检索结果-南通市图书馆

Metamorphic P-T conditions and ages of garnet-biotite schists in the Dahongshan Group from the southwestern Yangtze Block

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2024年第4期43卷 707-718页

作者： Jun-xiao Ma Guang-shu Yang Yong-feng Yan xiao-fei xu Yun-hua Ren Hui Zhao xiao-jun Zheng Yuan Qin Faculty of Land Resources Engineering Kunming University of Science and TechnologyKunming 650093China Geological Team 306 of Yunnan Non-Ferrous Metals Geological Bureau Kunming 650217China Yunnan Provincial Bureau of Non-Ferrous Geology Kunming 650051China

The Dahongshan Group,situated at the southwestern margin of the Yangtze Block,represents a geological unit characterized by relatively high-grade metamorphism in the *** paper investigates the garnet-biotite schist from the Laochanghe Formation of the Dahongshan Group,employing an integrated approach that includes petrological analysis,phase equilibrium modeling,and zircon U-Pb *** schist is mainly composed of garnet,biotite,plagioclase,quartz,rutile,and *** equilibrium modeling revealed the peak metamorphic conditions of 8-9 kbar and 635-675°*** further integrating the prograde metamorphic profile of garnet and geothermobarometric results,a clockwise P-T metamorphic evolution path is constructed,which includes an increase in temperature and pressure during the prograde ***-ICP-MS zircon U-Pb dating and zircon Ti thermometry constrains the post-peak metamorphic age of 831.2±7.2 *** with previously reported results,it is revealed that the southwestern margin of the Yangtze Block experienced a large-scale regional metamorphism during the Neoproterozoic(890-750 Ma),which is related to the collisional orogenic *** may be associated with the late-stage assembly of the Rodinia supercontinent or with local compression and subduction processes during the breakup of the Rodinia supercontinent.

关键词： Southwestern Yangtze Block Dahongshan Group Phase equilibrium modeling Zircon U-Pb dating Neoproterozoic metamorphism

Emphasizing Essential Words for Sentiment Classification Based onRecurrent Neural Networks

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2017年第4期32卷 785-795页

作者： fei Hu Li Li Zi-Li Zhang Jing-Yuan Wang xiao-fei xu College of Computer and Information Science Southwest University Chongqing 400715 China Network Centre Chongqing University of Education Chongqing 400065 China

With the explosion of online communication and publication, texts become obtainable via forums, chat messages, blogs, book reviews and movie reviews. Usually, these texts are much short and noisy without sufficient statistical signals and enough information for a good semantic analysis. Traditional natural language processing methods such as Bow-of-Word (BOW) based probabilistic latent semantic models fail to achieve high performance due to the short text environment. Recent researches have focused on the correlations between words, i.e., term dependencies, which could be helpful for mining latent semantics hidden in short texts and help people to understand them. Long short-term memory (LSTM) network can capture term dependencies and is able to remember the information for long periods of time. LSTM has been widely used and has obtained promising results in variants of problems of understanding latent semantics of texts. At the same time, by analyzing the texts, we find that a number of keywords contribute greatly to the semantics of the texts. In this paper, we establish a keyword vocabulary and propose an LSTM-based model that is sensitive to the words in the vocabulary; hence, the keywords leverage the semantics of the full document. The proposed model is evaluated in a short-text sentiment analysis task on two datasets: IMDB and SemEval-2016, respectively. Experimental results demonstrate that our model outperforms the baseline LSTM by 1%similar to 2% in terms of accuracy and is effective with significant performance enhancement over several non-recurrent neural network latent semantic models (especially in dealing with short texts). We also incorporate the idea into a variant of LSTM named the gated recurrent unit (GRU) model and achieve good performance, which proves that our method is general enough to improve different deep learning models.

