pws:個人網站服務器-中文百科頻道

服務器名稱

概述

PWS 全稱為 Personal Web Server，是微軟開發的個人網站服務器，主要應用于解決個人信息共享和 Web 開發。它是一個桌面形的 Web 服務器，使用它可以自動創建個性化主頁，以拖放的方式發布文檔，在它的幫助下，我們可以快速簡便地進行 Web 站點設置。

介紹

引用部分微軟的話就是：

“...在企業 Intranet 上，Personal Web Server 可用于以自身的格式快速共享文檔，或者将文檔轉換為 HTML，然後使用 PWS 在不同的操作系統共享這些文檔。”

“由于 Personal Web Server 支持 Active Server Pages，因此可以作為 Web 站點的開發和測試平台。在企業服務器上或 Internet 服務提供商處使用您的站點前，可以先在辦公室或家裡創建站點，并使用 Personal Web Server 進行測試。

病症名稱

概述

普達-威利綜合症英文全稱為Prader-Willi syndrome，為一種一種罕見疾病，目前證實為15号染色體缺失所緻,屬于遺傳疾病緻範疇。

臨床表現

患者表現為饑餓,且不能因進食而消除饑餓感，緻使患者暴飲暴食。有時患者會出現吃貓糧狗糧，甚至煤等不是食物的物品進行“充饑”。由于長期

的暴飲暴食患者表現為病态肥胖。同時患者可伴有智力低下及其它異常。

治療

該病尚無藥物治療，隻能通過控制飲食，加強鍛煉來對抗疾病。抑制食欲的藥物對該病無效。若不能有力的控制食欲，患者常因體重超标而引起的各種疾病而英年早逝。

系統名稱

概述

PWS：風切變預警系統

英文全稱為Predictive Windshear System

PWS

詳細介紹

現在飛機的氣象雷達大多都加裝了PWS預測風切變功能。飛機的GPWS 近地警告系統也提供低空風切變警告。判斷原理是多普勒頻移原理。飛機頂風産生正的多普勒頻移，順風産生負的多普勒頻移，如果在一個很短的距離内探測到明顯的正負風速變化，則可判斷為風切變。機組得到風切變警告後需立即采取措施，比如停止近進，複飛，風切變機動飛行，來躲開風切變。起飛和複飛時，飛機的自動駕駛系統會提供飛行指引，幫助機組進行正确的俯仰操作。進近時，如果遭遇嚴重風切變，機組應該脫開自動駕駛，進行人工飛行，否則有可能失速。不操縱飛機的駕駛員要密切監視垂速表和高度表，機組的快速反應和清醒的意識是非常重要的。

英文介紹

Windshear is a sudden, rapid change in wind velocity or direction. It is often found in –– but is not limited to –– thunderstorms or other highly unstable atmospheric events.

The most dangerous form of windshear is known as microburst, a vertical column of air rapidly descending toward the ground.

Upon reaching the ground, microburst spreads out horizontally, creating a horizontal outflow.

Entering a microburst is very dangerous for an airplane because the wind may be strong enough to overcome the maximum of climb performance.

Known as the Predictive Windshear System (PWS), this technology permits weather radar systems to scan the atmosphere ahead of an airplane and detect windshear before the airplane enters it.

Predictive Windshear System (PWS)

The Principle ofPWS

PWS

uses wind velocity data gathered by a Doppler weather radar system to identify the existence of a windshear.

Radar energy is emitted through the airplane's radome in order to gather atmospheric information such as wind speed and direction. The weather radar receiver/transmitter then uses this information, in addition to air data and inertial data, to determine the presence of a windshear.

The weather radar processor identifies wind velocity characteristic that indicate a rapid change in wind velocity or direction over a relatively small area. When the magnitude of the detected windshear reaches a predetermined intensity level, the system alerts the flight crew.

If thePWS

detects a windshear from a significant distance, the flight crew may be able to avoid it completely. If windshear is unavoidable, however,PWS

gives the flight crew valuable time to increase speed or altitude before the airplane enters a windshear.

The Principle ofPWS

PWSprovides windshear detection with very few operational changes that will affect flight crews.

First, the flight crew does not need to manually turn on the weather radar for it to operate in the windshear mode.

If not already turned on by the flight crew, the radar automatically turns on at 2,300 feet (700m) above ground level (AGL) for approach and landing coverage.

The radar also turns on automatically before takeoff—using air-ground and takeoff thrust logic—to provide windshear coverage during takeoff roll, rotation, and climbout.

The flight crew can manually activatePWS

on the ground by turning on the weather radar. The automatic activation ofPWS

does not affect the weather radar display; it will remain in the mode and range selected by the flight crew.

The Principle ofPWS

The PWS automatically sets weather radar gain and tilt when in a windshear mode. As a result, it is effective regardless of the settings made by the flight crew on the weather radar control panel.

Crew-selected tilt and gain are used when the radar is in a weather sweep.