RESEARCH ARTICLE
Pseudo-Static and Pseudo-Dynamic Stability Analysis of Tailings Dam Under Seismic Conditions
Debarghya Chakraborty ?Deepankar Choudhury
Received:30January 2012/Revised:8January 2013/Accepted:19January 2013/Published online:12February 2013óThe National Academy of Sciences,India 2013
Abstract In this paper the seismic slope stability analyses are performed for a typical section of 44m high water retention type tailings earthen dam located in the eastern part of India,using both the conventional pseudo-static and recent pseudo-dynamic methods.The tailings earthen dam is analyzed for different upstream conditions of reservoir like ?lled up with compacted and non-compacted dumped waste materials with different water levels of the pond tailings portion.Phreatic surface is generated using seepage analysis in geotechnical software SEEP/W and that same is used in the pseudo-static and pseudo-dynamic analyses to make the approach more realistic.The minimum values of factor of safety using pseudo-static and pseudo-dynamic method are obtained as 1.18and 1.09respectively for the chosen seismic zone in India.These values of factor of safety show clearly the demerits of conventional pseudo-static analysis compared to recent pseudo-dynamic analy-sis,where in addition to the seismic accelerations,duration,frequency of earthquake,body waves traveling during earthquake and ampli?cation effects are considered.Keywords Tailings earthen dam áSlope stability áSeismic load áAmpli?cation áSeepage áSafety factor
Introduction
Seismic slope stability analysis of embankments/dams is one of the most important tasks before construction.Especially,for important safety related structures,like tailings dams,it becomes very much essential.Available literature indicates that a signi?cant numbers of tailings earthen dams have failed during earthquakes because of slope failure.Seismic slope stability analysis of embank-ments/dams is one of the most important tasks before construction.Especially,for important structures like tail-ings dams it becomes very much essential;since the failure of tailings dam which stores waste material will release the toxic and/or corrosive stored tailings waste into the sur-rounding locality,and causing a disaster for mankind in that vicinity.To reduce such phenomenon,the static as well as the seismic analyses must be performed before constructing the tailings dam.
Since 1920s,the seismic stability of earthen dams has been analyzed by pseudo-static approach in which the effects of earthquakes are represented by constant hori-zontal and/or vertical seismic accelerations.Choudhury et al.[1]have provided some guidelines regarding the seismic design of earthen dams.Though the pseudo-static analysis is simple and straightforward,the representation of the complex,dynamic effect of earthquake shaking by constant horizontal and/or vertical accelerations is actually pretty crude.These horizontal and vertical seismic forces are expressed as the product of the horizontal and vertical seismic acceleration coef?cients (k h and k v )and weight of the potential sliding mass.In pseudo-static case,the values of k h and k v are assumed to be constant.Moreover,this method does not consider the effects of time,frequency and body waves traveling through the soil during the earthquake.
D.Chakraborty
Department of Civil Engineering,Indian Institute of Science,Bangalore 560012,India
e-mail:debarghya@civil.iisc.ernet.in
D.Chakraborty áD.Choudhury (&)
Department of Civil Engineering,Indian Institute of Technology,Bombay,Powai,Mumbai 400076,India
e-mail:dc@civil.iitb.ac.in;dchoudhury@iitb.ac.in
Proc.Natl.Acad.Sci.,India,Sect.A Phys.Sci.(January–March 2013)83(1):63–71DOI 10.1007/s40010-013-0069-5
In order to investigate the dynamic response of earthen embankment,Clough and Chopra[2]performed a two-dimensional plane-strain analysis with the usage of the?nite element method.Few researchers have used software pack-ages which are primarily based on Finite Element or Finite Difference Method.Seid-Karbasi and Byrne[3]carried out seismic analysis of tailings earthen dam using FLAC[4].By using PLAXIS[5]and TELDYN[6],Zhu et al.[7]obtained the seismic stability for a levee embankment.In order to investigate the seismic behaviour along with liquefaction susceptibility of a tailings dam,Chakraborty and Choudhury [8–10]used FLAC3D[11]and TALREN4[12].Zeng et al.
[13]conducted centrifuge model tests for determining the stability of coal-waste tailings dams.
To make the seismic analytical approach more realistic, Steedman and Zeng[14]proposed a method which considers the phase difference effect within the back?ll behind retaining wall using a simple pseudo-dynamic analysis of seismic earth pressure considering only horizontal seismic acceleration.In this method it is assumed that the shear modulus is constant with the depth of soil.Choudhury and Nimbalkar[15,16]further developed this pseudo-dynamic method of analysis and proposed a theory to compute the seismic earth pressure by considering both the shear and the primary waves propagating through the soil with variation in time by considering harmonic horizontal and vertical seis-mic accelerations.Application of pseudo-static method for design of waterfront retaining wall was described by Choudhury and Ahmad[17].Researchers like Choudhury and Ahmad[18],Choudhury and Nimbalkar[19]had shown the successful application of pseudo-dynamic method over conventional pseudo-static method for retaining wall design. Moreover,Choudhury and Ahmad[17,18]had highlighted the effect of hydrodynamic water pressure during earthquake events on the design of waterfront retaining wall.Hence, incorporation of all dynamic parameters in seismic analysis makes the pseudo-dynamic method more practical.
In this paper the seismic slope stability analyses are performed for a typical section of44m high water retention type tailings earthen dam,which stores non-radioactive nuclear waste material,located in the eastern part of India,which comes under seismic zone II of Indian seismic zone map(as per[20]).The seismic slope stability analyses are performed using both the conventional pseudo-static and recent pseudo-dynamic methods. Method of Analysis
The seismic slope stability analysis is performed for a typical section of water retention type tailings earthen dam storing non-radioactive nuclear waste material in the upstream side.Figure1shows the tailings earthen dam, which is44m high,224m wide,and655m in length with a4m wide horizontal crest.The slopes of the upstream and the downstream sides are1V:2.5H.Table1 presents the properties of various components of the tailings dam.
The tailings earthen dam is analyzed for two different conditions of the reservoir.Those are:
(i)C-1:Water table is at3.5m below the existing ground
level,
(ii)C-2:Water level in the reservoir is up to the top surface of the pond tailings portion.
Selection of appropriate seismic coef?cient is a very important part of the pseudo-static and pseudo-dynamic analysis.Since the location of dam comes under seismic zone II of Indian seismic zone map(as per[20]),it is considered that the value of horizontal seismic acceleration coef?cient(k h)=0.15and vertical seismic acceleration coef?cient(k v)= k h=0.075(as per[21]).
Limit equilibrium method is used to determine the factor of safety(FS)against slope failure.As per limit equilib-rium method,FS of a slope is given as,
FS?
resisting force
driving force
e1T
64 D.Chakraborty,D.Choudhury
Water Table is at 3.5m Below the Existing Ground Level (C-1)
Pseudo-static analysis for C-1
For this condition the details of forces along with the failure surface for the pseudo-static analysis of the tailings dam is shown in Fig.2.
From Fig.2,for pseudo-static analysis it can be written that,
Resisting force ?c l AB cos b tl BC cos a eT
tW 1tW 2eTàF v 1tF v 2eTf g cos a ?àF h 1tF h 2eTsin a tan u cos a
tW 3tW 4eTàF v 3tF v 4eTf g cos b
?àF h 3tF h 4eTsin b tan u cos b
Driving force ?W 1tW 2eTàF v 1tF v 2eTf g sin a cos a
?tF h 1tF h 2eTcos 2a
?
tW 3tW 4eTàF v 3tF v 4eTf g sin b cos b
?tF h 3tF h 4eTcos 2a ?
where c =cohesion of soil in the shell,/=soil friction angle in the shell.l AB ?44àh sin b ;l BCD ?h sin a ;l BF ?44àh
tan b à2:544àh eT;l BE
?l BF 2:5;l CE ?l BE
tan a
Again,l BF can be determined as,l BF =2.5h -h tan(90°-a )
Equating both l BF we get,a =90°-tan -1{(110tan b -(44-h ))/h tan b }
Now,F hi =k h W i and F vi =k v W i (here,i =1,2,3and 4)where W 1=0.5c l CE (h -l BE ),W 2=0.5c l CE l BE ,W 3=0.5c l BF l BE ,W 4=0.5c l BF (44-h ),
c is the unit weight of soil in the shell portion of the dam.Maximum values of b an
d a should b
e as follows,b max \tan à144=110eT?21:8 ;a max \90
Using Eq.(1),for b from 2°to 19°and different values of h (as shown in Fig.2)from 15to 42m the FS values are determined.
