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外部加环肋圆柱壳声散射数值和试验研究(英文) 被引量:1
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作者 周富霖 范军 +1 位作者 王斌 汤渭霖 《船舶力学》 EI CSCD 北大核心 2019年第6期728-740,共13页
双层壳体声散射特性研究对水中目标探测和识别具有重要意义。文章基于混合2-D/3-D有限元法对外部加环肋圆柱壳声散射进行数值建模,基于薄壳理论推导近似解析表达式对周期加肋圆柱壳的角度频率谱中Bragg散射和Bloch-Floquet弯曲波共振散... 双层壳体声散射特性研究对水中目标探测和识别具有重要意义。文章基于混合2-D/3-D有限元法对外部加环肋圆柱壳声散射进行数值建模,基于薄壳理论推导近似解析表达式对周期加肋圆柱壳的角度频率谱中Bragg散射和Bloch-Floquet弯曲波共振散射进行理论预报,并进行水池试验验证。与平板情况相比,圆柱薄壳中存在弯曲波a0、压缩波s0和剪切波T0三种弹性波,弯曲波对Bloch-Floquet波共振散射有重要作用。外部环肋板不仅通过影响壳体振动间接影响外部散射声场,而且作为散射子结构通过与外部流体耦合直接参与散射。与解析方法和物理声学方法相比,混合2-D/3-D有限元方法充分考虑了结构弹性、肋板与圆柱壳体之间的遮挡和多重散射效应,以及肋板与水的耦合作用,具有计算准确、高效等优点,能较好地解决复杂结构的中低频振动-声耦合问题。 展开更多
关键词 声散射 圆柱壳 外部环 有限元法
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论城市竞争力及评价方法和程序 被引量:20
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作者 李娜 于涛方 《人文地理》 CSSCI 北大核心 2005年第3期44-48,共5页
本文对国内外“竞争力”辨析的基础上,探讨了城市竞争力的概念。其结论是:城市竞争力是指一定竞争环境中,一个城市在发展过程中所具有的吸引、争夺、拥有、控制和转化资源,以创造价值或财富,提高居民生活水平和城市可持续发展的能力。... 本文对国内外“竞争力”辨析的基础上,探讨了城市竞争力的概念。其结论是:城市竞争力是指一定竞争环境中,一个城市在发展过程中所具有的吸引、争夺、拥有、控制和转化资源,以创造价值或财富,提高居民生活水平和城市可持续发展的能力。在城市竞争力概念和城市竞争力影响因素的“环境学派”、“资源学派”和“能力学派”基础上,本文分析了城市竞争力的一般评价方法:区域经济学方法、基准法和SWOT方法。最后总结了城市竞争力评价的一般程序。 展开更多
关键词 城市竞争力 内部资源 内部能力 外部环
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All-solid-state ultraviolet laser based on frequency doubling in an external ring cavity
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作者 SHEN Gao WANG Bao-shan +3 位作者 TAN Hui-ming PENG Ji-ying FU Xi-hong ZHAO Yu-huan 《Optoelectronics Letters》 EI 2007年第6期448-450,共3页
An all-solid-state ultraviolet laser based on frequency doubling in an external ring cavity with low input pump power is reported. Both second harmonic generation (SHG) and fourth harmonic generation (PRIG) occurr... An all-solid-state ultraviolet laser based on frequency doubling in an external ring cavity with low input pump power is reported. Both second harmonic generation (SHG) and fourth harmonic generation (PRIG) occurred in an external threemirrors ring cavity. The need for impedance matching of this cavity to the input radiation was eliminated and the cavity adaptation was simplified, because the mirrors were not highly reflecting at 1064 nm and the cavity resonates only at 532 rim. Experiment results demonstrate that the conversion efficiency of this external cavity is higher than that of the singlepass condition. 展开更多
关键词 固体 激光器 外部环空腔 频率重叠
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The Topical Use of Aprotinin in Cardiac Surgery with Cardiopulmonary Bypass
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作者 陈亦江 王晓伟 陈广明 《Journal of Nanjing Medical University》 2003年第1期23-29,共7页
Objective To investigate the effects of the topical use of aprotinin on thebasis of comprehensive blood conservations in cardiopulmonary bypass (CPB). Methods In a prospectiveclinical trial, 20 patients were randomly ... Objective To investigate the effects of the topical use of aprotinin on thebasis of comprehensive blood conservations in cardiopulmonary bypass (CPB). Methods In a prospectiveclinical trial, 20 patients were randomly divided into 2 groups. Control group: placebo was usedtopically. Aprotinin group: aprotinin was poured into the pericardial cavity before closure of thesternotomy. Before and 24h after surgery, hemoglobin (Hb), hematocrit (Hct), bleeding time (BT),clotting time (CT) and prothrombin time (PT) were measured. Meanwhile, amounts of the mediastinaldrainage and the hemoglobin loss were observed at 0, 2, 6 and 24h after operation. The samples fromthe mediastinal drainage were also collected to measure D-Dimer (D-D), tissue type plasminogenactivator (t-PA) activity, plasminogen activator inhibitor (PAI) activity and protein C (PC).Results In Aprotinin group, D-D, t-PA activity and PC were significantly reduced, compared withthose in Control group (P<0.05, P<0.05, P<0.01). On the contrary, PAI activity was significantlyincreased, compared with that in Control group. Amounts of the mediastinal drainage and thehemoglobin loss were decreased by 43% and 52%, compared with those in Control group. Conclusion Ourresults suggest that the topical use of aprotinin can have better effects on the basis ofcomprehensive moderate blood conservation. 展开更多
关键词 cardiopulmonary bypass APROTININ topical use
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Heading toward Artificial Intelligence 2.0 被引量:127
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作者 Yunhe Pan 《Engineering》 SCIE EI 2016年第4期409-413,共5页
