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1.
氟是环境污染元素。自然界中氟的存在形式。含氟工业。我国有关氟含量的规定。氟的危害。氟的治理。  相似文献   

2.
改革开放以来。我国“军转民”政策取得了丰硕的成果。一方面。一大批军工企业实现了向民品生产的转移。并成为了该民品所属行业的龙头老大。经过近二十年“军转民”的艰苦努力。一大批深受社会欢迎的军工行业的主导民品、支柱民品、优势民品和具有较好规模的第三产业如雨后春笋。蓬勃发展。形成一个军民结合型的国防科技工业的整体新格局。“军转民”政策。使大批军工企业走出困境。走上了新的军民结合的广阔大道。“军转民”政策稳定和锻炼了我国军工技术队伍。发展了我国国防工业。另一方面。一大批军用技术实现了向民用领域的转移。加大了民品的技术含量。促进了民品的技术进步。一大批民企由于采用了军工技术和利用了军工人才。实现了企业内部的产品更新换代,实现了产业升级,使企业获得了新生,获得了巨大的经济效益。“军转民”政策促进了我国科技进步和高新技术的发展。对地方经济、地区经济乃至整个国民经济的发展。起到了巨大的推动作用。“军转民”政策将继续在国防军工发展和国民经济建设中发挥长久的不可替代的作用。  相似文献   

3.
1团队冲突的类型根据团队冲突的主体划分。1)成员与团队之间的冲突。2)团队成员之间的冲突。根据团队冲突的影响因素划分。1)认知性冲突。2)情感性冲突。根据团队冲突的效果划分。1)建设性冲突。2)破坏性冲突。  相似文献   

4.
《科技潮》1999,(6)
5月,我走过这美丽的城市。这是个和平的城市。白天,阳光灿烂;夜晚,春风沉醉。人们在编织未来,渴望在那里面装满幸福、快乐、爱情和创造的自由……然而,它今天变了。我看见充满火的眼睛在街道上流动。愤怒像爆米花一样突然膨胀了,充满了城市的每个空间。震耳欲聋的怒吼像炽热的岩浆一样从火山口里喷发出来。这是一个愤怒的城市。这是为什么?我想问。去问蓝天、白云。问路旁如血一样盛开的鲜花。问白塔顶上缭绕不绝的鸽哨。问姑娘们诱人的时装。问在春天花园里唱《莫斯科郊外的晚上》的可爱的小伙子。问在大商场里不知疲倦的顾客。问在电脑旁熬过通宵的博士们。问热情好客又能侃能发牢骚的出租车司机。问从学校闸门放出来的欢快的孩子的潮流。……问我自已。  相似文献   

5.
詹想 《科学世界》2013,(9):88-89
仙女座是秋夜星空的代表星座之一。其中有一个著名的深空天体——仙女星系(M31)。这是在北半球大多数地区能看到的最亮、最大的河外星系。也是天文爱好者最喜欢观测和拍摄的目标之一。它是一个典型的旋涡星系。距离我们大约250万光年。换句话说。我们现在看到的。实际上是它250万年前的样子。在一个晴朗无月的夜晚。避开城市的灯光向它所在的天区望去。凭肉眼就能轻易地看到一个模模糊糊的光斑。用一台小望远镜。我们就能看到它明亮的核心。  相似文献   

6.
在普通人看来。火灾探测器似乎有些神秘莫测。在宾馆、饭店、商场等公众聚集场所稍加留心。你随处可以看到它的身影。然而我们对时时刻刻监视着火灾的它却常常视而不见。其实。认识火灾探测器。了解火灾探测器。对于我们早期控制火情。减少火灾损失大有裨益。掌握火灾探测器工作和安装的相关知识。对于广大城市居民。尤其是已经安装了火灾探测器等消防设备的单位。能够使火灾探测器更好的发挥作用。更好的保护人民的生命和财产安全。随着社会物质文明的进一步发展。火灾探测器进入寻常百姓家保护生命安全也是大势所趋。  相似文献   

7.
智能交通     
陈治光 《科技潮》2007,(11):8-13
交通是人类社会的一个必要元素,从某种角度看。人类社会的进步就是一部交通发展史。随着科技的不断进步。尤其是工业革命以来。人类的交通事业有了质的飞跃。从而拉近了整个世界的距离。如今。交通不再是一种地理和空间的桎梏。而是成为经济、政治、文化交流的重要媒介。发挥着重要的作用。然而伴随着城市化的步伐。交通的极速发展也给人类带来了环境污染、资源消耗、生态破坏、城市生活质量下降等一系列社会问题。  相似文献   

8.
你知道吗?     
你的手腕到肘的长度就是脚的长度。女人头发的直径是男人的一半。聪明人头发里的锌和铜比普通人的更多一些。世界上用得最多的名字是“穆罕默德”。所有大洲的英文名字的第一个字母和最后一个字母都是一样的。《圣经》是世界上卖得最多的书,也是遭窃最多的书。热水比冷水冻得快。骰子相对的两面点数相加为7。口琴是世上卖得最多的乐器。由于地球引力的关系,最高的山也不会超过15000米。要是在黑屋子里养金鱼,它会慢慢变白。蟋蟀的耳朵长在前腿膝盖的下面。蝴蝶用它们的腿来品味。骆驼奶不会凝固。游得最慢的鱼是海马,它每小时只能游16米。如…  相似文献   

9.
序号 题 目 作 者 期号 页码 1 调整我国农业机械高等教育的几点意见 宋亚欣 高良润 21 2 我国农业机械化的回顾与前瞻 吴相渣 11 3 关干发展我国植保机械的若干问题 高良润 19 4 我国衣村能源的利用、开发与节约 吴相e 41 5 改进与发展农用柴油机若干途径的探讨 谭NH 4 12 6 热处理技术的发展趋势和国内简况 周汝霖 4 25 。。___;。。_。I。_。。施钧亮 金树德 7 发展我国喷灌用喷头的探讨 ZZ告 一’”’“116 _。_。。,。;、l。。。/、。。一·。李世英 。。。,l\。;。。;。、;,。。。、,。、,、。。金树德 曹武陵 8 我国轻小型喷灌机具…  相似文献   

10.
《水浒传》是我国古典小说中的四大名著之一。从北宋末年在说书场上开始萌芽。历经南宋、元代200余年的提炼、修改。成为一连串的水浒故事。明初再由民间文人编纂成书。成书300年来。《水浒传》对中国历史的进程产生了重大影响。多次农民起义都是模仿水浒故事而发动起来的。因此专制王朝斥此书为“诲盗”之书。而屡次查禁。直到辛亥革命以后才全面开禁。但是从五四运动开始。一些研究者又对此书开展了马拉松式的争论。争论的问题包括:作者为谁?主题思想是什么?从成书以来一共出现了多少不同的版本? 经过了80多年的争论,直到现在。这些问题仍然没有解决。我国著名史学家史式教授今已84岁高龄。他在青年时代曾经参与过《水浒》的研究工作。与老一辈文化界人士多有交往。了解当时的争论情况。他现已接受邀请。重新主持《水浒》的研究工作。笔者特地拜访了他。请他介绍80年来有关《水浒》问题争论的经过。他对这些问题的具体意见,以及今后如何开展研究工作的打算,以飨读者。[编者按]  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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