379 research outputs found
An extended Prandtl solution for analytical modelling of the bearing capacity of a shallow foundation on a spatially variable undrained clay
No full textClassical bearing capacity theory was developed mainly based on spatially uniform soil properties, which cannot account for the influence of inherent soil variability. If the soil strength is heterogeneous, then using the average strength may overestimate the bearing capacity of foundations, because the failure mechanism may preferentially mobilise the weaker soils. In this study the aim is to establish a theoretical model using upper-bound solutions applied to the bearing capacity analysis of shallow foundations on undrained clay considering spatial variability. The model is derived on the principle of least energy dissipation using a four-parameter variation on Prandtl's mechanism. The theoretical model developed is verified by the random finite-element (FE) method in spatially varying soil conditions. The results show that the model can accurately capture the effect of spatially varying strength on the shallow foundation failure mechanism. The difference of bearing capacity factor between the proposed model and the FE model is within 5%, which demonstrates that the four-parameter model has an accuracy that is comparable to FE analysis with many hundreds of degrees of freedom. Another advantage of the theoretical model is that the possible non-convergence in FE analysis can be avoided, and hence, the calculation efficiency is significantly enhanced. The model is therefore suitable for rapid quantification of bearing capacity in spatially varying soils
Increased Mineral‐Associated Organic Carbon and Persistent Molecules in Allochthonous Blue Carbon Ecosystems
No full textABSTRACT Coastal wetlands contain very large carbon (C) stocks—termed as blue C—and their management has emerged as a promising nature‐based solution for climate adaptation and mitigation. The interactions among sources, pools, and molecular compositions of soil organic C (SOC) within blue C ecosystems (BCEs) remain elusive. Here, we explore these interactions along an 18,000 km long coastal line of salt marshes, mangroves, and seagrasses in China. We found that mineral‐associated organic C (MAOC) is enriched in BCEs dominated by allochthonous inputs and abundant active minerals, leading to an increased proportion of persistent organic molecules. Specifically, soils with large allochthonous inputs (> 50%) are characterized by a substantial contribution of MAOC (> 70%) to total SOC with a notable preservation of lipids (36%) across salt marshes, mangroves, and seagrasses. The burial of allochthonous particles, derived from external sources such as rivers or tidal influxes, facilitates the formation of stable MAOC through binding to mineral surfaces or occlusion within microaggregates. The proportions of particulate organic C (POC) and MAOC are important predictors for molecular compositions of soil organic matter. Lipid proportions within molecular composition decrease as POC and autochthonous C proportions increase. These findings provide new insights into the coupled control over SOC sequestration in BCEs, emphasizing the role of allochthonous inputs, proportions of carbon pools, and persistent organic components.National Natural Science Foundation of China https://doi.org/10.13039/501100001809National Key Research and Development Program of China https://doi.org/10.13039/501100012166Natural Science Foundation of Shandong Province https://doi.org/10.13039/50110000712
Code for the mQTL analyses in 2023 Nature Genetics
No full textCitation:
Analysis of blood methylation quantitative trait loci in East Asians identifies ancestry-specific effects associated with complex trait variation.
Qianqian Peng, Xinxuan Liu, Wenran Li, Han Jing, Jiarui Li, Xingjian Gao, Qi Luo, Charles E. Breeze, Siyu Pan, Qiwen Zheng, Guochao Li, Jiaqiang Qian, Liyun Yuan, Na Yuan, Chenglong You, Siyuan Du, Yuanting Zheng, Ziyu Yuan, Jingze Tan, Peilin Jia, Jiucun Wang, Guoqing Zhang, Xianping Lu, Leming Shi, Shicheng Guo, Yun Liu, Ting Ni, Bo Wen, Changqing Zeng, Li Jin, Andrew E. Teschendorff, Fan Liu, Sijia Wang
Pavement deterioration modeling and design of a composite pavement distress index for Kentucky interstate highways and parkways.
