低温贮藏的理论依据是什么?

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问题:

低温贮藏的理论依据是什么?

考点:农学谷物科学原理谷物科学原理题库
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横截面积S=0.2 m2、n=100匝的圆形线圈A处在如图所示的磁场内,磁感应强度变化率为0.02 T/s。开始时S未闭合,R1=4 Ω,R2=6Ω,C=30 μF,线圈内阻不计,求:

(1)闭合S后,通过R2的电流的大小;

(2)闭合S后一段时间又断开,问S断开后通过R2的电荷量是多少?

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Below is some advice on how to prevent cancer:

                                          8 Ways to Avoid Cancer in Your Life

1. Eat Blueberries

Aside from being a healthy and delicious snack, blueberries contain pterostilbene, which has important

colon(结肠) cancer-fighting prosperities. But wait, it gets better. Blueberries also offer a large dose of

vitamins C (14 milligrams per cup). So at breakfast, try to take in a cup and a half of blueberries in your

cereal or yogurt, or mixed with other berries.

2. Drink Pomegranate(石榴)Juice

The deep red juice of the pomegranate contains polyphenols, isoflavones and ellagic acid, which together

create a powerful anticancer mixture. Most recently, researchers from the University of Wisconsin at

Madison has discovered that 16 ounces of pomegranate juice per day also may inhibit the growth of lung

cancer.

3. Relax

Feeling stressed or worried? Find ways to relax and you may reduce your chances of developing cancer.

Purdue University researchers tracked 1,600 men over 12 years and found that half of those with high

levels of worry died during the study period. Only 20 percent of the optimists died before the study were

completed, while 34 percent of the extremely anxious men died of some type of cancer. Instead of

stressing about the past or future, focus on the present and relax!

4. Take Selenium(硒)

Selenium is well known for its cancer-fighting properties. In a study of almost 1,000 men, researchers

from the Journal of the National Cancer Institute found that when men with the lowest initial levels of

selenium in their bodies received a daily supplement over a 4 year period, they cut their prostate(前列腺) cancer risk by a remarkable 92 percent. However, it is possible to get too much of a good thing, so

monitor your intake of selenium-containing supplements, Brazil nuts, tuna, meats and grains carefully.

5. Eat Sushi(寿司)

Seaweed may not be your idea of a great snack, but it is high in fiber, calcium and iron, and dry, roasted

seaweed sheets used in sushi provide the additional benefits of vitamins A and C. Sushi rolls are also high

in protein- a typical spicy tuna roll has only 290 calories but packs 24 grams of protein. So don't skimp

(节省)on the Sushi!

6. Enjoy the Outdoors

Vitamin D causes early death of cancer cells. A study published in the American Journey of Clinical

Nutrition reported that women who supplemented their diets with 1,000 international. Units of vitamin

D every day had a 60 percent to 77 percent lower incidence of cancer ever a four-year period that did

women taking a placebo(无效对照剂). Experts recommend supplementing your fun in the sun with

1,100 to 2,000IU of vitamin D each day.

7. Breathe Clean Air

There's no question that secondhand smoke kills. A recent American Journal of Public Health study

showed that nonsmokers working in smoky places had three times the amount of carcinogen(致癌物质)

in their urine(尿) than nonsmokers working in smoke-free locations. What's worse, their levels of the

carcinogen rose 6 percent for every hour worked. Nine states have banned smoking in all workplaces,

bars and restaurants. The message is clear: Do whatever you can to avoid the cloud of smoke.

8. Break a Sweat

Even a small amount of exercise can offer major cancer-fighting benefits. In a study of 29,110 men

published in the International Journal of Cancer, men who exercised just once a week had a percent

lower risk of metastasis(转移性) prostate cancer than men who didn't work out at all. The better the

frequency, duration and intensity of the exercise, the bigger the reduction in risk, according to the study.

1. To prevent yourself from catching colon cancer, you should eat ____ as often as possible.

A. sushi    

B. blueberries    

C. pomegranates    

D. Vitamin D

2. A person is very likely to catch some type of cancer if ______.

A. he is very fond of exercise every day.

B. he is addicted to smoking  

C. he is always feeling extremely stressed or worried

D. he likes to have meals in restaurants

3. _____ will remarkably reduce the risk of men's prostate cancer.

A. Having a daily supplement of selenium

B. Drinking a cup of pomegranate juice every day

C. Breathing fresh air now and then

D. Taking exercise at least once a week

4. If you want to keep cancer away, it is particularly important to ______.

A. have a daily supplement of vitamins B and C

B. try to ignore the secondhand smoking

C. take in as many selenium-containing supplements as possible

D. having exercise as often as possible

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男,54岁,肝区疼痛3个月,查体肝肋下3cm,质硬,表面有大小不等结节,边缘钝而不整齐,有压痛

以下检查中对确定该患者诊断最有价值的是()

A.肝炎抗原抗体检查

B.腹部超声

C.腹部平片

D.肝功能

E.乙肝两对半

题型:问答题 简答题

纵隔9分法,通过第几胸椎下缘的水平线为中、下纵隔之分界线()

A.2

B.4

C.6

D.8

E.10

题型:问答题 简答题

菲利普斯曲线说明( )之间存在矛盾。

A.经济增长与充分就业
B.经济增长与稳定物价
C.稳定物价与充分就业
D.经济增长与国际收支平衡

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