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991.
992.
1.保护生态,促进人水和谐共处
重庆按照"预防为主、保护优先、综合治理"的思路,围绕建设"宜居重庆""森林重庆""健康重庆",大力实施库区生态保护、水环境治理工程,极大改善了库区环境条件,使库区的水体变得更加清澈、天空变得更加明净、 相似文献
993.
简要总结了滨海建筑物钢结构腐蚀的原因及防范措施.介绍了滨海某电厂采取的防腐方案,为其它类似工程提供一定的参考. 相似文献
994.
将膜分离技术与生物流化床工艺有机结合,采用结合后的膜生物流化床(Membrane-Fluidized Bed Bioreactor,MFBB)处理城市污水。试验以气水比作为曝气强度指标,考察了在气水比为15∶1、25∶1和45∶1的情况下MFBB的运行特性及曝气强度对其运行特性的影响。试验结果表明,系统的曝气强度并非越高越好,而是存在一个最佳值,本试验条件下的最佳气水比为25∶1,此时CODCr、NH3—N、TN去除率分别可达96.91%、98.02%和60.12%。稳定阶段的脱氢酶活性平均值达23.8μgTF/(mgMLSS.h)。 相似文献
995.
当水源水质碱度、硬度偏低,呈弱腐蚀性时,控制其水质化学稳定性的有效方法是再矿化工艺,再矿化工艺分两个步骤:①在混凝前先投加二氧化碳进行酸化,再投加石灰水进行中和,以提高碱度,且使pH处于混凝最佳值;②在滤后的主加氯后补加饱和石灰水,以保证出厂水水质稳定性。再矿化工艺能改善出厂水水质化学稳定性,提高供水水质和供水安全性,但运营成本较高。 相似文献
996.
997.
Whereas most research on Internetware has focused on new technologies for keeping track of a changing Internet,little attention has been paid to the software development process.A large portion of the software running the Internet is open source software.Open source software is developed both by volunteers and commercial companies,often jointly.Companies get involved in open source projects for commercial reasons,and bring with them a commercial software development process.Thus,it is important to understand how commercial involvement affects the software development process of open source projects.This article presents case studies of three open source application servers that are being developed jointly by a volunteer community and one primary software company.We are interested in better understanding developer behavior,specifically task distribution and performance,based on whether the developer is an external contributor,e.g.,a volunteer working in their spare time,or a commercial developer from inside the primary backing company who is being paid for their time.To achieve this,we look at issue reporting as an example of commercial involvement in open source projects.In particular,we investigate the distribution of tasks among volunteers and commercial developers by studying the source of reported issues and quantify the task performance on user experience via the issue resolution speed.We construct measures based on historical records in issue tracking repositories.Our results show that,with intensified commercial involvement,the majority of issue reporting tasks would be undertaken by commercial developers,and issue resolution time would be reduced,implying a better user experience.We hope our methods and results provide practical insights for designing an efficient hybrid development process in the Internetware environment. 相似文献
998.
A novel gray-level image encryption/decryption scheme is proposed, which is based on quantum Fourier transform and double random-phase encoding technique. The biggest contribution of our work lies in that it is the first time that the double random-phase encoding technique is generalized to quantum scenarios. As the encryption keys, two phase coding operations are applied in the quantum image spatial domain and the Fourier transform domain respectively. Only applying the correct keys, the original image can be retrieved successfully. Because all operations in quantum computation must be invertible, decryption is the inverse of the encryption process. A detailed theoretical analysis is given to clarify its robustness, computational complexity and advantages over its classical counterparts. It paves the way for introducing more optical information processing techniques into quantum scenarios. 相似文献
999.
Xun-Ru Yin Wen-Ping Ma Wei-Yan Liu Dong-Su Shen 《Quantum Information Processing》2013,12(9):3093-3102
An efficient bidirectional quantum secure communication protocol is proposed with two-photon entanglement. Compared with the previous protocol proposed by Shi et al., our protocol can achieve higher efficiency. Meanwhile, for the same length secret messages, only half of entangled photon pairs need to be prepared in our protocol. And the number of classical bits in public classical communication is also a half of that in the previous protocol. Moreover, the information leakage does not exist in our scheme. 相似文献
1000.
A scheme is proposed to deterministically generate a two atoms entangled state and a multiple atoms W state in two coupled cavities by one step. In the scheme, the populations of cavities and atoms excited are negligible under certain conditions with an adiabatic passage along a dark state. Furthermore, the interaction time needs not to be controlled exactly and keeps unchanged with the increasing of the number of qubits. In consideration that only one of the atoms needs to be operated, the realization in experiment can be relatively easier. 相似文献