With the popularization of the Intemet, permeation of sensor networks, emergence of big data, increase in size of the information community, and interlinking and fusion of data and information throughout human society... With the popularization of the Intemet, permeation of sensor networks, emergence of big data, increase in size of the information community, and interlinking and fusion of data and information throughout human society, physical space, and cyberspace, the information environment related to the current development of artificial intelligence (AI) has profoundly changed. AI faces important adjustments, and scientific foundations are confronted with new breakthroughs, as AI enters a new stage: AI 2.0. This paper briefly reviews the 60-year developmental history of AI, analyzes the external environment promoting the formation of AI 2.0 along with changes in goals, and describes both the beginning of the technology and the core idea behind AI 2.0 development. Furthermore, based on combined social demands and the information environment that exists in relation to Chinese development, suggestions on the develoDment of Al 2.0 are given. 展开更多
关键词 Artificial intelligence 2.0 Big data Crowd intelligence CROSS-MEDIA Human-machine hybrid-augmented intelligence Autonomous-intelligent system
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Influence of external circulation on sludge characteristics during start-up of internal circulation reactor 被引量:4
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作者 丁建南 王淀佐 《Journal of Central South University of Technology》 EI 2005年第4期425-429,共5页
The start-up of external circulationadded internal circulation(IC) reactor was finished in 26 d, 32 d fewer than that of IC reactor. To evaluate the influence of the added external circulation on the development of gr... The start-up of external circulationadded internal circulation(IC) reactor was finished in 26 d, 32 d fewer than that of IC reactor. To evaluate the influence of the added external circulation on the development of granular sludge, the characteristics of the granular sludge taken from the two tested laboratory-scale reactors during start-up were studied. The results show that the added external circulation can enhance biomass granulation, accelerate granule development and improve sludge characteristics. At the end of start-up, the granular size of sludge in external circulation-added IC reactor greatly increases with a size distribution much better than that of sludge in IC reactor. The granular sludge originated from external circulationadded IC reactor contains more extracellular polymers and has a greater settling velocity than that from IC reactor. Methanogenic activity of the granular sludge from the external circulationadded IC reactor started 26 d ago reaches 358.23mL·g -1 ·d -1 , 1.66 and 1.20 times as great as that of the sludge from the IC reactor started 26 d and 58 d ago respectively. 展开更多
关键词 external circulation internal circulation reactor characteristics of granular sludge
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Effects of pH management during deep hypothermic bypass on cerebral oxygenation: alpha-stat versus pH-stat 被引量:9
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作者 郦志军 尹小妹 叶箭 《Journal of Zhejiang University Science》 CSCD 2004年第10期1290-1297,共8页
Objective: There is a remarkable lack of scientific evidence to support the option to use alpha-stat or pH-stat management, as to which is more beneficial to brain protection during deep hypothermic CPB. This study ex... Objective: There is a remarkable lack of scientific evidence to support the option to use alpha-stat or pH-stat management, as to which is more beneficial to brain protection during deep hypothermic CPB. This study examined cortical blood flow (CBF), cerebral oxygenation, and brain oxygen consumption in relation to deep hypothermic CPB with alpha-stat or pH-stat management. Methods: Twenty-two pigs were cooled with alpha-stat or pH-stat during CPB to 15℃ esophageal temperature. CBF and cerebral oxygenation were measured continuously with a laser flowmeter and near-infrared spec-troscopy, respectively. Brain oxygen consumption was measured with standard laboratory techniques. Results: During CPB cooling, CBF was significantly decreased, about 52,2%±6.3% (P<0.01 vs 92.6%±6.5% of pH-stat) at 15℃ in alpha-stat, whereas there were no significant changes in CBF in pH-stat. While cooling down, brain oxygen extraction (OER) progressively decreased, about 9.5%±0.9% and 10.9%±1.5% at 15℃ in alpha-stat and pH-stat, respectively. At 31℃ the decreased value in pH-stat was lower than in alpha-stat (29.9%±2.7% vs 22.5%±1.9%; P<0.05). The ratio of CBF/OER were 2.0±0.3 in alpha-stat and pH-stat, respectively; it was kept in constant level in alpha-stat, and significantly increased by 19 ℃ to 15℃ in pH-stat (4.9±0.9 vs 2.3±0.4; P<0.01). In mild hypothermia, cerebral oxyhemoglobin and oxygen saturation in alpha-stat were greater than that in pH-stat (102.5%±1.4% vs 99.1%±0.7%; P<0.05). In deep hypothermia, brain oxygen saturation in pH-stat was greater than that in alpha-stat (99.2%±1.0% vs 93.8%±1.0%; P<0.01), and deoxyhemoglobin in pH-stat decreased more greatly than that in alpha-stat (28.7%±6.8% vs 54.1%±4.7%; P<0.05). Conclusions: In mild hypothermic CPB, brain tissue oxygen saturation was greater in alpha-stat than in pH-stat. However, cerebral oxygenation and brain tissue oxygen saturation were better in pH-stat than in alpha-stat during profound hypothermia. PH-stat strategy provided much more oxygen to brain tissue before deep hypothermic circulatory arrest. 展开更多
