bpf 中文意思是什麼

Objective to evaluate the diagnosis and therapy of post - pneumonectomy bronchopleural fistula ( bpf )

摘要目的探討肺切除術后支氣管胸膜瘺的診斷與防治特點。

Conclusion the key therapy for post - pneumonectomy bpf is to close the stoma and thoroughly eliminate the vomica

結論支氣管胸膜瘺重在預防，治療的關鍵在於封閉瘺口，徹底消滅膿腔。

Finally, a chebyshev function bpf with siw resonator was designed and realized by ltcc with 12 - layer substrate. a high performance elliptic function bpf with siw resonator was designed

在分析ltcc集成高q濾波器實驗結果的基礎上，設計了一個基於siw技術的9層基片的高性能的橢圓函數濾波器。

The susceptance due to discontinuity of the sections of the septum is accounted for. then construction parameters of the bpf is determined applying network synthesis theory. by the accurate model and highly efficient iteration algorihtm, the e - plane metal suptum waveguide bpf can be designed rapidly and accurately

用此cad軟體設計製做的e面單膜片濾波器、雙膜片濾波器和混合膜片濾波器均很好地滿足了設計指標的要求，能夠應用在毫米波合成孔徑雷達上。

For phonetic signal modulation, if the pass band range of the band pass filter ( bpf ) is 300hz - 3400hz, the anti - noise properties of laser are approximately independent of bias current and parameters of the cavity ; when the pass band range of bpf increases to a certain degree, modulating bias current and parameters of the cavity can improve the anti - noise properties of laser

對語音調制情況，如帶通濾波器的通帶范圍取為300hz - 3400hz ，則激光器的抗噪聲性能基本不依賴于偏置電流和腔內參數；當帶通濾波器的通帶范圍增大到一定程度，調整偏置電流和腔內參數可以實現半導體激光器的高抗噪聲性能。

Business and professional federation of hong kong bpf

香港工商專業聯會

An lpf can be simulated by setting the bpf ' s centre frequency to zero

將帶通濾波器的中心頻率設置到0 ，就可以模擬低通濾波器。

Bpf band - pass filter

帶通濾波器

A ka - band bpf would be developed and used in the rardar system

同時製做一隻ka波段的波導濾波器，用於毫米波合成孔徑雷達系統中。

Bpf band pass filter

帶通濾波器

Under special conditions a bpf may also be used as an lpf or as an hpf

在特殊條件下，帶通濾波器也可以用作低通濾波器或高通濾波器。

It also overcomed the dificulty to realize characteristics bpf with fractional bandwidth greater than about 5 % in the form of multi - metal insert waveguide filter

既提高了濾波器的阻帶性能，又避免了單純的多膜片結構能實現的濾波器帶寬較小的缺點。

The design process consisted of computer design by circuit simulation software integrate with electromagnetic simulation software, fabrication of microstrip bpf 、 lpf 、 the match circuits, cavity and test. when rf frequency is 91 ~ 97ghz, lo frequency is 47ghz, power is 10 dbm. the best conversion loss of the 2 and 4 sub - harmonic mixer is 13. 5 db and 23. 5db which is shown in the test

實測表明，在本振為47ghz ，功率10dbm ，測試射頻帶寬為91ghz 97ghz時，二次與四次分諧波混頻器變頻損耗最優處分別為12 . 7db和23db 。最後對實驗結果進行分析並提出改進措施。

This paper mainly focuses on the noise limiting by means of the direct sequence spread spectrum ( dsss ) and the analysis of the transmission performance of the plc and some digital modulation technology. the contents of the paper is as follows : 1 ) the technical feasibility is proved after simulating noise limiting principle of dsss by means of systemview, the simulation software ; 2 ) a kind of band pass filter ( bpf ) is realized according to the requirement of filter and the principle of butterworth approximation, which satisfies the index of performance of dsss. 3 ) the low voltage plc system includes the sc1128, the specific modulation / demodulation ic, the bpf filter and other circuit components, furthermore, the control function of system is realized by means of the personal computer and the microcontroller

