System Concept Need (technology Pull Technologies can fulfill need or requirement a Technologies can overcome barriers(imitations, constraints, etc. Opportunity(Technology Push) a Technologies can Create Opportunities

1. Introduction Hall thrusters are electrostatic ion accelerators in which the grid system (which serves in classical ion engines to anchor the negative charges used to accelerate the ions) is replaced with a relatively strong magnetic field perpendicular to the flow

Why Cost Estimation? Critically important part of system design Too high – lose the contract award Too low – over-run cost plus contracts, company loss on fixed price contracts

Outline Purpose of thermal control systems Review of heat transfer fundamentals Space system thermal analysis Equations Models Analysis programs

FINC 5000 Page 1 of 3 Fall 2005 Course FINC 5000 Finance Instructor Name: Lorraine Gilbertson Email: gilbertl@webster.edu Location Chengdu, China Course Description The student examines the general nature of financial management, the American financial system, taxes, and the major financial decisions of corporations. Specific attention is given to present value and capital budgeting; risk and asset pricing;

① Lymphocyte: a. T-lymphocytes: cytotoxic T cell: Tc C- kill the tumor cell, virus infective cell and foreign cell helper T cell: Th C- promotes activity of BLC and Tc C suppressor T cell: Ts C –regulate the function of BLC and TC

---Digestive system: Digestive tract Digestive gland

1. Components ---kidney : produce urine ---ureters ---bladder -cavity organs, conduct, store and ---urethra remove the urine ---functions: remove waste products of metabolism regulate the homeostasis secrete some bioactive factors- renin, erythropoietin

(1) extra-embryonic blood vessels ---blood island: at the middle of 3 rd week, wall of the yolk sac mesenchyma proliferate and form isolated cell clusters, the peripheral cell become flattened and differentiate into endothelial cell to from endothelial tube; central located cells are detached and develop into primitive blood cells(blood stem cell)

1、SQL (Structured query Language,结构化查询 语言)，功能包括查询、操纵、定义、控制。 2、功能丰富、语言简洁、使用灵活，倍受欢迎。 3、1974年由Boyce,Chamberlin提出，1975年在IBM 公司的System R上首次实现。原型称为SEQUEL(Structured English QUEry Language).1986年ANSI SQL-86标准，是第一个SQL 标准