检索结果-内蒙古大学图书馆

您好，读者！请登录

内蒙古大学图书馆

首页
概况
党建
资源
服务
科研支持
- 论文收录引用证明
- 科技查新
知识产权
档案馆
帮助

咨询与建议

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

您的常用邮箱：*

您的手机号码：*

问题描述：

当前已输入0个字，您还可以输入200个字

全部搜索
期刊论文
图书
学位论文
标准
纸本馆藏
外文资源发现
数据库导航
超星发现

高级检索

时间限定

出版年份：

文献类型

图书期刊文献学位论文多媒体

馆藏选择

电子馆藏纸本馆藏

核心期刊

全部期刊 SCI 收录期刊 SSCI 收录期刊 EI 收录期刊 CSCD 收录期刊 CSSCI 收录期刊

语言

中文英文

文献类型

期刊文献图书学位论文标准纸本馆藏

帮助

文字说明：

T=题名（书名、题名），A=作者（责任者），K=主题词，P=出版物名称，PU=出版社名称，O=机构（作者单位、学位授予单位、专利申请人），L=中图分类号，C=学科分类号，U=全部字段，Y=年（出版发行年、学位年度、标准发布年）

检索规则说明：

AND代表“并且”；OR代表“或者”；NOT代表“不包含”；(注意必须大写,运算符两边需空一格)

检索范例：

范例一：(K=图书馆学 OR K=情报学) AND A=范并思 AND Y=1982-2016
范例二：P=计算机应用与软件 AND (U=C++ OR U=Basic) NOT K=Visual AND Y=2011-2016

分类表

所选分类

>> <<

限定检索结果

文献类型

6,336 篇 会议
604 册 图书

馆藏范围

6,940 篇 电子文献
0 种 纸本馆藏

日期分布

学科分类号

6,234 篇 工学
- 5,064 篇 土木工程
- 842 篇 材料科学与工程（可...
- 763 篇 建筑学
- 547 篇 计算机科学与技术...
- 425 篇 交通运输工程
- 424 篇 地质资源与地质工...
- 358 篇 化学工程与技术
- 343 篇 环境科学与工程（可...
- 235 篇 水利工程
- 230 篇 力学（可授工学、理...
- 180 篇 农业工程
- 156 篇 动力工程及工程热...
- 153 篇 安全科学与工程
- 151 篇 机械工程
- 147 篇 软件工程
- 135 篇 冶金工程
- 130 篇 城乡规划学
- 123 篇 石油与天然气工程
- 84 篇 测绘科学与技术
- 81 篇 船舶与海洋工程
1,331 篇 理学
- 450 篇 物理学
- 357 篇 数学
- 302 篇 化学
- 181 篇 地球物理学
- 139 篇 大气科学
- 91 篇 统计学（可授理学、...
- 78 篇 海洋科学
236 篇 管理学
- 196 篇 管理科学与工程(可...
- 114 篇 工商管理
176 篇 农学
- 150 篇 作物学
66 篇 经济学
37 篇 法学
16 篇 医学
7 篇 军事学
1 篇 教育学

主题

235 篇 building constru...
213 篇 geoengineering, ...
165 篇 structural healt...
156 篇 geotechnical eng...
126 篇 sustainable deve...
113 篇 environment, gen...
110 篇 building materia...
106 篇 transportation t...
94 篇 machine learning
91 篇 sustainability
73 篇 construction man...
69 篇 sustainable arch...
66 篇 damage detection
65 篇 operational moda...
57 篇 reinforced concr...
56 篇 compressive stre...
54 篇 concrete
53 篇 civil engineerin...
53 篇 structural mater...
51 篇 climate change

机构

30 篇 belgorod state t...
25 篇 department of ci...
24 篇 univ transport t...
23 篇 univ alberta edm...
23 篇 concordia univ d...
22 篇 concordia univ m...
17 篇 univ alberta dep...
17 篇 politecn milan d...
17 篇 kazan state univ...
17 篇 srm inst sci & t...
16 篇 department of ci...
15 篇 university of re...
15 篇 southeast univ s...
15 篇 department of ci...
15 篇 univ naples fede...
14 篇 indian institute...
14 篇 univ naples fede...
13 篇 department of ci...
13 篇 department of ci...
13 篇 natl inst res & ...