关键词 PH management Cerebral oxygenation Deep hypothermia Cardiopulmonary bypass
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Major Power Diplomacy with Chinese Characteristics Is Moving forward Steadily
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作者 Wang Honggang 《Contemporary International Relations》 2017年第2期107-129,共23页
The year of 2016 witnessed the balance of internal and external situations, calm and steady actions and proper planning in major power diplomacy with Chinese characteristics. Those were reflected in the success of the... The year of 2016 witnessed the balance of internal and external situations, calm and steady actions and proper planning in major power diplomacy with Chinese characteristics. Those were reflected in the success of the G20 summit, the vigorous promotion of the"One Belt, One Road"(B&R) Initiative and the active promotion of international cooperation on development, which acquired positive response and general agreement from the international community and made special contributions to building a more just and reasonable international order.Those were also reflected in the active management of major power relations and sound responses to the changing situation in the surrounding area to create good external environment for domestic development. In addition, further expansion and defending of overseas interests set higher standards for Chinese diplomacy. Having been pushed by the era to the forefront, China is performing its responsibility as a major power in a peculiar way and will certainly make greater contributions to world peace and development. 展开更多
关键词 Chinese diplomacy global govemance major power relations surroundings B&R Initiative
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Study on the Flowering Regulator of the Paeonia suffruticosa "Hongdan Lan"
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作者 Min Deng Suping Gao Yang Guo 《Journal of Agricultural Science and Technology(B)》 2012年第7期824-834,共11页
In the study, Southwest peony varieties group of Paeonia suffruticosa "Hongdan Lan" were analyzed, test was mainly divided into two parts, one is the nature of the low temperature, through the external environment i... In the study, Southwest peony varieties group of Paeonia suffruticosa "Hongdan Lan" were analyzed, test was mainly divided into two parts, one is the nature of the low temperature, through the external environment is mainly (temperature, light) gibberellin and nutrition solution regulation, on the Tianpeng peony florescence control technological research. The second is to explore the flower forcing peony after anthesis regeneration technique. The main research results: comprehensive gibberellin peony flower induction of morphological and physiological indexes, such as gibberellin concentration of 150 mgFL and 200 mg/L the effect of flower induction was better than the other treatments; gibberelin (GA3) breaking the dormancy of the peony to blossom ahead of time has the promoter action, also has certain effect on nutritional growth; to premature flowering the abscisic acid (ABA) has opposite effect; whereas auxin (IAA) and corn (ZT) effect was not obvious; rejuvenation results showed that after a year of conservation and managemental measures, flower induction after the flower of peony played a very important role in the restoration. After the winter flower induction, peony flowerpot of soil hardening, through the soil replacement, repair of roots, flower peony recovery showed a very significant effect. 展开更多
关键词 TianPeng peony flowering regulation Gibberellin (GA3) nutrition solution accumulated temperature rejuvenation.
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Japan's Promotion Policy toward ASEAN Interconnections
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作者 Zhang Jiye 《Contemporary International Relations》 2017年第3期124-137,共14页
