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Conventional Forces can Explain the Anomalous Acceleration of Pioneer 10

Conventional Forces can Explain the Anomalous Acceleration of Pioneer 10
Conventional Forces can Explain the Anomalous Acceleration of Pioneer 10

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Conventional Forces can Explain the Anomalous Acceleration of Pioneer 10

Louis K.Sche?er ?

Cadence Design Systems 555River Oaks Parkway San Jose,CA 95134(Dated:February 7,2008)

Anderson,et al.?nd the measured trajectories of Pioneer 10and 11spacecraft deviate from the trajectories computed from known forces acting on them.This unmodelled acceleration (and the less well known,but similar,unmodelled torque)can be accounted for by non-isotropic radiation of spacecraft heat.Various forms of non-isotropic radiation were proposed by Katz,Murphy,and Sche?er,but Anderson,et al.felt that none of these could explain the observed e?ect.This paper calculates the known e?ects in more detail and considers new sources of radiation,all based on spacecraft construction.These e?ects are then modelled over the duration of the experiment.The model reproduces the acceleration from its appearance at a heliocentric distance of 5AU to the last measurement at 71AU to within 10percent.However,it predicts a larger decrease in acceleration between intervals I and III of the Pioneer 10observations than is observed.This is a 2sigma discrepancy from the average of the three analyses (SIGMA,CHASMP,and Markwardt).A more complex (but more speculative)model provides a somewhat better ?t.Radiation forces can also plausibly explain the previously unmodelled torques,including the spindown of Pioneer 10that is directly proportional to spacecraft bus heat,and the slow but constant spin-up of Pioneer 11.In any case,by accounting for the bulk of the acceleration,the proposed mechanism makes it much more likely that the entire e?ect can be explained without the need for new physics.

PACS numbers:04.80.-y,95.10.Eg,95.55.Pe

I.INTRODUCTION

In [1],Anderson et https://www.doczj.com/doc/602810086.html,pare the measured trajec-tory of spacecraft against the theoretical trajectory com-puted from known forces acting on the spacecraft.They ?nd a small but signi?cant discrepancy,referred to as the unmodelled or anomalous acceleration.It has an approximate magnitude of 8×10?8cm s ?2directed approximately towards the Sun.Needless to say,any acceleration of any object that cannot be explained by conventional physics is of considerable interest.These spacecraft have been tracked very accurately over a pe-riod of many years,so the data are quite reliable,and the analysis,though complex,has been reproduced by Markwardt[2].Explanations for the acceleration fall into two general categories -either new physics is needed or some conventional force has been overlooked.

One of the most likely candidates for the anomalous acceleration is non-isotropic radiation of spacecraft heat.This is an appealing explanation since the spacecraft dis-sipates about 2000watts total;if only 58watts of this to-tal power was directed away from the sun it could account for the acceleration.The bulk of the spacecraft heat is radiated from the two Radioisotope Thermoelectric Gen-erators (RTGs),which convert the heat of decaying plu-tonium to electrical power to run the spacecraft.The remainder of the heat is radiated from various spacecraft components as a result of electrical power dissipation,and by a few small Radioisotope Heater Units (RHUs)

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than the observed acceleration.The discrepancy is small (less than 1σ)from the analysis of Markwardt[2],but roughly a 2σdiscrepancy from the average results of the three analyses.

Getting radiation forces right is notoriously di?cult.Even for Cassini,whose construction is well known,the predicted and measured values di?er by 50%[3].How-ever,the total force can be no larger than the sum of the possible components,though it can easily be less.Therefore the main job is to show that enough force is available;any lesser result is easily explained.

II.

THE ANOMALOUS ACCELERATION

As the Pioneer spacecraft recede from the sun,solar forces decrease and only gravitational forces,and an oc-casional maneuver,should a?ect the trajectory of the spacecraft.Anderson,et al.noticed that a small ad-ditional acceleration needed to be added to make the measured data and computations match.This is the anomalous acceleration,which started to become notice-able about 5AU from the sun.It was roughly the same for Pioneer 10and 11,as shown in Figure

1.

FIG.1:Unmodelled acceleration as a function of distance from the sun,by Anderson et al.[3].

Additional constraints come from further study of Pi-oneer 10,since the data are higher quality and the data span is long enough to provide signi?cant constraints due to the radioactive decay of the heat sources.Figure 2,re-produced from [4],shows the measured acceleration 1987to 1998.(Although they have di?erent horizontal axes,

Figure 2largely follows Figure 1chronologically.Pio-neer 10was at 40AU in 1987.)The authors divide the history into three intervals.Interval I is January 1987to July of 1990,interval II from July of 1990to July of 1992,and interval III is from July of 1992to the June of 1998.The authors make this distinction by looking at the spin rate of the craft (see Figure 3).In intervals I and III it was decreasing smoothly,but in interval II it decreased quickly and irregularly.They therefore consider the data from interval II to be less reliable than intervals I and III,since whatever a?ected the spin in interval II (probably gas leaks)may also have a?ected the

acceleration.

FIG.2:Unmodelled acceleration and an empirical ?t from Turyshev[4].

More recent analyses have re?ned these results some-what,though the main conclusions remain unchanged.Three di?erent analyses have been reported in the litera-ture.SIGMA and CHASMP are two di?erent trajectory modelling programs each with many possible analysis op-tions.We use the best Weighed Least Squares (WLS)results from each program,from [3].Markwardt[2]wrote an new program with the explicit goal of an independent re-analysis.

Table I shows the most recent results from [3],which ?ts a constant,independent acceleration in each inter-val.Table II shows the results of Markwardt’s re-analysis which ?ts a constant plus a linear term to the data from 1987-1994.His best solution is

a (t )=?8.13·10?8cm /sec 2+3.7·10?17t cm /sec 3

where t is the time in seconds since the beginning of 1987.Accelerations are in units of 10?8cm s ?2.For convenience,we show the amount of directed power,in watts,that would be needed to account for each acceler-ation,assuming the 241kg estimate of spacecraft mass from [3].

Note that each program claims very small formal er-rors,but the programs di?er from each other by far greater amounts.Therefore the errors are probably sys-

TABLE I:Summary of results from Anderson,et al.[3] Interval SIGMA equiv

accel.watts Jan87-Jul908.00±0.0159.6

56.77.91±0.01

equiv.

accel.

55.7

(all data,constant acc.)

Jan87-Jul907.98±0.02

58.8

(from linear?t)

Jan87-Jul907.93±0.02

51.6

(extrapolated from linear?t)

FIG.5:Reproduction of Figure3.1-2from[5].A few lines were removed for clarity,and the main equipment compart-ment is shaded in.

and internally-mounted sensors are in an instrument bay (“squashed”hexagon)mounted on one side of the central hexagon.

At present only about65W of power is available to Pi-oneer10[8].Therefore,all the instruments are no longer able to operate simultaneously.But the power subsystem continues to provide su?cient power to support the cur-rent spacecraft load:transmitter,receiver,command and data handling,and the Geiger Tube Telescope(GTT)sci-ence instrument.