No full textPavement deterioration is one of the most important driver for prioritizing pavement management and preservation (PMP) projects. The primary goal of this thesis is to provide reasonable predictive functions from multiple linear regression (MLR) models and artificial neural networks (ANN) that can be adopted by Kentucky Transportation Cabinet (KYTC). Furthermore, we use analytic hierarchy process (AHP) to design a composite pavement distress index in order to help Kentucky Transportation Cabinet (KYTC) prioritizing PMP projects based on 11 different distress indices. Numerical results show that the MLR models provide relatively high R square values of approximately 0.8. Both MLR and ANN models have small average squared errors (ASE). Finally, for all nine distress indices studied in this thesis, MRL models are recommended to KYTC due to their simplicity, interpretability along with robust performance that is comparable to the ANN model. Finally, a priority rating method is developed using analytical hierarchy process and it integrates 11 pavement distress indices into one priority score. A case study shows that the propose AHP-based rating method overcomes the drawback of KYTC’s current rating system for overemphasizing the international roughness index (IRI) among all distress indices
Transforming Programs between APIs with Many-to-Many Mappings
No full textTransforming programs between two APIs or different versions of
the same API is a common software engineering task. However,
existing languages supporting for such transformation cannot
satisfactorily handle the cases when the relations between
elements in the old API and the new API are many-to-many
mappings: multiple invocations to the old API are supposed to be
replaced by multiple invocations to the new API. Since the
multiple invocations of the original APIs may not appear
consecutively and the variables in these calls may have different
names, writing a tool correctly to cover all such invocation
cases is not an easy task. In this paper we propose a novel
guided-normalization approach to address this problem. Our core
insight is that programs in different forms can be
semantics-equivalently normalized into a basic form guided by
transformation goals, and developers only need to write rules for
the basic form to address the transformation. Based on this
approach, we design a declarative program transformation
language, PATL, for adapting Java programs between different
APIs. PATL has simple syntax and basic semantics to handle
transformations only considering consecutive statements inside
basic blocks, while with guided-normalization, it can be extended
to handle complex forms of invocations. Furthermore, PATL ensures
that the user-written rules would not accidentally break def-use
relations in the program. We formalize the semantics of PATL on
Middleweight Java and prove the semantics-preserving property of
guided-normalization. We also evaluated our language with three
non-trivial case studies: i.e. updating Google Calendar API,
switching from JDom to Dom4j, and switching from Swing to
SWT. The result is encouraging; it shows that our language allows
successful transformations of real world programs with a small
number of rules and little manual resolution
OP0298 PCSK9 IN ATHEROSCLEROTIC INFLAMMATION OF LUPUS PATIENTS AND MURINE MODEL OF LUPUS WITH ATHEROSCLEROSIS
No full textPersistence of soil microbial function at the rock-soil interface in degraded karst topsoils
No full textThis is the author accepted manuscriptsExtensive and progressive rock emergence in karst ecosystems may cause localized variations in soil biogeochemical and microbial properties, and thus produce nutrient cycling 'hot spots' that could alter functional responses to perturbation. Here, we investigated the differences between microbial compositions and functions in topsoils at the rock-soil interface (RSI) compared with adjacent bulk soil along a gradient of increasing human perturbation in the Chinese Karst Critical Zone Observatory. Microbial abundance decreased with increasing perturbation and was higher at the RSI compared to bulk soil. Compared with the bulk soil, C-cycling and N cycling enzyme activities at the RSI were 72–427% higher, respectively, and those related to N cycling were 72–98% higher, and were greatest in primary forest and abandoned land. Mineral contents explained the large variances in enzyme activities suggesting that mineral availability modified microbial functions for nutrients acquisition in nutrient-poor karst system. The significantly larger nutrient contents of RSI soil in the primary forest suggest that weathering of the karst rocks in unperturbed environments is the primary source of nutrients, which is driven by microbial enzyme production. The enzyme activities related to C and N cycling were highest in abandoned land, which suggests a rapid switch in microbial function caused by nutrient limitation when cultivation ceased. In conclusion, soil microbial abundance and function next to karst rocks is higher than bulk soils and persists after recovery. This suggests that the potential for long-term recovery of very degraded karst landscapes is possible after abandonment because microbial functions for C and nutrient cycling persist in RSI 'hot spots'.Natural Environment Research Council (NERC
