pans发表论文
大米即稻米，目前根据生活环境的不同，分为水/旱/海三种稻米。我们常说的大米，指的就是水稻的粳（jīng）米部分。而从水稻到大米，需要经历如下这些过程（可见注一）：
【关于水稻（大米）的起源（注二）】
2017年5月30日，中央电视台报道说，距今约1万年前，在长江下游地区发现的水稻化石近一步确立了中国在世界农业起源中的水稻驯化地位。这项研究由中科院地质与地球物理研究所的吕厚远研究员与国内同行合作完成，相关论文发表在新一期美国《国家科学院学报》（PANS）上。
注一（点击可放大）：
注二：详细可见新华社华盛顿2017-05-29日报道，或搜索《研究显示水稻约1万年前在长江下游开始驯化》一文。
从物种分布来看，大约在5万年前，在云南地区已经出现了早期的稻属植物。故推测亚洲最早种植稻谷的地区应该是云南地区。 虽然在长江下游发掘的某遗址中存在稻作证据，但这不能表明长江下游的中国先民是最早的种稻人。故以下说法不能采信。 大米历史上最早的种稻人是长江下游的中国先民，早在7000年前，我国长江下游的原始居民已经完全掌握了水稻的种植技术，并把稻米作为主要食粮。
由来：从物种分布来看，大约在5万年前，在云南地区已经出现了早期的稻属植物。故推测亚洲最早种植稻谷的地区应该是云南地区。
湖南道县与江西万年县考古发现，约一万三千多年前人类开始种植食用，新石器以前人类应该是口腔咀嚼全稻原谷。
在长江下游发掘的河姆渡遗址中存在稻作证据。大米历史上最早的种稻人是长江下游的中国先民，早在7000年前，中国长江下游的原始居民已经完全掌握水稻的种植技术，并把稻米作为主要食粮。
长江中下游河姆渡文化在约七千年以后人类进入新石器时代，杵臼发明被应用，人类知道清理分离不益食的谷壳与米糠。此后不久应该发现用水淘洗是一种更高效的去杂清理工序，淘米工序的高效去菌除氧化糠层及尘埃，人们仍在延用，杵臼制米装备直至二十世纪七十年代仍有使用。
十九世纪未辊式米机被发明，碾米效率得以大幅度提高。二十世纪中期喷风米机问世，碾米效果得以较大的改善。
二十世纪后期制米技术快速发展，光电色选自动清理水平不断提高，加之北方寒地粳稻种植的不断扩大，1988年免淘米在黑龙江省大庆市粮食局第二制米厂规模生产。1989年50吨/天生产线上马。
生长分布
水稻原产于中国和印度，七千年前中国长江流域的先民们就曾种植水稻。稻生长的最北限是中国的黑龙江省呼玛，但主要的生长区域是中国南方。
一、华南双季稻稻作区：位于南岭以南，中国最南部。包括闽、粤、桂、滇的南部以及台湾省、海南省和南海诸岛全部。
二、华中双季稻稻作区：东起东海之滨，西至成都平原西缘，南接南岭，北毗秦岭、淮河，是中国最大的稻作区。
三、西南高原单双季稻稻作区：地处云贵和青藏高原，黔东湘西高原。
四、华北单季稻稻作区：位于秦岭、淮河以北，长城以南，关中平原以东，包括京、津、冀、鲁和晋、陕、苏、皖的部分地区。
五、东北早熟单季稻稻作区：位于辽东半岛和长城以北，大兴安岭以东，及内蒙古东北部。
六、西北干燥区单季稻稻作区：位于大兴安岭以西，长城、祁连山与青藏高原以北。
参考资料来源：百度百科--水稻
参考资料来源：百度百科--大米
发表pans论文
大米即稻米，目前根据生活环境的不同，分为水/旱/海三种稻米。我们常说的大米，指的就是水稻的粳（jīng）米部分。而从水稻到大米，需要经历如下这些过程（可见注一）：
【关于水稻（大米）的起源（注二）】
2017年5月30日，中央电视台报道说，距今约1万年前，在长江下游地区发现的水稻化石近一步确立了中国在世界农业起源中的水稻驯化地位。这项研究由中科院地质与地球物理研究所的吕厚远研究员与国内同行合作完成，相关论文发表在新一期美国《国家科学院学报》（PANS）上。
注一（点击可放大）：
注二：详细可见新华社华盛顿2017-05-29日报道，或搜索《研究显示水稻约1万年前在长江下游开始驯化》一文。
pnas影响因子是8.6~10分。
2008 ~ 9.38
2009~ 9.432
2010~ 9.771
2011~ 9.681
2012~9.737
2013~ 9.809
5-year impact factor：10.727
统计比较发现，小期刊（年发表论文数少于35）影响因子在相邻年间的波动超过40%，对于年发表论文数超过150的期刊来说，其影响因子也有15%左右的波动。因此，在评价中若考虑到影响因子在一定范围的这种随机变化性，是难以给影响因子定量化的。
扩展资料：
不能单单凭影响因子（IF）的高低来判断期刊的权威性，如美国科学院院报（PNAS）虽然每年的IF在10.0 左右，但是大家都知道其在学术界的影响力和权威性与
PNAS收录的文献涵盖生物、物理和社会科学，2008年的影响因子为9.38，2009年影响因子为9.432。在SCI综合科学类期刊中排名第三位，因而已成为全球科研人员不可缺少的科研资料。
参考资料来源：百度百科-美国科学院院刊
教授，博士生导师。现任西南大学农业部蚕桑学重点实验室副主任，第十届全国政协委员。 西南大学校长助理兼动物科技学院院长。主要从事家蚕突变基因、资源及细胞生物学研究。主持承担了“973”、“948”、“863”、国家科技基础调查专项、国家产业技术体系、国家科技攻关、国家自然科学基金、博士点基金课题及省、市重点科研课题30余项。在家蚕基因分析及遗传资源研究、家蚕细胞系的建立等方面有创新成果和突出成就，在《Science》、《PANS》和《JBC》等国内外学术刊物上发表研究论文200余篇，参加编写出版学术专著5部，获重庆市自然科学一等奖2项、四川省科技进步一等奖1项、国家自然科学四等奖1项和四川省第二届青年科技奖。1994年评为国家级有突出贡献的中青年专家，1995年获国家教委“跨世纪优秀人才培养计划”资助，1996年被批准进入国家“百千万人才工程”一、二层次和“神农计划”首批提名。
由来：从物种分布来看，大约在5万年前，在云南地区已经出现了早期的稻属植物。故推测亚洲最早种植稻谷的地区应该是云南地区。
湖南道县与江西万年县考古发现，约一万三千多年前人类开始种植食用，新石器以前人类应该是口腔咀嚼全稻原谷。
在长江下游发掘的河姆渡遗址中存在稻作证据。大米历史上最早的种稻人是长江下游的中国先民，早在7000年前，中国长江下游的原始居民已经完全掌握水稻的种植技术，并把稻米作为主要食粮。
长江中下游河姆渡文化在约七千年以后人类进入新石器时代，杵臼发明被应用，人类知道清理分离不益食的谷壳与米糠。此后不久应该发现用水淘洗是一种更高效的去杂清理工序，淘米工序的高效去菌除氧化糠层及尘埃，人们仍在延用，杵臼制米装备直至二十世纪七十年代仍有使用。
十九世纪未辊式米机被发明，碾米效率得以大幅度提高。二十世纪中期喷风米机问世，碾米效果得以较大的改善。
二十世纪后期制米技术快速发展，光电色选自动清理水平不断提高，加之北方寒地粳稻种植的不断扩大，1988年免淘米在黑龙江省大庆市粮食局第二制米厂规模生产。1989年50吨/天生产线上马。
生长分布
水稻原产于中国和印度，七千年前中国长江流域的先民们就曾种植水稻。稻生长的最北限是中国的黑龙江省呼玛，但主要的生长区域是中国南方。
一、华南双季稻稻作区：位于南岭以南，中国最南部。包括闽、粤、桂、滇的南部以及台湾省、海南省和南海诸岛全部。
二、华中双季稻稻作区：东起东海之滨，西至成都平原西缘，南接南岭，北毗秦岭、淮河，是中国最大的稻作区。
三、西南高原单双季稻稻作区：地处云贵和青藏高原，黔东湘西高原。
四、华北单季稻稻作区：位于秦岭、淮河以北，长城以南，关中平原以东，包括京、津、冀、鲁和晋、陕、苏、皖的部分地区。
五、东北早熟单季稻稻作区：位于辽东半岛和长城以北，大兴安岭以东，及内蒙古东北部。
六、西北干燥区单季稻稻作区：位于大兴安岭以西，长城、祁连山与青藏高原以北。
参考资料来源：百度百科--水稻
参考资料来源：百度百科--大米
论文发表在PANS
大米即稻米，目前根据生活环境的不同，分为水/旱/海三种稻米。我们常说的大米，指的就是水稻的粳（jīng）米部分。而从水稻到大米，需要经历如下这些过程（可见注一）：
