某钢筋混凝土框架柱基础,柱截面500mm×500mm。基础埋深2.0m,经修正后的地基持力层承载力特征值fa=230kPa。基础埋深范围内土的加权平均重度γm= 18.0kN/m3。基础混凝土为C25,混凝土抗拉强度设计值ft=1.27N/mm2;钢筋采用HPB235,fv=210N/mm2。基础下做100厚C10混凝土垫层,基础台阶拟采用阶梯形,每阶高度300,基础总高度900mm。上部结构荷载效应的标准组合:Fy=2780kN。 如果基础底面尺寸采用4m×4m,则可以计算出基底净反力为()。
A. 173.8kPa
B. 222.6kPa
C. 138.5kPa
D. 168.0kPa
The immune system is equal in complexity to the combined intricacies of the brain and nervous system. The success of the immune system in defending the body relies on a dynamic regulatory communications network consisting of millions and millions of cells. Organized into sets and subsets, these cells pass information back and forth like clouds of bees swarming around a hive. The result is a sensitive system of checks and balances that produces an immune response that is prompt, appropriate, effective and self-limiting. At the heart of the immune system is the ability to distinguish between self and non-self. When immune defenders encounter cells or organisms carrying foreign or non-self molecules, the immune troops move quickly to eliminate the invaders. Virtually every body cell carries distinctive molecules that identify it as self. The body’’s immune defenses do not normally attack tissues that carry a self marker. Rather, immune cells and other body cells coexist peaceably in a state known as self-tolerance. When a normally functioning immune system attacks a non-self molecule, the system has the ability to remember the specifics of the foreign body. Upon subsequent encounters with the same species of molecules, the immune system reacts accordingly. With the possible exception of antibodies passed during lactation ( 哺乳期 ), this so-called immune system memory is not inherited. Despite the occurrence of a virus in your family, your immune system must learn from experience with the many millions of distinctive non-self molecules in the sea of microbes in which we live. Learning necessitates producing the appropriate molecules and cells to match up with and counteract each non-self invader. Any substance capable of stimulating an immune response is called an antigen. Tissues or cells from another individual (except an identical twin, whose cells carry identical self-markers ) act as antigens; because the immune system recognizes transplanted tissues as foreign, it rejects them. The body will even reject nourishing proteins unless they are first broken down by the digestive system into their primary, non-antigenic building blocks. An antigen announces its foreignness by means of intricate and characteristic shapes called epitopes( 抗原决定基), which stick out from its surface. Most antigens, even the simplest microbes, carry several different kinds of epitopes on their surface, some may even carry several hundred. Some epitopes will be more effective than others at stimulating an immune response. Only in abnormal situations does the immune system wrongly identify self as non-self and execute a misdirected immune attack. The result can be so-called autoimmune disease. The painful side effects of these diseases are caused by a person’’s immune system actually attacking itself The remembering power of a person’’s immune system is
A. mostly descended from his/her ancestors.
B. partially passed down from his/her mother.
C. mainly acquired through fighting foreign cells.
D. basically generated by communications network.
Speech, whether oral or written, is a used commodity. If we are to be heard, we must (1) our words from those (2) to us within families, peer groups, societal institutions, and political networks. Our utterances position us both in an immediate social dialogue (3) our addressee and, simultaneously, in a larger ideological one (4) by history and society. We speak as an individual and also, as a student or teacher, a husband or wife, a person of a particular discipline, social class, religion, race, or other socially constructed (5) . Thus, to varying degrees, all speaking is a (6) of others’ words and all writing is rewriting. As language (7) , we experience individual agency by infusing our own intentions (8) other people’s words, and this can be very hard.(9) , schools, like into churches and courtrooms, are places (10) people speak words that are more important than they are. The words of a particular discipline, like those of "God the father" or of "the law," are being articulated by spokespeople for the given authority. The (11) of the addressed, the listener, is to acknowledge the words and their (12) . In Bakhtin’s (13) , "the authoritative word is located in a distanced zone, organically connected with a (14) that is felt to be hierarchally higher."(15) , part of growing up in an ideological sense is becoming more "selective" about the words we appropriate and, (16) , pass on to others. In Bakhtin’s (17) , responsible people do not treat (18) as givens, they treat them as utterances, spoken by particular people located in specific ways in the social landscape. Becoming alive to the socio-ideological complexity of language use is (19) to becoming a more responsive language user and, potentially, a more playful one too, able to use a (20) of social voices, of perspectives, in articulating one’s own ideas. Read the following text. Choose the best word(s) for each numbered blank and mark A, B, C or D on ANSWER SHEET 1.11()
A. character
B. role
C. function
D. user