Pseudo-dynamic analysis for C-1
In the present study,the pseudo-dynamic method is also used,in which the ?nite shear and primary wave velocities (V s and V p )are considered.The assumptions in the pseudo-dynamic method are as follows:
(a)The shear modulus is constant with depth,
(b)The seismic accelerations acting on the slope is
assumed to be harmonic sinusoidal accelerations.Under earthquake condition,the shear wave velocity (V s )and primary wave velocity (V p )can be expressed as V s =(G /q )1/2and V p =(G (2-2m )/q (1-2m ))1/2
Table 1Properties of various components of the tailings dam (modi?ed after Chakraborty and Choudhury [8])Parameters
Dam soil at various locations Core
Shell Compacted tailings Pond tailings Foundation soil layer Density (kg/m 3)16401830190019001830Cohesion (c )(kPa)3531.2514.714.731.25Friction angle (/)28°28°15.2°12°28°Shear modulus (MPa)53.56190.2595.3945.64217.35Poisons ratio 0.40.30.350.350.2Porosity
0.250.30.250.250.3Permeability (m/s)
1910
-10
1910
-8
1910
-8
1910
-8
1910-8
Pseudo-Static and Pseudo-Dynamic Stability Analysis
65
respectively.Here,G is the maximum shear modulus of soil =190.25MPa (for the shell portion),q is the density of soil =1830kg/m 3(for the shell portion),m is the Poisson’s ratio of soil =0.3(for the shell portion).So,in the present analysis,V s =322m/s and V p =603m/s.Fundamental period (T )is determined by T ?2:9H t ?????????
q =G p (where H t =height of the dam above toe of the slopes =44m)and computed as 0.39s [21].
It is assumed that both the horizontal and vertical vibrations,with accelerations a h (=k h g )and a v (=k v g ),respectively,start exactly at the same time,and there is no phase shift between these two vibrations [15,16].For this condition the details of forces along with the failure surface for the pseudo-dynamic analysis of the tailings dam is shown in Fig.3.From Fig.3for pseudo-dynamic analysis it can be written that,
Resisting force ?c l AB cos b tl BC cos a eT
tW 1tW 2eTàQ v 1et TtQ v 2et TeTf g cos a ?àQ h 1et TtQ h 2et TeTsin a tan u cos a tW 3tW 4eTàQ v 3et TtQ v 4et TeTf g cos b ?àQ h 3et TtQ h 4et TeTsin b t tan u cos b
Driving force ?W 1tW 2eTàQ v 1et TtQ v 2et TeTf g
?sin a cos a tQ h 1et TtQ h 2et TeTcos 2a ?
tW 3tW 4eTàQ v 3et TtQ v 4et TeTf g
?sin b cos b tQ h 3et TtQ h 4et TeTcos 2a
?
Now,for segment 1horizontal and vertical seismic inertia forces are,
Q h 1et T?
Z h 1
m 1z eTa h 1z ;t eTdz and Q v 1et T?
Z h 1
m 1z eTa v 1z ;t eTdz
respectively.
The mass of a thin element of the failing mass in seg-ment 1of thickness dz at a depth z from the crest level is m 1={2.5z -z tan(90°-a )}(c /g )dz ,
a h 1z ;t eT?a h sin x t àeh 1àz T=V s eTand
a v 1z ;t eT?a v sin x t àeh 1àz T=V p
àá
Q h 1et T?c k h =4p 2àá
2:5à1=tan a eTeT
?k 2sin2p t =T eTàk 2sin2pn 1à2p h 1k cos2p t =T eT??Q v 1et T?c k v =4p 2àá
2:5à1=tan a eTeT
g 2sin2p t =T eTàg 2sin2pw 1à2p h 1g cos2p t =T eT??where,k ?TV s ;n 1?et =T Tàeh 1=V s T T;g ?TV p and w 1?et =T Tàeh 1=V p T T:
Similarly for segments 2,3and 4the horizontal inertia forces (Q h 2et T;Q h 3et T;Q h 4et T)and vertical inertia forces (Q v 2(t ),Q v 3(t ),Q v 4(t ))are determined.
Using Eq.(1),for various values of b and h (as shown in Fig.3)FS values are determined.Finally using the opti-mization technique the minimum value of pseudo-dynamic FS is obtained.
Water Level in the Reservoir is up to the Top Surface of the Pond Tailings Portion (C-2)Pseudo-static analysis for C-2
After seepage analysis using SEEP/W [22]software package the actual phreatic surface through the dam section is obtained as shown in Fig.4.In Fig.4the co-ordinates of few points on the phreatic line are shown considering the middle of the core portion of the dam at the existing ground level as (0,0)point of the co-ordinate system.
In order to calculate the factor of safety using the pseudo-static and the pseudo-dynamic method the phreatic surface is modi?ed as shown in Fig.5(the ?rm line).It is considered that the failure surface is passing beyond the phreatic surface through the dam section.Therefore,for
66 D.Chakraborty,D.Choudhury
this case of analysis when the water level in the reservoir is up to the top of the pond tailings portion the value of h 1and h 2(Figs.6and 7)are taken for the analysis as,h 1C (44–25)=19m,b B tan -1(25/114)=12.3°and h 2C 20m.
It should be mentioned that,because of the incorpora-tion of the seepage effect on the seismic stability of the tailings earthen dam,the problem has become complicated.In order to reduce the complexity of the problem,the soil properties of the tailings portion of the dam is considered
as same as that of the shell portion of the dam,though their actual properties are marginally different from each other.This can be considered as a limitation of the present analysis.
For this condition,the details of forces along with the failure surface for the pseudo-static analysis of the tailings dam is shown in Fig.6and for pseudo-static analysis it can be written that,
where,c 01(=31.25kN/m 2)and c 02(=35kN/m 2)are the effective cohesion of the soil in the shell portion and core
Resisting force ?c 01l ABC tc 02l CD tc 01l DE
àá
tW 1tW 2tW 5eTàF v 1tF v 2tF v 5eTf g cos b àF h 1tF h 2tF h 5eTsin b àU 1? tan u 01tW 3tW 6tW 8eTàF v 3tF v 6tF v 8eTf g cos b àF h 3tF h 6tF h 8eTsin b àU 2? tan u 01tW 4tW 7tW 9tW 10eTàF v 4tF v 7tF v 9tF v 10eTf g cos b àF h 4tF h 7tF h 9tF h 10eTsin b àU 3
"#tan u 01
Driving force ?W 1tW 2tW 5eTàF v 1tF v 2tF v 5eTf g sin b tF h 1tF h 2tF h 5eTcos b ?
tW 3tW 6tW 8eTàF v 3tF v 6tF v 8eTf g sin b tF h 3tF h 6tF h 8eTcos b ? t
W 4tW 7tW 9tW 10eTàF v 4tF v 7tF v 9tF v 10eTf g sin b tF h 4tF h 7tF h 9tF h 10eTcos b
"#Pseudo-Static and Pseudo-Dynamic Stability Analysis
67
portion of the dam respectively.u 01=28°and u 02=28°are the effective soil friction angle of the soil in the shell portion and core portion of the dam respectively.h 1=44-114tan b and h 2=44-110tan b ,
l ABC ?110=cos b ;l CD ?4=cos b ;l DE ?h 1=sin b and l EF
?h 1=tan b :
Now,F hi =k h W i and F vi =k v W i (here,i =1,2,3,4,…10)
W DEF ?W 1tW 2tW 3?0:5c 1;sat l EF h 1;W CDFG
?W 3tW 6tW 8?0:5c 2;sat h 1th 2eT4;W GHI ?W 4?0:5c 1;bulk 19e2:5?19T;W ABCJ ?W 10?0:5c 1;sat e2:5?h 2Te44àh 2Tand W CHIJ ?W 7tW 9
?0:5c 1;sat e2:5?h 2à2:5?19Teh 2à19T;where,c 1,sat (=21.3kN/m 3)and c 2,sat (=18.9kN/m 3)are the saturated unit weight of soil in the shell and core portion of the dam respectively.
c 1,bulk =bulk unit weight of soil in the shell por-tion =18.3kN/m 3.