作者

22 篇 sreevalsa kolath...
22 篇 krishna r. reddy
20 篇 formisano antoni...
19 篇 imanpour ali
16 篇 ubertini filippo
16 篇 rainieri carlo
15 篇 landolfo raffael...
15 篇 indraratna buddh...
15 篇 de matteis gianf...
14 篇 kelvin tsun wai ...
14 篇 nik-bakht mazdak
14 篇 sanjay kumar shu...
14 篇 matos jose c.
14 篇 nassar khaled
14 篇 ashraf el damatt...
14 篇 m. shahria alam
13 篇 berardi umberto
13 篇 arvind kumar agn...
13 篇 serge desjardins
13 篇 gentile carmelo

语言

6,447 篇 英文
490 篇 其他
3 篇 中文

检索条件"丛书名=Lecture Notes in Civil Engineering"

共 6940 条记录，以下是411-420 订阅

全选清除本页清除全部题录导出标记到"检索档案"

详细简洁

排序：

Research on Sea Trials and Applications of Deep-Sea Autonomous and Remotely Operated Vehicle 11th

Research on Sea Trials and Applications of Deep-Sea Autonomo...

引用

11th International Conference on Coastal and Ocean engineering

作者： Yugang, Ren Xiaoyu, Zhang Xiang, Gao Xianpeng, Shi Shandong Univ Sci & Technol Coll Marine Sci & Engn Qingdao 266590 Shandong Peoples R China Natl Deep Sea Ctr Qingdao 266237 Shandong Peoples R China

ISBN: (纸本)9789819601837;9789819601813;9789819601806

Deep submersibles are the "magic weapon" for entering, exploring, developing, and governing the ocean. Their technological level and development directly affect our deep-sea rights, especially in the fields of structure, sensing, dynamics, etc. The advanced level of submersibles greatly represents the development level of deep-sea technology, and has always been the "bull's-eye" pursued by countries around the world for competition. The article focuses on the current development status of all sea deep duplex hybrid deep submersibles, and introduces the development status of ARVs at home and abroad;Based on the project, a detailed description was given of the sea trials of the 3000 m and 8000 m deep duplex hybrid submersible. Finally, based on the experience of sea trials and combined with the operational and maintenance requirements of the national deep-sea base for deep diving technology and equipment, the ARV operation mode was discussed, and the prospects for future commercial applications were analyzed.

关键词： Deep-sea exploration Hybrid deep submersibles Sea trials Operation mode Scientific applications

来源：评论

学校读者我要写书评

暂无评论

Transportation Asset Management is in Need of a Dependable Foundation 5th

Transportation Asset Management is in Need of a Dependable F...

引用

5th International Conference on Transportation Geotechnics

作者： Anderson, Scott Vessely, Mark Hille, Madeline Porter, Michael Mitchell, Sterling Sala, Zac BGC Engn Inc Golden CO 80401 USA BGC Engn Inc Vancouver BC Canada

ISBN: (纸本)9789819782239;9789819782215;9789819782208

As transportation owners move to manage assets in risk-informed ways, they are well served by a dependable foundation. What is meant here is not whether asset foundations are well built, but how reliably their future state can be predicted. Here we focus on ground movement, where most change is episodic and results from rare events, with the rarest events causing the most change, for example, through earthquakes, floods, and landslides. For other processes, change is more gradual and yet still occurs at a meaningful rate. Wide-area observations through aerial lidar and satellite InSAR are revealing this. A dependable Transportation Asset Management (TAM) foundation is a process where this is understood spatially and reflected in models of future performance related to safety, dependability, and cost. Another reason TAM needs a dependable foundation is so that observations made by others can be put into context. Not long ago, essentially all asset performance data and their changes were collected by the owner. Now, crowdsourcing of observations, consortiums of local owners for aerial lidar and national governments for InSAR, are ways in which observations on performance are being made by other people or interests. Owners can now find themselves being the last to know about changes to their assets rather than the first to know. In this sense, a dependable TAM foundation is a platform that provides opportunity to build from these observations, and not get turned around by them. International examples presented here demonstrate the value of a dependable TAM foundation.