【关于水稻（大米）的起源（注二）】
2017年5月30日，中央电视台报道说，距今约1万年前，在长江下游地区发现的水稻化石近一步确立了中国在世界农业起源中的水稻驯化地位。这项研究由中科院地质与地球物理研究所的吕厚远研究员与国内同行合作完成，相关论文发表在新一期美国《国家科学院学报》（PANS）上。
注一（点击可放大）：
注二：详细可见新华社华盛顿2017-05-29日报道，或搜索《研究显示水稻约1万年前在长江下游开始驯化》一文。
由来：从物种分布来看，大约在5万年前，在云南地区已经出现了早期的稻属植物。故推测亚洲最早种植稻谷的地区应该是云南地区。
湖南道县与江西万年县考古发现，约一万三千多年前人类开始种植食用，新石器以前人类应该是口腔咀嚼全稻原谷。
在长江下游发掘的河姆渡遗址中存在稻作证据。大米历史上最早的种稻人是长江下游的中国先民，早在7000年前，中国长江下游的原始居民已经完全掌握水稻的种植技术，并把稻米作为主要食粮。
长江中下游河姆渡文化在约七千年以后人类进入新石器时代，杵臼发明被应用，人类知道清理分离不益食的谷壳与米糠。此后不久应该发现用水淘洗是一种更高效的去杂清理工序，淘米工序的高效去菌除氧化糠层及尘埃，人们仍在延用，杵臼制米装备直至二十世纪七十年代仍有使用。
十九世纪未辊式米机被发明，碾米效率得以大幅度提高。二十世纪中期喷风米机问世，碾米效果得以较大的改善。
二十世纪后期制米技术快速发展，光电色选自动清理水平不断提高，加之北方寒地粳稻种植的不断扩大，1988年免淘米在黑龙江省大庆市粮食局第二制米厂规模生产。1989年50吨/天生产线上马。
生长分布
水稻原产于中国和印度，七千年前中国长江流域的先民们就曾种植水稻。稻生长的最北限是中国的黑龙江省呼玛，但主要的生长区域是中国南方。
一、华南双季稻稻作区：位于南岭以南，中国最南部。包括闽、粤、桂、滇的南部以及台湾省、海南省和南海诸岛全部。
二、华中双季稻稻作区：东起东海之滨，西至成都平原西缘，南接南岭，北毗秦岭、淮河，是中国最大的稻作区。
三、西南高原单双季稻稻作区：地处云贵和青藏高原，黔东湘西高原。
四、华北单季稻稻作区：位于秦岭、淮河以北，长城以南，关中平原以东，包括京、津、冀、鲁和晋、陕、苏、皖的部分地区。
五、东北早熟单季稻稻作区：位于辽东半岛和长城以北，大兴安岭以东，及内蒙古东北部。
六、西北干燥区单季稻稻作区：位于大兴安岭以西，长城、祁连山与青藏高原以北。
参考资料来源：百度百科--水稻
参考资料来源：百度百科--大米
发表论文通常只有两种渠道，要么自己投，要么找论文发表机构代投，不管走哪种渠道，最后都是要发表到期刊上的。
期刊，也叫杂志，在上个世纪在出版界曾经是重量级的存在，那个时候互联网还没有兴起，人们阅读文章获取资讯远远没有现在方便，杂志就成为一个很重要的传播媒介。
但现在随着社会的进步，科技的发展，纸媒已经大大没落了，很多期刊被砍掉了，剩下来的大多数不得不自谋出路，学术期刊更是如此，因为这个受众面是很窄的，基本没法盈利，所以只能靠收取版面费来维持，当然，有国家财政拨款的那种不在这个范围。
我们现在发表学术论文，出于严谨性权威性等原因的考虑，还是要发表到纸质期刊上，编辑会用电子邮箱或者内部的系统来收稿，但不会有一个网络平台有发表论文的资质，即使是知网和万方这样的网站，也只是论文数据库，并不是论文发表平台。
所以发表论文的时候，还是要先去选取目标期刊，然后再找到这本期刊的投稿邮箱，或者是找到靠谱的论文发表机构，由代理进行代投，最后都是发表到纸质期刊上的，见刊后一两个月左右被知网收录，就可以检索到了。
pans发表论文费用
The Basics A jet engine can be divided into several distinct sections: intake, compressor, diffuser, combustion chamber, turbine, and exhaust. These sections are much like the different cycles in a four-stroke reciprocating engine: intake, compression, power and exhaust. In a four-stroke engine a fuel/air mixture is is brought into the engine (intake), compressed (compression), and finally ignited and pushed out the exhaust (power and exhaust). In it's most basic form, a jet engine works in much the same way. * Air comes in the front of the engine where it enters the compressor. The air is compressed by a series of small spinning blades aptly named compressor blades and leaves at a high pressure. The pressure ratio between the beginning and end of the compressor can be as much as 48:1, but almost always 12:1 or more. * The air now enters the diffuser, which is nothing more than an area where the air can expand and lower it's velocity, thus increasing its pressure a little bit more. * The high pressure air at the end of the diffuser now enters the combustion chamber where it is mixed with fuel, ignited and burned. * When the fuel/air mixture burns, the temperature increases (obviously) which makes the air expand. * This expanding gas drives a set of turbine blades located aft of the combustion chamber. At least some of these turbine blades are connected by a shaft to the compressor blades to drive them. Depending on the type of engine, there may be another set of turbine blades used to drive another shaft to do other things, such as turn a propeller or generator. * The left over energy not extracted by the turbine blades is pushed out the back of the engine (exhaust section) and creates thrust, usually used to drive an airplane forward. The types of jet engines include: * Turbojet * Turbofan * Turboprop * Turbo shaft Turbojet The turbojet is the simplest of them all, it is just as described in "The basics" section. This style was the first type of jet engine to be used in aircraft. It is a pretty primitive style used mostly in early military jet fighters such as the F-86. Its use was discontinued, for the most part, in favor of the more efficient turbofans. Actually, I should clarify that. Each type of engine is most efficient under certain conditions. Turbojets are most efficient at high altitudes and speeds above the speed of sound. See the diagram at the end of this page for relative efficiencies of each style engine. Turbofan Turbofans make up the majority of jet engines being produced and used today. A turbofan engine uses an extra set of turbine blades to drive a large fan, typically on the front of the engine. This fan differs from a propeller in that there are many small blades and they are inside of a duct. The fan sits just in front of the normal intake, some of the air driven by this fan will enter the engine, while the rest will go around the outside. The amount of air that bypasses the engine is different for each type of airplane. The different styles are called high and low bypass engines. Bypass ratio is the ratio of how much air goes through the fan, to how much goes through the engine. Typical bypass ratios would be 1:1 for a low bypass and 5:1 or more for a high bypass. Low bypass engines are more efficient at higher speeds, and are used on planes such as military aircraft, while high bypass engines are used in commercial airliners. Turboprop Turboprops are similar to turbofans in that they incorporate an extra set of turbine blades used to drive the propeller. Unlike the turbofan engines, nearly all the thrust produced by a turboprop is from the propellor, hardly any thrust comes from the exhaust. These engines are used mostly on smaller and slower planes such as commuter aircraft that fly to the smaller airports. As you can see from the efficiency chart below, turboprops are very efficient over a fairly wide range of speeds. They would probably be used more often on large transport aircraft, except for one problem: they have propellors. The general public does not like propellors, as they appear to be old-fashioned and unsafe. However, the military knows better and uses them on several large transport aircraft. Turbo shaft Turbo shaft engines are very similar to turboprop engines, but instead of driving a propellor, they are used to drive something else. Many helicopters use them to drive their rotors, and airliners and other large jets use them to generate electricity. Also, the Alaska Pipeline uses them at the pump stations to pump oil. Overall Overall the big difference between these engines is how they take a chunk of air and move it. Newton's third law states that Force equals mass times acceleration. Applying this to turbine engines: the turboprop takes a large chunk and accelerates it a little bit, while the turbojet takes a small chunk and accelerates the heck out of it, and the turbofan is somewhere in between these two. These different methods of moving air also have to do with how much noise each engine makes. The turbojet makes the most noise because there is a large difference in velocities of the blast of air coming out the exhaust and the surrounding air. The air from the fan on a turbofan