超细氮化铝粉末被广泛应用于大规模集成电路生产等领域。其制取原理为: Al2O3+

题型:计算题

问题:

超细氮化铝粉末被广泛应用于大规模集成电路生产等领域。其制取原理为:

Al2O3+N2+3C2AlN+3CO↑

由于反应不完全,氮化铝产品中往往含有碳和氧化铝杂质。为测定该产品中有关成分的含量,进行了以下两个实验:

(1)称取20.00 g样品,将其加入过量的NaOH浓溶液中共热并蒸干,AlN跟NaOH溶液反应生成NaAlO2,并放出氨气6.72 L(标准状况)。

①上述反应的化学方程式为_____________________________________________________;

②该产品中AlN的质量分数为_______________________________。

(2)另取10.00 g样品置于反应器中,通入2.016 L(标准状况)O2,在高温下充分反应后测得气体的密度为1.34 g·L-1(已折算成标准状况,AlN不跟O2反应)。该产品中含杂质碳__________g。(此问需写出计算过程)

考点:碳单质及化合物单质硅硅酸盐硅酸(原硅酸)
题型:计算题

始基子宫是()

A.子宫极小,无内膜回声,无法分清子宫体或子宫颈

B.子宫各径线明显小于正常值,子宫颈与子宫体等长或稍长

C.子宫底和体部稍宽,宫底中线处略凸向子宫腔

D.子宫横径增宽,宫底中央略向外突起,内膜回声分左右两部分,均延续至宫底

E.子宫横径增宽,宫底中央略向外突起,内膜回声分左右两部分,在宫腔中部或下部双侧内膜回声汇合

题型:计算题

What I said was so     that I finally convinced them    my honesty.

A.convincing; of

B.convincing, for

C.convinced; of

D.convinced; for

题型:计算题

在物理学中,把______叫做功.公式表示为______,功的国际单位是______.

题型:计算题

阅读理解。

     Last year, I took a sightseeing trip to Washington, DC.I heard a voice say, "Can you help me?"

When I turned around, I saw an elderly blind woman with her hand extended. Immediately, I pulled

out all of my change and placed it on her hand without even looking at her. But the blind woman

smiled and said, "I don't want your money. I just need help finding the post office."

     In an instant, I realized what I had done.I acted with prejudice―I judged another person simply

for what I assumed she had to be. I hated what I saw in myself.

     The thing I had forgotten about myself is that I am an immigrant.I left Honduras and arrived in

the US at the age of 15.I started my new life with two suitcases,my brother and sister. Through the

years, I have been a doorkeeper, cashier and pizza delivery driver among many other humble (卑微的)

jobs,and eventually I became a network engineer.

     In my own life, I have experienced prejudice. I remember a time―at the age of 17―when I was a

busboy, I heard a father tell his little boy that if he did not do well in school, he would end up like

me.

     But now, living in my American middle-class lifestyle, it is too easy to forget my past, to forget

who I am, where I have been,and to lose sight of where I want to be going.That blind woman on the

streets cured me of my blindness. She reminded me of my belief in humility (谦虚).  By the way, I helped

that lady to the post office. I hope to thank her for the priceless lesson.

1. How did the writer give the blind woman money?

A. In a modest way

B. In a polite way

C. In an impatient way.

D. In a painful way

2. According to the text, the writer ______.

A. still lives a poor life

B. was busy with his work

C. was born in Honduras

D. was a native of Washington D.C.

3. According to the text, the author most probably agrees that one should ______.

A. be nice to the elderly and the disabled

B. try to experience different kinds of culture

C. treat others equally with love and respect

D. think about one's past as often as possible

4. What would be the best title of the text?

A. A priceless lesson

B. An act of prejudice

C. A sightseeing trip

D. A humble moment

题型:计算题

下列关于法的特征的表述,正确的是:

A.当事人可以依据普通的法律提出诉讼请求,但不能直接依据宪法提起诉讼,所以法的可诉性,主要是指普通的法律,而不包括宪法
B.民族自治区可以对国家统一实行的法律进行变通执行,这体现了法的普遍性的例外
C.法是以权利义务的模式来调整社会关系的,人们遵守一定的权利义务就能实现一定的后果。遵守自然法则的要求,同样也能实现一定的后果,所以自然法则也是法的范畴
D.法是由公共权力机制制定的,村委会是由村民选举产生的,由村委会制定的村规民约对村民有约束力,也属于法的范畴

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