地衣快速人工繁殖方法

地衣是真菌和藻类共生的植物,藻类制造有机物,真菌吸取水份包被藻体,作为一种独特的生物体具有重要的经济价值和生态价值。地衣可以用来治疗多种疾病,其提取物是重要的医药和化工原料,有的地衣还是人类和动物的食物来源。地衣能生活在各种环境中,特别能耐干旱,寒冷,是植物界拓荒的先锋。然而地衣生长速度缓慢,依靠自然繁殖无法满足对地衣的大量需求,只有通过人工快速繁殖才能解决这一难题。本栏目推荐的地衣的快速繁殖方法,包括地衣原土的准备,繁殖基质的准备,繁殖床的准备,营养调理剂的应用,撒种,管理等系列技术。可以用于开辟     

哪些药不能热水服?

一杯热水配上药片直接喝下去,是不少人喝药时的惯用动作,其实这样做很可能让一些药的效果大打折扣。活菌制剂药物:常用的乳酶生(含有活肠链球菌),整肠生(含有地衣芽孢杆菌),金双歧(含双歧杆菌、嗜酸乳杆菌和肠球菌)等药物都是口服活菌制剂。这些活菌怕光、怕湿,不耐热,不宜用热水服用。此外,活疫苗类     

地球上生命的进程

要是你从人的角度去考虑生命这个问题,显然我们也很难不这么做,生命是个古怪的东西.它迫不及待地起步,但起步以后又似乎不大急着往前走. 想一想地衣.地衣大概是地球上最坚强的可见生物,也是最没有雄心壮志的生物之一.它们会很乐意生长在阳光明媚的教堂墓地早,但它们尤其乐意在别的生物都不愿意去的环境早茂盛生长--在风吹雨打的山顶上,在北极荒原,那里除了岩石、风雨和寒冷以外几乎什么也没有,也几乎没有竞争.在南极洲的许多地区,那早实际上别的什么也不长,你却可以看到大片大片的地衣--有400种--忠诚地依附在每一块风吹雨打的岩石上.     

’98/’99秋冬羊毛布料流行趋势

近日,国际羊毛局率先披露了’98/’99年秋冬季羊毛布料的流行趋势,该趋势共分七大主题,分别为: 细腻质感 灵感来自早餐桌上的营养食品,如新鲜牛奶、滑腻奶油、生鸡蛋、燕麦片、面包和热牛奶上的泡泡。衍生出的色彩有柔嫩的玫瑰色、肤色、小麦色、奶油色、玉米色、浅咖啡色、淡紫色及粉灰色。这一系列的羊毛布料以双面异色布、双向弹性布料为主,最适合简洁的款式,可以作多层次穿着的休闲服装面料。 斑驳纹理 灵感来自岩石经过自然界的风化、侵蚀之后,形成的表面纹理、斑驳痕迹。色彩偏向深沉一类,如地衣苔藓绿、玛瑙红、铁锈红、     

互联网生态圈:一个好汉N个帮

2000年的春天,互联网经济正如黄昏前绚烂的彩霞,光 彩照人。五个媒体背景的年轻人写了一本大部头的《互联网经 济生态报告》,计划每半年更新一次。那是一份很不错的报告, 于是对后面的续集,大家翘首以待。但几年过去了,一直也不见 有什么结果。 尽管报告没有着落,互联网作为一种生态系统的存在,却 丝毫没有改变自己的固有进程。那个叫做"互联网生态圈"的 东西像地衣一样,在冰冷的岩石上顽强地蔓延开来,它们的目 标是长成森林。     

锚、网、带、索、喷联合支护

爆破后必须及时出碴，打锚杆眼、挂网、钢带、安装锚杆、喷碹一气呵成，尽量减少炮后岩体在无支护状态下的裸露时间（不超过2h），将喷碹由原来的原班一次改为每循环一次。新生煤矿在松软岩层中大力推广锚、网、带、锚索、喷联合支护技术，提高松软岩巷的掘进速度，尤其是在一采区水仓和水泵房以及紧急避难硐室掘进中取得了较好的效果。     

眼、耳、鼻、舌、身 音乐 拯救我们

不同的音乐作用于人的感觉器官，由于旋律、速度、音调等不同，可分别产生镇静安定、轻松愉快、活跃兴奋等不同的作用，从而能调节情绪，稳定内环境，达到镇痛、降压、催眠等效果。所以，很多人都会利用听音乐来缓解压力。     

京、沪、苏、浙、鲁、粤高技术制造业竞争力比较

北京市“十二五”规划明确提出要率先在全国形成创新驱动的发展格局，深化产业结构调整、切实做到高端引领将成为重要途径之一。本文通过对京、沪、苏、浙、鲁、粤六个国内高技术大省的高技术制造业竞争力进行比较，提出北京高技术制造业应着力于巩固现有优势，并创造新的优势。     

