检索结果-南通市图书馆

Vertical variations in planar lamination of marine shale: Elucidating hydrodynamic changes during the Ordovician-Silurian transition on the Upper Yangtze Block

引用

Journal of Palaeogeography 2025年第01期14卷 221-244页

作者： Zhen-Sheng Shi Tian-Qi Zhou Hui-Bo Song yong-Bin Niu Sha-Sha sun Department of Unconventional Oil and Gas Research Institute of Petroleum Exploration and DevelopmentPetroChina College of Resources and Environment Henan Polytechnic University

The hydrodynamics and their evolution on the Upper Yangtze Block during the Ordovician-Silurian transition period remain unclear. The present study is an assessment of how regional and global events may have influenced the hydrodynamic evolution based on a planar lamination investigation of the shales from the Upper Yangtze Block. Analyses of large thin sections and argon-ion polished thin sections using field emission-scanning electron microscopy(FE-SEM) showed that there are four types of planar lamination, namely, silty graded planar lamination(SGPL), silt-clay graded planar lamination(SCGPL), silt-clay interlaminated planar lamination(SCIPL), and paper-like planar lamination(PPL). SGPL is formed by turbidity current with a flow speed less than 15 cm/s. SCGPL is formed by turbidity currents with a flow speed less than 15 cm/s for normal grading type and 15-25 cm/s for alternating grading type. SCIPL has a continuum of sparsely spaced type, closely spaced type, and alternating type, which is formed by bottom current with an increasing flow speed from 15 to 25 cm/s to above 25 cm/s. PPL can be divided into normal grading and composite grading types. The former is formed by vertical settling, while the latter is formed by bottom current with a flow speed of 5-15 cm/s. Vertically, types of planar lamination varied from SGPL to PPL and then SCIPL manifesting the waxing and waning of flow speed with a positive excursion at graptolite biozone Metabolograptus extraordinarius(WF4) and a negative excursion at graptolite biozone Persculptograptus persculptus(LM1). The sudden decrease in flow speed across Linxiang and graptolite biozone Paraorthograptus pacificus(WF3) and the subsequent progressive increase from graptolite biozone Akidograptus ascensus(LM2)to graptolite biozone Demirastrites triangulatus(LM6) and to graptolite biozone Stimulograptus sedgwickii(LM8) during deposition of the Ordovician-Silurian transition succession on the Upper Yangtze Block were linked to th

关键词： Planar lamination Wufeng Formation Longmaxi Formation Ocean circulation Black shale

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Improving precision base editing of the zebrafish genome by Rad51DBD-incorporated single-base editors

引用

Journal of Genetics and Genomics 2025年第1期52卷 105-115页

作者： Zhilin Zhong Xueli Hu Renjie Zhang Xu Liu Wenqi Chen Shubin Zhang Jianjian sun tao P.Zhong Shanghai Frontiers Science Center of Genome Editing and Cell Therapy Shanghai Key Laboratory of Regulatory BiologyInstitute of Biomedical Sciences and School of Life SciencesEast China Normal UniversityShanghai 200241China Guangdong Cardiovascular Institute Guangdong Provincial People's HospitalSouthern Medical UniversityGuangzhouGuangdong 510100China

Single-base editors,including cytosine base editors(CBEs)and adenine base editors(ABEs),facilitate accurate C·G to T·A and A·T to G·C,respectively,holding promise for the precise modeling and treatment of human hereditary *** base editing and expanded base conversion range have been achieved in human cells through base editors fusing with Rad51 DNA binding domain(Rad51DBD),such as ***,we show that hyA3A-BE4max catalyzes C-to-T substitution in the zebrafish genome and extends editing positions(C_(12)-C_(16))proximal to the protospacer adjacent *** develop a codon-optimized counterpart zhyA3A-CBE5,which exhibits substantially high C-to-T conversion with 1.59-to 3.50-fold improvement compared with the original *** these tools,disease-relevant hereditary mutations can be more efficaciously generated in *** introduce human genetic mutation rpl11^(Q42*)and abcc6a^(R1463C) by zhyA3A-CBE5 in zebrafish,mirroring Diamond-Blackfan anemia and Pseudoxanthoma Elasticum,*** study expands the base editing platform targeting the zebrafish genomic landscape and the application of single-base editors for disease modeling and gene function study.