In Japan's support for ASEAN countries' connection building can be seen its policy visions in functional positioning, geographical layout and connotation constitution. As part of a systematic policy framework,... In Japan's support for ASEAN countries' connection building can be seen its policy visions in functional positioning, geographical layout and connotation constitution. As part of a systematic policy framework, Japan supports ASEAN transregional and outside-regional connections with the Mekong subregion as focal point, pushes forward metropolitan interconnection of ASEAN countries with Jakarta a priority,promotes building infrastructure, develops rules, and constructs better external environments for connectivity, all while advancing its Partnership for Quality Infrastructure to attract ASEAN countries' cooperation.Because of Japan's economic interests and geopolitical strategy toward ASEAN countries, Japan's policy influences China's Belt and Road Initiative and China should properly respond to Japan's actions. 展开更多
关键词 JAPAN ASEAN Southeast Asia development Sino-Japanese relations
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Investor Relations (IR) in Business Communication on the Example of Poland
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作者 Ryszard Kamifiski 《Journal of Modern Accounting and Auditing》 2013年第11期1483-1496,共14页
This paper focuses on investor relations (IR) as an element of companies' communication with the external environment. It shows the place and role of IR in communication with the general market, and the stock excha... This paper focuses on investor relations (IR) as an element of companies' communication with the external environment. It shows the place and role of IR in communication with the general market, and the stock exchange market in particular. The study is illustrated with an example of IR in Poland, a relatively new European Union (EU) member state and an emerging market. As can be seen, IR goes beyond the traditionally understood maintenance of communication with the capital market. It is also shown that the main role of IR ought to be the reduction of investment risk and enhancement of the companies' value, which is of particular significance in light of the current globalization of capital markets. It has been found that Polish companies, especially those listed on the Warsaw Securities Exchange (WSE), commonly rely on IR as a means of communication with the environment. And yet, as the results of the analysis show, the quality of that communication is still far from satisfactory, despite efforts undertaken by various external entities to encourage more focus on the development of IR, or understanding of the company's relevant staff of its important role. 展开更多
关键词 investor relations (IR) public relations (PR) business communication financial reporting STAKEHOLDERS capital market securities exchange/stock exchange information technologies
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An Analysis of the Indian Modi Administration's Policy on the South China Sea Issue
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作者 Lou Chunhao 《Contemporary International Relations》 2017年第4期48-71,共24页
Geographically, India is not a country in the region of the South China Sea, nor is it a country concerned in the issue on a geopolitical level or a US ally in the Asia-Pacific region. It has been very cautious to avo... Geographically, India is not a country in the region of the South China Sea, nor is it a country concerned in the issue on a geopolitical level or a US ally in the Asia-Pacific region. It has been very cautious to avoid taking sides in the South China Sea issue. However, since Modi took office in 2014, changes have taken place in the external environment that India faces, in maritime safety strategy, as well as in India's policies toward the US and China. India is becoming increasingly active in the issue of the South China Sea, voicing criticism and taking precautions against China. While India's policy on the South China Sea will not be completely the same as that of the United States and Japan, due to concerns for its own interests in the future, it is quite possible that India will take advantage of the issue of the South China Sea and will adopt more comprehensive ways to get involved in the issue. 展开更多
关键词 The Modi administration policy on the South China Sea Sino-Indian relations
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An Analysis of the Great Power Strategy of India's Modi Government
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作者 Wang Xiaowen 《Contemporary International Relations》 2017年第4期102-125,共24页