关键词： short text understanding long short-term memory (LSTM) gated recurrent unit (GRU) sentiment classification deep learning

Optimized energy thresholds in a spectral computed tomography scan for contrast agent imaging

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2019年第3期30卷 15-27页

作者： Kai-Xin Huang Zhi Deng xiao-fei xu Yu-Xiang Xing Department of Engineering Physics Tsinghua University Key Laboratory of Particle and Radiation Imaging Ministry of Education Tsinghua University

Spectral computed tomography(CT) based on photon counting detectors(PCDs) is a well-researched topic in the field of X-ray imaging. When PCD is applied in a spectral CT system, the PCD energy thresholds must be carefully selected, especially for K-edge imaging, which is an important spectral CT application. This paper presents a threshold selection method that yields better-quality images in K-edge imaging. The main idea is to optimize the energy thresholds ray-by-ray according to the targeted component coefficients, followed by obtaining an overall optimal energy threshold by frequency voting. A low-dose pre-scan is used in practical implementations to estimate the line integrals of the component coefficients for the basis functions. The variance of the decomposed component coefficients is then minimized using the Cramer–Rao lower bound method with respect to the energy thresholds. The optimal energy thresholds are then used to take a full scan and gain better image reconstruction with less noise than would be given by a full scan using the non-optimal energy thresholds. Simulations and practical experiments on imaging iodine and gadolinium solutions, which are commonly used as contrast agents in medical applications, were used to validate the method. The noise was significantly reduced with the same dose relative to the non-optimal energy thresholds in both simulations and in practical experiments.

关键词： Spectral CT Contrast agent imaging Cramer-Rao lower bound Thresholds optimization Kedge

Sperm origins and concentration do not impact the clinical outcomes in intracytoplasmic sperm injection cycles

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2018年第5期20卷 454-458页

作者： Cen Yang Ze-Hong Zhou Dan-Ni Zheng xiao-fei xu Jin Huang Ying Lian Jie Qiao Center for Reproductive Medicine Department of Obstetrics and Gynecology Peking University Third Hospital Beijing 100191 China Beijing Key Laboratory of Reproductive Endocrinology and Assisted Reproduction Technology Beijing 100191 China Key Laboratory of Assisted Reproduction Ministry Of Education Beijing 100191 China

In the present study, we evaluated the impact of sperm origins and concentration on the clinical outcomes of intracytoplasmic sperm injection （ICSI） cycles. A total of 1201 IC51 cycles were retrospectively analyzed for male azoospermia or oligozoospermia between January 2015 and December 2015 in the Peking University Third Hospital. Patients were divided into three groups （Group 1 vs Group 2/3; surgically extracted sperm vs ejaculated sperms）： Group 1 included 343 ICSI cycles and Group 2 analyzed 388 cycles on semen with sperm concentration 〈5 × 10^6 m1-1 （severe oligozoospermia group）. Group 3 included 470 cycles with sperm concentration between 5×10^6 m1-1 and 15 × 10^6 m1-1 （mild oligozoospermia group）. Fertilization rates, clinical pregnancy rates, and live birth rates were analyzed and compared among groups of different semen origins and concentrations on the oocyte retrieval day. Group 2 showed a lower fertilization rate than Group 3 （62.9%± 21.6% vs 66.8% ± 22.1%, P 〈 0.05）. There were no statistically significant differences in clinical pregnancy rate per transfer （51.3%, 46.7%, and 50.0%, respectively）, live birth rate per transfer （44.4%, 40.9%, and 41.4%, respectively）, accumulative live birth rate （58.3%, 51.0%, and 52.1%, respectively）, twin birth rate （18.4%, 10.6%, and 12.6%, respectively）, and birth defects rate （0, 0.3%, and 0.2%, respectively） among three groups. The results of this study indicated that sperm origins and concentration do not imDact the clinical outcomes in ICSI cycles.