engine "shields" the blast in the center by having the slower moving air from the fan surround it. Then the turboprop is the quietest of all because the air it's moving is relatively slow. A pressure - volume diagram (or a P-V diagram) is a useful tool in thermodynamics. In this case, it relates the pressure and volume of the gas moving through the engine at different stages. A P-V diagram can also be helpful in finding the work output of an engine. Work equals the integral of pressure with respect to volume. Or is simpler form, work equals the area enclosed in the diagram above. The above cycle is the Brayton cycle, or the cycle used by aircraft gas turbine engines. Explanation of the above cycle: * Air enters the inlet at point 1 at atmospheric pressure. * As this air passes through the compressor (from point 1 to 2), the pressure rises adiabatically (no heat enters or leaves the system). * Now the air enters the combustion chamber (from point 2 to 3), is mixed with fuel, and burned at a constant pressure. * Finally, the air goes through the turbine and out the exhaust (point 3 to 4) where the gases expand and do work. Thus, the pressure drops and the volume increases. The Compressor There are two main styles for turbine compressors: the axial and the centrifugal. The Axial Compressor * The axial type compressor is made up of many small blades, called rotor vanes, arranged in rows on a cylinder whose radius gets larger towards the back (as can be seen from the above picture). These blades act much like small propellors. * In between these rotor vanes are stator vanes which stay in a fixed spot and straighten the air coming out of the previous stage of rotor vanes before it enters the next stage. * On some newer engines, the angle of these stator vanes can be adjusted for optimum efficiency. * Each stage (1 row of rotor and stator vanes) generally provides for a pressure rise of about 1.3:1 (so after the first stage, the pressure would be 1.3 above atmospheric, after the second it would be 1.69, 2.2, etc...). The Centrifugal Compressor * Air enters the centrifugal compressor at the front and center. The blades then sling the air radially outwards where it is once again collected (at a higher pressure) before it enters the diffuser. * Pressure rise per stage is usually about 4 to 8:1 (higher than axial). These can be sombined in series (that is the exit of the first leads to the entrance of the next) to produce a greater pressure rise. But more than two stages is not practical. - Jet engines are rated in "pounds of thrust," while turboprops and turboshaft engines are rated in "shaft horsepower" (SHP). This is because it is difficult to hook up a dynamometer (power measuring device) to the column of air coming out of a jet engine, while it is easy to hook one to the shaft of a turboprop. - An equivalent measure to horsepower is thrust horsepower (THP). THP = (Thrust x MPH) / 375. or THP = SHP x 80% in the case of turboprop engines (the 80% is because the propeller "slips" a little in flight). - Exhaust gases exit the exhaust at upwards of 1000 mph or more and can use 1000 gallons of fuel/hour or more. - Turbine engines run lean. Unlike gasoline engines, turbines take in more air than they need for combustion. - Fuel can be injected into the exhaust section to burn with this unused air for extra thrust. This is called