Over the past two years, India's Modi government has demonstrated the following features: focusing on the goals of becoming a great power and shaping India's South Asian dominance, expanding the scope of diplo... Over the past two years, India's Modi government has demonstrated the following features: focusing on the goals of becoming a great power and shaping India's South Asian dominance, expanding the scope of diplomatic strategy, emphasizing the role of soft power and focusing on self-development as well as external environment. Modi's great power strategy is deeply influenced by the Indian realistic international political outlook and, to a certain extent, reflects the governing philosophy of the Bharatiya Janata Party. The great power strategy is Modi's governing foundation and governing style, embedding Modi distinctive personal style. Under the influence of the great power strategy, China and India have increased their economic cooperation scope, widening the forms of public diplomacy, with an obvious geopolitical collision; India is taking more measures to check China. 展开更多
关键词 INDIA Modi government great power strategy Sino-India relations
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Management of the Higher Education Institution in the Ethical Actions Context
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作者 Seweryn Cichofl 《Chinese Business Review》 2015年第5期246-252,共7页
Managing the university in the context of ethics is one of many elements in the management of this specific organization. The task of university is functioning based on universal values, mission, vision, ethical codes... Managing the university in the context of ethics is one of many elements in the management of this specific organization. The task of university is functioning based on universal values, mission, vision, ethical codes, and responsibility and worthy behavior towards internal and external environment. In the era of globalization and constant changes, only a modernly managed higher education institution, acting according to principles of ethics, is able to meet requirements of surroundings. Behaviors of academic community should promote ethical actions in higher education institutions. It should be noted that the reputation, prestige in higher education, should also be based on the proceedings consistent with ethics. 展开更多
关键词 managing the higher education institutions ETHICS ethical actions ethical code ethical principles
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The Exploration of Reasons Why Southeast Asia Countries Have Strong Insecurity About the Rise of China
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作者 Lyu xiaoli Bai Ruixin 《Cultural and Religious Studies》 2018年第3期204-214,共11页
The word, “China’ rise”, has highlighted the rapidity and suddenness of China’s development, and the Southeast Asia region, both in history and in reality, has a close relationship with China. In face of the giant... The word, “China’ rise”, has highlighted the rapidity and suddenness of China’s development, and the Southeast Asia region, both in history and in reality, has a close relationship with China. In face of the giant’s rise, some Southeast Asia countries have reduced their sense of certainty and control over this external environment, which causes their insecurity. The reasons of this phenomenon include the factor of history, ideology, geopolitics, overseas Chinese and extraterritorial states intervention. We should go start with national and ideological barriers, combine the analysis of the sense of certainty and control, to understand the underlying causes of insecurity. 展开更多
关键词 the rise of China Southeast Asia the sense of certainty and control the reasons
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Today's Risks and Difficulty of Chinese Commercial Banks
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作者 Dong Liwei Hai Dong 《Journal of Modern Accounting and Auditing》 2012年第10期1535-1540,共6页
According to the Top 1,000 world banks released by the British authoritative magazine The Banker, the profits made by Chinese banking industry in 2011 had accounted for one-third of the global banking profits, and nea... According to the Top 1,000 world banks released by the British authoritative magazine The Banker, the profits made by Chinese banking industry in 2011 had accounted for one-third of the global banking profits, and nearly 100 banks had been included in the Top 1,000 world banks list. This proves that China's commercial banks have been standing in the forefront of the world. While achieving such impressive results, China's risks and uncertainties due to the constraints of the internal and external environment cannot be ignored. Those risks are mainly about the risks of the over-estimation of the expected return for financial products, the high credit concentration, as well as the seldom use of financially derivative products. Therefore, it is difficult to avoid risks by the portfolio management, which restricts the further improvement of the competitiveness of commercial banks. 展开更多