The sunward side of the spacecraft is the back,and the anti-sunward side,in the direction of motion,is the front[9].

B.Gas leaks

Gas leaks are always a prime suspect when unmodelled spacecraft accelerations are found.As the authors them-selves say“Although this e?ect is largely unpredictable, many spacecraft have experienced gas leaks producing accelerations on the order of10?7cm/s2”[3].Further-more the authors think that gas leaks are a signi?cant part of the spin behavior.Why then do they think that gas leaks are not the source of the acceleration?They present four arguments:

?The e?ect seems constant over long periods of time

(many years).

?The acceleration does not change as a result of

thruster activity,as many gas leaks do(as valves

seat/unseat.)

?The e?ect is roughly the same on two spacecraft,

Pioneer10and11.

?A force big enough to cause the acceleration would

cause bigger spin changes than are observed unless

it was directed along the spin axis.

In rebuttal,there are many possible sources of gas leaks, not all of which are variable or a?ected by thruster ac-tivity.(The same authors[3]speculate that a gas leak causes the spin-up of Pioneer11,which is also constant and una?ected by maneuvers through4years.)Further-more,the two spacecraft were intended to be identical,so an identical artifact such as a gas leak would not be sur-prising,and it might be aligned with the axis.In short, it would require an unusual gas leak,duplicated on each spacecraft,to cause the observed e?ect,but it is certainly allowed by physics.

In[3],the error budget for gas leaks is set as follows: First,take the biggest uncommanded spin-rate change, assume it was caused by gas leaks,assume the leak was at the spin thrusters,and then increase it a little.Thus they are setting the budget to the biggest known leak on this particular spacecraft.This is hardly a rigorous method for estimating the maximum possible size of an unknown leak,since there could be more than one leak, and locations other than the thrusters require a bigger leak for the same spin change.Furthermore,as the au-thors note,other spacecraft are known to have had larger leaks.Clearly at least some of the authors of[3]are not convinced by their own argument since they still suspect gas leaks as the cause of the unmodelled acceleration([3], Section XII).

C.Non-isotropic radiation-previous work Murphy suggests that the anomalous acceleration seen in the Pioneer10/11spacecraft can be,“explained, at least in part,by non-isotropic radiative cooling of the spacecraft.”[10],The main idea is that heat from the main and instrument compartments would radiate through the cooling louvers on the front of the craft.An-derson,et al.argue in reply[11]that over the data span in question the louver doors were already closed(if the doors were open then the e?ect would surely be signif-icant).They conclude“the contribution of the thermal radiation to the Pioneer anomalous acceleration should be small.”They also argue that the spacecraft power is decreasing,but the unmodelled acceleration is not.

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Sche?er[12]points out that the front of the spacecraft has a much higher emissivity than typical thermal blan-kets(even with the louvers closed),and therefore the majority of the heat will radiate from the front in any case.Anderson,et al.[13]dispute this,based on the emissivity data in[5],which assigns a high emissivity to the thermal blanket.(This data is true but misleading-it speci?es the emissivity of the outer layer of the blanket. This is very di?erent from the emissivity of the blanket as a whole,called the e?ective emissivity,which is quite low.The next section has a more in-depth discussion of this point.)

Katz[14]proposes that at least part of the acceleration is generated by radiation from the RTGs re?ecting o?the back of the antenna.Anderson et al.in[15]argue that this e?ect must be small since the antenna is end-on to the RTGs,and hence gets very little illumination. Slusher(as credited by Anderson)proposed that the forward and backward surfaces of the RTGs may emit non-equally.Anderson et al.conclude there is no credible mechanism to explain the large di?erence in surfaces that would be required if this was to explain the whole e?ect.

IV.DISCUSSION

We consider asymmetrical radiation from5sources-the RTGs themselves,the two spacecraft compartments, RTG radiation re?ected from the antenna,the Radioiso-tope Heater Units(RHUs)on the spacecraft,and radi-ation from the feed that misses the antenna.We also consider one modelling error,a mis-estimation of the re-?ectivity of the antenna to solar radiation.

Consider thermal radiation from the spacecraft body with the louvers closed,as they have been since9AU. An extremely simple argument shows that the electri-cal power dissipated in the main spacecraft compartment must result in a signi?cant amount of thrust.The Pi-oneer antenna points roughly at the sun,and the in-strument compartment is directly behind the antenna. Since the antenna blocks radiation in the sunward di-rection,the waste heat must be preferentially rejected anti-sunward.Referring to Figure5,a good scale model is a60watt bulb about4cm behind a25cm diameter pie dish.The dish casts a huge shadow in the sunward direction,resulting in an average anti-sunward thrust. However,the e?ciency of conversion of heat to thrust is higher than this simple argument indicates.From[5],“The Pioneer F/G thermal control concept consists of an insulated equipment compartment with passively con-trolled heat rejection via an aft[25]mounted louver sys-tem.”Since even a closed louver is a much better radia-tor than thermal insulation,most of the radiation occurs from the front.It’s as simple as that!

Instrument heat may also contribute to thrust,but possibly with less e?ciency.This is because the instru-ments could possibly radiate at right angles to the spin axis through their observation ports,which are not cov-ered with thermal blankets.Furthermore,the science compartment is much closer to the edge of the dish than the main compartment,so the dish will shadow much less of any thermal radiation generated by the science instruments.

We estimate the e?ciency using the spacecraft con-struction.Assuming a uniform internal temperature,the power emitted from each surface is proportional to the area times the e?ective emissivity of the surface.The front and back of the central equipment compartment have about1.3m2area,and the sides about1.5m2to-tal.The sides and the rear of the compartment are cov-ered with multi-layer insulation(MLI)[5].When calcu-lating radiation from multi-layer insulation,the correct value to use is the“e?ective”emissivity,?eff,which ac-counts for the lower temperature of the outer layer[16]. (Anderson[13]points out that the outer layer of the MLI has an emissivity of0.70according to[5].This is not a contradiction because the outer layer of the MLI is much colder than the interior-that’s how MLI works.) From[16],the multilayer insulation from on Pioneer10 has an e?ective emissivity of0.007to0.01(see Figure 6).Assuming a value of0.0085,and a1998internal tem-perature of241K[17],the main compartment will lose about4watts total through the MLI on the sides and back(Even this may be an over-estimate.Two of the sides are facing1Kw IR sources just2meters away,and may even conduct heat into the compartment.).Allow-ing a few watts for conduction losses through wires and struts,perhaps10%of the power(about6watts)goes through the back,10%through the sides,and the remain-ing80%through the front.The back radiation will have a near zero e?ciency(it squirts out from between the dish and the compartment at right angles to the?ight path). Radiation from the side should be about10%e?cient, assuming Lambertian radiation and a45degree obstruc-tion by the dish.Radiation from the front will be about 66%e?cient,again assuming Lambertian emission.The overall e?ciency of main bus radiation could therefore be as high as54%.