关键词： azoospermia clinical outcomes intracytoplasmic sperm injection oligozoospermia sperm concentration

Successful treatment of plasma exchange-refractory thrombotic thrombocytopenic purpura with rituximab:A case report

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2020年第12期8卷 2617-2622页

作者： Jian Chen Jing-Xia Jin xiao-fei xu xuan-xuan Zhang Xing-Nong Ye Jian Huang Department of Ultrasonography The Fourth Affiliated Hospital of Zhejiang University School of MedicineYiwu 322000Zhejiang ProvinceChina Department of Hematology The Fourth Affiliated Hospital of Zhejiang University School of MedicineYiwu 322000Zhejiang ProvinceChina

BACKGROUND Thrombotic thrombocytopenic purpura(TTP),a subtype of thrombotic microangiopathy,has a very high fatality rate if there is no timely diagnosis or ***,we report a case of TTP refractory to high displacement plasma exchange,which was later successfully treated with *** SUMMARY Here we report a case of refractory TTP in a 63-year-old woman with a low platelet count and decreased ADAMTS13 *** platelet count was 9×109/L,hemoglobin level was 81 g/L,and ADAMTS13 was<5%.She was diagnosed with thrombotic thrombocytopenic *** 8 d of daily plasma exchange(PEX),her platelet levels were still ***,after 6 d of treatment with rituximab,her platelet count increased and ADAMTS13 activity returned to *** PEX can cure most patients,but the relapse rate can be up to 50%-60%.This case suggested that rituximab can improve the curative efficiency of PEX and prevent disease relapse in TTP.

关键词： Thrombotic thrombocytopenic purpura ADAMTS13 Plasma exchange Rituximab Case report

Characteristics and genesis of tuffaceous shale oil lithofacies:A case study of Lucaogou Formation in Santanghu Basin

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Research 2024年第1期9卷 37-47页

作者： Dongsheng xiao Xiong fei xu Jilun Kang Yiting Zhang PetroChina Tuha Oilfield Company Exploration and Development Research Institute China

Lucaogou Formation in the Santanghu Basin is a special lacustrine fine-grained sedimentary deposits rich in volcanic debris and carbonate,with abundant shale oil ***,understanding of shale oil characteristics and genesis remains ***,sedimentary environment,and formation mechanisms of tuffaceous shale oil are investigated based on core and thin section observations,X-ray diffraction,field emission SEM and geochemical *** show that three mixed lithofacies types are developed in Lucaogou Formation:blocky tuff,laminated tuffaceous dolomite,and laminated dolomitic *** lithofacies types are characterized by high content of felsic and dolostone,widespread organic matter,and low clay *** of tuffaceous shale oil sweet spots is primarily influenced by four factors:inputting of volcanic ash as a high-quality source rocks and reservoirs provides good material basis;devitrification of volcanic glass,calcitization,and dissolution are crucial for formation of reservoirs;expulsion of source rocks with high-abundance organic matter expulsion facilitates migration and accumulation of hydrocarbon in adjacent reservoirs;fracture development improves reservoir permeability to form highly productive sweet *** analyzing characteristics and genesis of tuffaceous shale oil,the main controlling factors of reservoir physical property and oil saturation are clarified,which is of great significance for selection of shale oil exploration zones.

关键词： shale oil Tuffaceous Formation mechanism Lucaogou formation Santanghu basin

Resection of bilateral occipital lobe lesions during a single operation as a treatment for bilateral occipital lobe epilepsy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2021年第34期9卷 10518-10529页

作者： Yan-En Lyu xiao-fei xu Shuang Dai Min Feng Shao-Ping Shen Guo-Zhen Zhang Hong-Yan Ju Yao Wang xiao-Bo Dong Bin xu Seventh Clinical School of Medicine Beijing University of Chinese MedicineTongchuan 727031Shaanxi ProvinceChina Neurosurgery and Epilepsy Centre Dongzhimen HospitalBeijing University of Chinese MedicineBeijing 100700China Neurosurgery and Epilepsy Centre General Hospital of Beijing Military Commanding RegainBeijing 100700China