关键词： Transportation asset management Data management Remote sensing Lidar change detection Satellite InSAR

来源：评论

学校读者我要写书评

暂无评论

Geotechnical and Geophysical Characterization of Delhi Metro Tunnel Alignment: Section Between RK Ashram and Nabi Karim 5th

Geotechnical and Geophysical Characterization of Delhi Metro...

引用

5th International Conference on Transportation Geotechnics

作者： Sundaram, Ravi Gupta, Sorabh Gupta, Sanjay Sharma, Saurabh Cengrs Geotech Pvt Ltd A-100 Sect 63 Noida India Delhi Metro Rail Corp New Delhi India

ISBN: (纸本)9789819782239;9789819782215;9789819782208

To evaluate the stratigraphy along an underground tunnel alignment between RK Ashram and Nabi Karim for the Delhi Metro, a detailed study was performed. This included geotechnical investigation by drilling boreholes, performing in situ permeability tests and dilatometer tests together with geophysical surveys such as seismic refraction tests, electrical resistivity tomography, and crosshole seismic tests. Using a combination of geotechnical and geophysical testing, a reliable geotechnical-cum-geophysical model was developed to characterize the ground profile and trend of rock along the metro alignment.

关键词： Geotechnical investigation Geophysical survey Site characterization RK Ashram Nabi Karim Delhi Metro

来源：评论

学校读者我要写书评

暂无评论

Dynamic Shading Device with Phase Change Materials: A Proof-of-Concept Towards Improving Thermal Comfort 9th

Dynamic Shading Device with Phase Change Materials: A Proof-...

引用

9th International Building Physics Conference

作者： Goncalves, Margarida Figueiredo, Antonio Almeida, Ricardo M. S. F. Vicente, Romeu Samagaio, Antonio Univ Aveiro Dept Civil Engn RISCO Risks & Sustainabil Construct Aveiro Portugal Polytech Inst Viseu Sch Technol & Management Dept Civil Engn Viseu Portugal Univ Porto Inst R&D Struct & Construct LFC CONSTRUCT LFC Fac Engn FEUP Porto Portugal Univ Aveiro Dept Environm & Planning Aveiro Portugal

ISBN: (纸本)9789819783151;9789819783137;9789819783120

Integration of renewable energy sources coupled with innovative construction systems can enhance building efficiency. Recognizing the substantial impact of the building sector's carbon footprint, there is a growing emphasis on decarbonization strategies aimed at improving the energy performance of the built environment to reduce overall energy consumption and greenhouse gas emissions. Dynamic Facades can play a crucial role in achieving this objective, as their adaptability to environmental changes can boost both energy efficiency and thermal comfort in buildings. On the other hand, the increasing trend of using Phase Change Materials (PCM) underscores the considerable potential of these solutions in enhancing building thermal performance. However, one key challenge of PCM applications in buildings lies in ensuring their complete daily charge and discharge cycle. This research introduces a proof-of-concept featuring a novel dynamic shading device incorporating PCM. A prototype was built and tested at the real-scale, one with a conventional curtain and the other with the dynamic shading device incorporating PCM. Monitoring was conducted to assess the system's performance according to different strategies to optimize the system's full potential. The system operates by sliding the device from the indoor compartment to a discharging chamber to potentiate the PCM phase change. This prototype, for overheating control, demonstrated the PCM's thermal regulation capacity, achieving reductions of up to 1.1 degrees C in maximum peak temperatures.

关键词： Dynamic Facade Indoor Shading Solutions PCM Energy Efficiency Thermal Comfort

来源：评论

学校读者我要写书评

暂无评论

Experimental Study on Utilization of Recycled Concrete Aggregates in Bituminous Concrete

Experimental Study on Utilization of Recycled Concrete Aggre...