Is it reasonable for the front of the main compartment to radiate the47watts or so this requires?At an aver-age temperature of241K,and assuming a?at surface, this would require an average emissivity of0.19.From a picture of the Pioneer10replica in the National Air and Space Museum[18],the front of the spacecraft is rather complex,with considerable surface area(such as a rather large cylinder that connects to the booster)and a variety of surface?nishes.There are also some fairly large instru-ments on the front of the spacecraft,such as the plasma analyzer[5].Although the louver blades themselves have a low emissivity of0.04[5],a composite emissivity of0.19 seems reasonable.

The main conclusion seems quite robust.Multi-layer insulation is speci?cally designed to reduce heat losses, whereas the louvers have at most one layer of obstruction even when closed,and by de?nition are riddled with dis-continuities,which are a major source of heat leaks[16].

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FIG.6:Figure from[16].Pioneer F became Pioneer10.

The lowest emissivity material on the front,0.04,has at

least4times the highest quoted emissivity of the sides

and back.Surely,therefore,a majority of the heat will

be radiated from the front of the spacecraft.

A.Feed pattern of the radio beam

An ideal radio feed antenna would illuminate its dish

uniformly,with no wasted energy missing the dish.How-

ever,the feed is physically small and cannot create such a

sharp edged distribution,so some radiation always spills

over the edge.Since dish area is wasted if not fully il-

luminated,an optimum feed(for transmission)normally

allows about10%of the total power to miss the dish.

This power is converted to sunward thrust with an e?-

ciency of0.7since it is directed roughly45degree angle

to the spin axis.The rest of the energy hits the antenna

and is re?ected sunward.If?F EED is the fraction of the

energy that misses the antenna,and the transmitter is8

watts,then the net thrust towards the sun is

(8w)(?FEED·0.7?(1??FEED))

This is negative as expected,since most of the radiation

is sunward.

As a side note,the radio beam is circularly polarized

and thus carries angular momentum away from the space-

craft.A circularly polarized beam of power P and wave-

lengthλwill impart a torque T of

λ

T=P

7

to3%is certainly plausible in the absence of additional data.

Asymmetrical RTG radiation(to one side,not fore and aft)could also be the cause of the slow but constant spin-up observed on Pioneer11.This would explain why the spin-up is almost constant in value and una?ected by manuevers.

D.Revisiting RTG re?ection

Some of the waste heat from the RTGs will re?ect from the back of the high gain antenna and be converted to thrust,as proposed by Katz[14].Anderson et al.[15]ar-gue that at most30watts of radiation hit the antenna, and hence RTG re?ection cannot account for the whole acceleration,which is true.Similarly,Slabinski[21],in an unpublished analysis from1998,concluded that roughly 28watts of radiation hits the antenna,and hence the whole e?ect could not be explained.However,it is clear the e?ect is real,and can provide a signi?cant fraction of the observed anomaly.Only the exact amount is in question.

The RTGs are not on-axis as viewed from the antenna. From Figure5,we see that the centerline of the RTGs is behind the center of the antenna.Measurements from this diagram indicate this distance is about23.8cm. (Slabinski[21]independently estimated26cm for this dis-tance.)Another?gure(not included here)from[5]shows the far end of the RTGs is120.5inches(or3.06meters) from the centerline.The near end of the RTGs will then be about60cm further in,or at about2.46meters from the center.The antenna extends1.37meters from the center,so the rim of the antenna is69.8cm o?axis and 1.09meters away radially.Thus the edge of the antenna, where the illumination is by far the brightest,views the inner RTG at an32.6degree angle.This is far from on-axis.

The?ns of the RTGs radiate symmetrically,and all are visible from the antenna,so the center of this illumina-tion will be23.8cm behind the antenna.The cylindrical center of the RTG is about8.4cm in radius[22]so this illumination will come from at about15.4cm behind the antenna.The?ns have more area than the cylinder,so for this calculation we take a rough weighted average and assume a cylindrical Lambertian source20cm behind the antenna.We assume the inner RTG is centered2.66me-ters from the center,and the outer RTG2.91meters. The area blocked by the antennas is shown in Figure 7in spherical coordinates.Numerical integration of the two areas shows about12watts for the near RTG and 8watts for the far one if the total RTG power is2000 watts.This does not include radiation from the endcaps or supporting rods.

Combining the analyses,we conclude that at least20 watts,but no more than30watts,of radiation hits the antenna.In this paper,we will use25watts as the basis for further analysis.This energy is turned into thrust

by FIG.7:Antenna size in spherical coordinates from RTGs. Radial axis is angle from the centerline in radians;other axis is angle around this line with the magnetometer de?ned as zero.

two e?ects.First,the antenna shadows radiation which would otherwise go forward.An angle in the middle of the antenna is about17degrees forward;this corre-sponds to an e?ciency of0.3(the true e?ciency is prob-ably higher since the edge is both at a greater angle and more brightly illuminated.)Next,the energy that hits the antenna must go somewhere.Some will be absorbed and re-radiated;some will bounce into space,and some will bounce and hit the instrument compartment,and be re?ected or re-radiated from there.A detailed account-ing seems di?cult,but an overall e?ciency of0.6to0.9 seems reasonable(0.3for shadowing and0.3to0.6for re?ection and re-emission).

E.Total of all e?ects

Here we sum the maximum value of all the e?ects as of1998.The total is more than enough to account for the acceleration,giving us the freedom to reduce some of the e?ciencies if needed to?t the data.

TABLE III:Available thrust from di?erent sources as of1998 Source of e?ect E?c.Decay Rad from RHUs0.50.78%/year

257.5

Antenna radiate0.60.68%/year

200018

Feed pattern0.70%

7.2-7.2

Rad.,main bus0.54see text

10.1

Total

8

F.Antenna solar re?ectivity

In this section we argue that a mismodelled solar re?ec-

tion might account for the sudden onset of the anomalous

force shown in?gure1.This argument is o?ered only as

a possible explanation of the onset and initial decrease of

the anomalous acceleration;it is not relevant to the ex-

istence,magnitude,or source of the acceleration at later

times since past about30AU the contribution from the

solar radiation is negligable.

First,we show there is surely a possibility of error in

these coe?cients since the numbers for the two space-

craft disagree.We start with the data from Anderson,

averaging the SIGMA and CHASMP values.We assume,

following Anderson(section VII-B),that the trajectory

was?t correctly but the mass used in the calculation

was incorrect.We correct the?tted values using the best

available estimates for spacecraft mass,keeping the ac-

celeration(and hence trajectory)the same.We would

TABLE IV:Solar re?ectivity from Anderson,et al.[3]

Spacecraft?tted K resulting

true K

Pioneer10 1.73 1.66

239.7232

9

TABLE V:Instrument power1987-2001.IPP=Imaging Pho-topolarimeter,TRD=Trapped Radiation Detector,PA= Plasma Analyzer

Dates Notes

Jan87-Oct93IPP o?Oct93

8.1

Nov93-Sep95PA o?Sep95

0.8

c·m

[?RHU·RHU(d)+

?RT G·RT G(d)+

(8w)(?FEED·0.7?(1??FEED))+

?INST·INST(d)+

?BUS·BUS(d)?

