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离体神经纤维某一部位受到适当刺激时，受刺激部位细胞两侧会出现暂时性的电位变化产生神经冲动。图示该部位受刺激前后，膜两侧电位差的变化。请回答： 神经冲动在离体神经纤维上以局部电流的方式双向传导，但在动物体内，神经冲动的传导方向是单向的，总是由胞体传向______。
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As much as murder is a staple in mystery stories, so is love. Love may be a four-letter word, or the greatest of the trio of faith, hope, and love. It may appear in a mystery as the driving force behind the plot and the characters. Or it may appear as an aside in a sub-plot, a light spot in a heavy story. But it’s there. Even Valentine knew love was worth dying for. An emotion this strong gets a lot of attention. Love has its own special day, St. Valentine’s Day. According to legend, the Roman emperor Claudius Ⅱ needed soldiers to fight for him in the far reaches of the Roman Empire. He thought married men would rather stay home than go to war for a couple of years, so he outlawed marriage and engagements. This did not stop people from falling in love. Valentine, a priest, secretly married many young couples. For this crime, he was arrested and executed on February 14. St. Valentine’s Day was off to a rocky start. Love, secrecy, crime and death, love prevailed, and the day lost its seamy side. Valentine’s Day became a day to exchange expressions of love. Small children give each other paper hearts. Adults exchange flowers and chocolates. Everyone has an attack of the warm fuzzies. Valentine’s Day was popular in Europe in the early 1800s as a day men brought gifts to the women they loved. Gradually the expectations grew higher, the gifts got bigger, and eventually the holiday collapsed under the weight of the bills. It was revived when the custom of exchanging love letters and love cards replaced the mandatory gifts. A young man’s love was measured in how much time he spent making a card with paper, lace, feathers, beads, and fabric. If the young man wasn’t good with scissors and glue, the job could be hired out to an artist who made house calls. Valentine’s Day grew more popular when machine-made cards became available, and people didn’t have to make their own. In England in 1840, the nation-wide Penny Post made it cheap for everyone to send Valentine cards. In the United States, national cheap postal rates were set in 1845, and valentines filled the mail. "Roses are red, violets are blue" was a popular verse on Valentine cards. Other holidays are associated with particular flowers—the Christmas poinsettia, the Easter lily—but Valentine’s Day has no specific flower. Instead, it has colors—red, pink, and white. Red symbolizes warmth and feeling. White stands for purity. According to one romantic rower’code, messages can be spelled out with flowers. Gardenias say "I love you secretly". Violets say "I return your love". Roses say "I love you passionately". Not surprisingly, the rose is now the top-seeded flower of love. But love mostly goes wrong in mystery stories. Very badly wrong. Somebody do something wrong. Husbands, wives, and lovers kill each other. Or kill for each other. Stack the characters up in any kind of love triangle, and watch how the angles are knocked off. Love is unrequited, thwarted and scorned. Murders are motivated by real or imaginary love, or the lack of it. That famous novelist Ernest Hemingway said, "If two people love each other there can be no happy end to it". So it goes in the mystery. Justice may win, but love is often the loser. In addition to plots driven by love, or the lack of it, there are sleuths who encounter love in the solving of the crime. The handsome or beautiful detective meets the suspect or the client. Their affair grows around, and in spite of, the murder. Think of the movies Casablanca and Chinatown. Barbara D’Amato offers a different twist on this theme in "Hard Feelings". The amateur sleuth meets a suspect or investigating officer and love smolders around the crime. Rose DeShaw’s "Love with the Proper Killer" is such a story. In a series of novels, if the continuing character is living a full life, love enters the storyline somewhere. Dorothy L. Sayers’ sleuth Lord Peter Wimsey fell in love with Harriet Vane while he sleuthed his way through a few books. Sherlock Holmes remained aloof, but Dr. Watson fell in love and married between impossible crimes. There were no such temptations for Hercule Poirot or Jane Marple, but Agatha Christie created Tuppence and Tommy Beresford as a detecting couple. Real crimes are sometimes motivated by love, and are written about in true crime books. E.W. Count describes one such case in "Love is a Risk." "Married to a Murderer," by Alan Russell, follows the crime one step further. Feeling an attack of the warm fuzzies Do something sweet for someone you love. Then do something sweet for yourself. Settle back with soft music and savor the online mysteries of love and romance in the Valentine and Romance Mysteries sections of this site. Which of the following statements is NOT true about St. Valentine’s Day
As a probing psychologist he is the unrivalled master among all living British and American novelists. Neither do any of his colleagues possess his fantastic imaginative powers and his ability to create characters. His subhuman and superhuman figures, tragic or comic in a macabre way, emerge from his mind with a reality that few existing people—even those nearest to us—can give us, and they move in a milieu whose odors of subtropical plants, ladies’ perfumes, Negro sweat, and the smell of horses and mules penetrate immediately even into a Scandinavian’s warm and cosy den. As a painter of landscapes he has the hunter’s intimate knowledge of his own hunting-ground, the topograpber’s accuracy, and the impressionist’s sensitivity. Moreover—side by side with Joyce and perhaps even more so—Faulkner is the great experimentalist among twentieth-century novelists. Scarcely two of his novels are similar technically. It seems as if by this continuous renewal he wanted to achieve the increased breadth which his limited world, both in geography and in subject matter, cannot give him.
