Puppy Behaviour: Your Dogs Amazing Sense Of Smell狗狗的行为：您的狗惊人的嗅觉

The canine nose has something like twenty times as many primary receptor cells as the human nose.警犬鼻子像21倍，许多初级受体细胞作为人类鼻子。 How all of this works to detect odors is one of the great scientific wonders of the world.如何所有这一切的工程检测气味是一个伟大的科学奇迹世界。 Studies in a number of species have found that different regions of the mucous lining within the nose have different chemical properties, more readily absorbing chemicals of one particular molecular shape or another, or preferentially absorbing in one region chemicals that are more water soluble and in another chemicals that are more fat soluble.研究了一些物种的发现，不同区域的黏膜内层鼻子内有不同的化学性质，更容易吸收化学品的一个特定的分子形状或他人，或优先吸收在一个地区化学品，更多的水溶性，并在另一化学品，更多的脂溶性。

The ability of the nose to make precise chemical distinctions is truly extraordinary.的能力鼻子作出明确的化学品的区别是真正了不起的。 Some pairs of chemicals that exist in nature are identical in every way - they are made up of exactly the same elements, joined together in exactly the same three-dimensional sequence - except that one is the three-dimensional mirror image of the other.一些对化学品中存在的性质是相同的各种方式-他们是由完全相同的内容，共同在完全相同的三维序列-除了一个三维镜像的其他。 Yet such "stereoisomers" frequently have a dramatically different odor, indicating that the nose can sort them out by their complex shape alone.然而，这种“立体”经常有一个显着不同的气味，这表明鼻子可以排序由他们自己单独形状复杂。 The molecule carvone, for example, has the odor of caraway in one of its stereoisomers, the odor of oil of spearmint in its mirror-image form.香芹酮的分子，例如，有异味的香芹籽在其立体异构体，气味的油留兰香在其镜像的形式。

Measurements of the acuity of the dog's nose suggest that the dog is many times more sensitive than man to the presence of minute quantities of odor molecules wafting in the air, but the data are all over the map.测量视力的狗的鼻子表明，狗是许多倍更敏感的人比在场的分钟数量的气味分子飘到空气中，但数据都在地图上。 This is probably in part because the threshold for detecting different chemicals no doubt varies dramatically according to the particular chemical involved.这可能是部分原因是因为门槛不同的化学品检测毫无疑问，差异很大的特定化学品涉及。 Some comparative studies have found that dogs can detect certain organic chemicals at concentrations a hundred times less than people are able to; for other compounds the dog's edge may be a factor of a million or more.一些比较研究发现，狗可以检测某些有机化学品的浓度一百倍不到人们能够;的其他化合物狗的边缘可能是因素之一万或更多。 In police and security work, dogs can detect the odor from natural gas leaks, concealed narcotics, explosives, and currency, all at levels well below the threshold at which humans are aware of the odor.在警察和保安工作，可以侦测犬的气味从天然气泄漏，隐瞒毒品，炸药和货币，所有的水平远远低于阈值在人类认识到气味。

In controlled studies dogs could detect human scent on a glass slide that had been lightly fingerprinted and then left outdoors for as much as two weeks, or indoors for as much as a month; they could pick which of six identical steel tubes had been held in the hands of a person for no more than five seconds; they could distinguish between T-shirts worn by two identical twins who ate different foods, or by two nonidentical twins who lived in exactly the same environment and ate exactly the same foods.在控制的研究可以发现狗人体气味的载玻片已掉以轻心指纹，然后离开户外多达两个星期，或在室内多达一个月;他们可以选择其中的6个相同的钢管一直被关押在手中的人不超过5秒;他们可以区分的T恤衫穿的两个双胞胎谁吃不同的食物，或者由两个异卵双胞胎谁住在完全相同的环境，吃一模一样的食物。

More than such a remarkable sensitivity to trace odors, it is the ability to pick out particular odors of interest from a welter of competing smells and to match and distinguish them that is the dog's most impressive olfactory feat.以上这样一个显着的敏感性追踪气味，它是能够挑选出特别的兴趣气味从一个混乱竞争的味道和比赛，并区分这是狗的嗅觉最令人印象深刻的壮举。 This ability is surely a reflection of the dog's superior olfactory computing powers, for it requires not just smelling but analyzing.这种能力无疑是反映了狗的嗅觉计算上级的权力，因为它不仅要求气味，但分析。 Dogs have no innate interest in the smell of people, narcotics, or hundred-dollar bills; but if trained repeatedly to focus on certain categories of smells, they can perform mind-boggling feats of cross-matching.狗没有天生的兴趣，嗅觉的人，毒品，或100美元的帐单;但如果受过训练的多次把重点放在某些类别的气味，他们可以执行令人难以置信的壮举跨匹配。