天然的物质

Firstly, it introduces the composing and nature of natural water body, discusses the reasons, major types of water pollution, transfer, transformation and self-purification mechanism of various pollutants and features of water resources, water pollution situation in China .

一是介绍了天然水体的组成和性质，讨论了水污染形成的原因、主要类型、水体中各种污染物质迁移、转化与自净的机制及我国的水资源特点、水污染的状况。

Ca is widely abundant in nature and its rodioisotope 41 Ca is a cosmogenic nuclide with a half\|life of 10 5 years. However, the 41 Ca/ 40 Ca ratio in natural samples is very low and can only be measure d by accelerator mass spectrometry. The application of 41 Ca is ve ry i mportant not only in the life science but also in geological dating, global envi ronment change studies and astrophysics.

1 引言Ca在自然界中广泛存在，它不仅是人体中含量最丰富的元素之一[1] ，也是众多其他物质的组成部分。41Ca(半衰期为 1.0 3× 10 5a)属于Ca的放射性同位素中的一种，其衰变方式为轨道电子俘获，只发射3.3keV的X射线，天然样品中41Ca 40 Ca的值很小。

Our corporation since establishment consistently adheres to natural materials and does the research and development of safe and healthy products. Japanese cedar and hinoki cypress which are indigenous to Japan become fire resistant and do not produce toxic gas even when set fire once they are treated with our ecologically friendly product called 'Super FX3200'.

本公司自成立以来一直致力于安全、健康产品的研究，自主开发的以天然材料成分为主的耐热粘合剂和粘合性耐热涂层剂产品---&超级FX3200系列&和用该产品处理的日本柏日本杉板材，具备耐火性而不会燃烧、不会冒烟、不会释放有毒气体，是对人友好、让人感到放心、安全、满意的产品，在甲醛等化学物质引发的致病建筑综合症不断地危害人们健康的今天，越来越受到人们的关注和青睐。

In the mean time, it benefits microorganism decompose organic matter, aged algae, uneaten food and other hazardous substances; transfer them to new nutrient elements then re-promote the sustained and steady growth of monoplast algae; supply fish, prawn seedling sufficient natural live food; improve survival ratio and growth rate of fish and prawn seedling, cut down the cost of cultivation etc.

该产品为浮游单细胞藻类提供均衡且全面的营养元素，使单细胞藻类快速生长；同时，有益微生物分解有机质、老化的藻类及残饵等有害物质，转化成新的营养元素循环提供单细胞藻类持续稳定的生长；为鱼、虾幼苗提供充足的天然活饵料，从而提高鱼、虾苗的成活率及生长速度，降低养殖成本等。

By micro-analysis on the aging fibers, it indicates that attack of alkali hydrates to vegetable fibers is serious and the flexibility becomes lower and the brittleness becomes increase for the calcium hydroxide crystal conglomerated in the fibers bosom.

通过对老化后纤维的微观分析发现，水泥水化后的碱性物质对天然植物纤维的侵蚀较大，Ca_2晶体在纤维内腔中的沉积使纤维的柔性降低，脆性增加，在长期干湿循环作用下，纤维水泥基材料的抗折强度下降。

By using the "mechanical wounding"experimental system estabilished by us, and light- and electron microscopy, autoradiography and radioisotope technique, immuno-fluorescence localization, homologous clone and RACE technique, in situ mRNA hybridization and ELISA et al., we investigated the relationship between the transportation of exogenous JA and the secondary laticifer differentiation, the relationship between the producton and accumulation of endogenous JA and the laticifer differentiation from cambia, and the effect of appling exogenous jasmonates on the natural rubber production.

利用我们建立的机械伤害诱导乳管分化的实验系统，采用光学显微镜和电子显微镜技术、同位素示踪和放射自显影技术、免疫荧光定位技术、同源克隆和RACE技术、mRNA原位杂交和ELISA等技术，研究了外源茉莉酸在橡胶树体内的移动及其对维管形成层分化次生乳管的诱导效应、内源茉莉酸与乳管分化的关系以及茉莉酸类物质对天然橡胶产量的影响。

The product has green-yellow fluorescence at excitation wavelength of 355 nm and emission wavelength of 478 nm, and the fluorescence intensity could be enhanced in the presence of acetone.

三、流动注射在线氧化荧光法测定氯普噻吨的的研究利用在硫酸介质中二氧化铅可使无天然荧光的氯普噻吨氧化而转变为在最大激发波长和最大发射波长分别为393nm和452nm的强荧光物质，而且丙酮对该荧光体系有强烈增敏作用的现象，建立了以醋酸纤维素固定化的二氧化铅作为固相反应器的流动注射在线氧化荧光法测定氯普噻吨的新方法。

Generally the catalysts have high activity and good selectivity. At present the coupling reactions of organoborahes with terminal olefins s acid chlorides and aryl halides play an important synthetic approaches in organoborane chemical. The catalysts can be used by many kinds of organometal compounds such as: irons cobalt nickel ruthenium rhodium palladiums titaniums zirconiums tins indium and lithium organic compounds; The achievement has been amazed in preparing of unsaturated or saturated compounds and in synthesizing of natural products bioactive molecules and chiral compounds.

目前，卤代烃与不饱和烃的偶联反应和有机硼试剂与酰卤和卤代烃的偶联反应已成为有机合成的研究热点，此类反应可用铁、钴、镍、钌、铑、钛、锆、锡、铟、锂等多种有机金属化合物来催化，用于形成含饱和或不饱和C-C键的化合物，并已在天然产物、液晶、具有生理活性物质和手性化合物的合成中应用。

When purify carries the suspension colloid grain of negative electric charge in natural raw water, it is OK that its element linear grows the positive electrical charge that contains in catenary to be opposite remove electric sex to counteract the double function that reachs adsorption to bridge at the same time, and water-solubility of starch of this kind of modified is good, burnt viscosity is stable, cast impose kind agile, it is a kind of function exceedingly good organic, inorganic and compound high polymer garrulous coagulates agent.

在去除天然原水中带负电荷的悬浮胶体颗粒时，其分子线性长链中所带有的正电荷对可以同时起到电性中和及吸附(物质表面吸住周围介质中的分子或离子现象)架桥的双重功能，而且这种改性淀粉水溶性好，糊粘度稳定，投加方式灵活，是一种性能优异的有机-无机复合高分子絮凝(使液体中悬浮微粒集聚变大或形成絮团，从而加快粒子聚沉，达到固-液分离的过程)剂。

Collagen has many useful features such as low antigenicity, controllable biodegradation, biological absorbable properties, haemostatic properties, ability to promote cellular growth and attachment.,which make it an excellent naturally occurring biomaterial, it has a wide application in medicinal industry and clinical medicine.

胶原蛋白是一种天然存在的具有很高利用价值的生物物质，其特有的极低的抗原性、可生物降解性、生物吸收性、止血性能和促进细胞生长的功能，使得近年来在医药工业和医学临床的研究和应用日益广泛。

They weren't aggressive, but I yelled and threw a rock in their direction to get them off the trail and away from me, just in case.

他们没有侵略性，但我大喊，并在他们的方向扔石头让他们过的线索，远离我，以防万一。

In slot 2 in your bag put wrapping paper, quantity does not matter in this case.

在你的书包里槽2把包装纸、数量无关紧要。