U is the force due to pore water pressure.Where,U 1?0:5h 1c w eTl DE ;U 2?0:5h 2c w th 1c w eTl CD ;U 3?c w =2cos b eT2h 2à19eTt47:5?tan b f g 47:5?t47:5?tan b th 2à19eTf g 62:5
c w =unit weight of water =10kN/m 3.
Using Eq.(1),for b from 2°to 12.3°the FS values are calculated.
Pseudo-dynamic analysis for C-2
For this condition the details of forces along with the failure surface for the pseudo-dynamic analysis of the tailings dam is shown in Fig.7.
From Fig.7for pseudo-dynamic analysis it can be written that,
Resisting force ?c 01l ABC tc 02l CD tc 01l DE
àá
tW 1tW 2tW 5eTàQ v 1et TtQ v 2et TtQ v 5et TeTf g cos b àQ h 1et TtQ h 2et TtQ h 5et TeTsin b àU 1? tan u 01tW 3tW 6tW 8eTàQ v 3et TtQ v 6et TtQ v 8et TeTf g cos b àQ h 3et TtQ h 6et TtQ h 8et TeTsin b àU 2? tan u 02tW 4tW 7tW 9tW 10eTàQ v 4et TtQ v 7et TtQ v 9et TtQ v 10et TeTf g cos b àQ h 4et TtQ h 7et TtQ h 9et TtQ h 10et TeTsin b àU 3
!tan u 01
Driving force ?W 1tW 2tW 5eTàQ v 1et TtQ v 2et TtQ v 5et TeTf g sin b tQ h 1et TtQ h 2et TtQ h 5et TeTcos b ?
tW 3tW 6tW 8eTàQ v 3et TtQ v 6et TtQ v 8et TeTf g sin b tQ h 3et TtQ h 6et TtQ h 8et TeTcos b ? t
W 4tW 7tW 9tW 10eTàQ v 4et TtQ v 7et TtQ v 9et TtQ v 10et TeTf g sin b tQ h 4et TtQ h 7et TtQ h 9et TtQ h 10et TeTcos b
!68 D.Chakraborty,D.Choudhury
Now,for segment 1horizontal and vertical seismic inertia forces are,
Q h 1et T?c 1;sat k h =4p 2tan b
àá
?k 21sin 2pn 1àk 21sin 2p t =T eTt2p e19Tk 2
1cos 2pn 1 Q v 1et T?c 1;sat k v =4p 2tan b
àá
?g 21sin 2pw 1àg 21sin 2p t =T eTt2p e19Tg 2
1cos 2pw 1
?
where,k 1=TV s 1,n 1=(t /T )-(19/V s 1T ),g 1=TV p 1,w 1
=(t /T )-(19/V p 1T )and V s 1=322m/s and V p 1=603m/s for shell,V s 2=182m/s and V p 2=338m/s for core.Similarly for segments 2–10the horizontal inertia forces (Q h 2(t )-Q h 10(t ))and vertical inertia forces (Q v 2(t )-Q v 10(t ))are determined.
Using Eq.(1),for b from 2°to 12.3°,the FS values are determined and using the optimization technique the min-imum value of pseudo-dynamic FS is obtained.
Results and Discussions
When water table is at 3.5m below the existing ground level (C-1)the results of pseudo-static and pseudo-dynamic analysis are presented using Figs.8and 9respectively.From Fig.8the minimum value of pseudo-static FS is obtained as 1.52for b =3°and h =41m,and from Fig.9the minimum value of pseudo-dynamic FS is obtained as 1.49for b =4°and h =40m.
When water level in the reservoir is up to the top surface of the pond tailings portion (C-2)the results of pseudo-static and pseudo-dynamic analysis are presented using Fig.10.It should be mentioned that,under this condition the seismic stability analysis is carried out with the assumption of a single planer failure surface.As a conse-quence of that assumption,the distance of the failure sur-face from the crest of the dam will not come into consideration;the factor of safety will depend only on angle b (i.e.the angle between failure plane and horizontal
ground surface).However,for case C-1,the seismic sta-bility analysis is carried out by considering a bilinear
Fig.8Variation of FS values with the variation of the values of h for different values of b ,with k h =0.15and k v =0.075(for C-1)using pseudo-static analysis
Fig.9Variation of FS values with the variation of the values of h for different values of b ,with k h =0.15and k v =0.075(for C-1)using pseudo-dynamic analysis
Pseudo-Static and Pseudo-Dynamic Stability Analysis 69
failure surface.As a consequence of that assumption,the distance (h ,refer Fig.2)of the failure surface from the crest of the dam will come into consideration,and the factor of safety will depend on both the b angle and h .For a particular angle b there will be a particular h value for which factor of safety will become lowest or critical.So,for the case C-1,a similar ?gure (as Fig.10)is not possible to draw.
From Fig.10,the minimum value of pseudo-static FS is obtained as 1.18for b =10°,and the minimum value of pseudo-dynamic FS is obtained as 1.09for b =11.5°.The static factor of safety of the slope of the dam is obtained by considering the values of k h and k v equal to zero (0,0).The minimum value of static factor of safety of slope for the tailings earthen dam when the water table is 3.5m below the existing ground surface is obtained as 2.28for b =5°and h =40m.Similarly,the minimum value of static factor of safety of slope for the tailings earthen dam when the water level in the reservoir is up to the top of the pond tailings portion is obtained as 2.2for b =12.3°.
It can be noted that,with the consideration of seepage effect,the reduction in the factor of safety values from static to seismic analysis is about 46.4%(in case of pseudo-static analysis)to 50.5%(in case of pseudo-dynamic analysis).However,in absence of seepage,the reduction in the factor of safety value is about 33.3%(in case of pseudo-static analysis)to 34.7%(in case of pseudo-dynamic analysis).It clearly indicates the importance of considering the seepage effect at the time of designing a tailings earthen dam under seismic load-ing conditions.This observation is on the similar line as was reported by Choudhury and Ahmad [17,18]for the design of waterfront retaining wall under seismic conditions.
Conclusions
Pseudo-static and pseudo-dynamic methods of analyses are used for the seismic stability analysis of a 44m high water retention type tailings dam at eastern India which stores non-radioactive nuclear waste material in the upstream side.
For the case when the water table is at 3.5m below the existing ground level,the pseudo-static factor of safely value is obtained as 1.52and the pseudo-dynamic factor of safety is obtained as 1.49for k h and k v values of 0.15and 0.075respectively.When the water level in the reservoir is up to the top of the pond tailings portion,the factor of safety values are 1.18and 1.09respectively using pseudo-static and pseudo-dynamic approach.Now,following Seed [23],for safe design under seismic loading condition,the factor of safety against slope failure should be greater than 1.15.Hence,when the water level in the reservoir is up to the top of the pond tailings portion,though the pseudo-static analysis indicate that the dam is safe under seismic loading condition,pseudo-dynamic condition results infer that the dam is unsafe in presence of seismic forces.It clearly shows the demerits of conventional pseudo-static analysis compared to recent pseudo-dynamic analysis,where in addition to the seismic accelerations,duration,frequency of earthquake,body waves traveling during earthquake are considered.