Revealing an Interconnected Interfacial Layer in Solid-State Polymer Sodium Batteries
No full textReplacing the commonly used nonaqueous liquid electrolytes in rechargeable sodium batteries with polymer solid electrolytes is expected to provide new opportunities to develop safer batteries with higher energy densities. However, this poses challenges related to the interface between the Na-metal anode and polymer electrolytes. Driven by systematically investigating the interface properties, an improved interface is established between a composite Na/C metal anode and electrolyte. The observed chemical bonding between carbon matrix of anode with solid polymer electrolyte, prevents delamination, and leads to more homogeneous plating and stripping, which reduces/suppresses dendrite formation. Full solid-state polymer Na-metal batteries, using a high mass loaded Na3V2(PO4)3 cathode, exhibit ultrahigh capacity retention of more than 92 % after 2 000 cycles and over 80 % after 5 000 cycles, as well as the outstanding rate capability.Accepted Author ManuscriptRST/Storage of Electrochemical Energ
High-Resolution Paleomagnetic Secular Variation Since ∼13 ka From a Loess Section in Northwest China and a Regional Geomagnetic Directional Model for East Asia
No full textOriginal data of this paper have been uploaded to the MagIC database (https://earthref.org/MagIC/19798) (Fan et al., 2024a). The MATLAB executable file of SCHA.EAS14k model which can generate the paleosecular variation curves of the geomagnetic field directional elements within a spherical cap of 25° centered at 30ºN, 108ºE has been uploaded to the EarthRef database https://earthref.org/ERDA/2729 (Fan et al., 2024b).Paleomagnetic secular variation (PSV) records provide important information for the dynamic processes of the Earth's geomagnetic field, and also can be used for regional stratigraphic correlation. We conducted a paleomagnetic study on a high sedimentation rate Holocene loess section (the Minle section) with precise 14C age constraints in Northwest China. Rock magnetic results indicate that single domain and pseudo-single-domain magnetites are the main magnetic carriers of the natural remanent magnetization. Combining the alternating field demagnetization and thermal demagnetization results, we obtained a high-resolution PSV record with both absolute declination and inclination since ∼13 ka. Combining with previously published sedimentary records in East Asia, we developed an East Asian PSV reference curve over the past 14 ka (EASed14k) by relocating all the data to a common location (30ºN, 108ºE) and averaging them through Fisher statistics. We further generated a regional geomagnetic directional model spanning the past 14 ka for East Asia (SCHA.EAS14k), using the in situ PSV records and applying the revised spherical cap harmonic analysis in space and cubic B-spline in time. The predicted directional curves from this model at the common location are consistent with the EASed14k curves, which represent the first-order variation of the geomagnetic field in this area. The established reference curve and regional model for East Asia in this study will be used for regional and global comparison of the geomagnetic field.We express our gratitude to the editor team (Mark J. Dekkers and Agnes Kontny) and two anonymous reviewers for their constructive comments. We thank Min Zhang, Yifei Hou, Kaixian Qi, Yukai Luo and Hongyi Qiu for their helpful discussions. This work was supported by the National Natural Science Foundation of China (42488201, 42388101, 41974077, 41621004). S.C. acknowledges support from the Key Research Program of the Institute of Geology and Geophysics (CAS Grant IGGCAS-201905) and the Chinese Academy of Sciences (CAS) Pioneer Hundred Talents Program. J.X. acknowledges support from the Second Tibetan Plateau Scientific Expedition and Research Program (STEP) (Grant 2019QZKK0704).Peer reviewe
Research on effects of ions on the determination of suspended solid content in the oilfield injection water
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