引用

2023 International Conference on Environmental Geotechnology, Recycled Waste Materials and Sustainable engineering

作者： Randhawa, Ayushi Sharma, Umesh Punjab Engn Coll Deemed Univ Chandigarh 160012 India

ISBN: (纸本)9789819797790;9789819797776;9789819797769

Rapid urbanization, the implementation of new infrastructure projects, and the development of the construction industries all result in the generation of massive amount of construction and demolition waste. Pavement construction costs a huge amount of money and uses a lot of resources. To minimize investment and lower the need for raw materials, it is crucial to implement a tried-and-true methodology for building and maintaining roads. Using recycled materials for construction of roads can be a sustainable solution. This can address a number of issues, such as the use of land for waste disposal, resource depletion, landfill overflow, water pollution, and so on. The goal of the current study is to examine the characteristics of recycled concrete aggregates (RCA) and potential applications in bituminous concrete (BC). Marshall mix design was used to examine the properties of bituminous mixes using RCA as coarse aggregates versus mixes comprising just virgin aggregates. In this paper, investigation on the possible utilization of RCA in bituminous concrete proposes preparation of modified mixes by replacing 10, 20, 30, 40, and 50% virgin aggregates with RCA at varying bitumen percentages of 5, 5.5, and 6%. It was observed that although the stability value of the mix decreases as the RCA content rises, the measured volumetric properties for the RCA samples were more stable than for conventional mixes and fell within acceptable recommended limits. At a bitumen content of 5.5%, RCA can be used as a 30% replacement for natural aggregates in bituminous concrete. Material cost analysis also suggested that the utilization of RCA in road construction is an economical and sustainable solution.

关键词： Recycled concrete aggregates Bituminous concrete Marshall stabiity Volumetric properties Sustainability

来源：评论

学校读者我要写书评

暂无评论

Simulation-Based Assessment of Thermal and Humidity Stress Deterioration in Clay Sculptures from Baosheng Temple, Suzhou, China 9th

Simulation-Based Assessment of Thermal and Humidity Stress D...

引用

9th International Building Physics Conference

作者： Luo, Zhenhao Lu, Yishan Xie, Huarong Hokoi, Shuichi Li, Yonghui Southeast Univ Sch Architecture Nanjing 210096 Peoples R China Southeast Univ Minist Educ Key Lab Urban & Architectural Heritage Conservat Nanjing 210096 Peoples R China Southeast Univ Architecture Internalizat Demonstrat Sch Nanjing 210096 Peoples R China

ISBN: (纸本)9789819783076;9789819783052;9789819783045

Clay sculptures, an important component of China's immovable cultural relics, are usually preserved in grotto temples and temple buildings they embedded in. The physical environment of these buildings therefore affects the distribution of heat and moisture within the clay sculptures, especially on the surfaces. This also results in deterioration such as peeling, cracking, etc. To simulate and assess the stress deterioration generated inside the clay sculptures under the fluctuation of thermal and humidity environment, this paper takes the Arhat statue of Baosheng Temple in Suzhou, China, as an example, and simulated its internal thermal and humidity distribution through the heat and moisture transfer model. Combined with the elasticity mechanics model, this paper selected the points 0.5 cm from the statue surface to calculate the thermal and humidity stress at these points. The simulation and monitoring results show that the simulated maximum thermal and humidity stress at 0.5 cm from the surface of the statue in the in-situ environment is 392 kPa (tensile stress), which means the existence of material damage risk. The simulation shows that the fluctuation of ambient temperature in Baosheng Temple Museum of Antiquities will cause a risk of stress deterioration on the surface of the statue. Therefore, for the preservation of clay statues, the thermal and humidity fluctuations of the physical environment should be reduced.

关键词： cultural heritage preservation clay sculptures heat and moisture transfer thermal and humidity stress risk assessment

来源：评论

学校读者我要写书评

暂无评论

Mechanical Performance at High Temperatures of FRCC for Permanent Moulds 4th

Mechanical Performance at High Temperatures of FRCC for Perm...