关键词 expected return credit concentration risk control
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Countermeasures of Financing Difficulties of Small and Micro Enterprises in China
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作者 SUN Changfeng 《International English Education Research》 2015年第12期80-82,共3页
Financing difficult problem has seriously restricted the further development of small and micro enterprises in our country. This paper analyzes and discusses the Countermeasures of the financing difficulties of small ... Financing difficult problem has seriously restricted the further development of small and micro enterprises in our country. This paper analyzes and discusses the Countermeasures of the financing difficulties of small and micro enterprises in our country from two aspects of the external environment and internal self. 展开更多
关键词 Small and micro enterprises FINANCING DIFFICULTY
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Analysis on Sustainable Development of CNPC Mud Logging Business
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作者 Zheng Yi Liu Yingzhong Zhang Zaixu 《China Oil & Gas》 CAS 2016年第2期16-22,共7页
As oil and gas development gets more difficult, the market competition in engineering technology services tends to be fiercer. CNPC mud logging business is facing double challenges from tedmology and market. We analyz... As oil and gas development gets more difficult, the market competition in engineering technology services tends to be fiercer. CNPC mud logging business is facing double challenges from tedmology and market. We analyzed both external and internal environment for CNPC logging business development, made clear the opportunities and challenges, gained insights in to the existing problems, and proposed countermeasu res from the aspects of management system, service mode, proyqtability, techniques and equipment, market expansion, and personnel training. 展开更多
关键词 CNPCi lVIud logging business Managemeni system Service node Profitabili Market expansion Sustainable development
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Analysis on the Factors Restricting the Entrepreneurship Quality Education for the Young Peasant Workers Back to Hometown in Yunnan Province and the Related Strategies
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作者 Muqing PENG Fei HU 《International Journal of Technology Management》 2013年第10期57-59,共3页
Entrepreneurship quality education is not only the standpoint and focus of entrepreneurship education, but also the key point in entrepreneurship education. In this paper, based on three aspects (the educated, the su... Entrepreneurship quality education is not only the standpoint and focus of entrepreneurship education, but also the key point in entrepreneurship education. In this paper, based on three aspects (the educated, the subjects implementing education, and external environment), the main factors restricting the entrepreneurship quality education for the young peasant workers back to hometown in Yunnan province are analyzed, and also the governmental strategies of a clear purpose and a powerful applicability are further explored. 展开更多
关键词 Young Peasant Workers to Hometown the Improvement of Entrepreneurial Quality Restricting Factors STRATEGIES
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Characters of Urban Development and Its Spatial Morphology Underground Space Influences on Urban
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作者 Chen Zhilong Yang Xiaobin 《Review of Global Academics》 2014年第2期205-215,共11页
Underground building with such major functions as underground traffic, commerce, culture and recreation, especially the multifunctional underground large-scale public complex, has become a significant part of the over... Underground building with such major functions as underground traffic, commerce, culture and recreation, especially the multifunctional underground large-scale public complex, has become a significant part of the overaU functional structure or even the core of a city. Therefore, the expression of the architectural appearance, and characters of underground building, as well as the integration between the building and its external environment constitute an important part in improving overall functional structure and optimizing cityscape. From the perspective of space and environment shaping, the author explores the architectural appearance, and characters of underground building and its external environment, provides several basic design patterns with further discussion. 展开更多
关键词 Underground space Urban morphology Architectural appearance CHARACTER
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