26.1 Introduction 26.2 Carriers and channels form water soluble paths through the membrane 26.3 Ion channels are selective 26.4 Neurotransmitters control channel activity 26.5 G proteins may activate or inhibit target proteins 26.6 G proteins function by dissociation of the trimer 26.7 Growth factor receptors are protein kinases 26.8 Receptors are activated by dimerization 26.9 Receptor kinases activate signal transduction pathways

In motorships there are two main circuits, one salt , one fresh. The salt circuit is: sea inlet box (seachest) - pump(s) - f.w. coolers in series (first LT then HT) – turbo blower aftercoolers in parallel (if any) – provision condenser in parallel (if any) - overboard

Open systems using gravity tanks, etc., are rarely met nowadays and Figure 1.8 shows a characteristic arrangement of pressure tanks, calorifiers and pumps for a large ship. The fresh water pumps are self-priming, drawing from storage tanks and discharging through filters to a rising main, branched to give a cold supply and a hot supply in closed circuit through a calorifier. A tank kept under pressure by an external supply of compressed air rests on the system and provides the head necessary

In motorships the oil, after passing through main and motion bearings and oil-cooled pistons, etc., is either retained in the bedplate or flows by gravity to a sump tank. In either case, the oil pumps, which may be self￾priming, submerged centrifugal or rotary positive displacement, draw the oil through magnetic strainers and discharge to: filters - oil coolers - engine lubricating and/or cooling manifolds

Extrusion cooking is a relatively recent form of food processing. Forcing material through a hole is the process of extrusion. Sausage extruders were devel￾oped in the nineteenth century as simple forming machines. Eventually pasta was produced in extruders. Flour and water were added at one end of the machine

中华人民共和国国家标准：海水水质标准（GB 3097—1997）Sea water quality standard

Wave motion is the most universal physical phenomenon, we discover the wave motion all around us. Mechanical waves—acoustic wave, water wave Electromagnetic waves—radio, light wave Matter waves—electron wave

Crystallization is one of the oldest methods known for recovering pure solids from a solution. The Chinese, for example, were using crystallization to recover common salt from water some 5000 years ago. The perfection and beauty of the crystal which fascinated the early tribes now leads to a product of high purity and attractive appearance

Diversity of species Ecology – Found worldwide in soil, water, vegetation, and microbial flora of animals and humans – Some are always associated with disease

一、转译成主语 1. 宾语转译成主语（动词宾语和介词宾语） Water has a density of 62.4 pounds per cubic foot.. 2. 表语转译成主语 Rubber is a better dielectric but a poorer insulator than air