K SOLAR?SOLAR(d)]

To examine the?t,we use the plots from[3,4],and try to?t them with our model.We make three?ts.The?rst is a conservative?t,using only known and documented spacecraft characteristics.The second is the nominal?t, adding in e?ects such as RTG asymmetry that are plau-sible but not proven.The third is constructed to get the best possible?t to the data,but might be physically unrealistic.

The conservative?t uses only known and documented spacecraft characteristics.These are that the front of the spacecraft is a better radiator than the sides[5,16],and that the antenna will block and re?ect some of the RTG radiation[3,5,14,21].A good?t is obtained with ??RT G=0.01.25watts hit the antenna,30%block-

age e?ciency,and50%re?ection e?ciency.

??INST=0.51.Instruments same as main bus for

simplicity.

??BUS=0.51.About80%the main bus heat goes

out the front,with Lambertian e?ciency.

This model correctly predicts58.6watts in interval I, but predicts a decrease in interval III to48.6watts.This is a17%decrease as opposed to the3%measured in Anderson and10.6%of Markwardt.This model does not explain the onset at5AU,and overpredicts the rate of decrease,but it shows that at most20%of the e?ect can be due to new physics.At the very least,80%of the e?ect can be accounted for by entirely conventional physics, based on known,documented,and measured spacecraft construction.

The nominal?t adds radiation from the RHUs,asym-metrical radiation from the RTGs,feed spillover,and so-lar re?ectance mis-modelling.These sources are all plau-sible but neither proven or disproven by any records or measurements found so far.The?t assigns the same ef-?ciency to main compartment heat and instrument heat. This avoids much of the need to look at spacecraft con-struction details and instrument history,since the accel-eration only depends on the total electrical power.

The additional sources allow a better?t since RHU and RTG heat decays more slowly than electrical heat,feed spillover does not decay at all,and we can now model the onset of the anomalous acceleration at5AU.Once again,many parameter choices give similar results.We get a reasonable?t over the entire data span with the following coe?cients:

??RHU=0.5,the RHUs radiate like point sources

behind the antenna.

??RT G=0.016.0.3%RTG asymmetry,30%block-

age e?ciency,and50%re?ection e?ciency.

??F EED=0.1.10%of the feed power misses the

antenna

??INST=0.39.Instrument heat radiates as main

bus heat for simplicity.

??BUS=0.39.About60%of the main bus heat goes

out the front,with Lambertian e?ciency.

?K SOLAR=0.2.Antenna re?ection estimates are

too low by0.2.

The?t to the data is shown in Figures8and9.The agreement seems reasonable in both regimes.In partic-ular,the early anomalous acceleration between15and 40AU is?t well by this model.In Figure8two other models are shown,all assuming that a1/r2error of some sort(here solar constant mismodelling)is responsible for the onset.The middle trace assumes the acceleration is a pure exponential with an88year half life.This is the form for a model that assumes RTG radiation(direct or re?ected)is asymmetric but spacecraft electrical heat is radiated isotropically.Between15and40AU this model underpredicts the observed decrease,where the nominal model?ts much better.This strongly favors a model where radiation from the spacecraft bus is a major con-tributor to the anomalous acceleration.The lower trace is a constant acceleration plus an error that scales as 1/r2.This shows that if the acceleration is indeed con-stant at large distances,a di?erent explanation for the onset is required.

The?t from1987to1998,shown in Figure9,also looks reasonable.We compare this model to the consen-sus of the most recent analyses[3][2].Using the param-eters above,the average sunward thrust is58.0watts in interval I,and50.2watts in interval III.We can adjust the the parameters to get the correct overall average,or

FIG.9:Figure from[4],with?tted data added.The dotted line is Turyshev’s empirical?t;the solid line is the model hypothesized in this paper.

the right acceleration in interval I,but in either case we would expect to see a13.2%decrease from interval I to III,where only a5.6%decrease is observed.The7.6% discrepancy is about2standard deviations out.Taken at face value,this makes it unlikely at about the2% level that this hypothesis alone accounts for all the mea-sured result.However,the re-analysis by Markwardt[2] has concluded that the data does not rule out a slowly decreasing force,at least if the the decrease is an ex-ponential with a half life of more than50years.(This corresponds to a9%decrease in the6.75year span be-tween the midpoints of intervals I and III).The decrease here is not strictly exponential,but is close in in size and

allowed by Markwardt.

an even better?t to the accelera-

by assigning di?erent e?cien-

and main compartment heat.For

the RHUs radiate like point sources

0.3%RTG asymmetry,30%

and60%re?ection e?ciency.

10%of the feed power misses the

About half the main bus heat radi-

with Lambertian e?ciency.

Instruments radiate mostly to the

.2.Antenna re?ection estimates are

.

only a4.9%discrepancy(10.5%

measured)on the I-III decline and

?t at earlier times.This is only

deviations from the consensus model,

?t for Markwardt.However,?g-

reasonable di?erence between instru-

and main compartment e?ciency is

one hand the two compartments

bay is closer to the edge of

has has side facing ports that extend

blankets.On the other hand the two

and conductively coupled.

detailed analysis it’s very hard to

plausible di?erence in e?cien-

radiation o?ers a parsimonious ex-

the anomalous acceleration and the

Anderson et al.note that the Pioneer

is almost perfectly correlated with

Radiation from the front of the

explains this.The needed emis-

plausible-in1986,there were97watts available,and13w-meters of torque mea-sured.Assuming the radiation is emitted50cm from the axis(the louver location),if the radiation was canted at an average angle of15.5degrees from the normal to the surface,it could provide the observed torque.Such an angle would decrease the conversion of power into thrust by only4%,leaving that argument intact.The louvers, covering the front surface and all canted to one side when closed,provide a natural explanation for the asymme-try required.One obvious objection to this explanation is that it predicts Pioneer11should be spinning down as well,instead of the spin-up that is actually observed. This is not a serious problem since the unknown spin-up mechanism,possibly gas leaks or RTG asymmetry,can easily overpower the small torque induced by main bus radiation.

In any case,the proposed explanation,by accounting for the bulk of the e?ect,makes it more likely that con-

ventional physics can account for the entire unmodelled acceleration.Conventional explanations for the remain-ing discrepancy include other unmodelled e?ects such as gas leaks,inaccuracies in the simple thermal model,or the e?ects of a complex?tting procedure applied to noisy data.

VI.CONCLUSIONS AND FUTURE WORKS No new physics is needed to explain the behavior of the Pioneer spacecraft.Either gas leaks or thermal radiation, or a combination of the two,could explain both the linear and angular accelerations that are measured.

A strong thermal e?ect is certainly present,based only on the construction of the Pioneers.Estimates show it can account for the magnitude of the unmodelled accel-eration to within the errors,but overpredicts the rate of change.The antenna shadowing of main compartment radiation and the radiation from the RTGs falling on the antenna seem particularly robust sources of acceleration since they are only based on geometry.These e?ects alone account for more than half the acceleration.The other sources-RHU radiation,di?erential RTG radia-tion,and di?erential emissivity-depend more on con-struction details,but all seem plausible.

