinds in 4 categories of rocky desertification control models have been formed, and 435 kinds of plant species can be used for ecological restoration in rocky desertification areas, including 376 species of shrubs and 59 species of herbs. Finally, combined with geographical location, climate and altitude, this paper preliminarily summarizes the suitable restoration vegetation, and points out the shortcomings in the studies on the control of rocky desertification, so as to provide an important theoretical reference for the subsequent research on the restoration and control of rocky desertification vegetation. [ABSTRACT FROM AUTHOR]

The karst area in Southwest China is an important region for the implementation of sustainable development strategies in China, as well as an area with extremely fragile ecological environment and concentrated distribution of rocky desertification. As a "National Pilot Zone for Sustainable Development" and "National Pilot Demonstration Zone for the Innovative Sustainable Development Agenda", Gongcheng Yao autonomous county of Guangxi is an important demonstration area for the coordinated development of karst landscape resource conservation and special ecological agriculture. Therefore, exploring the spatiotemporal evolution and the driving mechanism of rocky desertification in this area can provide an important scientific basis for the comprehensive management of rocky desertification, and the protection and restoration of karst ecosystem in China's pilot zones for sustainable development. Based on remote sensing images of Landsat series satellite from 2000, 2005, 2010, 2015, and 2021, this study extracted information on rocky desertification by the interpretation of human-computer interaction, and quantitatively analyzed the spatiotemporal evolution law of rocky desertification in Gongcheng county. Meanwhile, by combining data of carbonate rock and land use, this study revealed the inherent driving mechanisms of geological conditions and land use changes about the evolution of rocky desertification in Gongcheng county. The study results show that the rocky desertification in Gongcheng county experienced three stages: accelerated deterioration from 2000 to 2005, rapid improvement from 2005 to 2015 and slow deterioration from 2015 to 2021. The total area of rocky desertification ranged from 88.96--229.55 km2. From 2000 to 2005, the rocky desertification in Gongcheng county shifted from no rocky desertification to mild and intermediate rock desertification, and reversely, it showed improvement from 2005 to 2021. The rocky desertification presented a spatial pattern of development from north to south in Gongcheng county. Xiling town, Lianhua town and Ping'an town were the main areas where rocky desertification occurred, accounting for 55.47%--61.31% of the total rocky desertification area of the county. In 2005 and 2010, when the rocky desertification was relatively severe, it was mainly at a moderate level in Xiling town, while it was mainly at a mild level in other years. In addition, the rocky desertification of Gongcheng county mainly occurred in the limestone area, accounted for 71.42%--75.85% of the total rocky desertification area of this county. But the rocky desertification area in orchards and shrub land accounted for 35.92%--39.21% and 31.77%--31.86% of the county's total area, respectively. The study results indicate that there exist strong karstification, severe soil erosion/leakage, and insufficient materials and slow rates of soil forming due to the wide distribution of pure limestone in Gongcheng county. Besides, the long-term cultivation of single economic fruit forests such as peaches and plums in orchards has led to a decline in fruit tree quality, and a large number of fruit trees have been cut down in recent years, resulting in an exacerbation of rocky desertification. Therefore, the local authority in Gongcheng county should consider constructing three-dimensional ecological planting model in the karst areas such as Xiling town, Lianhua town and Ping'an town during the comprehensive treatment of rocky desertification, so as to promote the coordinated and sustainable development of ecological industry, rocky desertification control and social economy. [ABSTRACT FROM AUTHOR]