Acknowledgement Authors would like to acknowledge the ?nan-cial support received from Atomic Energy Regulatory Board (AERB),Mumbai,Government of India for funding the sponsored research project no.AERB/CSRP/31/07to carry out the present research study.
References
1.Choudhury D,Sitharam TG,Subba Rao KS (2004)Seismic design of earth retaining structures and foundations.Curr Sci 87:1417–1425
2.Clough RW,Chopra AK (1966)Earthquake stress analysis in earth dams.J Eng Mech ASCE 92(EM2):197–211
3.Seid-Karbasi M,Byrne P (2004)Embankment dams and earth-quakes.Hydropower Dams 2:96–102
4.FLAC (2000)Fast lagrangian analysis of continua user’s guide,version 4.Itasca Consulting Group,Minneapolis
5.PLAXIS (2002)PLAXIS 2D:Reference manual,version 8.0.Plaxis BV,Delft
6.TELDYN (1998)TELDYN—users’manual.TAGAsoft Limited,Lafayette
7.Zhu Y,Lee K,Collison GH (2005)A 2D seismic stability and deformation analysis.In:Geo-frontiers 2005,ASCE,Austin,pp 1–15
8.Chakraborty D,Choudhury D (2009)Investigation of the behavior of tailings earthen dam under seismic conditions.American J Eng Appl Sci 2(3):559–564
9.Chakraborty D,Choudhury D (2011)Seismic behavior of tailings dam using FLAC 3D .ASCE Geotechnical Special Publication No.
211:3138–3147
Fig.10Variation of the pseudo-static and pseudo-dynamic FS values with the variation of the values of b ,for k h =0.15and k v =0.075(for C-2)
70 D.Chakraborty,D.Choudhury
10.Chakraborty D,Choudhury D(2012)Seismic stability and liq-
uefaction analysis of tailings dam.Disaster Adv5(3):15–25 11.FLAC3D(2006)Fast lagrangian analysis of continua in3
dimensions User’s guide,version3.1.Itasca Consulting Group, Minneapolis
12.TALREN4(2007)TALREN4user’s guide,version2.0.3.Ter-
rasol Geotechnical Consulting Engineers,Montreuil Cedex 13.Zeng X,Wu J,Rohlf RA(1998)Seismic stability of coal-waste
tailings dams.ASCE Geotechnical Special Publication No75: 950–961
14.Steedman RS,Zeng X(1990)The in?uence of phase on the
calculation of pseudo-static earth pressure on retaining wall.
Geotechnique40(1):103–112
15.Choudhury D,Nimbalkar S(2005)Seismic passive resistance by
pseudo-dynamic method.Geotechnique55(9):699–702
16.Choudhury D,Nimbalkar S(2006)Pseudo-dynamic approach of
seismic active earth pressure behind retaining wall.Geotech Geol Eng24(5):1103–1113
17.Choudhury D,Ahmad SM(2007)Design of waterfront retaining
wall for the passive case under earthquake and tsunami.Appl Ocean Res29:37–4418.Choudhury D,Ahmad SM(2008)Stability of waterfront retaining
wall subjected to pseudodynamic earthquake forces.J Waterway Port Coastal Ocean Eng ASCE134(4):252–260
19.Choudhury D,Nimbalkar S(2008)Seismic rotational displace-
ment of gravity walls by pseudodynamic method.Int J Geomech ASCE8(3):169–175
20.IS:1893—Part1(2002)Indian standards criteria for earthquake
resistant design of structures.Bureau of Indian Standard(BIS), New Delhi
21.IS:1893(1984)Indian standard criteria for earthquake resistant
design of structures.Reaf?rmed2003,fourth revision.Bureau of Indian Standard(BIS),New Delhi
22.SEEP/W(2007)SEEP/W user’s guide,version7.03.Geo-Slope
International Ltd.,Calgary
23.Seed HB(1979)Considerations in the earthquake-resistant design
of earth and rock?ll dams.Geotechnique29(3):215–263
Pseudo-Static and Pseudo-Dynamic Stability Analysis71
* 声明 鼎阳科技有限公司,版权所有。 未经本公司同意,不得以任何形式或手段复制、摘抄、翻译本手册的内容。 ⅠSDS1000系列数字存储示波器简介 SDS1000 系列数字示波器体积小巧、操作灵活；采用彩色TFT-LCD及弹出式菜单显示，实现了它的易用性，大大提高了用户的工作效率。此外，SDS1000 系列性能优异、功能强大、价格实惠。具有较高的性价比。SDS1000 实时采样率最高 2GSa/s 、存储深度最高 2Mpts, 完全满足捕捉速度快、复杂信号的市场需求；支持USB设备存储，用户还可通过U盘或LAN 口对软件进行升级，最大程度地满足了用户的需求；所有型号产品都支持PictBridge 直接打印，满足最广泛的打印需求。 SDS1000系列有二十一种型号： [ SDS1000C系列 ]: SDS1102C、SDS1062C、SDS1042C、SDS1022C [ SDS1000D系列 ]:SDS1102D、SDS1062D、SDS1042D、SDS1022D [ SDS1000CM系列 ]: SDS1152CM、SDS1102CM、SDS1062CM [ SDS1000CE系列 ]: SDS1302CE、SDS1202CE、SDS1102CE、SDS1062CE [ SDS1000CF系列 ]: SDS1304CF、SDS1204CF、SDS1104CF、SDS1064CF [ SDS1000CN系列 ]:SDS1202CN、SDS1102CN ●超薄外观设计、体积小巧、桌面空间占用少、携带更方便 ●彩色TFT-LCD显示，波形显示更清晰、稳定 ●丰富的触发功能：边沿、脉冲、视频、斜率、交替 ●独特的数字滤波与波形录制功能 ●Pass/Fail功能，可对模板信号进行定制 ●3种光标模式、32 种自动测量种类