引用

4th FIB International Conference on Concrete Sustainability

作者： Assi Rabelo, Nathalia Maria Oliveira Barros, Joaquim Antonio Couto Fernandes Cunha, Vitor Manuel Univ Minho Dept Civil Engn ISISE P-4800058 Guimaraes Portugal

ISBN: (纸本)9783031806742;9783031806728;9783031806711

The lack of systematic and reliable approaches to inspection, maintenance and repair in the construction sector contributes to increase the repair and maintenance costs, loss of functionality and safety of structures. Accordingly, accidental events that can cause severe damage to the structure and jeopardize the building's safety, such as by e.g. fire, should also be taken into account. Considering the above and aiming to enhance the performance of reinforced concrete (RC) structures, conventional formwork can be replaced by an innovative panel made up of a cementitious matrix reinforced with fibres, which will provide the structural element with a less porous surface, thus helping to improve the durability of the structural element and its performance at high temperatures. Therefore, this study aims to improve the mechanical performance at high temperatures of fibre reinforced cement-based composites (FRCC) containing polypropylene (PP) and polyvinyl alcohol (PVA) fibres. Additionally, slag and micro-silica were incorporated into the mixture as supplementary cementitious materials to achieve a denser cementitious matrix. The cementitious composite's cracking behaviour at high temperatures was enhanced by introducing both PP and PVA fibres. An experimental campaign was carried out to evaluate the effect of PP fibre content, ranging from 0.5 to 1.5% by volume, on the physical and mechanical properties of the cement composite, while keeping the PVA fibre content constant at 0.5% by volume. This study presents and discusses multiple properties of the FRCC developed for the permanent moulds' panel, such as workability, variation in colour, compressive behaviour, as well the loss of mass for specimens exposed at different high temperatures (i.e., 400 degrees, 600 degrees and 800 degrees). The experimental results are presented and discussed.

关键词： Fibre reinforced cement-based composites high-temperature polypropylene and polyvinyl alcohol fibres mechanical properties

来源：评论

学校读者我要写书评

暂无评论

Geotechnical Design Challenges Related to Emergency Repair of a Transportation Corridor After a Fault Rupture Event and Potential Repair Options, Including Use of Lightweight Cellular Concrete 5th

Geotechnical Design Challenges Related to Emergency Repair o...

引用

5th International Conference on Transportation Geotechnics

作者： Balachandran, Somalingam Wykoff, Jeff GENTERRA Consultants Inc Geotech Engn Dept Irvine CA 92618 USA Cell Crete Business Dev Dept Monrovia CA USA

ISBN: (纸本)9789819782192;9789819782178;9789819782161

The paper presents an overview, from the geotechnical engineering perspective, of a dike embankment that serves as a transportation corridor and crosses San Andreas Fault in Coachella Valley, California and potential alternatives that were considered for emergency repair of the dike embankment if an earthquake causes a fault rupture through the dike embankment, including the use of Lightweight Cellular Concrete (LCC) for an interim and quick repair to protect lives and important facilities located on the protected side. This paper also covers recent applications and state of practice of LCC in California for transportation related projects. This paper covers the following key issues: (1) project requirements, (2) site conditions and constraints, (3) geologic-seismic hazards, (4) analysis of alternatives for emergency repair after a fault rupture through the dike embankment, (5) a review of state of practice in using LCC for transportation projects, and (6) a summary of recent LCC projects related to transportation projects, including projects related to protecting roadways along the coastline.

关键词： Fault rupture Dike embankment Lightweight cellular concrete

来源：评论

学校读者我要写书评

暂无评论

Physicochemical Properties of PVA and PE Fibers and Their Impact on the Mechanical Properties of Cement-Based Composite Materials 2nd

Physicochemical Properties of PVA and PE Fibers and Their Im...

引用

2nd International Conference on Geosynthetics and Environmental engineering

作者： Dong, Shun Tan, Yaosheng Lu, Qi Liu, Gang Gao, Chao Cao, Ya Three Gorges Corp Wuhan 430010 Peoples R China Changjiang Water Resources Commiss Changjiang River Sci Res Inst Wuhan 430010 Peoples R China Changjiang Water Resources Commiss Wuhan 430010 Peoples R China