Southwest China is one of the three largest continuous karst clusters in the world; therefore, studies on karst rocky desertification in this area are very important. For more than 20 years' control, the decreasing area and risk of karst rocky desertification has contributed to the continuous ecological improvement. Nowadays, studies on rocky desertification mainly focus on the eight provinces in Southwest China, which have been designated as rocky desertification monitoring areas by the Chinese government. After the first phase of the comprehensive control project for karst rocky desertification in 2016, the expansion trend of rocky desertification in the southwest region was effectively curbed. Subsequent articles published tend to focus on analyzing the current situation, comprehensive management, or species adaptability of rocky desertification monitoring areas. However, the Qinba region in Shaanxi Province is located outside the monitoring area. In the process of studying the karst geological relics of the Zhenba Sanyuan Tiankeng Group, signs of rocky desertification have been found, but there still exists a research gap in the investigation and research on karst rocky desertification in this area which is one of the areas with the richest biodiversity in China, known as "ecological lung", "central water tower" and "biological gene bank". Unfortunately, this area is burdened with poverty, so the investigation and study of karst rocky desertification in the Qinba region of Shaanxi Province is of great significance to ensure green and high-quality development and ecological civilization construction. In this paper, by analyzing the current situation of karst rocky desertification in Southwest China, we summarized its harm to the ecological environment and social economy, clarify natural and human factors resulting in rocky desertification, and integrate the typical treatment experience in Southwest China. We also introduce three technical methods, including remote sensing interpretation, UAV remote sensing survey and analysis of carbonate dissolution rate, to provide a scientific basis for studies on karst rocky desertification in the Qinba region of Shaanxi Province. Study results show that the area of karst rocky desertification in the Qinba region covers 63.37 km², and the areas of severe, moderate and mild rocky desertification cover 17.97 km², 21.60 km² and 23.80 km², respectively. Based on the survey results, there are both regional differences and some similarities in distribution patterns in the areas of rocky desertification development. Specifically, the degree of rocky desertification in the limestone area is more severe than that in the dolomite area. It is also more severe in the area with developed water system than that in the arid and semi-arid area, and the more active the new structure is, the more severe the rocky desertification is. Compared to the Southwest China, the degree of karst rocky desertification in the Qinba region of Shaanxi Province is relatively light, with a smaller distribution area, mainly due to the less rainfall in the study area. The karst rocky desertification in Beiyang mountain of Zhen'an county is the most severe, with an area of 7.28 km². In the 1960s, a large-scale free-range of livestock severely damaged vegetation. The indiscriminate deforestation by humans further exacerbated the process of rocky desertification. The rocky desertification in Hailuogong village of Shanyang county is also severe, covering an area of 5.83 km², because the landform in this area is a typical peak-cluster depression, which is likely developed into rocky desertification. The contradiction between people and land needs to be solved urgently. In conclusion, more monitoring and research efforts are needed in Beiyang mountain and Hailuogong where the rocky desertification is severe. Firstly, we should clarify the causes of rocky desertification in the Qinba region and compare them with the causes in Southwest China to determine whether the rocky desertification is mainly resulted from natural factors or human factors. Secondly, we should know how to clarify the causes of karst rocky desertification in the Qinba region; for example, we can dynamically monitor the change of rock desertification by field verification, remote sensing interpretation, climate change analysis, etc. We can also calculate the contribution rate of each influence factor by geographical detector model. Thirdly, we should further study influence factors of karst dissolution rate. We can monitor physical and chemical properties of soil (soil moisture, carbon dioxide concentration, pH, organic matter content and porosity) in areas with moderate to severe rocky desertification, and analyze the relationship between dissolution rate and physical and chemical properties of soil in rocky desertification areas. Finally, in order to provide basic data for carbon neutrality research in Shaanxi, we should conduct studies on the carbon sink of rocky desertification areas in the Qinba region, with the methods such as dissolution test pieces and hydrochemical runoff. [ABSTRACT FROM AUTHOR]