关键词： Zebrafish Base editor Rad51DBD ZhyA3A-CBE5 PXE syndrome

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Single-atom“surgery”on chiral all-dialkynyl-protected superatomic silver nanoclusters

引用

Science Bulletin 2025年第3期70卷 365-372页

作者： Chengkai Zhang Wei-Dan Si Wei-Dong Tian Wan-Jun Xiao Zhi-yong Gao Zhi Wang Chen-Ho Tung Di sun School of Chemistry and Chemical Engineering State Key Laboratory of Crystal MaterialsShandong UniversityJinan 250100China School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiang 453007China

The manipulation of single atom within the metallic kernel of nanoclusters has attracted considerable attention due to its potentials to elucidate kernel-based structure-property relationships at the single-atom ***,new-designed chiral bialkynyl ligands,have been chosen as protective agents to isolate two pairs of 8-electron superatomic silver nanoclusters,R/S-Ag39 and R/S-Ag40.X-ray diffraction analysis reveals that Ag39 and Ag40 with the same number of chiral ligands,possess a closely analogous silver skeleton but a single-atomic *** incorporation of an extra Ag40th atom into Ag40 evokes two significant changes of structure and property compared to Ag39:(i)a reduction in the symmetry of the entire nanocluster,resulting in an enhancement of kernel-related asymmetry g-factor;(ii)a regulation of the transitions(1P→1D and Ligand(π)→1D)of excited state,leading to a second near-infrared(NIR-II,1000-1700 nm)phosphorescent emission red-shift from 1088 to 1150 *** work not only provides vital insights into the relationship between structures and ground/excited states chiroptical activities at the single-atom level,but also presents bialkynyl as a promising stabilizing agent for building superatomic metal nanoclusters.

关键词： Single atom manipulation Chiral bialkynyl ligands Superatomic silver nanoclusters NIR-Il phosphorescence

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Delaying wheat sowing date and increasing sowing rate promotes lignin synthesis and reduces lodging

引用

Crop Journal 2025年第1期13卷 269-280页

作者： Li, Chunhui Cui, Haixing Jin, Min sun, Shufang Wang, Jiayu Luo, yongli Li, yong Wang, Zhenlin State Key Laboratory of Wheat Improvement Agronomy College of Shandong Agricultural University Shandong Tai'an 271000 China

Population size plays a crucial role in determining wheat yields. Altered carbohydrate accumulation resulting from increased competition between populations and individuals leads to poor-quality stems. The sowing date can mitigate competition in densely planted populations. However, the underlying mechanism by which it confers resistance to wheat lodging remains elusive. In this study, Zimai 28 (lodging-sensitive variety) and Shannong 28 (lodging-resistant variety) were used with three sowing treatments on October 22 (S1), October 28 (S2), and November 3 (S3). The sowing rate was adjusted to ensure adequate population size and consistency in the overwintering populations across sowing dates (300 plant m−2 for S1, 375 plant m−2 for S2, and 525 plant m−2 for S3). The lodging resistance in winter wheat was increased by delayed sowing and increased sowing rate, which led to a reduction in tiller numbers and fostered primary stem development. A reduction in the overwinter cumulative temperature from 500 to 450 °C, coupled with an elevation in sowing rates from 300 to 375 plant m−2 (transition from S1 to S2), corresponded with a notable increase in structural carbohydrates (lignin, cellulose, hemicellulose, and pectin) by 175.07 mg g−1. Additionally, there was a moderate increase in non-structural carbohydrates, including soluble sugars and starch, by 15.54 mg g−1. Delayed sowing and increased sowing rate elevated the precursor contents of lignin synthesis. Enhanced metabolic activity of related pathways ultimately increased dimer/trimer content. In summary, this study highlights the pivotal role of lignin metabolites and cross-linked structures in determining the stem stiffness breaking strength. © 2024

关键词： Carbohydrates Lignin metabolism Lodging Stem quality Wheat

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

In situ measurement of environmental γ radiation dose rates of key nuclides for large radioactive surface sources

引用

Nuclear Science and Techniques 2025年第1期36卷 69-79页

作者： Ze-Qian Wu Jian sun Wei-Qi Huang Bai-Rong Wang Jin-Xing Cheng Jiang-Feng Wu yong-Hong Wang Biao Yuan Sheng Qi Kun Shan Institute of NBC Defence Beijing 102205China Beijing New-High Technology Academy Beijing 100094China