an afterburner. - A water/methanol mixture can be injected into the intake to increase the air density, and thus increase thrust. - Turbine engines can be built on a small scale as well. The turbine pictured below has a diameter of 4mm and runs at 500,000 rpm. It was built by at MIT for purposes of powering an aircraft with a wing span of about 5 inches that was projected to fly about 35 - 70 mph with a range of about 40 - 70 miles. micro turbine - The ignition system on turbine engines is only necessary for starting, afterwards it is self sustaining. In jets, the ignition system is also turned on for added saftey in "critical" stages of flight, such as takeoff and landing. - A device similar to a spark plug is used for the ignition process, but it has a larger gap. The spark is about 4 to 20 Joules (watts/second) at about 25000 volts and occurs between 1 and 2 times per second. - Turbine engines will run on just about anything, they prefer Jet-A (AKA diesel, kerosene, or home heating oil), but can burn unleaded, burbon, or even very finely powdered coal! - The above snowmachine uses an Allison turbine engine, a very common engine in helicopters (such as the Bell 206 Jet Ranger shown below). A lot of horsepower can be put into a small package! Note the intake and compressor are at the front of the engine, then the two side tubes take the compressed air and bring it around back to the combustion chamber and turbine and the exhaust exits out the middle. There are many engines out there with strange configurations like this. Communications Technology Your Rights and what the Data Protection Commissioner can do to help Right of Access The personal information to which you are entitled is that held on computer or in a manual filing system that facilitates access to information about you. You can make an access request to any organisation or any individual who has personal information about you. For example, you could make an access request to your doctor, your bank, a credit reference agency, a Government Department dealing with your affairs, or your employer. If you find out that information kept about you by someone else is inaccurate, you have a right to have that information corrected (or "rectified"). In some circumstances, you may also have the information erased altogether from the database - for example, if the body keeping the information has no good reason to hold it (i.e. it is irrelevant or excessive for the purpose), or if the information has not been obtained fairly. You can exercise your right of rectification or erasure simply by writing to the body keeping your data. In addition, you can request a data controller to block your data i.e. to prevent it from being used for certain purposes. For example, you might want your data blocked for research purposes where it held for other purposes. If an organisation holds your information for the purposes of direct marketing (such as direct mailing, or telephone marketing), you have the right to have your details removed from that database. This right is useful if you are receiving unwanted "junk mail" or annoying telephone calls from salespeople. You can exercise this right simply by writing to the organisation concerned. The organisation must write back to you within 40 days confirming that they have dealt with your request. Right to complain to the Data Protection