If the tunnel construction work is done in the karst area, the tunnel shall keep a certain distance from the karst cave to ensure the stability of the surrounding rock and support. If the distance between the tunnel and the filled karst cave with high water pressure is short, it is easy to cause the instability and damage of tunnel face or the circumferential surrounding rock, thus resulting in karst water inrush, mud inrush, collapse and other disasters. Especially, the karst cave concealing around the tunnel is often difficult to be accurately predicted. Therefore, the study of the critical safety distance between the karst cave and the tunnel plays a vital role in the evaluation and prevention of disasters caused by concealing filled karst cave. Studies on the critical safety distance between tunnel and karst cave can be divided into qualitative research, semi-quantitative research and quantitative research. Qualitative research, such as judging the influence degree of karst cave on tunnel through numerical analysis, is generally conducted to comprehensively analyze the factors affecting the stability of structure for water burst prevention and obtain the empirical critical safety value. Semi-quantitative research mainly focuses on theoretical calculation, which can be roughly sub-divided into three types: simplified beam slab model based on strength theory, catastrophe theory model and the model of crack tension-compression shear based on fracture mechanics. Mainly focusing on numerical simulation, quantitative research is conducted to set up multiple groups of numerical tests for calculation, and to obtain the calculation model of safety distance through linear regression. The safety distance between the tunnel and the filled karst cave can be explored by theoretical calculation and numerical simulation test. Based on the bending and shear strength theory, the mechanical calculation models of the filled karst cave at the top, bottom and side of the tunnel are established by using the fixed beam model at both ends. Meanwhile, the self-weight of the internal filler and the pore water pressure are taken into account. Given the influence of the surrounding rock pressure above the karst cave on the waterproof rock stratum, the critical safety distance between the tunnel and the karst cave can be explored, and the calculation formula of the distance in different circumferential positions can be deduced. However, this formula does not consider the excavation effect of the tunnel and the process of support, nor can it reflect the changes of the displacement, stress and plastic zone of the surrounding rock. Therefore, it is difficult to obtain a universal formula to express relationship. It is necessary to supplement the predicted safety distance with the help of numerical simulation. In this study, the numerical model of the critical safety distance between the filled karst cave and the tunnel at different circumferential positions was established by FLAC 3D software. Based on the method of orthogonal experimental design (a total of 48 numerical test schemes), the stability of surrounding rock has been evaluated by the distribution range of plastic zone of surrounding rock caused by tunnel excavation. If the plastic zone connects the tunnel with the karst cave, the distance between these two indicates that the surrounding rock is unstable, and thereby the critical safety distance can be calculated. The results of critical safety distance under different working conditions were also analyzed by range analysis and variance analysis. Besides, the law and significance of three influencing factors--the level of surrounding rock, the water pressure in karst cave and the karst cave size--on the critical safety distance were explored. Through the nonlinear multiple regression analysis of the orthogonal test results, the prediction formula of the critical safety distance between the filled karst cave and the tunnel at different circumferential positions was established respectively. The results show that the critical safety distance increases with the increase of surrounding rock level, pressure of karst cave water and the karst cave size. The comprehensive influence degree of the three factors can be ranked from the strongest to the weakest as follows: the surrounding rock level, the pressure of karst cave water and karst cave size. Finally, the research results were applied to Yangzong tunnel project to verify the rationality and applicability of the prediction model of critical safety distance. The results show that the safety distance predicted based on the strength theory is relatively conservative, and the predicted results based on the numerical test are close to the reserved distance. The predicted results have a certain reference for the project of karst tunnel with water abundance. [ABSTRACT FROM AUTHOR]

The cosmic-ray neutron sensing (CRNS) is an emerging method for continuously monitoring soil water content (SWC) at an intermediate scale. However, when multiple hydrologic units are present within its footprint, the potential application of CRNS in water resources management is restricted. Here we propose a new strategy to predict point-scale SWC in root zone established on CRNS-based soil moisture and improved relative difference method. A total of 768 days of soil moisture data were collected by CRNS at the intermediate scale and EC-TM sensors at the point scale in a karst catchment. The original and improved mean relative difference methods predicted point-scale SWCs within and without the effective measuring depth, respectively. The mean effective measuring depth was 13.16 cm, ranging from 10.13 to 19.23 cm. Both land use type and soil structure played essential roles in regulating point scale SWC in the soil profile. Point-scale SWC in root zone can be predicted accurately (P < 0.001) based on SWC data derived from the CRNS system. The prediction accuracy of point scale SWC can be improved by increasing the averaging time of the soil moisture values. Our results demonstrated that the proposed strategy was reliable for CRNS to predict SWC beyond the effective measurement depth. This study provides a good perspective for effectively managing of water resources in areas with complex hydrological processes. • Both land use type and soil structure have important effects on soil moisture. • CRNS can accurately predict deep soil moisture at point scale. • The prediction accuracy of soil moisture can be improved by increasing averaging time. • CRNS is an effective tool for water resources management in small watershed. [ABSTRACT FROM AUTHOR]