To monitor nuclear and radiation emergencies,it is crucial to obtain accurate in situ measurements of the environmentalγ radiation dose rate from key radionuclides,particularly for large radioactive surface *** methods currently used for measuring dose rates are inadequate for obtaining the dose rates of key radionuclides and have large angular response errors when monitoring surface *** address this practical problem,this study proposes three methods for measuring the dose rate:the weighted peak total ratio,mean value regression,and numerical integration *** methods are based on energy-spectrum measurement data,and they were theoretically derived and numerically ***,a 1-m-long hexagonal radioactive surface source was integrated into a larger surface *** situ measurement experiments were conducted on a large radioactive surface source using a dose-rate meter and a portable HPGespectrometer to analyze the errors of the three aforementioned methods and verify their validity.

关键词： Environmentalγradiation dose rate HPGespectrometer Key radionuclides Radioactive surface source

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Assessing the ecological effects of the World's Largest Forestry Eco-engineering: Three-North Protective Forest Program within the initially scheduled range from 1978 to 2022

引用

Science China(Life Sciences) 2025年第2期68卷 314-327页

作者： Xiao Zheng Jiaojun Zhu G.Geoff Wang Qiaoling Yan tao sun Lining Song Tian Gao Yirong sun Xiufen Li Kai Yang Jinxin Zhang Lizhong Yu Ke Qi Lanlin Zhao Deliang Lu Zhanyuan Lu CAS Key Laboratory of Forest Ecology and Silviculture Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China Qingyuan Forest CERN National Observation and Research StationShenyang 110016China Department of Forestry and Environmental Conservation Clemson UniversityClemson 29634USA Agronomy College Shenyang Agricultural UniversityShenyang 110866China University of Chinese Academy of Sciences Beijing 100049China Inner Mongolia Academy of Agricultural&Animal Husbandry Sciences Hohhot 010031China

China's Three-North Protective Forest Program(TNP) is the world's most ambitious afforestation project(ongoing from 1978 to 2050), which aims to increase forest coverage through afforestation and reforestation, protect agriculture, reduce soil erosion, and control desertification. Although TNP has been ongoing for 45 years, its rationales and effects remain uncertain. Here, we conducted a rangewide assessment of TNP by analyzing data from >10,000 scenes of satellite images and >50,000 field survey plots. The TNP range and definitions of shelterbelts, arboreal forests, and shrublands were changed during the study period, but we used the initial TNP range(4.07 million km2) and the definitions in 1978 for keeping the consistency, comparability, and comprehensiveness. The TNP increased forest coverage from 5.05% in 1978 to 9.69% in 2022, with arboreal forests, shrublands, and shelterbelts increasing by 42.5%, 184.4%,and 53.6%, respectively. However, only 40.1% of the 471,113 km2afforested area was established between 1978 and 2022. The wellestablished shelterbelts improved crop yield by 4.3%-9.5%, but only 10.2% of all the farmlands in TNP regions(TNR) were protected. The total area of soil erosion due to hydraulic forces was reduced by 447,363 km2, with 61% of this reduction attributed to TNP. TNP contributed to the reduction of desertification by 15%, largely due to the low rate of afforestation success and the largely decreased grasslands. The total carbon sequestration from TNP was 1.96 Pg C. Moreover, water storage in TNR showed a decreasing trend, but the contribution rate of TNP was only 7.8%. Our results illustrate that forestry eco-engineering projects are feasible in the management and restoration of arid and semi-arid degraded lands, but attention must be paid to fully considering the ecological carrying capacity of water resources, matching the species to sites, strengthening the post-afforestation management, as well as keeping the balances between composit

关键词： Three-North Program northern China protective forest ecological impacts 45 years

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Evaluation of surgical strategy for low anterior resection syndrome using preoperative low anterior resection syndrome score in China

引用

World Journal of Gastrointestinal Surgery 2025年第1期17卷 175-183页

作者： Yang-tao Pan Yi-Min Lv Shi-Chao Zhou Dan-Yan Luo Hao sun Wei-Feng Lao Wei Zhou Department of Colorectal Surgery Sir Run Shaw Hospital Affiliated with Zhejiang UniversityHangzhou 310016Zhejiang ProvinceChina School of Mathematics Nanjing Audit UniversityNanjing 211815Jiangsu ProvinceChina Department of Surgery Zhejiang Hospital of Traditional Chinese Medicine(Zhejiang University of Traditional Chinese Medicine First Affiliated Hospital)Hangzhou 310000Zhejiang ProvinceChina NBU Health Science Center Ningbo UniversityNingbo 315000Zhejiang ProvinceChina