Commissioner What happens if someone ignores your access request, or refuses to correct information about you which is inaccurate? If you are having difficulty in exercising your rights, or if you feel that any person or organisation is not complying with their responsibilities, then you may complain to the Data Protection Commissioner, Mr Mead, who will investigate the matter for you. The Commissioner has legal powers to ensure that your rights are upheld. The Data Protection Commissioner will help you to secure your rights: * with advice and information * by intervening directly on your behalf if you feel you have not been given satisfaction * by taking action against those failing to fulfil their obligations. SEE APPENDIX 2 FOR CASE STUDY Ergonomics Ergonomics (from Greek ergon work and nomoi natural laws) is the study of designing objects to be better adapted to the shape of the human body and/or to correct the user's posture. Common examples include chairs designed to prevent the user from sitting in positions that may have a detrimental effect on the spine, and the ergonomic desk which offers an adjustable keyboard tray, a main desktop of variable height and other elements which can be changed by the user. Ergonomics also helps with the design of alternative computer input devices for people who want to avoid repetitive strain injury or carpal tunnel syndrome. A normal computer keyboard tends to force users to keep their hands together and hunch their shoulders. To prevent the injuries, or to give relief to people who already have symptoms, special split keyboards, curved keyboards, not-really-keyboards keyboards, and other alternative input devices exist. Ergonomics is much larger than looking at the physiological and anatomical aspects of the human being. The psychology of humans is also a key element within the ergonomics discipline. This psychological portion of ergonomics is usually referred to as Human factors or Human factors engineering in the U.S., and ergonomics is the term used in Europe. Understanding design in terms of cognitive workload, human error, the way humans perceive their surrounds and, very importantly, the tasks that they undertake are all analysed by ergonomists. [IMAGE] With video conferencing consideration should be taken in positioning of camera and screens so as to avoid neck strain. Codec 1. (COder/DECoder or COmpressor/DECompressor) Hardware or software that encodes/compresses and decodes/decompresses audio and video data streams. The purpose of a codec is to reduce the size of digital audio samples and video frames in order to speed up transmission and save storage space. The goal of all codec designers is to maintain audio and video quality while compressing the binary data further. Speech codecs are designed to deal with the characteristics of voice, while audio codecs are developed for music. Codecs may also be able to transcode from one digital format to another; for example, from PCM audio to MP3 audio. The codec algorithms may be implemented entirely in a chip or entirely in software in which case the PC does all of the processing. They are also commonly implemented in both hardware and software where a sound card or video capture card performs some of the processing, and the main CPU does the rest. When analog signals are entered into a computer, cellphone or other device via a