Green construction is an advanced concept and development trend in engineering construction. It is cold and arid in frigid plateau regions in western China, where the ecological environment is vulnerable to engineering constructions and other human activities. Hence, the time and cost for environmental remediation are much larger than in other areas. Based on the principles and category of green construction, this paper discusses the overall and partial relationship between green construction and green construction operation, presents the technical construction process of the green construction of a tunnel, and puts forward the key points of green construction with the construction practice for tunnels in frigid plateau regions as the engineering background. The main contents and results are as follows: (1) The breakthrough points of the research on green construction include five first-level evaluation indicators of savings the land, energy, water resources, materials, and human resources, as well as protection for personnel health and environment, i.e., five savings and two protections. A comprehensive evaluation system suitable for green construction is proposed and established. (2) The paper summarizes the following essential aspects: the fine classification and safety evaluation of surrounding rock, the changes in the seepage field in the construction process, and the establishment of a standardized construction system. (3) A green construction evaluation was conducted on the tunnel of the Yindajihuang Project, and the green evaluation results were obtained. The evaluation results are basically consistent with the actual situation. In addition, intelligent construction technology should be the orientation of green construction for tunnels. The research would be helpful to the implementation of green construction ideas and technologies for tunnels in frigid plateau regions and the persistence of green and sustainable development. [ABSTRACT FROM AUTHOR]

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Experimental research was carried out to investigate the characteristics of tip vortex cavitation (TVC) caused by tip vortex in an oscillating hydrofoil. Shanghai Shipping and Research Institute's looped cavitation tunnel served as the site of the experiments. The hydrofoil used as the test was NACA (National Advisory Committee for Aeronautics) 63820. Two high-speed cameras, one torque sensor, and six hydrophones were employed to capture the cavitation patterns, the torque exerted on the hydrofoil, and the cavitation noise, respectively. The cavitation flow under static angle of attack (AoA) and the dynamic AoA have all been investigated in order to have a better knowledge of the differences between the TVC surrounding these two conditions. The AoA of 8.5°, 10°, and 14.5° and the AoA range of 1.8°–16° were selected for the static condition research and the dynamic condition study, respectively. A tip vortex flow was created between the tip of the stationary hydrofoil and the ceiling of the tunnel test section. To investigate the impact of the cavitation number on the growth of TVC surrounding the pitching hydrofoil, various pressure environments were built up. As for the experiment environment, cavitation numbers 2.47, 2.00, and 1.66 were used. The results indicate: (1) under static conditions, decreasing cavitation and increasing AoA lead to increased stability and topological complexity of TVC. (2) Comparing and analyzing cavitation patterns during the ascending, static, and descending processes reveal that the strongest cavitation intensity during the descending process, followed by static conditions, with the least intensity during the ascending process. (3) The frequency properties under pitching motion include those of each static AoA condition, although the acoustic characteristic of higher AoA has a stronger influence on that of dynamic condition. [ABSTRACT FROM AUTHOR]

Copyright of Carsologica Sinica is the property of Institute of Karst Geology, CAGS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Carsologica Sinica is the property of Institute of Karst Geology, CAGS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Carsologica Sinica is the property of Institute of Karst Geology, CAGS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Lithium‐sulfur (Li‐S) batteries have been regarded as promising next‐generation energy storage systems due to their high energy density and low cost, but their practical application is hindered by inferior long‐cycle stability caused by the severe shuttle effect of lithium polysulfides (LiPSs) and sluggish reaction kinetics. This study reports a La2O3‐MXene heterostructure embedded in carbon nanofiber (CNF) (denoted as La2O3‐MXene@CNF) as a sulfur (S) host to address the above issues. The unique features of this heterostructure endow the sulfur host with synergistic catalysis during the charging and discharging processes. The strong adsorption ability provided by the La2O3 domain can capture sufficient LiPSs for the subsequent catalytic conversion, and the insoluble thiosulfate intermediate produced by hydroxyl terminal groups on the surface of MXene greatly promotes the rapid conversion of LiPSs to Li2S via a "Wackenroder reaction." Therefore, the S cathode with La2O3‐MXene@CNF (La2O3‐MXene@CNF/S) exhibits excellent cycling stability with a low capacity fading rate of 0.031% over 1000 cycles and a high capacity of 857.9 mAh g−1 under extremely high sulfur loadings. Furthermore, a 5 Ah‐level pouch cell is successfully assembled for stable cycling, which delivers a high specific energy of 341.6 Wh kg−1 with a low electrolyte/sulfur ratio (E/S ratio). [ABSTRACT FROM AUTHOR]