This explanation also explains some other puzzles:the values of acceleration of Pioneer10and11would be expected to be similar,but not identical,as observed. The acceleration and the observed torque(on Pioneer10) share a common origin,and the torque is proportional to the main bus heat,as observed.Other spacecraft,built along the same general principles,would be expected to show a similar e?ect,but planets and other large bodies would not,as is observed.

The hypothesis here predicts an eventual,unambigu-ous decrease in the anomalous acceleration.If the accel-eration remains constant,on the other hand,the hypoth-esis will be refuted.Extending the analysis of Markwardt to the whole Pioneer data span would be useful,since it it currently stops at1994and it directly includes the possibility of a non-constant acceleration.Extending the analysis of Anderson by including post1998data would be helpful as well.

If Pioneer10remains operational,additional data may allow us to improve our understanding of the unmodelled acceleration.The di?erence between constant accelera-tion and the decrease predicted by the hypothesis of this paper grows quadratically with time.Since the beginning of data in1987,by2002the two solutions di?er by4.4 cm/sec,or a doppler shift of0.58Hz.Thus a single good 2002measurement could tell the two hypotheses apart. Unfortunately the signal is now very weak,to the point where the standard JPL receivers have trouble locking onto the signal[7].Careful recording of the return signal might probably work,though,with the frequency recov-ered through long averaging.Bigger telescopes such as Arecibo,the VLA,or Greenbank,might conceivably be pressed into service as well.

More detailed modeling,using the Pioneer materials, construction details,and history,could provide a much better estimate of the magnitude of this e?ect.A suit-ably detailed thermal model,measured in a cold vac-uum chamber,would provide the strongest evidence for or against this hypothesis.

Longer term,other proposed experiments such as LISA[24]are designed speci?cally to reduce the system-atics that bedevil retrospective analyses like Pioneer. (LISA is expected to be about105times better in this respect.)If the anomalous acceleration is not detected in these more precise experiments,then almost surely the unmodelled acceleration of Pioneer10is caused by over-looked prosaic sources such as those proposed here.

VII.ACKNOWLEDGEMENTS

I’d like to thank Edward Murphy and Jonathan Katz for comments and suggestions on an earlier version of this document;Edward Murphy also sent copies of the documents he found while investigating the same e?ect. Larry Lasher and Dave Lozier of the Pioneer project were kind enough to answer questions about the probe.John Anderson suggested adding the statistical likelihood cal-culations.Victor Slabinski forwarded his own indepen-dent antenna re?ection calculations,and George Herbert proposed the RTG bleaching hypothesis.An anonymous referee provided useful suggestions.

[1]J.D.Anderson,https://www.doczj.com/doc/602810086.html,ing,https://www.doczj.com/doc/602810086.html,u,A.S.Liu,M.

M.Nieto,and S.G.Turyshev,Phys.Rev.Lett.81,2858 (1998).Eprint gr-qc/9808081.

[2]C.Markwardt,“Independent Con?rmation of the Pio-

neer10Anomalous Acceleration”,Eprint gr-qc/0208046 [3]J.D.Anderson,https://www.doczj.com/doc/602810086.html,ing,https://www.doczj.com/doc/602810086.html,u,A.S.Liu,M.M.

Nieto,and S.G.Turyshev,“Study of the Anomalous Ac-celeration of Pioneer10and11.”,Phys.Rev.D65(2002) 082004,Eprint gr-qc/0104064.[4]S.G.Turyshev,J.D.Anderson,https://www.doczj.com/doc/602810086.html,ing,https://www.doczj.com/doc/602810086.html,u,

A.S.Liu,and M.M.Nieto,“The Apparent Anomalous,

Weak,Long-Range Acceleration of Pioneer10and11”, the XXXIV-th Rencontres de Moriond Meeting on Grav-itational Waves and Experimental Gravity.Les Arcs, Savoi,France1999.Eprint gr-qc/9903024.

[5]Pioneer F/G Project:Operational Characteristics,Pio-

neer Project NASA/ARC document No.PC-202(NASA, Washington,D.C.,1970).

[6]Web based summary of Pioneer:

https://www.doczj.com/doc/602810086.html,/pioneer10 [7]Another web summary:

https://www.doczj.com/doc/602810086.html,/

Space

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1、偏爱----张芸京 2、阴天----莫文蔚 3、眼泪----范晓萱 4、我要我们在一起---=范晓萱 5、无底洞----蔡健雅 6、呼吸----蔡健雅 7、原点----蔡健雅&孙燕姿 8、我怀念的----孙燕姿 9、不是真的爱我----孙燕姿 10、我也很想他----孙燕姿 11、一直很安静----阿桑 12、让我爱----阿桑 13、错过----梁咏琪 14、爱得起----梁咏琪 15、蓝天----张惠妹 16、记得----张惠妹 17、简爱----张惠妹 18、趁早----张惠妹 19、一念之间----戴佩妮 20、两难----戴佩妮 21、怎样----戴佩妮 22、一颗心的距离----范玮琪 23、我们的纪念日----范玮琪 24、启程----范玮琪 25、最初的梦想----范玮琪 26、是非题----范玮琪 27、你是答案----范玮琪 28、没那么爱他----范玮琪 29、可不可以不勇敢----范玮琪 30、一个像夏天一个像秋天----范玮琪 31、听,是谁在唱歌----刘若英 32、城里的月光----许美静 33、女人何苦为难女人----辛晓琪 34、他不爱我----莫文蔚 35、你是爱我的----张惠妹 36、同类----孙燕姿 37、漩涡----孙燕姿 38、爱上你等于爱上寂寞----那英 39、梦醒了----那英 40、出卖----那英 41、梦一场----那英 42、愿赌服输----那英 43、蔷薇----萧亚轩 44、你是我心中一句惊叹----萧亚轩

45、突然想起你----萧亚轩 46、类似爱情----萧亚轩 47、Honey----萧亚轩 48、他和他的故事----萧亚轩 49、一个人的精彩----萧亚轩 50、最熟悉的陌生人----萧亚轩 51、想你零点零一分----张靓颖 52、如果爱下去----张靓颖 53、我想我是你的女人----尚雯婕 54、爱恨恢恢----周迅 55、不在乎他----张惠妹 56、雪地----张惠妹 57、喜欢两个人----彭佳慧 58、相见恨晚----彭佳慧 59、囚鸟----彭羚 60、听说爱情回来过----彭佳慧 61、我也不想这样----王菲 62、打错了----王菲 63、催眠----王菲 64、执迷不悔----王菲 65、阳宝----王菲 66、我爱你----王菲 67、闷----王菲 68、蝴蝶----王菲 69、其实很爱你----张韶涵 70、爱情旅程----张韶涵 71、舍得----郑秀文 72、值得----郑秀文 73、如果云知道----许茹芸 74、爱我的人和我爱的人----裘海正 75、谢谢你让我这么爱你----柯以敏 76、陪我看日出----蔡淳佳 77、那年夏天----许飞 78、我真的受伤了----王菀之 79、值得一辈子去爱----纪如璟 80、太委屈----陶晶莹 81、那年的情书----江美琪 82、梦醒时分----陈淑桦 83、我很快乐----刘惜君 84、留爱给最相爱的人----倪睿思 85、下一个天亮----郭静 86、心墙----郭静 87、那片海----韩红 88、美丽心情----RURU