BACKGROUND Despite improved survival rates in rectal cancer treatment,many patients experience low anterior resection syndrome(LARS).The preoperative LARS score(POLARS)aims to address the limitations of LARS assessment by predicting outcomes preoperatively to enhance surgical *** To investigate the predictive accuracy of POLARS in assessing the occurrence of *** This study enrolled a total of 335 patients who underwent laparoscopic or robotic low anal sphincter-preserving surgery for rectal *** were categorized into three groups according to their POLARS score:no LARS(score 0-20),minor LARS(score 21-29),and major LARS(score 30-42).The QLQ-C30/CR29 scores were compared among these groups,and the agreement between POLARS predictions and the actual LARS scores was *** The study population was divided into three groups:major LARS(n=51,27.42%),minor LARS(n=109,58.6%),and no LARS(n=26,13.98%).Significant differences in the QLQ-C30 scales of social function,diarrhea,and financial impact were detected between the no LARS and major LARS groups(P<0.05)and between the minor LARS and major LARS groups(P<0.05).Similarly,significant differences were detected in the QLQ-CR29 scales for blood and mucus in the stool,fecal incontinence,and stool frequency between the no LARS and minor LARS groups(P<0.05),as well as between the minor LARS and major LARS groups(P<0.05).The predictive precision for major LARS using the POLARS score was 82.35%(42/51),with a recall of 35.89%(42/117).The mean absolute error(MAE)between the POLARS score and the actual LARS score was 8.92±*** contrast,the XGBoost(extreme gradient boosting)model achieved a lower MAE of 6.29±4.77,with a precision of 84.39%and a recall of 74.05%for predicting major *** The POLARS score demonstrated effectiveness and precision in predicting major LARS,thereby providing valuable insights into postoperative symptoms and patient quality of ***,the XGBoost model exh

关键词： Low anterior resection syndrome Preoperative assessment Predictive Accuracy Quality of life Machine learning

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Safe flight corridor constrained sequential convex programming for efficient trajectory generation of fixed-wing UAVs

引用

Chinese Journal of Aeronautics 2025年第1期38卷 537-550页

作者： Jing sun Guangtong XU Zhu WANG Teng LONG Jingliang sun School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Huzhou Institute Zhejiang UniversityHuzhou 313000China Department of Automation North China Electric Power University(Baoding)Baoding 071003China

Generating dynamically feasible trajectory for fixed-wing Unmanned Aerial Vehicles(UAVs)in dense obstacle environments remains computationally *** paper proposes a Safe Flight Corridor constrained Sequential Convex Programming(SFC-SCP)to improve the computation efficiency and reliability of trajectory ***-SCP combines the front-end convex polyhedron SFC construction and back-end SCP-based trajectory optimization.A Sparse A^(*)Search(SAS)driven SFC construction method is designed to efficiently generate polyhedron SFC according to the geometric relation among obstacles and collision-free *** transforming the nonconvex obstacle-avoidance constraints to linear inequality constraints,SFC can mitigate infeasibility of trajectory planning and reduce computation ***,SCP casts the nonlinear trajectory optimization subject to SFC into convex programming subproblems to decrease the problem *** addition,a convex optimizer based on interior point method is customized,where the search direction is calculated via successive elimination to further improve *** experiments on dense obstacle scenarios show that SFC-SCP can generate dynamically feasible safe trajectory *** studies with state-of-the-art SCP-based methods demonstrate the efficiency and reliability merits of ***,the customized convex optimizer outperforms off-the-shelf optimizers in terms of computation time.