In this study, a statistical analysis of historical and projected values of the annual, seasonal, and supra-seasonal precipitation concentration index (PCI) was conducted for different stations in the Cheliff watershed. Statistical methods such as breakpoint and trend analysis using Pettitt and Mann–Kendall tests were used for the PCI values of annual, monthly, and supra-seasonal precipitation data between 1950 and 2014. The PCI values varied between 14.24% and 24.86% annually, between 10.75% and 18.74% seasonally, and between 11.23% and 26.98% supra-seasonally. According to the Pettitt and Mann–Kendall tests, there was an insignificant change in precipitation distribution during the study period. Spatial analysis using the inverse distance weighting (IDW) method confirmed the minor variability in precipitation distribution in the study area. The Pearson correlation coefficient between oscillation indices and PCI values at different scales showed significant values with the Mediterranean Oscillation index (MOi), North Atlantic Oscillation (NAO), and Western Mediterranean Oscillation index (WeMOi), highlighting their potential influence on annual PCI values. For the climate projection scenarios, projected PCI values align with historical PCI values. Application of Pettitt and Mann-Kendall tests to the projected PCI series shows that there will not be a significant change in future precipitation distribution. [ABSTRACT FROM AUTHOR]

Copyright of Arid Land Geography is the property of Chinese Academy of Sciences, Xinjiang Institute of Ecology & Geography and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to solve problems with conventional in-house fracturing fluid friction test device, such as small size, low pipe flow velocity, and large difference from the real flow situation on site, we use a large-scale field experimental simulation method and the fracturing pump truck as the power source to realize the friction resistance test of fracturing fluid under ultra-high-speed flow, and test a total of 16 groups of fracturing fluid samples. The results show that the friction properties of fracturing fluids prepared with different kinds of polymers are obviously different. The drag reduction rate of low-viscosity fracturing fluid and medium viscosity fracturing fluid show 4 kinds of trend with the increase of flow rate: decreasing linearly, increasing linearly, increasing first and then decreasing, and decreasing first and then increasing. The experimental device adopts a pipeline system with multiple pipe diameters and lengths, and the experimental flow rate can reach up to 100 m/s. It is currently the highest flow rate fracturing fluid flow testing experimental device known in China, which can meet the experimental requirements of future on-site large displacement construction. The experimental results have important guiding significance for the field application of fracturing fluid. [ABSTRACT FROM AUTHOR]

Aims: Slope position affects soil nutrients and plant diversity, thereby altering arbuscular mycorrhizal fungi (AMF) communities. However, the effect of slope position on the relationship between plant diversity, soil nutrients, and AMF communities remains unclear. Methods: We characterized soil physicochemical properties, plant diversity, and the colonization, diversity, and composition of AMF on the upper, middle, and lower slopes of karst shrub ecosystems. Results: A lower slope increased the availability of soil nutrients such as available nitrogen, phosphorus, and potassium in the rainy and warm seasons. Slope position influenced AMF colonization and plant diversity. Specifically, plant richness was higher on lower and middle slopes than on upper slopes. AMF colonization intensity was higher on the lower and middle slopes than on the upper slope, and increased in the rainy and warm seasons compared to the that in the dry and cool seasons. Greater nodes and edges among AMF taxa caused more connection and complexity in the co-occurrence networks on lower and middle slopes than on upper slopes. The lower slope had relatively high available nutrients, soil thickness, and strong water capacity that improved plant growth, which in turn enhanced AMF colonization because of the mutually beneficial relationship between AMF and plants. Conclusions: Our results demonstrated that lower and middle slopes increase AMF colonization and interactions among AMF taxa by inducing plant growth with high diversity under rich soil nutrient conditions. Therefore, strengthening the colonizing strategies of AMF may substantially improve nutrient uptake and transfer during the recovery of abandoned agricultural lands. [ABSTRACT FROM AUTHOR]