2020健身行业现状及前景趋势

2020年健身行业现状及 前景趋势 2020年

目录 1.健身行业现状 (4) 1.1健身行业定义及产业链分析 (4) 1.2健身市场规模分析 (5) 1.3健身市场运营情况分析 (6) 2.健身行业存在的问题 (9) 2.1缺乏市场和行业标准、运作规范和职业资质准入 (9) 2.2专业化程度低 (9) 2.3市场短期和投机行为普遍 (9) 2.4管理水平较低 (9) 2.5供应链整合度低 (10) 3.健身行业前景趋势 (10) 3.1中国运动健身行业迎来新突破 (10) 3.2需求释放,健身群体规模整体保持增长,健身文化逐渐成为主流11 3.3互联网入局,突破时间、空间限制,带来全新健身体验 (11) 3.4健身行业经历洗牌阶段,建立新格局 (11) 3.5行业协同整合成为趋势 (11) 3.6生态化建设进一步开放 (12) 3.7细分化产品将会最具优势 (12) 3.8需求开拓 (13) 4.健身行业政策环境分析 (13)

4.1健身行业政策环境分析 (13) 4.2健身行业经济环境分析 (14) 4.3健身行业社会环境分析 (14) 4.4健身行业技术环境分析 (14) 5.健身行业竞争分析 (16) 5.1健身行业竞争分析 (16) 5.1.1对上游议价能力分析 (16) 5.1.2对下游议价能力分析 (16) 5.1.3潜在进入者分析 (17) 5.1.4替代品或替代服务分析 (17) 5.2中国健身行业品牌竞争格局分析 (17) 5.3中国健身行业竞争强度分析 (18) 6.健身产业投资分析 (18) 6.1中国健身技术投资趋势分析 (19) 6.2中国健身行业投资风险 (19) 6.3中国健身行业投资收益 (20)

猜你歌答案大全 所有歌曲歌名答案更新

猜你歌答案大全所有歌曲歌名答案更新是一款玩法和 很类似的游戏,不过个人感觉该游戏的画面要强上不少,这里第一时间放出 ,注意是全部都 哦。 下面就是游戏中的所有答案,注意前面的是歌手,如果是合唱的歌曲,就会有好几个歌手名字哦,最后的一部分则是歌曲的名字。 猜你歌答案第一部分: 动力火车,当 风凤凰传奇,最炫民族风 周杰伦,菊花台 凤凰传奇,月亮之上 林俊杰,江南 林俊杰,一千年以后

任贤齐,伤心太平洋 周杰伦,发如雪 蔡依林,爱情三十六计邓丽君,月亮代表我的心陈奕迅,十年 沙宝亮,暗香 周杰伦,七裡香 周杰伦,青花瓷 张信哲,爱如潮水Beyond,光辉岁月 高胜美,千年等一回 光良,童话 林志炫,单身情歌

任贤齐,心太软 张信哲,爱就一个字 张宇,雨一直下 F4,流星雨 陈奕迅,王菲,因为爱情猜你歌答案第二部分: 老狼,同桌的你 梁静茹,勇气 刘德华,男人哭吧不是罪 Beyond,海阔天空 蔡卓妍、林俊杰,小酒窝 範玮琪,最初的梦想 飞儿乐团,我们的爱情 林俊杰,曹操 刘德华,爱你一万年 刘若英,后来 毛阿敏,同一首歌 信乐团,离歌 张靓颖,画心 凤凰传奇,荷塘月色 黄安,新鸳鸯蝴蝶梦 黄小琥,没那么简单 李谷一,难忘今宵 梁静茹,宁夏 射雕英雄传,铁血丹心 孙燕姿,绿光 周杰伦,东风破 张学友,吻别 陈奕迅,浮夸

凤凰传奇,自由飞翔 猜你歌答案第三部分: 韩红,青藏高原 李圣杰,痴心绝对 梁静茹,会呼吸的痛 潘玮柏,弦子,不得不爱 曲婉婷,我的歌声 苏打绿,小情歌 萧亚轩,最熟悉的陌生人 张惠妹,听海 周华健,朋友 张韶涵,隐形的翅膀 张学友,一千个伤心的理由 陈奕迅,爱情转移

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中国健身行业的现状以及新发展 健身俱乐部落户海内不外短短几年,却发展得异常红火。 作为该行业核心支柱的健身教练在公家心目中究竟印象如何呢?近日,中国青年报社调查中央、智联招聘和新浪招聘联合进行的一项职业吸引力调查发现,30%的公家觉得“现在做健身教练这行的鱼龙混杂,高素质健身教练却未几”。调查中,28%的公家以为“随着健身热兴起,教练市场肯定需求火爆”。 据08年8月,劳动和社会保障部宣布的“北京市二季度职业排行榜”显示,健身、娱乐场所服务职员作为“新生气力”首次入榜,跻身北京市二季度最轻易就业的20个职业。 现在的健身教练培训机构如雨后春笋般的涌入健身事业大潮,培训项目也五花八门。由此可见健身行业的发展正以惊人的速度从我们身边崛起。而现如今我们需要的是具备健身教练专业培训体系和专业培训技能的培训机构。目的清楚,落到实处——“信誉是教育的本质,质量是教育的核心。”集团操课类着名的培训机构主要集中在北京、武汉、上海等几个城市。而从健身教练的收入水平上来看,排在前面的是深圳、广东、北京、上海等大中型的城市,在这几个城市从业的教练月薪过万是很正常的事情。所以,根据自己的需求,找对地方,才是成为专业操课教练的条件。 健身教练行业目前存在的问题: 1.公家以为健身教练是吃青春饭的 a)很多人以为教练职业是个青春饭,这种认识是不准确 的。能把动作做得好看、有力度好像是教练能立足于领操台

的基本条件,但跟着会员对健身熟悉的不断深化,教练的专业知识是否过硬会成为更重要的评判尺度。此外,经验和服务意识也是赢得顾客的枢纽。国外也有岁数很大的人仍旧在做健身教练。现在从事教练这个职业的人大多是年青人,但是跟着健身行业的发展,以后很可能会泛起四五十岁的资深教练,他们不仅具有很高的理论知识,同时还能够在一线对会员健身做出很全面正确的指导。 b)健身教练的基本素质:1丰硕的理论知识;2亲身的健 身体会;3为人师表的立场。三者缺一不可,而理论知识和健身体会若非长时间参与是很难获得的,为人师表的立场则是一个成功运动员转型做教练的意识形态,很多优秀运动员退役后做不了教练就是因为他平时不留意观察和总结的结果,很多优秀运动员也从来没想过转型做教练。所以可以看出:长时间的积累是一个真正优秀教练的铺路石。 2.健身教练三大来源 a)记者在采访中了解到,目前健身教练的来源主要有三部分组成,或者是健身俱乐部会员,由于成绩凸起,被升格为教练;或者是相关体育专业毕业生毕业后直接进入健身俱乐部;再有就是通过参加培训班,考到有关健身教练资格。 b)据了解,教练中的相当一部门是兼职。科班出身的有扎实的理论功底,但往往会显得缺少个性,而培训班出身的健身教练可能由于培训班的良莠不齐以及缺少同一的尺度而导致水准得不到保障。 c)某健身会所的工作职员说:“我们聘用的教练是需要证书的,什么证书无所谓,口试合格的就可以录用任教。”