蚕蛹在水产动物营养中的应用研究-畜牧渔业论文 蚕蛹在水产动物营养中的应用研究 彭强 （中国海洋大学海水养殖教育部重点实验室，山东青岛266003） 摘要：随着水产养殖的集约化，作为传统蛋白源的鱼粉供应有限、价格高涨，使得我国优质蛋白源短缺问题日益突出，严重影响着我国水产养殖业的长远发展。我国是一个蚕桑大国，蚕蛹资源丰富，同时蚕蛹具有蛋白含量高、氨基酸平衡等优点，适宜作为水产饲料中鱼粉的优质替代物。目前已有少量研究关注蚕蛹在水产饲料中的应用，效果各不相同，具体机制有待研究，本文就其在水产饲料中的应用综述如下。 关键词：鱼粉；蚕蛹；营养 由于全球自然生态环境的限制，海洋、淡水捕捞已经不能满足人们日益增长的水产品需要。因此要扩大水产养殖业的发展，来提高水产品的供应量。而水产养殖业的发展又需要以水产饲料行业作为支撑。蛋白含量高、氨基酸组成平衡、适口性强、能够被鱼类高效利用的鱼粉，被广泛作为鱼类饲料中的优质蛋白源[1]。近年来鱼粉资源紧张，价格波动较大，而我国却长期依赖进口，严重影响我国水产饲料行业的健康发展，因此寻找优质蛋白源替代鱼粉意义重大。我国是一个蚕桑大国，蚕蛹资源丰富，每年鲜蚕蛹产量可达10万吨以上，加之蚕蛹蛋白含量高、不饱和脂肪酸丰富、维生素均衡，蚕蛹蛋白的提取和精制方法多样且技术成熟，适宜作为水产养殖的优良蛋白原料[2]。 1蚕蛹的特性以及营养评价 蚕蛹是缫丝产业的副产物，脂肪含量较高，容易氧化和酸败而产生难闻的臭味，
一直没有在水产业上得到充分重视，仅仅被当做粗饲蛋白源来处置。蚕蛹中含粗蛋白50%～70%，氨基酸组成与鱼粉相似，且鱼类必需氨基酸中的色氨酸与缬氨酸含量明显高于鱼粉，不饱和脂肪酸以及微量元素等含量丰富[3]。蚕蛹必需氨基酸指数（EAAI）按照FAO/WHO的标准为111.14，与蛋白标准品酪蛋白十分接近，高于鱼粉的99.72，这说明蚕蛹必需氨基酸比例均衡，利于被鱼类消化吸收。从氨基酸分（AAS）以及化学分(CS)分析中可知蚕蛹的限制性氨基酸为亮氨酸和蛋氨酸，这与某些植物蛋白源一致，说明蚕蛹营养组成虽好但作为鱼类饲料蛋白源还需考虑强化亮氨酸和蛋氨酸组成[4]。 2蚕蛹在水产动物营养中的应用 2.1对水产动物生长性能的影响 在新型蛋白源开发的研究中，新型实用饲料对鱼类生长性能的影响是首先关注的问题。一般情况下，新蛋白源替代鱼粉的实验中，随着新蛋白源含量的升高，鱼类的生长逐渐缓慢，但蚕蛹也有相反的情况，这是因为不同的鱼类对蚕蛹的喜爱或者耐受程度不一样。淡水鱼或者杂食性鱼类对替代的敏感性较低，肉食性鱼类往往对鱼粉的依赖性较大，想实现高替代难度大。 蚕蛹添加进饲料中的形式无外乎与其他蛋白源一起添加、或者经过脱脂除臭等不同的预处理再添加或与晶体氨基酸一起添加等几种形式。目前对蚕蛹添加进饲料中的研究主要集中在淡水鱼上，尤其是杂食性鱼类。鉴于鱼类食性的关系，它们基础饲料中的鱼粉含量相较于海水肉食性鱼类很少。蚕蛹与蛤肉混合可以替代印度鲤鱼饲料中50%的鱼粉[5]。在有卡特拉魮、印度鲮、南亚野鲮、银鲤的混养系统中，经过发酵的蚕蛹替代鱼粉过后还能提高存活率以及特定生长率[6]。在建鲤上，经过脱脂处理的蚕蛹可以替代50%的鱼粉而对生长没有负面影响[7]；
蚕蛹蛋白纤维混纺纱的开发 赵瑞芝汪吉艮 （江苏大生集团有限公司） 摘要:探讨蚕蛹蛋白纤维混纺纱的开发。通过研究蚕蛹蛋白纤维纺纱性能，根据后道产品对纱线性能和质量的要求，合理选配原料，研究纤维预处理工艺，设定各工序纺纱工艺参数，有效解决了因蚕蛹蛋白纤维可纺性较差而产生的纺纱技术难题，使条干、强力和毛羽等纱线质量指标满足后道高品质产品的要求。 关键词:蚕蛹蛋白纤维；氨基酸 中图分类号：TS104.2 文献标志码：B 文章编号：1001-7415（2011）00-0000 作者简介：赵瑞芝（1968－），女，高级工程师，南通，226002 收稿日期：2011-03-13 蚕蛹蛋白纤维是一种新型的再生蛋白质纤维，是综合利用高分子技术、生物工程技术和化纤纺丝技术，从蚕蛹中萃炼出优质蛋白PC，与天然纤维素共混后制成的新型生物质纤维。在加工过程中，采用高科技工艺，使蛋白质富集在纤维表面，形成皮芯结构的蛋白质纤维。蛋白PC中含有18种氨基酸，每种氨基酸的含量都在15mg/g以上，其中丝氨酸、苏氨酸、色氨酸、酪氨酸等对人体皮肤十分有益，可保持肌肤表皮细胞活性，延缓肌肤氧化衰老。而纤维的皮芯结构又能保证氨基酸与皮肤充分接触，最大限度地发挥呵护肌肤的特殊功效。 蚕蛹蛋白纤维纱线可用于生产高档服装面料、T恤、内衣、床上用品等产品，目前已有厂家用蚕蛹蛋白纤维纯纺纱和混纺纱开发了高档针织内衣。蚕蛹蛋白纤维产品既保留了真丝织物的优点，又克服了真丝织物娇嫩、色牢度差、易缩、易皱、易泛黄、遇强碱易脆损等缺陷，产品柔软细腻、透气舒适、亲肤美肤、环保健康、染色绚丽，与真丝织物相比，存在较大的价格优势，具有较好的市场前景。本文以蚕蛹蛋白纤维/Modal 50/50 14.5tex纱为例，对其生产工艺进行介绍。 1原料选配 蚕蛹蛋白纤维主要技术指标：干断裂强度2.33cN/dtex，湿断裂强度1.59cN/dtex，干断裂伸长率19.9%，初始模量43.97 cN/dtex，细度1.71 dtex，长度37.8 mm，抗酸断裂强度2.26cN/dtex，抗碱断裂强度2.31cN/dtex，蛋白含量8.6%（水洗后蛋白损失极少），回潮率12.8%。 Modal纤维主要技术指标：干断裂强度3.23cN/dtex，湿断裂强度2.11cN/dtex，干断裂伸长率14.1%，线密度1.3dtex，长度39.0 mm，含油率0.31%，回潮率10.4%。
LED-ECS编辑控制系统V5.2 用 户 手 册 目录 第一章概述 (3) 1.1LED-ECS编辑控制系统介绍 (3) 1.2运行环境 (3) 第二章安装卸载 (3) 2.1安装 (3) 2.2卸载 (5) 第三章软件介绍 (5) 3.1界面介绍 (5) 3.2操作流程介绍 (13) 3.3基本概念介绍 (21) 第四章其他功能 (25) 4.1区域对齐工具栏 (25) 4.2节目对象复制、粘贴 (26) 4.3亮度调整 (26) 第五章发送 (27) 5.1发送数据 (27) 第六章常见问题解决 (28) 6.1计算机和控制卡通讯不上 (28) 6.2显示屏区域反色或亮度不够 (29)
6.3显示屏出现拖尾现象，显示屏的后面出现闪烁不稳定 (29) 6.4注意事项 (31) 6.5显示屏花屏 (31) 6.6错列现象 (32) 6.7杂点现象 (32) 第一章概述 1.1LED-ECS编辑控制系统介绍 LED-ECS编辑控制系统，是一款专门用于LED图文控制卡的配套软件。其具有功能齐全，界面直观，操作简单、方便等优点。自发布以来，受到了广大用户的一致好评。 1.2运行环境 ?操作系统 中英文Windows/2000/NT/XP ?硬件配置 CPU:奔腾600MHz以上 内存:128M 第二章安装卸载 2.1LED-ECS编辑控制系统》软件安装很简单，操作如下：双击“LED-ECS编辑控制系统”安装程序，即可弹出安装界面，如图2-1开始安装。如图所示 图2-1 单击“下一步”进入选择安装路径界面，如图2-2，如果对此不了解使用默认安装路径即可 图2-2 图2-3 单击“完成”，完成安装过程。 2.2软件卸载如图2-2 《LED-ECS编辑控制系统V5.2》提供了自动卸载功能，使您可以方便的删除《LED-ECS编辑控制系统V5.2》的所有文件、程序组件和快捷方式。用户可以在“LED-ECS编辑控制系统V5.2”组中选择“卸载LED-ECS编辑控制系统V5.2”卸载程序。也可以在“控制面板”中选择“添加/删除程序”快速卸载。卸载程序界面如图2-4，此时选择自动选项即可卸载所有文件、程序组和快捷方式。 图2-4 第三章、软件介绍
示波器的使用方法教程 ST-16示波器的使用 示波器是有着极其广泛用途的测量仪器之一〃借助示波器能形象地观察波形的瞬变过程，还可以测量电压。电流、周期和相位，检查放大器的失真情况等〃示波器的型号很多，它的基本使用方法是差不多的〃下面以通用ST一16型示波器为例，介绍示波器的使用方法。 面板上旋钮或开关的功能 图1是ST一16型示波器的面板图。 示波器是以数字座标为基础来显示波形的〃通常以X轴表示时间，Y轴表示幅度〃因而在图1中，面板下半部以中线为界，左面的旋钮全用于Y轴，右面的旋钮全用于X 轴。面板上半部分为显示屏。显示屏的右边有三个旋钮是调屏幕用的〃所有的旋钮，开关功能见表1。其中8、10，14，16号旋钮不需经常调，做成内藏式。
显示屏读数方法 在显示屏上，水平方向X轴有10格刻度，垂直方向Y轴有8格刻度〃这里的一格刻度读做一标度，用div表示〃根据被测波形垂直方向(或水平方向)所占有的标度数，乘以垂直输入灵敏度开关所在档位的V／div数(或水平方向t／div)，得出的积便是测量结果。Y轴使用10：1衰减探头的话还需再乘10。 例如图2中测电压峰—峰值时，V／div档用0〃1V／div，输入端用了10 ： l 衰减探头，则Vp－p＝0〃1V／div×3〃6div×10＝3〃6V，t／div档为2ms／div，则波形的周期：T＝2ms／div×4div＝8ms。 使用前的准备 示波器用于旋钮与开关比较多，初次使用往往会感到无从着手。初学者可按表2方式进行调节。表2位置对示波器久藏复用或会使用者也适用。
使用前的校准 示波器的测试精度与电源电压有关，当电网电压偏离时，会产生较大的测量误差〃因此在使用前必须对垂直和水平系统进行校准。校准方法步骤如下： 1〃接通电源，指示灯有红光显示，稍等片刻，逆时针调节辉度旋钮，并适当调准聚焦，屏幕上就显示出不同步的校准信号方波。 2〃将触发电平调离“自动”位置，逆时针方向旋转旋钮使方波波形同步为止。并适当调节水平移位(11)和垂直移位(5)。 3〃分别调节垂直输入部分增益校准旋钮(10)和水平扫描部分的扫描校准旋钮(14)，使屏幕显示的标准方波的垂直幅度为5div，水平宽度为10div，如图3所示，ST一16示波器便可正常工作了。 示波器演示和测量举例 一，用ST一16示波器演示半波整流工作原理： 首先将垂直输入灵敏度选择开关(以下简写V／div)拨到每格0〃5V档，扫描时间转换开关(s／div)拨至每格5ms档，输入耦合开关拨至AC档，将输入探头的两端与电源变压器次级相接，见图4，这时屏幕显示如图5(a)所示的交流电压波形。 如果将探头移到二极管的负端处，这时屏幕上显示图5(b)所示的半波脉冲电压波形〃接上容量较大的电解电容器C进行滤波，调节一下触发电平旋钮(15)，在示波器屏幕上可看到较为平稳的直流电压波形，见图5(c)。电容C的容量越大，脉冲成分越小，电压越平稳。