Copyright of Carsologica Sinica is the property of Institute of Karst Geology, CAGS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Carsologica Sinica is the property of Institute of Karst Geology, CAGS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Oil Drilling & Production Technology / Shiyou Zuancai Gongyi is the property of Shiyou Zuancai Gongyi Bianjibu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Straw return in rice (Oryza sativa L.) paddy has been heavily criticized for its potential to influence ammonia (NH3) volatilization loss due to irrational fertilizer N application. Therefore, improving the N fertilization strategies within residue straw systems is necessary to reduce N loss from NH3 volatilization. This study investigated how the incorporation of oilseed rape straw and the urease inhibitor affected NH3 volatilization, fertilizer N use efficiency (FNUE), and rice yields over two growing seasons (2018–2019) in the purple soil region. This study arranged eight treatments combined straw (2, 5, 8 ton ha−1, named 2S, 5S, 8S, respectively), with urea or urease inhibitor (UI, 1% NBPT) with three replicates, which included control (CK), UR (Urea, 150 kg N ha−1), UR + 2S, UR + 5S, UR + 8S, UR + 2S + UI, UR + 5S + UI, UR + 8S + UI, based on the randomized complete block method. Our results indicated that incorporating oilseed rape straw increased NH3 losses by 3.2–30.4% in 2018 and 4.3–17.6% in 2019 than the UR treatment, attributing to the higher NH4+-N content and pH value within floodwater. However, the UR + 2S + UI, UR + 5S + UI and UR + 8S + UI treatments reduced NH3 losses by 3.8%, 30.3%, and 8.1% in 2018 and 19.9%, 39.5%, and 35.8% in 2019, separately compared to their corresponding UR plus straw treatments. According to the findings, adding 1% NBPT significantly decreased NH3 losses while incorporating 5 ton ha−1 oilseed rape straw. Furthermore, adding straw, either alone or in conjunction with 1% NBPT, increased rice yield and FNUE by 0.6–18.8% and 0.6–18.8%, respectively. Otherwise, NH3 losses scaled by yield in the UR + 5S + UI treatment decreased significantly between all treatments in 2018 and 2019. These results suggest that optimizing the oilseed rape straw rate combined with 1% NBPT applied with urea efficiently increased rice yield and reduced NH3 emissions in the purple soil region of Sichuan Province, China. [ABSTRACT FROM AUTHOR]

Copyright of Carsologica Sinica is the property of Institute of Karst Geology, CAGS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Carsologica Sinica is the property of Institute of Karst Geology, CAGS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• N addition increased the rates of most N transformation processes in the valley. • N addition decreased the rates of most N transformation processes on the slope. • Topography modulates effects of N deposition on soil N transformations. Soil nitrogen (N) transformations play key roles in ecosystem productivity and other functions of terrestrial ecosystems via regulating soil N availability. Although the effects of elevated atmospheric N deposition on soil N transformations have been intensively investigated, it remains unclear whether the effects are mediated by topography, which impacts multiple soil abiotic and biotic properties. Here, we conducted an N addition experiment consisting of three treatments: control (0 kg N ha−1 yr−1), moderate N addition (50 kg N ha−1 yr−1), and high N addition (100 kg N ha−1 yr−1) in the valley and on the slope, respectively, of a subtropical karst forest. Under the control, protein depolymerization, amino acid uptake, nitrification and dissimilatory nitrate reduction to ammonium (DNRA) rates were significantly higher on the slope than in the valley attributed to the higher soil dissolved organic carbon, total dissolved N and pH on the slope. Nitrogen addition significantly increased the rates of protein depolymerization, amino acid uptake, mineralization, nitrification and DNRA through alleviating microbial carbon limitation in the valley, but decreased the rates of depolymerization, amino acid uptake, mineralization and DRNA by enhancing microbial carbon and phosphorus limitations on the slope. The increase in soil N transformations, microbial N use efficiency (NUE) and microbial biomass N but lowered microbial N turnover time resulted in a 94 % increase of total microbial necromass N in the valley under N addition. However, increase in NUE and microbial biomass N led to a 33 % decrease of necromass N due to enhanced microbial necromass destabilization on the slope under N addition. Our results suggest that the responses of soil N transformations to N addition may be mediated by topography, and hence highlight the importance of incorporating topography into Earth system models to better predict soil N dynamics in forest in the context of elevated atmospheric N deposition. [ABSTRACT FROM AUTHOR]

• Runoff and sediment yield responded to karst distribution patterns. • KC, COHESION, LPI, and SPLIT dominantly influenced runoff generation. • A highly fragmented carbonate rock landscape effectively increased runoff. • Distribution patterns explained more variations in runoff than sediment yield. Aquatic karst landscapes are highly heterogeneous and vulnerable to environmental conditions due to carbonate rock dissolution by flowing water, freshwater movement and sediment transport. However, the landscape metrics commonly used in landscape ecology do not consider the spatial distribution of carbonate rocks in karst watersheds because these metrics are derived from land use/land cover maps. Therefore, this study investigated the effects of distribution patterns of karst landscapes on annual runoff and sediment yield in 40 heterogeneous karst watersheds in southwest China. The results show that the distribution patterns of karst landscapes significantly influenced annual runoff and sediment yield. A general linear model explained 74% of the runoff variations, indicating that the distribution pattern was the principal factor affecting runoff. Although these patterns significantly affected sediment yield, the general linear model accounted for only 52% of the sediment yield variations. Thus, the distribution patterns showed larger effects on runoff than sediment yield. This may be because landscape metrics of karst distribution patterns could not fully reflect the three-dimensional (3D) hydrogeological structure of karst watersheds. It is necessary to investigate the effects of 3D hydrogeological structures and hydrological and sediment connectivity on sediment yield. This will facilitate a more in-depth understanding of soil erosion mechanisms in karst watersheds. [ABSTRACT FROM AUTHOR]