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2018年健身行业分析报告

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一、2018健身热持续,新机遇带来增长重启 1、健身行业概况:2020年预期登上千亿元大关 2015年健身热情升温、公共健身设施、新型健身俱乐部等的出现使得商业健身行业重启快速增长。而2017年,热词“A4腰”、“马甲线”持续“霸屏”社交网络,健身这一大众运动不仅是各路明星圈粉的手段,更是年轻人群争相参与的活动之一。根据智研咨询发布的《2017-2022年中国健身房行业市场需求预测及投资前景分析报告》预计,未来五年有望保持12%的年复合增长率,到2020年将达到1230亿元。 2014年以来体育产业以超出政府预期的状态呈跨越式发展和政 策的利好不无关系:2014年“46号文”《国务院关于加快发展体育产业促进体育消费的若干意见》发布。2016年,更是有《“健康中国2030”规划纲要》和《关于加快发展健身休闲产业的指导意见》两条政策相继发布,强调重点发展全民健身及业余体育,引导社会资本参与健身休闲产业,到2025年健身休闲产业规模达到3万亿元。

健身行业市场研究报告

健身行业市场研究报告 (内部资料稿) 泰实医疗 2019年12月

目录 第一部分健身产业概况 (4) 1.1 健身产业定义及产业链 (4) 1.2 健身产业主要政策汇总 (4) 第二部分全球健身市场现状 (5) 2.1 全球健身产业市场规模 (5) 2.2 全球主要国家健身产业情况 (5) 2.3 主要国家健身俱乐部数量 (6) 第三部分国内健身市场现状 (8) 3.1 中国健身产业发展特点 (8) 3.2 健身俱乐部数量 (8) 3.3 健身俱乐部会员数 (9) 3.4 健身器材收入规模 (9) 3.5 中国健身产业规模 (10) 第四部分国内企业竞争格局 (11) 4.1 信隆健康 (11) 4.2 舒华体育 (12) 4.3 威尔仕 (12) 4.4 一兆韦德 (12) 4.5 浩沙健身 (12) 第五部分未来发展趋势 (14) 5.1 健身产业规模预测 (14)

5.2 龙头企业市场份额提高 (14) 5.3 智能化健身趋势兴起 (14)

一、健身产业概况 随着我国人民健身意识的进一步提升和健身房商业模式的进一步成熟,我国健身产业发展迅速。2016年体育总局与国务院分别颁布《体育发展十三五规划》、《全民健身计划(2016-2020)》,提出到2020年,每周参加1次及以上体育锻炼的人数达7亿,经常参加体育锻炼的人数达4.35亿,体育消费总规模达1.5万亿元等,目标是把全民健身打造成国家名片。 (一)健身产业定义及产业链 健身除了体育含括的项目之外,还有很多内容,例如,写字、唱歌、做家务、瑜伽等。健身大致分为器械锻炼和非器械锻炼。狭义的健身是指以健身俱乐部/工作室为主要场所,并且通常借助体育器械进行锻炼的活动。 健身产业上游涉及健身器械、教练培训等,中游主要是各类健身服务,下游则是各类健身服装/装备等。 (二)健身产业主要政策汇总 随着我国经济社会的快速发展,越来越多的人注重运动健身。同时我国政府高度重视体育活动在增强体质、提高健康水平中的重要作用。 1995年,国务院颁布实施《全民健身计划纲要》; 2007年,国务院下发《关于加强青少年体育增强青少年体质的意见》; 2014年,国务院下发《关于加快发展体育产业促进体育消费的若干意见》; 2016年6月,为促进健身产业发展、增强全民身体素质,国务院印发《全民健身计划(2016—2020年)》。对发展群众体育活动、倡导全民健身新时尚、推进健康中国建设做出了明确部署; 2017年8月11日,针对中国居民参加体育健身活动状况实际,国家体育总局发布了《全民健身指南》。

我国健身器材行业发展概况

我国健身器材行业发展概况 (一)行业概述 1、市场容量与增长趋势 (1)体育产业迎来市场化发展的历史机遇 伴随我国经济发展进入新常态以及产业结构转型,体育产业作为新的经济增长动力之一对于国民经济的拉动作用得以凸显。国家也密集出台一系列的产业支持政策,推动体育产业的快速健康发展。 国家统计局数据显示,2012 -2015 年,我国体育产业总规模分别为9,500 亿元、11000 亿元、13575 亿元和17,107 亿元,各年实现增加值3,136 亿元、3,563 亿元、4,041 亿元和5,494 亿元,占当年GDP 比例分别为0.60%、0.63%、0.64% 和0.8%,体育产业规模年均增长率达到了22%。 从全球体育产业占GDP 的比重看,以美国、法国等为代表的体育强国,其体育产业占GDP 的比重均达到2.5%以上,全球平均水平亦达到了 2.1%,而我国该比例仅为0.8%左右,仍然具有较大的发展空间。 根据《体育发展“十三五”规划》、《体育产业发展“十三五”规划》以及国务院发布的《国务院关于加快发展体育产业促进体育消费的若干意见》,预计到2020 年,我国体育产业总规模将超过3 万亿元,产业增加值占GDP 的比重将达到 1.0%。2025 年,体育产业总规模将超过 5 万亿元,成为推动经济社会持续发展的重要力量。在国家产业政策的引导和支持下,我国体育产业迎来市场化发展的历史机遇。 (2)体育用品行业规模占体育产业整体规模一半以上 根据46 号文以及《国家体育产业统计分类》(2015 年)的界定,我国的体育产业主要包括产品制造和服务提供两大类,前者包括健身器材、运动服装、运动鞋等体育用品的制造,后者包括竞赛表演、健身休闲活动、场馆服务、中介培训、体育培训等。其中,体育用品行业是我国体育产业中发展较早,也是目前发展较为成熟的细分行业之一。