BACKGROUND Neurosurgical treatment of severe bilateral occipital lobe epilepsy usually involves two operations several mos *** To evaluate surgical resection of bilateral occipital lobe lesions during a single operation as a treatment for bilateral occipital lobe *** This retrospective case series included patients with drug-refractory bilateral occipital lobe epilepsy treated surgically between March 2006 and November *** Preoperative evaluation included scalp video-electroencephalography(EEG),magnetic resonance imaging,and *** surgery(bilateral occipital craniotomy),epileptic foci and important functional areas were identified by EEG(intracranial cortical electrodes)and cortical functional mapping,*** were followed up for at least 5 years to evaluate treatment outcome(Engel grade)and visual *** 20 patients(12 males)were aged 4-30 years(median age,12 years).Time since onset was 3-20 years(median,8 years),and episode frequency was 4-270/mo(median,15/mo).Common manifestations were elementary visual hallucinations(65.0%),flashing lights(30.0%),blurred vision(20.0%)and visual field defects(20.0%).Most patients were free of disabling seizures(Engel grade I)postoperatively(18/20,90.0%)and at 1 year(18/20,90.0%),3 years(17/20,85.0%)and≥5 years(17/20,85.0%).No patients were classified Engel grade IV(no worthwhile improvement).After surgery,there was no change in visual function in 13/20(65.0%),development of a new visual field defect in 3/20(15.0%),and worsening of a preexisting defect in 4/20(20.0%).CONCLUSION Resection of bilateral occipital lobe lesions during a single operation may be applicable in bilateral occipital lobe epilepsy.

关键词： Drug-resistant epilepsy Occipital lobe epilepsy Bilateral lesions One-stage surgery Treatment outcome Visual fields

Application of tissue engineering in the treatment of stress urinary incontinence

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Medical Journal 2009年第5期122卷 571-576页

作者： SONG xiao-fei FU Qiang xu Yue-min Department of Urology Shanghai Sixth People's Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200233 China

Stress urinary incontinence is one of the most common diseases in urology. The main treatments for stress urinary incontinence are pharmacotherapy, physicobehavioral therapy and ***, the results of present methods are not satisfactory. Tissue engineering is a newly emerging technology that may provide a novel method for the treatment of stress urinary incontinence.

关键词： stress urinary incontinence tissue engineering muscle-derived stem cells adipose-derived stem cells myoblast fibroblast

Differentially-grown cobalt regulators cooperatively involved in the tandem catalysis for high-yield production of second amines

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 2444-2450页

作者： Jinhui xu xiao Wang Ying Wang fei Wang Lingling Zhang Wenjie Cui Shuyan Song Hongjie Zhang State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China Department of Chemistry Tsinghua UniversityBeijing 100084China

One-pot tandem catalysis has been regarded as one of the most atomic economic ways to produce secondary amines,the important platform molecules for chemical synthesis and pharmaceutical manufacture,but it is facing serious issues in overall *** promotional effects are highly desired for boosting the activity and regulating the selectivity of conventional tandem *** this work,we report a high-performance tandem catalyst with maximized synergistic effect among each counterpart by preciously manipulating the spatial structure,which involves the active CeO_(2)/Pt component as kernel,the densely-coated N-doped C(NC)layer as selectivity controller,and the differentially-grown Co species as catalytic performance *** comprehensive investigations,the unique growth mechanism and the promotion effect of Co regulators are ***,the surface-landed Co clusters(Cocs)are crucial to selectivity by altering the adsorption configuration of benzylideneaniline ***,the inner Co particles(Cops)are essential for activity by denoting their electrons to neighboring *** from the unique promotion effect,a remarkably-improved catalytic efficiency(100%nitrobenzene conversion with 94%N-benzylaniline selectivity)is achieved at a relatively low temperature of 80℃,which is much better than that of CeO_(2)/Pt(100%nitrobenzene conversion with 12%N-benzylaniline selectivity)and CeO_(2)/Pt/NC(35%nitrobenzene conversion with 94%benzylideneaniline selectivity).

关键词： tandem catalysis CeO_(2) hierarchical structure heterogeneous catalyst dual-site materials