1、PLA纤维的生产工艺、结构特点和主要性能 生产工艺：工艺? PLA切片→干燥→螺杆挤压→预过滤→纺丝箱→冷却上油→卷绕→热盘拉伸→DT纤维 （1）切片干燥：像PET一样，PLA切片必须经过干燥处理后才能进行熔融纺丝。PLA属聚酯类产品，由于其聚合物在活跃和潮湿的环 境中会通过酯键断裂发生水解而产生降解，造成分子量大幅下 降，从而严重影响成品纤维的品质，因此纺丝前要严格控制PLA 聚合物的含水率。PLA切片干燥后含水率与干切片特性粘度的控 制尤为重要，因为含水率控制不当引起的分子量损失将给正常的 熔融纺丝带来困难。 （2）熔融纺丝：由于具有高结晶性和高取向性，PLA纤维具有高耐热性和高强度，且无需特殊的设备和操作工艺，应用常规的加工工 艺便可进行纺丝。但 PLA纤维不同于芳香酯的PET，其熔点175℃ （由差示扫描量热DSC法测定）与PET的260℃差距较大，且熔 融纺丝成形较PET困难，主要表现在PLA的热敏性和熔体高粘度 之间的矛盾。要使PLA在纺丝成形时具有较好的流动性和可纺 性，必须达到一定的纺丝温度，但PLA物料在高温下，尤其是经 受较长时间的相对高温时极易发生热降解，因此造成PLA熔融成 形的温度范围极窄。 （3）? 纺丝组件：由于PLA熔体的表观剪切粘度随剪切速率的增大而下降，表现为切力变稀流动现象。因为在剪切应力的作用下，大 分子构象发生变化，长链分子偏离平衡构象而沿熔体流动取向，
表现出预取向性，从而使体系解缠并使大分子链彼此分离，导致PLA熔体的表观剪切粘度下降。因此，必须通过加强剪切来降低其表观粘度，进而解决PLA聚合物热敏性和熔体高粘度之间的矛盾，实现纺丝的顺利进行。 （4）速率和卷绕超喂：在生产过程中，为保证PLA纤维有一定的取向度，同时希望拉伸应力和卷绕应力在纺丝过程中得到及时有效地消除，有效控制卷绕张力是关键。另外，由于PLA纤维的玻璃化温度较低，易造成卷绕过程中应力松驰加剧，使纤维沿轴向发生一定尺寸的收缩。在尽可能保证卷绕稳定的情况下，适当增大卷绕超喂率，在不影响成形的前提下，减少卷绕张力，相应调整摩托辊与筒子的接触压力，可以得到优质的大卷装丝。 （5）拉伸温度、速度：在平牵机上，热盘的温度即为拉伸温度，作为影响纤维的重要条件之一，选择合适的拉伸温度是提高纤维物理-机械性能的关键。低温时，拉伸初生PLA纤维时易发生脆性断裂，随着拉伸温度的提高，塑性变形越来越明显，PLA纤维结构单元包括链段和大分子的活动性随温度升高而增大。同时，随着温度的提高，一方面由于PLA大分子在拉伸过程中发生取向，伸直链段的数目增多，而折叠链段的数目减少；另一方面，由于拉伸过程中发生了结晶，片晶之间的连接链相应增加，从而提高了PLA纤维的强度和抗拉性，表现在纤维的物理性能上是纤维的断裂强度明显增大，断裂伸长率也增加。 结构特点：PLA纤维形态结构如图，由图可知，PLA纤维的横截面呈非
混凝土搅拌站控制系统使用说明书 长沙中联重工科技发展股份有限公司
目录 一．产品简介........................................................ - 1 - 二．系统组成........................................................ - 2 - 2.1 硬件需求.................................................................................................................................... - 2 - 2.1.1上位机部分....................................................................................................................... - 2 - 2.1.2 下位机部分...................................................................................................................... - 2 - 2.1.3 通信部分.......................................................................................................................... - 3 - 2.1.4 打印机部分...................................................................................................................... - 3 - 2.1.5 仪表部分.......................................................................................................................... - 3 - 2.1.6 动力保护、控制部分...................................................................................................... - 3 - 2.1.7监控系统部分.................................................................................................................. - 3 - 2.2 软件需求..................................................................................................................................... - 3 - 2.2.1 操作系统.......................................................................................................................... - 3 - 2.2.2数据库：.......................................................................................................................... - 4 - 2.2.3 其他工具.......................................................................................................................... - 4 - 三．系统安装........................................................ - 5 - 3.1硬件安装方法............................................................................................................................ - 5 - 3.1.1 动力部分和监控部分的安装：...................................................................................... - 5 - 3.1.2 上位机的安装.................................................................................................................. - 5 - 3.1.3 打印机的安装.................................................................................................................. - 5 - 3.1.4 可编程的安装.................................................................................................................. - 5 - 3.2 软件安装方法............................................................................................................................. - 6 - 3.3 系统登陆..................................................................................................................................... - 6 - 四．系统调试........................................................ - 8 - 4.1 校秤............................................................................................................................................. - 8 - 4.2 调试输出信号............................................................................................................................. - 9 - 五．系统操作....................................................... - 10 - 5.1 准备工作................................................................................................................................... - 10 - 5.1.1 关于手动操作台............................................................................................................ - 10 - 5.1.2 电源开启顺序................................................................................................................ - 10 - 5.2 生产信息录入.......................................................................................................................... - 10 - 5.2.1 基本信息........................................................................................................................ - 10 - 5.2.1.1 客户管理.......................................................................................................... - 10 - 5.2.1.2 车辆管理...........................................................................................................- 11 - 5.2.1.3 工程管理.......................................................................................................... - 12 - 5.2.1.4 系统管理.......................................................................................................... - 13 - 5.2.2 生产信息........................................................................................................................ - 15 - 5.2.2.1 生产任务单...................................................................................................... - 15 - 5.2.2.2 配比通知单...................................................................................................... - 17 - 5.2.2.3 生产记录（生产明细）.................................................................................. - 17 - 5.2.2.4 生产调度（生产登记）.................................................................................. - 18 - 5.2.2.5 手工录入.......................................................................................................... - 20 - 5.2.2.6 生产统计.......................................................................................................... - 21 -
蚕蛹要煮几分钟 蚕蛹中是含有丰富的维生素、蛋白质和脂肪酸等物质的，因此，在生活中，蚕蛹是被作为一种营养价值极高的食物的，而大多数的人在平常也会经常性购买蚕蛹来食用，一般来讲，蚕蛹最常用的方法便是用盐水煮，那么，蚕蛹要煮几分钟?下面就让给大家介绍一下，希望大家能够有所了解。 蚕蛹是人类的一种新营养源，蚕蛹是卫生部批准的“作为普通食品管理的食品新资源名单”中唯一的昆虫类食品。 蚕蛹的蛋白质含量在50%以上，远远高于一般食品，而且蛋白质中的必需氨基酸种类齐全，蚕蛹蛋白质由18种氨基酸组成，其中人体必需的8种氨基酸含量很高。蚕蛹中的这8种人体必需的氨基酸含量大约是猪肉的2倍，鸡蛋的4倍，牛奶的10倍，8种人体必需的氨基酸营养均衡，比例适当，符合联合国粮农组织和世界卫生组织的要求，非常适合人体的需要，是一种优质的昆虫蛋白质。(蚕蛹好吃，营养，但需要注意，少数人对蚕蛹过敏。) 盐水煮蚕蛹，属于原汁原味的健康清淡版吃法，而且一次可以多煮，把煮熟的蚕蛹直接浸泡在卤水中，随吃随取，简单方便。在冬季的北方，这盐水煮蚕蛹用来待客，是既有面子又省事儿的
一道菜，备受煮妇喜爱。 材料 主料：蚕蛹500克。 调料：食盐适量、葱2段、姜4片、八角1个。 制作步骤 1、蚕蛹冲洗干净，入锅 2、添加没过的水，添加葱姜和八角，大火煮开 3、添加盐和料酒，继续煮5分钟，关火 4、煮好的蛹浸泡在卤水中，随吃随取 小提示： 1、喜欢嫩口的，煮开即可关火，喜欢肉质紧致的，可以多煮一会儿;
2、盐比平常做菜多一点就行。 蚕蛹要煮几分钟?根据上文对盐煮蚕蛹的做法介绍可知，用盐煮蚕蛹的做法大概是需要五分钟的时间，对于追求食物营养价值的人来说，蚕蛹这种食材是其最应该选择常吃的食物，除此之外，蚕蛹的做法也是值得大家去进行学习和掌握的。
蚕蛹怎么造句 导读：蚕蛹拼音 【注音】：canyong 蚕蛹解释 【意思】：蚕吐丝做茧以后变成的蛹。 蚕蛹造句： 1、另外，研究小组指出，蚕蛹大部分成分都是蛋白质，并且对于人体所必需的氨基酸，蚕蛹的含量是猪肉的2倍，是鸡蛋和牛奶的4倍。 2、针对睫毛受损，如掉，断睫毛，有较好的修复能力，独特的蚕丝和蚕蛹精华卷翘同时不仅拉长、加密，还有滋养的效果。 3、目的：研究蚕蛹蛋白对小鼠免疫功能的影响。 4、你将我用银白包围，好似蚕蛹一般，我想最后我也会破茧而飞吧。 5、结果蚕蛹多糖明显增强B淋巴细胞和T淋巴细胞的增殖，促进小鼠巨噬细胞的吞噬活力和溶血素抗体生成。 6、他们利润增长，部分原因是蚕蛹了新的市场策略。 7、目的探讨柞蚕蛹虫草对黑腹果蝇寿命、吃食次数、性功能及繁殖能力的影响。 8、几个月前我在一家中国餐馆品尝了一盘炸蚕蛹，相当有营养，但没有我想的那么美味。 9、研究结果表明，柞蚕蛹皮的主要成分为油脂、蛋白质、几丁
质和无机盐。 10、推测家蚕蛹虫草有较好的延缓衰老作用。 11、产品涉及蚕蛹虫草、蛹虫草及其制品。 12、结果：蚕蛹多糖能明显增强B淋巴细胞和T淋巴细胞的增殖，促进小鼠巨噬细胞的吞噬活力和溶血素生成。 13、蚕蛹蛋白是一种优质纯天然全价蛋白质，因特殊气味、颜色等限制了其进一步开发与利用。 14、方法：测定蚕蛹蛋白对小鼠淋巴细胞增殖、巨噬细胞吞噬活力及溶血素生成的影响。 15、结论柞蚕蛹性脑病是以锥体外系症状伴烦躁和恐惧为主要表现的预后良好的疾病。 16、报道了酶法水解蚕蛹蛋白工艺的实验研究，并对水解产物进行了分析。 17、目的从野蚕蛹血淋巴中分离纯化抗菌肽，并研究野蚕抗菌肽对体外培养癌细胞的杀伤作用及超微结构的影响。 18、对这些方法应用于蚕蛹酶解蛋白制备血管紧张素转换酶抑制肽的QSAR研究中的可能性进行分析。 19、目的探讨柞蚕蛹性脑病的临床特征。 20、以蚕蛹为原料，采用一种简便的提取工艺提取蚕蛹蛋白质。 21、采收的蚕蛹被丢入沸水会散开成为长丝线。 22、蚕蛹含有丰富的蛋白质，且含人体所必需的各种氨基酸。 23、探讨了蚕蛹油脂的提取方法。通过试验确定了浸出法的最佳
KONZE
——可编程中央控制系统——
安 装 使 用 手 册
中文版
可编程多媒体中央控制系统安装使用手册 2009 [02]
适用型号：KZ-1800
可编程多媒体中央控制系统安装使用手册
目录