锂、铍、铌、钽矿

锂、铍、铌、钽是稀有金属主要品种，用途甚广。在稀有金属分类中，锂、铍为稀有轻金属：铌、钽为稀有难熔金属。锂（Li）是自然界中最轻的金属，银白色．比重0．534，熔点180℃，沸点1342℃。锂是由瑞典化学家贝齐里乌斯（J．J．Berzelius）的学生瑞典人阿尔费德松U．A.Arfvedson）于1817年在分析研究从攸桃岛（Uto）采得透锂长石时首次发现的，     

国家发改委、商务部、人民银行、证监会、银监会、保监会“一把手”答记者问

张平说．从统计的数据来看，9月份、10月份经济已经出现了明显的企稳回升的迹象。但是．从发改委对形势的分析来看．企稳的基础还不够稳固。针对经济运行中出现的一些新情况、新问题，尤其是在全球经济复苏缓慢、金融危机挥之不去这样一个背景下．必须做长期应对困难和挑战的准备。     

Workfare,welfare, agency,and well-being

Workfare programs are state-instituted programs that require able-bodied persons with children of school age who wish to claim welfare payments to participate in job training programs, and, eventually, to enter the work force. The philosophy of workfare is based on the value of work and the goal of self-determination. However, as a mandatory program for welfare recipients, workfare requires of those recipients certain duties which, according to those who challenge workfare, interfere with the freedom to choose what one will do with one's life. Whether some form of workfare will be adopted as part of our national welfare system remains to be seen. What the debate about such a program suggests is that welfare, in itself, by ignoring the necessity of security and education for full human agency, neither satisfies basic needs nor prepares its recipients for any life other than that of dependency. With all its difficulties workfare nevertheless presents an alternative to welfare that, at least in theory, more closely identifies its purpose with the values of our society.     

Externalities, Indivisibility, Nonreplicability, and Agglomeration

In this paper we argue that the impact of external scale economies and diseconomies on city size is not nearly as clear-cut as it is tacitly believed in urban economics. Similarly, city-size distortions are not caused by externalities alone. Indivisibility and nonreplicability, which prevent establishing the “right” number of cities, may represent a source for city-size distortions which can be stronger than the standard resource misallocation resulting from external scale economies and diseconomies. It follows that a direct population dispersion policy is not just an inferior substitute to Pigouvian taxes and subsidies but rather a useful complement.     

Returns to specialization,competition, population,and growth

Using an expanding-variety endogenous growth model with purposive human capital accumulation, this paper provides an alternative explanation of why we may observe an ambiguous correlation between product market competition (PMC) and economic growth, and between population and economic growth rates. Our explanation is based on the notion of ‘returns to specialization’. Under the model's assumptions, PMC and economic growth are ambiguously correlated when returns to specialization are decreasing, whereas population growth and productivity growth are ambiguously correlated when returns to specialization are increasing. From a theoretical point of view, these results are explained by the presence or absence of an ‘increasing production-complexity’ effect associated to the use of a larger number of intermediate-input varieties in the same production process.     

Mean,median, mode IV

This note continues the discussion about the well-known mean-median-mode inequality (Runnenburg , 1978, van Zwet , 1979, and Dharmadhikari and Joag-dev , 1983). A discrete analogue of this inequality is proved under similar conditions as those used for the classical Khinchin unimodality on R .     

Debt,equity, and information

Most firms issue financial assets such as debt or equity (e.g. bonds or stock) to outside investors. While these financial assets differ greatly in their characteristics, their diversity has received little attention in the literature. Filling this important gap in the literature, this paper views debt and equity as financial contracts, and asks why they are optimal instead of other financial contracts. By endogenizing the bankruptcy process, this paper shows how debt and equity arise as a consequence of an optimal allocation of cash-flow rights and monitoring rights, and how equity leads to dividend signaling.     

Skills,core capabilities,and the choice between merging,allying, and trading assets

We analyze two firms’ choice between merging, allying, and trading assets. We consider a setting in which firms have assets, skills, and core capabilities; skills are the component of organizational capital that increases in the course of joint operations, core capabilities the component that does not. We find that the two firms trade assets for them to operate separately in case the two firms have high initial skills; the two firms merge in case they have similar core capabilities; they ally where there is little equilibrium double moral hazard. We compare the times to dissolution in the alliance with those to divesture or post-merger integration in the merger; for all but the last jointly operated asset, we find that joint operations cease earlier in the alliance than in the merger.     

Debt,deficits, and inflation

This article sketches the theory of debt finance and cites historical evidence on the sustainability of debt. If it is accepted that the future should under the current circumstances of COVID‐19 help to alleviate the problems of the present, then debt finance is in principle appropriate. It need not lead to an explosive rise in the debt‐to‐GNP ratio. British history shows that the theory can work in practice. A satisfactory outcome, however, depends on government being reliable, honest, and competent. Trust is easily lost and hard to restore.     

Investment, expropriation, and unionization

In this paper, I examine an economy where output is produced from labor, capital and public services, and where firms and labor unions bargain over labor conditions and lobby the government over union bargaining power and public services. I compare three institutional cases: (a) competitive wage settlement, (b) bargaining over wages and employment, and (c) bargaining over wages only. I show that in cases (a) and (b) the government expropriates investment rents, but right-to-manage bargaining (c) protects investors from this expropriation.