关键词： Fixed-wing unmanned aerial vehicle Efficient trajectory planning Safe flight corridor Sequential convex programming Customized convex optimizer

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Prediction of intrusive gas pores caused by resin burning in sand core for iron castings

引用

China Foundry 2025年第1期22卷 23-32页

作者： Ji-wu Wang Xiao-long Wang Yu-cheng sun Yu-hang Huang Xiu-ming Chen Xiong-zhi Wu Na Li Jin-wu Kang tao Jing Tian-you Huang Hai-liang Yu School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China Weichai Power Co. Ltd.Weifang 261061ShandongChina School of Mechanical Engineering Central South UniversityChangsha 41000China School of Materials Science and Engineering Key Laboratory for Advanced Materials Processing TechnologyTsinghua UniversityBeijing 100084China

In the production of castings,intrusive gas pore represents a kind of common defects which can lead to leakage in high gas-tightness requirement castings,such as cylinder blocks and cylinder heads for *** occurs due to the intrusion of gases generated during the resin burning of the sand core into castings during the casting ***,a gas generation and flow constitution model was established,in which the gas generation rate is a function of temperature and time,and the flow of gas is controlled by the gas release,conservation,and Darcy's *** heat transfer and gas flow during casting process was numerically *** dangerous point of cores is firstly identified by a virtual heat transfer method based on the similarity between heat transfer and gas flow in the sand *** gas pores in castings are predicted by the gas pressure,the viscosity and state of the melt for these dangerous *** distinct sand core structures were designed and used for the production of iron castings,and the simulated gas pore results were validated by the obtained castings.

关键词： gas pore numerical simulation iron casting sand core resin

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Classification and diagnosis of cervical lesions based on colposcopy images using deep fully convolutional networks: A man-machine comparison cohort study

引用

Fundamental Research 2025年第1期5卷 419-428页

作者： Dong, Binhua Xue, Huifeng Li, Ye Li, Ping Chen, Jiancui Zhang, tao Chen, Lihua Pan, Diling Liu, Peizhong sun, Pengming Laboratory of Gynecologic Oncology Department of Gynecology Fujian Maternity and Child Health Hospital College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics Fujian Medical University Fujian Fuzhou 350001 China Fujian Key Laboratory of Women and Children's Critical Diseases Research Fujian Fuzhou 350001 China Medical Center of Cervical Disease and Colposcopy Fujian Maternity and Child Health Hospital Fujian Fuzhou 350001 China Department of Gynecology and Obstetrics Quanzhou First Hospital Fujian Medical University Fujian Quanzhou 362000 China College of Computer Science and Technology Huaqiao University Fujian Xiamen 361021 China Department of Pathology Fujian Maternity and Child Health Hospital Fujian Fuzhou 350001 China College of Engineering Huaqiao University Fujian Quanzhou 362021 China School of Medicine Huaqiao University Fujian Quanzhou 362021 China

Colposcopy is an important technique in the diagnosis of cervical cancer. The development of computer-aided diagnosis methods can mitigate the shortage of colposcopists and improve the accuracy and efficiency of colposcopy examinations in China. This study proposes the Dense-U-Net model for colposcopy image recognition. This was a man–machine comparison cohort study. It presents a novel artificial intelligence (AI) model for the diagnosis of cervical lesions through colposcopy images using a Dense-U-Net image semantic segmentation algorithm. The Dense-U-Net model was created by applying the methods of “deepening the network structure,” “applying dropout” and “max pooling.” Moreover, image-based and population-based diagnostic performances of the AI algorithm and physicians with different levels of specialist experience were compared. In total, 2,475 participants were recruited, and 13,084 colposcopy images were included in this study. The diagnostic accuracy of the Dense-U-Net model increased significantly with increasing colposcopy images per patient. As the number of images in the training set increased, the diagnostic accuracy of the Dense-U-Net model for cervical intraepithelial neoplasm 3 or worse (CIN3+) diagnosis increased (P = 0.035). The rate of diagnostic accuracy (0.89 vs 0.85, P < 0.001) of CIN3+ lesions using the Dense-U-Net model was higher than that of expert colposcopists, and the missed diagnosis (0.06 vs 0.07, P = 0.002) and false positive (0.05 vs 0.08, P < 0.001) were lower. Moreover, Dense-U-Net is more accurate in diagnosing the type III cervical transformation zone, which is difficult to diagnose by experts (P < 0.001). The Dense-U-Net model also showed higher diagnostic accuracy for CIN3+ in an independent test set (P < 0.001). To diagnose the same 870 test images, the Dense-U-Net system took 1.76 ± 0.09 min, while the expert, senior, and junior colposcopists took 716.3 ± 49.76, 892.1 ± 92.30, and 3034.7 ± 259.51 min, respectively. The study

关键词： Auxiliary diagnosis Cervical lesions Colposcopic image Dense-U-Net Lesion segmentation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：