microphone or video source such as a VHS tape or TV, analog-to-digital converters create the raw digital audio samples and video frames. Speech, audio and video codecs are typically lossy codecs that compress data by altering the original format, which is why "codec" means "encoder/decoder" and "compressor/decompressor." If a codec uses only lossless compression in which the original data is restored exactly, then it would not be a coder/decoder. This is a subtle point, but the two meanings of the acronym have been confusing. LAN A local area network (LAN) is a computer network covering a local area, like a home, office or small group of buildings such as a college. The topology of a network dictates its physical structure. The generally accepted maximum size for a LAN is 1000m2. LANs are different from personal area networks (PANs), metropolitan area networks (MANs) or wide area networks (WANs). LANs are typically faster than WANs. The earliest popular LAN, ARCnet, was released in 1977 by Datapoint and was originally intended to allow multiple Datapoint 2200s to share disk storage. Like all early LANs, ARCnet was originally vendor-specific. Standardization efforts by the IEEE have resulted in the IEEE 802 series of standards. There are now two common wiring technologies for a LAN, Ethernet and Token Ring. Wireless technologies are starting to evolve and are convenient for mobile computer users. A number of network protocols may use the basic physical transport mechanism including TCP/IP. In this case DHCP is a convenient way to obtain an IP address rather than using fixed addressing. LANs can be interlinked by connections to form a Wide area network. A router is used to make the connection between LANs. WAN WANs are used to connect local area networks together, so that users and computers in one location can communicate with users and computers in other locations. Many WANs are built for one particular organisation and are private, others, built by Internet service providers provide connections from an organisation's LAN to the Internet. WANs are most often built of leased lines. At each end of the leased line, a router connects to the LAN on one side and a hub within the WAN on the other. A number of network protocols may use the basic physical transport mechanism including TCP/IP. Other protocols including X.25 and ATM. Frame relay can also be used for WANs. Ethernet Ethernet is normally a shared media LAN. All stations on the segment share the total bandwidth, which is either 10 Mbps (Ethernet), 100 Mbps (Fast Ethernet) or 1000 Mbps (Gigabit Ethernet). With switched Ethernet, each sender and receiver pair have the full bandwidth.When using Ethernet the computers are usually wired to a hub or to a switch. This constitutes the physical transport mechanism. Fiber-optic Ethernet (10BaseF and 100BaseFX) is impervious to external radiation and is often used to extend Ethernet segments up to 1.2 miles. Specifications exist for complete fiber-optic networks as well as backbone implementations. FOIRL (Fiber-Optic Inter Repeater Link) was an earlier standard that is limited to .6 miles distance.
pans期刊投稿
面筋球的煎炸改进自Chen等人（1998）的方法。100g的湿面筋球通过三个相继的油炸锅连续煎炸。每个锅（34 cm内径，26cm高）含有约10升的豆油。在第一、第二和第三个锅的油煎时间分别是120、90和70秒。第一、第二和第三个锅的温度分别是135 ± 3, 157 ±3, and190 ± 3℃。
PNAS是Proceedings of the National Academy of Sciences的缩写，翻译过来是《美国国家科学院院刊》