At the northern Cascadia subduction zone, the subducting Explorer and Juan de Fuca plates interact across a transform deformation zone, known as the Nootka fault zone (NFZ). This study continues the Seafloor Earthquake Array Japan Canada Cascadia Experiment to a second phase (SeaJade II) consisting of nine months of recording of earthquakes using ocean-bottom and land-based seismometers. In addition to mapping the distribution of seismicity, including an MW 6.4 earthquake and aftershocks along the previously unknown Nootka Sequence Fault, we also conducted seismic tomography, which delineates the geometry of the shallow subducting Explorer plate (ExP). We derived hundreds of high-quality focal mechanism solutions from the SeaJade II data. The mechanisms manifest a complex regional tectonic state, with normal faulting of the ExP west of the NFZ, left-lateral strike-slip behaviour of the NFZ, and reverse faulting within the overriding plate above the subducting Juan de Fuca plate. Using data from the combined SeaJade I and II catalogs, we have performed double-difference hypocentre relocations and found seismicity lineations to the southeast of, and oriented 18° clockwise from, the subducted NFZ, which we interpret to represent less active small faults off the primary faults of the NFZ. These lineations are not optimally oriented for shear failure in the regional stress field, which we inferred from averaged focal mechanism solutions, and may represent paleo-configurations of the NFZ. Further, active faults interpreted from seismicity lineations within the subducted plate, including the Nootka Sequence Fault, may have originated as conjugate faults within the paleo-NFZ. [ABSTRACT FROM AUTHOR]

On behalf of the journal, AGU, and the scientific community, the editors of Geophysical Research Letters would like to sincerely thank those who reviewed manuscripts for us in 2022. The hours reading and commenting on manuscripts not only improve the manuscripts, but also increase the scientific rigor of future research in the field. With the advent of AGU's data policy, many reviewers have also helped immensely to evaluate the accessibility and availability of data, and many have provided insightful comments that helped to improve the data presentation and quality. We greatly appreciate the assistance of the reviewers in advancing open science, which is a key objective of AGU's data policy. We particularly appreciate the timely reviews in light of the demands imposed by the rapid review process at Geophysical Research Letters. We received 6,687 submissions in 2022 and 5,247 reviewers contributed to their evaluation by providing 8,720 reviews in total. We deeply appreciate their contributions in these challenging times. Plain Language Summary: Individuals in italics provided three or more reviews for GRL in 2022. Key Points: The editors thank the 2022 peer reviewers [ABSTRACT FROM AUTHOR]

Ion implantation is an effective way to control performance in semiconductor technology. In this paper, the fabrication of 1~5 nm porous silicon by helium ion implantation was systemically studied, and the growth mechanism and regulation mechanism of helium bubbles in monocrystalline silicon at low temperatures were revealed. In this work, 100 keV He ions (1~7.5 × 1016 ions/cm2) were implanted into monocrystalline silicon at 115 °C~220 °C. There were three distinct stages in the growth of helium bubbles, showing different mechanisms of helium bubble formation. The minimum average diameter of a helium bubble is approximately 2.3 nm, and the maximum number density of the helium bubble is 4.2 × 1023 m−3 at 175 °C. The porous structure may not be obtained at injection temperatures below 115 °C or injection doses below 2.5 × 1016 ions/cm2. In the process, both the ion implantation temperature and ion implantation dose affect the growth of helium bubbles in monocrystalline silicon. Our findings suggest an effective approach to the fabrication of 1~5 nm nanoporous silicon, challenging the classic view of the relationship between process temperature or dose and pore size of porous silicon, and some new theories are summarized. [ABSTRACT FROM AUTHOR]