一定条件下,体积为5L的密闭容器中,0.5molX和0.5molY进行反应:2X

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问题:

一定条件下,体积为5L的密闭容器中,0.5molX和0.5molY进行反应:2X(g)+Y(g)Z(g),经60s达到平衡,生成0.15molZ。下列说法正确的是[ ]

A.将容器体积变为10L,Z的平衡浓度变为原来的1/2

B.以Y浓度变化表示的反应速率为0.0005mol·L-1·s-1

C.若增大压强,则物质Y的转化率减小

D.若降低温度,X的体积分数增大,则该反应的△H<0

考点:影响化学平衡的因素化学反应速率的计算
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Social-networking sites offer users easy ways to present idealized images of themselves, even if those ideals don’t always square with their real-world personalities. Psychology researcher Soraya Mehdizadeh has discovered a way to poke through the offline-online curtain: she has used Faeebook to predict a person’s level of narcissism and self-esteem.

Mehdizadeh, who conducted the study as an undergraduate at Toronto’s York University, gained access to the Faeebook accounts of 100 college students and measured activities like photo sharing, wall postings and status updates; she also studied how frequently users logged on and how often they remained online during each session. Her findings were published recently in Cyberpsyehology, Behavior and Social Networking.

After measuring each subject using the Narcissism Personality Inventory and Rosenberg Self-Esteem Scale, Mehdizadeh, who graduated from York this past spring, discovered narcissists and people with lower self-esteem were more likely to spend more than an hour a day on Facebook and were more prone to post self-promo-tional photos ( striking a pose or using Photoshop, for example). Narcissists were also more likely to showcase themselves through status updates (using phrases like "I’m so glamorous I bleed glitter") and wall activity (posting self-serving links like " My Celebrity Look-alikes" ).

Self-esteem and narcissism are often interrelated but don’t always go hand in hand. Some psychologists believe that narcissists--those who have a pervasive pattern of grandiosity, a need for admiration, as well as a lack of sympathy--unconsciously inflate their sense of self-importance as a defense against feeling inadequate. Not enough empirical research has been produced to confirm that link, although Mehdizadeh’s study seems to support it. Because narcissists have less capacity to sustain intimate or long-term relationships, Mehdizadeh thinks that they would be more drawn to the online world of virtual friends and emotionally detached communication.

Although it seems that Facebook can be used by narcissists to fuel their inflated egos, Mehdizadeh stops short of proclaiming that excessive time spent on Faeebook can turn regular users into narcissists. She also notes that social-networking sites might ultimately be found to have positive effects when used by people with low self-esteem or depression. "If individuals with lower self-esteem are more prone to using Facebook," she says, "the question becomes, ’ Can Facebook help raise self- esteem by allowing patients to talk to each other and help each other in a socially interactive environment’ I don’t think it’s necessarily a bad thing that people with low self-esteem use Facebook.

which of the following is used for predicting a person’s level of narcissism and self-esteem()

A. Activities the subjects take apart in

B. Frequency of the experimental object

C. Frequency of the experimental object’s renewing photos

D. The contents of the log of the experimental object

题型:选择题

方程x2-xy-5x+5y-1=0的整数解是 ______.

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已知定义在R上的函数f(x)满足:f(x+y)=f(x)+f(y)+2xy(x+y),(x、y∈R),f(1)=-1.

(1)求f(0)和f(-2)的值;

(2)若f(5)=m,试用m表示f(-5);

(3)试判断f(x)的奇偶性(要写出推理过程).

题型:选择题

下列关于线性表叙述中不正确的是( )。

A.可以有几个节点没有前件

B.只有一个终端节点,无后件

C.除根节点和终端节点外,其他节点都有且只有一个前件,也有且只有一个后件

D.线性表可以没有数据元素

题型:选择题

阳树脂由Ca、Mg型再生为H型,其体积()。

A.保持不变

B.变大

C.变小

D.随再生程度而变小

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