Students of United States history, seeking to identify the circumstances that encouraged the emergence of feminist movements, have thoroughly investigated the mid-nineteenth-century American economic and social conditions that affected the status of women. These historians, however, have analyzed less fully the development of specifically feminist ideas and activities during the same period. Furthermore, the ideological origins of feminism in the United States have been obscured because, even when historians did take into account those feminist ideas and activities occurring within the United States, they failed to recognize that feminism was then a truly international movement actually centered in Europe. American feminist activists who have been described as "solitary" and "individual theorists" were in reality connected to a movement—utopian socialism—which was already popularizing feminist ideas in Europe during the two decades that culminated in the first women’s rights conference held at Seneca Falls, New York, in 1848. Thus, a complete understanding of the origins and development of nineteenth-century feminism in the United States requires that the geographical focus be widened to include Europe and that the detailed study already made of social conditions be expanded to include the ideological development of feminism. The earliest and most popular of the utopian socialists were the Saint-Simonians. The specifically feminist part of Saint-Simonianism has, however, been less studied than the group’s contribution to early socialism. This is regrettable on two counts. By 1832 feminism was the central concern of Saint-Simonianism and entirely absorbed its adherents’ energy. Hence, by ignoring its feminism, European historians have misunderstood Saint-Simonianism. Moreover, since many feminist ideas can be traced to Saint-Simonianism, European historians’ appreciation of later feminism in France and the United States remained limited. Saint-Simon’s followers, many of whom were women, based their feminism on an interpretation of his project to reorganize the globe by replacing brute force with the rule of spiritual powers. The new world order would be ruled together by a male, to represent reflection, and a female, to represent sentiment. This complementarity reflects the fact that, while the Saint-Shnonians did not reject the belief that there were innate differences between men and women, they nevertheless foresaw an equally important social and political role for both sexes in their Utopia. Only a few Saint-Simonians opposed a definition of sexual equality based on gender distinction. This minority believed that individuals of both sexes were born similar in capacity and character, and they ascribed male-female differences to socialization and education. The envisioned result of both currents of thought, however, was that women would enter public life in the new age and that sexual equality would reward men as well as women with an improved way of life. According to the passage, the society envisioned by most Saint-Simonians would be one in which ______.
Joy and sadness are experienced by people in all cultures around the world, but how can we tell when other people are happy or despondent It turns out that the expression of many emotions may be universal. Smiling is apparently a universal sign of friendliness and approval. Baring the teeth in a hostile way, as noted by Charles Darwin in the nineteenth century, may he a universe sign of anger. As the originator of the theory of evolution, Darwin believed that the universal recognition of facial expressions would have survival value. For example, facial expressions could signal the approach of enemies (or friends) in the absence of language. Most investigators concur that certain facial expressions suggest the same emotions in a people. Moreover, people in diverse cultures recognize the emotions manifested by the facial expressions. In classic research Paul Ekman took photographs of people exhibiting the emotions of anger, disgust, fear, happiness, and sadness. He then asked people around the world to indicate what emotions were being depicted in them. Those queried ranged from European college students to members of the Fore, a tribe that dwells in the New Guinea highlands. All groups including the Fore, who had almost no contact with Western culture, agreed on the portrayed emotions. The Fore also displayed familiar facial expressions when asked how they would respond if they were the characters in stories that called for basic emotional responses. Ekman and his colleagues more recently obtained similar results in a study of ten cultures in which participants were permitted to report that multiple emotions were shown by facial expressions. The participants generally agreed on which two emotions were being shown and which emotion was more intense. Psychological researchers generally recognize that facial expressions reflect emotional states. In fact, various emotional states give rise to certain patterns of electrical activity in the facial muscles and in the brain. The facial-feedback hypothesis argues, however, that the causal relationship between emotions and facial expressions can also work in the opposite direction. According to this hypothesis, signals from the facial muscles ("feedback") are sent back to emotion centers of the brain, and so a person’s facial expression can influence that person’s emotional state. Consider Darwin’s words: "The free expression by outward signs of an emotion intensifies it. On the other hand, the repression, as far as possible, of all outward signs softens our emotions." Can smiling give rise to feelings of good will, for example, and frowning to anger Psychological research has given rise to some interesting findings concerning the facial-feedback hypothesis. Causing participants in experiments to smile, for example, leads them to report more positive feelings and to rate cartoons (humorous drawings of people or situations) as being more humorous. When they are caused to frown, they rate cartoons as being more aggressive. What are the possible links between facial expressions and emotion One link is arousal, which is the level of activity or preparedness for activity in an organism. Intense contraction of facial muscles, such as those used in signifying fear, heightens arousal. Self-perception of heightened arousal then leads to heightened emotional activity. Other links may involve changes in brain temperature and the release of neurotransmitters (substances that transmit nerve impulses.) The contraction of facial muscles both influences the internal emotional state and reflects it. Ekrnan has found that the so-called Duchenne smile, which is characterized by "crow’s feet" wrinkles around the eyes and a subtle drop in the eye cover fold so that the skin above the eye moves down slightly toward the eyeball, can lead to pleasant feelings. Ekman’s observation may be relevant to the British expression "keep a stiff upper lip" as a recommendation for handling stress. It might be that a "stiff" lip suppresses emotional response—as long as the lip is not quivering with fear or tension. But when the emotion that leads to stiffening the lip is more intense, and involves strong muscle tension, facial feedback may heighten emotional response. Ekman has found that ______.
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