概述 ........................................................................................................................................................ 3 注意事项................................................................................................................................................. 3 第一章 产品简介 .................................................................................................................................... 4
KZ—1800 一体化可编程多媒体中央控制系统 ............................................ ...4
第二章 设备包装说明............................................................................................................................. 5 第三章 系统主机与电脑的连接 .............................................................................................................. 5 第四章 应用设备连接............................................................................................................................. 5 第五章 投影机控制线连接 ..................................................................................................................... 6
KZ－1800 一体化中央控制系统........................................................... 6
第六章 电动屏幕接线图 ......................................................................................................................... 6 第七章 操作面板使用说明 ..................................................................................................................... 7
KZ－1800 一体化中控面板............................................................... 7
本手册说明 ............................................................................................................................................. 8
第2页共8页
示波器的使用 【实验目的】 1.了解示波器的结构和示波器的示波原理； 2.掌握示波器的使用方法，学会用示波器观察各种信号的波形； 3.学会用示波器测量直流、正弦交流信号电压； 4.观察利萨如图，学会测量正弦信号频率的方法。 【实验仪器】 YB4320/20A/40双踪示波器，函数信号发生器，电池、万用电表。 图1实验仪器实物图 【实验原理】 示波器是一种能观察各种电信号波形并可测量其电压、频率等的电子测量仪器。示波器还能对一些能转化成电信号的非电量进行观测，因而它还是一种应用非常广泛的、通用的电子显示器。 1．示波器的基本结构 示波器的型号很多，但其基本结构类似。示波器主要是由示波管、X轴与Y轴衰减器和放大器、锯齿波发生器、整步电路、和电源等几步分组成。其框图如图2所示。
图2示波器原理框图 (1)示波管 示波管由电子枪、偏转板、显示屏组成。 电子枪：由灯丝H、阴极K、控制栅极G、第一阳极A1、第二阳极A2组成。灯丝通电发热，使阴极受热后发射大量电子并经栅极孔出射。这束发散的电子经圆筒状的第一阳极A1和第二阳极A2所产生的电场加速后会聚于荧光屏上一点，称为聚焦。A1与K之间的电压通常为几百伏特，可用电位器W2调节，A1与K 之间的电压除有加速电子的作用外，主要是达到聚焦电子的目的，所以A1称为聚焦阳极。W2即为示波器面板上的聚焦旋钮。A2与K之间的电压为1千多伏以上，可通过电位器W3调节，A2与K之间的电压除了有聚焦电子的作用外，主要是达到加速电子的作用，因其对电子的加速作用比A1大得多，故称A2为加速阳极。在有的示波器面板上设有W3，并称其为辅助聚焦旋钮。 在栅极G与阳极K之间加了一负电压即U K﹥U G，调节电位器W1可改变它们之间的电势差。如果G、K间的负电压的绝对值越小，通过G的电子就越多，电子束打到荧光屏上的光点就越亮，调节W1可调节光点的亮度。W1在示波器面板上为“辉度”旋钮。 偏转板：水平(X轴)偏转板由D1、D2组成，垂直(Y轴)偏转板由D3、、D4组成。偏转板加上电压后可改变电子束的运动方向，从而可改变电子束在荧光屏上产生的亮点的位置。电子束偏转的距离与偏转板两极板间的电势差成正比。 显示屏：显示屏是在示波器底部玻璃内涂上一层荧光物质，高速电子打在上面就会发荧光，单位时间打在上面的电子越多，电子的速度越大光点的辉度就越大。荧光屏上的发光能持续一段时间称为余辉时间。按余辉的长短，示波器分为长、中、短余辉三种。 (2)X轴与Y轴衰减器和放大器 示波管偏转板的灵敏度较低(约为0.1～1mm/V)当输入信号电压不大时，荧光屏上的光点偏移很小而无法观测。因而要对信号电压放大后再加到偏转板上，为此在示波器中设置了X轴与Y轴放大器。当输入信号电压很大时，放大器无法正常工作，使输入信号发生畸变，甚至使仪器损坏，因此在放大器前级设置有衰减器。X轴与Y轴衰减器和放大器配合使用，以满足对各种信号观测的要求。
纺织新材料及染整加工特性 在20世纪40年代，科技发达国家开始研制和生产粘胶、涤纶、锦纶、腈纶等化学纤维。在相继半个世纪中，由于合成纤维具有强度高、弹性好、耐穿耐用以及易护理等优点，化学纤维得到迅猛发展，其化纤总量超过了天然纤维。从80年代开始，科技高速发展，人们对纺织品要求越来越高，普通的化学纤维满足不了不同的需要，因此，日本、美国、德国等相继开发出新合纤、差别化和功能性纤维，增加了许多纺织新材料，使纺织产品具有多元化、功能化、仿真化和个性化特点。近年来生产这些化纤原料的石油资源严重短缺，化纤的生产量受到一定限制。因此，许多研究者和开发商寻找其它途径，利用自然界丰富的动植物资源，开发纺织新材料，满足纺织品发展需要。本文对近年来开发的纺织新材料的基本特性和染整加工特点作些阐述。 1 纺织新材料的开发应用及基本特性 1·1 新型天然纤维 1·1·1 天然彩色棉 天然彩棉是一种自身具有天然色彩的棉花新品种，具有色泽自然、质地柔软、穿着舒适、不用染色加工、减少污染环境的一种生态环保纤维。目前，彩棉基本色调只有棕色和绿色两大类，由于彩棉深浅不一，可显现出多种颜色。彩棉虽然有许多优点，但存在可纺性差，色泽不稳定、易变色等缺点。彩棉形态结构与白棉相似，纤维较细、生成的纤维素次生胞壁很薄，胞腔很大，色素主要分布在纤维次生胞壁中。彩棉中纤维素含量占85%-90%，而由棉中纤维素含量在 94%左右。其余物质主要是蜡质，其含量是白棉的6-13倍，灰分含量是白棉的1.4-1.6倍，蛋白质含量是白棉的1.75-2.1倍，含氮物质也较多。彩棉中铜、铁、锌、铂含量高于白棉，其它金属含量低于白棉。彩棉中天然色
MCR型SVC控制系统 技术使用说明书 山东泰开电力电子有限公司 2009年02月
1、概述 山东泰开电力电子有限公司MCR型SVC控制系统（以下简称MCR控制系统）适用于电压等级为6KV～35KV的MCR型SVC装置的自动调节与监控。本系统采用组屏安装方式，可以完成对MCR的全面监控。该系统运用快速调节算法，实现对无功的快速补偿，可有效抑制电压波动、闪变，并可减少电力系统中的谐波、负序，提高功率因数。从而起到改善电能质量，提高生产效率的作用。 2、主要技术参数 2.1 工作环境条件 a.环境温度：-5～+40℃ b.相对湿度：10%～90% c.大气压力：86～106kPa 2.2 电源 2.2.1 交流电源 a.额定电压：220V，允许偏差-15%～+10% b.频率：50Hz，允许偏差±0.5Hz c.波形：正弦，波形畸变不大于5% 2.2.2 直流电源 a.额定电压：220V b.允许偏差：-20%～+10% c.纹波系数：不大于5% 2.3 二次回路额定参数 2.3.1 额定参数 a.交流电流：5A b.交流电压：100V c.频率：50Hz 2.3.2 功率消耗 a.交流电流回路：当IN=5A 时，每相不大于1VA 当IN=1A 时，每相不大于0.5VA b.交流电压回路：当额定电压时，每相不大于1VA 2.3.3 过载能力
a.交流电流回路：1.2倍额定电流，连续工作 b.交流电压回路：1.2倍额定电压，连续工作 c.直流电源回路：80%～110%额定电压，连续工作 3、结构说明 MCR控制系统主要包括：MCR调节装置1台、MCR同步装置1台，另外还包括24V 直流电源、转换开关和空气开关等。所有部件安装于一面屏内，各装置间的关键信号采用光纤连接，从而保证了其可靠的抗干扰能力。屏体平面布置如图3.0.0所示。 图3.0.0 平面布置图