本課題在對低壓電力線的傳輸特性和數字調制技術進行分析的基礎上，將通信理論中的直接序列擴頻技術（ dsss ）用於解決低壓電力線通信的干擾問題，主要研究內容如下： （ 1 ）用通信模擬軟體systemview對dsss技術的通信和抗干擾原理進行模擬分析，分別對時域和頻域下採用dsss技術前後接收信號的頻譜進行分析，驗證dsss技術在本系統中的可行性； （ 2 ）由dsss技術對濾波系統的要求，根據濾波理論分析了巴特沃思型濾波器的逼近原理並設計了合適的濾波電路； （ 3 ）用調制解調晶元sc1128和自行設計的濾波器加之輔助外圍電路，構造出低壓電力線載波通信系統，並採用atmel公司的單片機設計了接收和發射電路的微控制器； （ 4 ）分別對採取抗干擾措施前後輸入和輸出信號進行對比實驗，並對結果進行分析，驗證了dsss技術對干擾信號的抑制作用。

This solutions includes adopting the ndis protocol driver as packet capture module, the kpf filter as packet filter which came from the revising and improving of the bpf filter, hypercuts with rule updating ability as packet classification algorithm.

該方案包括以ndis協議驅動程序實現報文捕獲、以對bpf過濾器改進和增強后的kpf為報文過濾器，以增加了規則更新能力的hypercuts演算法為報文分類演算法。

With the theory and the graphs, the initial sizes of bpf were obtained, and then the final sizes were obtained by the software simulation

結合濾波器理論設計的耦合值與所創建的圖表，確定濾波器的初始尺寸，通過軟體對濾波器參數的微調，最終得到濾波器的精確模型。

Though the problem can be remedied by all bpf files assuming that the interface has been set into promiscuous mode and utilizing a filter to reject foreign packets, this has not thoroughly solved the problem and will trouble programmers to add many special instructions. this paper includes a solution to this bpf ' s problem, and the solution has been implemented on freebsd 4. 7, as a result, it also makes bpf provide a better interface to application program

目前為補救這個問題，在對bpf編程時，應用程序都要假定以太網卡已經被設置成了混雜模式，從而應該在它的過濾程序中添加許多專門的語句來過濾混雜模式下的外部數據包，這樣做雖然能大致解決（並沒有完全解決）此問題，卻給對bpf的編程造成了相當大的麻煩。

Secondly, we implement a bpf model called mybpf on linux as a kernel module. it can collect packets within the netfilter frame, provide the applications with an interface in char device file manner and be attached to the nf _ ip _ pre _ routing hook defined by netfilter frame for ipv4 as a hook function. finally, we evaluate the performance between mybpf and other bpf on sock _ packet socket

該模塊以字元設備文件的形式為應用程序提供介面，並在netfilter框架為ipv4定義的nf _ ip _ pre _ routing鉤子上掛接了一個鉤子函數，該鉤子函數實現bpf虛擬機，完成對數據包的捕獲；最後，本文對mybpf模塊作了相應的測試並與在sock _ packet套介面上實現的bpf做了性能比較。

A novel e - plane metal insert waveguide filter is presented in this paper. comparing to conventional e - plane waveguide filter, great improvments have been made in stop - band attenuation of a bpf

為了提高e面全金屬膜片矩形波導濾波器的阻帶性能，本文對濾波器的結構做了改進，採用了混合膜片的形式。

This dissertation is a part of the research project, " millimeter wave synthetic aperture radar ( sar ) ", which is the pre - researchful item of the elelctric 10th institute of ministry of information industry. it ' s aim is to improve performance of stop - band of waveguide band - pass filter ( bpf )

本論文工作是中國電子科技集團公司第十研究所「十五」預研項目「毫米波合成孔徑雷達」中的一部分。要求對目前的e面全金屬膜片波導濾波器進行改進，提高其阻帶性能。