Homogeneous Second System of Center-focus Type to System Concluding Parameters;

中心-焦點(diǎn)型齊二次系統(tǒng)參數(shù)化簡問題

Designed principle of the rotational stand uses for measuring a camber with double focuses;

一種雙焦點(diǎn)曲面的測量用轉(zhuǎn)動架的設(shè)計(jì)原理

A kind of directness arithmetic about conic′s focus;

二次曲線焦點(diǎn)的直接求法

The focal points of their arguments such as advance informed agreement (AIA), risk assessment and risk management, information exchange and other related issues have been expounded and analyzed.

生物技術(shù)的安全性（生物安全）問題已經(jīng)引起了國際社會的嚴(yán)重關(guān)注，不同國家的生物安全能力的巨大差異，使他們對國際生物安全立法的內(nèi)容和形式等問題產(chǎn)生了很大的分歧，爭論的焦點(diǎn)集中在提前知情同意、風(fēng)險(xiǎn)評估和風(fēng)險(xiǎn)管理、資料交換等問題上；本文就上述問題進(jìn)行了闡述和分析，并指出了國際生物安全立法的發(fā)展趨

Based on the Lyapunov stability theory,through improving related theorem,obtain simple and effective methods of judging center or the focal point of nonlinear system and estimating the attraction territory of non-autonomous system.

從Lyapunov穩(wěn)定性理論出發(fā),通過將有關(guān)定理改進(jìn),得到判斷非線性系統(tǒng)的中心或焦點(diǎn)及估計(jì)非自治系統(tǒng)的吸引域的簡便而有效的方法。

By the definitions of the conjugate point and the focal point in a geodesic,the paper proves that for any geodesic γ:［0,+∞)→M,in a complete Gauss surface M with positive curvature,there exists t＞0 such that γ(t) is a focal point of γ(0).

從測地線的共軛點(diǎn)、焦點(diǎn)的定義出發(fā),證明了對任意具正曲率的完備二維Gauss曲面,γ:[0,+∞)→M為測地線,則存在t>0,γ(t)是γ(0)之焦點(diǎn)。

Study on the twin-focus technique in laser welding;

激光焊接中的雙焦點(diǎn)技術(shù)

The most popular detection methods both at home and aboard are introduced,and a method on the position control system for beam focus is presented during laser beam cutting process based on CCD,which can accurate detect and control the laser focus position during laser beam cutting process by using the laser triangulation and CCD imaging system coordination digital image proce.

激光焦點(diǎn)位置的檢測與控制是激光切割系統(tǒng)中的關(guān)鍵技術(shù)之一。

According to the interaction and degree of interaction between electron beam and metal, the EB focal spot is classified to the static focal spot, the quasi-dynamic focal spot and the dynamic foca.

回顧了焦點(diǎn)定義和測量方法 ,首次明確將電子束流焦點(diǎn)狀態(tài)與焊接過程建立直接聯(lián)系 ,揭示了具有焊接特征焦點(diǎn)與測量方法的內(nèi)在關(guān)系 ,并根據(jù)束流與金屬是否產(chǎn)生作用和作用的程度 ,將焦點(diǎn)分類成靜態(tài)焦點(diǎn)、準(zhǔn)動態(tài)焦點(diǎn)和動態(tài)焦點(diǎn)。