ISBN: (纸本)9789819777686;9789819777662;9789819777655

During the formation process of cement-based composite materials, the interior exhibits strong alkalinity, and the ability of fibers to enhance Engineered Cementitious Composites (ECC) largely depends on the fibers' good alkali resistance. In this study, polyvinyl alcohol (PVA) and polyethylene (PE) fibers were selected to simulate the effects of an alkaline mortar environment on the physicochemical properties and mechanical properties of fibers, and ECC with high strain hardening characteristics were prepared based on the properties of the two fibers. The workability and mechanical properties of ECC were evaluated through flowability tests, compressive tests, and flexural tests. Experimental results show that PE fibers exhibit stable performance in the simulated alkaline mortar environment, with retention rates of fracture strength and tensile strain at 91.64% and 95.05% after soaking for 3 days, respectively. In comparison, the retention rates of fracture strength and tensile strain of PVA fibers are 85.09% and 60.16%, respectively. Mortar performance tests demonstrate that at a PE content of 2.5% and a water-to-binder ratio of 0.27, the ultimate tensile strength reaches 7.1 MPa and the ultimate tensile strain reaches 6.6%. For PVA fibers at a content of 2.5% and a water-to-binder ratio of 0.31, PVA-ECC exhibits the maximum ultimate tensile strength and ultimate tensile strain, at 4.7 MPa and 1.4%, respectively. The incorporation of PE fibers in ECC results in better strain hardening characteristics due to the stronger alkali resistance of PE fibers. The high strength and high elastic modulus characteristics of PE fibers are well matched with the high-strength mortar matrix, and the energy dissipation bridging effect of fibers is significant. This study for the first time identifies the influence of fiber alkali corrosion resistance on the mechanical properties of ECC, providing experimental support and reference for the selection and proportioning of fiber raw ma

关键词： PVA PE ECC Cement based composite material Mechanical property

来源：评论

学校读者我要写书评

暂无评论

A Statistical Review on the on Usage of Geopolymer Composites in Roads

A Statistical Review on the on Usage of Geopolymer Composite...

引用

2023 International Conference on Environmental Geotechnology, Recycled Waste Materials and Sustainable engineering

作者： Nasir, Humaib Singh, Davinder Dr BR Ambedkar Natl Inst Technol Jalandhar Punjab India

ISBN: (纸本)9789819797790;9789819797776;9789819797769

The extensive acceptance of geopolymers has proven to have a wide range of scope to absolutely participate to ecological aspects in each economic and manufacturing sector, with the usage of construction waste materials can help in decrease in carbon footprint. Intensive analysis and survey have been done on geopolymers throughout the past two decades, highlighting the scope of supplementary cementitious materials that are activated through alkalis to interchange with normal hydraulic cement. However, there are a variety of issues noticed for the acceptance of these geopolymer-based cements abundant of the analysis into geopolymers using fly ash and alkali solutions. It has been found that these alkali-activated solutions are extremely corrosive. But sodium and potassium salt solutions are projected as additional easy and highly acceptable for business. The extremely inconstant nature of C & D wastes is supposed to be the attention for analysis, having combined styles which can help to target domestically on the market waste materials. Abundant analysis has targeted on geopolymer binders developed using heat-based curing. But it can lead to increased energy consumption thereby reducing environmental benefits, which actually acts as limitation of cast in situ applications, analysis focusing on curing conditions, focusing the problems of strength, and setting time is needed. Sturdiness problems had been considered to be self-addressed with studies focusing on the strength of geopolymers being decreased for shorter durations after continuous curing and potential issues about salt-based corrosion of reinforcing steel;more analysis is suggested for performing analysis of leachate development for waste materials-based geopolymers. The aim of this review is to analyze the waste-based geopolymers to showcase the issues and limitations for adoption of these materials with the aim for future acceptance of these materials.

关键词： Geopolymers Reclaimed asphalt pavement (RAP) Alkaline solution Geopolymerization

来源：评论

学校读者我要写书评

暂无评论

没有更多数据了...

全选清除本页清除全部题录导出标记到“检索档案”

共500页 << < 38 39 40 41 42 43 44 45 46 47 > >>

检索报告对象比较合并检索0

隐藏清空

合并搜索

回到顶部

执行限定条件

内容：

评分：

请选择保存的检索档案：

请选择收藏分类：

订阅名称：

通借通还

温馨提示：

图书名称：

借书校区：

取书校区：

手机号码：

邮箱地址：

一卡通帐号：

电话和邮箱必须正确填写，我们会与您联系确认。

联系人：

所在院系：

联系邮箱：

联系电话：

内蒙古自治区呼和浩特市赛罕区大学西街235号邮编: 010021

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

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：