运动健身器材行业分析报告

一、运动健身器材行业的概况 运动健身器材是竞技体育比赛和健身锻炼所使用的各种器械、装备及用品的总称。 运动健身器材主要有3种分类方法:依据体育运动的项目分类这是将所有与同一运动项目有关的器材和装备等归为一类的方法,如田径器材、举重器材、冰雪器材等。依据体育器材的性质分类一般可分为指定器材、自备器材、场地器材和其他器材等4类。依据体育器材的用途分类分为竞技体育器材、国防军事体育器材、中国民间体育器材、健身健美体疗康复器材、儿童体育游艺器材、伤残人竞技器材、辅助性器材等。 随着生活水平的提高,人们越来越注意身体健康和体型的美丽,为此在健美方面的投资也日益增加。未来欧洲、亚洲和拉丁美洲将是市场的主要增长点,逐渐富裕的人群将会提高自己对健康生活方式的追求,并将成为健身器材的主要消费者。 城市居民对体育用品的消费已经从低档为主向中高档方向发展,农村居民尤其是已经进入小康生活标准的农村地区,对中低档体育用品的消费也将逐步形成新的需求。随着农村地区收入的增加将使健身市场的潜力变成现实,中国健身器材市场的年销售额逐年增长,中国人对健康的关注正在形成个黄金市场。 二、运动健身器材所处生命周期位置 根据生命周期理论的销售增长率划分法:销售增长率大于

10%为成长期,0.1%-10%为投入期或成熟期,小于0则为衰退期,根据该理论我们对运动健身器材产业行业的发展做出如下推断: 行业处于成长期时,顾客成群增加,消费者开始注重产品质量和可靠性,企业开始竞争前扩张,准备积极应对竞争。已进入行业的企业拥有较高获利能力,但由于行业竞争者的进入,产品价格开始下降。运动健身行业正处于行业生命周期的成长阶段,是已进入企业扩张市场、抢占市场份额的最好时机。 三、运动健身器材行业的SWOT分析 S(竞争优势):中国有广大的市场,便宜的人力资源和原材料市场,及政府的各种优惠政策,中国处于高速发展的

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2016-2022年中国健身房行业现状分析与发 展趋势研究报告 报告编号:1612601

行业市场研究属于企业战略研究范畴,作为当前应用最为广泛的咨询服务,其研究成果以报告形式呈现,通常包含以下内容: 一份专业的行业研究报告,注重指导企业或投资者了解该行业整体发展态势及经济运行状况,旨在为企业或投资者提供方向性的思路和参考。 一份有价值的行业研究报告,可以完成对行业系统、完整的调研分析工作,使决策者在阅读完行业研究报告后,能够清楚地了解该行业市场现状和发展前景趋势,确保了决策方向的正确性和科学性。 中国产业调研网https://www.doczj.com/doc/602810086.html,基于多年来对客户需求的深入了解,全面系统地研究了该行业市场现状及发展前景,注重信息的时效性,从而更好地把握市场变化和行业发展趋势。

一、基本信息 报告名称:2016-2022年中国健身房行业现状分析与发展趋势研究报告 报告编号:1612601←咨询时,请说明此编号。 优惠价:¥6750 元可开具增值税专用发票 Email: 网上阅读: 温馨提示:如需英文、日文等其他语言版本,请与我们联系。 二、内容介绍 健身房是城市里用来健身的场所。一般而言,都有齐全的器械设备,有较全的健身及娱乐项目,有专业的教练进行指导,有良好的健身氛围。 2016-2022年中国健身房行业现状分析与发展趋势研究报告对我国健身房行业现状、发展变化、竞争格局等情况进行深入的调研分析,并对未来健身房市场发展动向作了详尽阐述,还根据健身房行业的发展轨迹对健身房行业未来发展前景作了审慎的判断,为健身房产业投资者寻找新的投资亮点。 2016-2022年中国健身房行业现状分析与发展趋势研究报告最后阐明健身房行业的投资空间,指明投资方向,提出研究者的战略建议,以供投资决策者参考。 中国产业调研网发布的《2016-2022年中国健身房行业现状分析与发展趋势研究报告》是相关健身房企业、研究单位、政府等准确、全面、迅速了解健身房行业发展动向、制定发展战略不可或缺的专业性报告。 正文目录 第一部分产业发展分析 第一章产业发展现状与趋势 第一节国际健身房产业发展现状与趋势 一、国际健身房产业发展现状 二、国际健身房产业发展趋势 三、国外健身俱乐部入驻中国的优势

大学生健身房现状调查与分析

大学生健身房现状调查 与分析 Document serial number【UU89WT-UU98YT-UU8CB-UUUT-UUT108】

苏州大学文正学院健身房现状调查与分析 背景: 现代社会对健康的理解发生了改变。联合国世界卫生组织明确指出:“健康不但是没有身体缺陷和疾病,还要有完整的生理、心理状态和社会适应能力。”也就是说,人的健康不仅包括生理健康,同时包括心理健康。国内外心理学家、医学家对心理健康问题有不少精辟见解。心理学家麦灵格说:“心理健康,是指人们对于环境以及人们相互之间具有最高效率及快乐的适应情况。不只是要有效率,也不只是要能有满足之感,或是能愉快地接受生活的变故,而要三者都具备。心理健康的人应能保持平静的情绪,有敏锐的智能,适合于社会环境的行为和愉快的气质。”健身不仅可以强健体格,也可以帮助人们释放压力,缓解紧张情绪,保持心情舒畅,有利于身心健康。这也使健身越来越受到大众的喜爱。 随着科技进步以及互联网的普及,大大改变了信息的传播方式及速度,有效提高了学习工作的效率,使人们的生活节奏越来越快,再加上高密度的学习和高压力的工作,使大学生普遍运动不足,导致健康状况下降。大学生的健康问题已成为一个社会问题,越来越多的大学生意识到健身的重要,这使得大学生对健身房的需求逐年增大。 根据最新的健康调查报告显示,我们越来越多的大学生处于亚健康状态。 现状调查与分析:

从高中步入了大学,很多学生的空余时间变得多了起来,其中有不少大学生选择了课外锻炼。课外锻炼主要有室内和室外之分,室内则以在健身房锻炼为主。然而文正学院在健身房这一方面做的有所欠缺,甚至几近于不合格! 首先有一点我们都得承认的是,文正学院起码有了健身房了,这比起有的大学连健身房都没有要好的多了(不过没有健身房的大学好像也没有几所)!同时,在调查健身房的问题是,也调查了一下大学生去健身房的目的,也无外乎以下几种:强身健体、减肥、保持体形、扩大社交、缓减压力、提高运动技能等等。不过很多大学生只有在大量的空闲时间时才会去健身房锻炼! 下面来简单的介绍一下文正学院健身房的具体情况,文正学院健身房大约有三个宿舍那么大的面积,主要是在学校操场看台的右侧位置,紧邻乒乓球馆。由于场地的限制,学校健身房内的设施以小型健身器械为主,主要有、、曲柄杠铃、弹簧拉力器、健身盘、弹力棒、等。 其实在健身房设施器材方面,同学们并不是要求太严格,毕竟虽然大家相较于中学来说空余时间比较多,但是有相当一部分人还是以学业为重,健身为辅;当然,还有一部分同学则痴迷于网络游戏,对于健身这一方面不太重视。所以说,很多学生对于健身器材方面还是比较满意的,毕竟大家并不是长时间泡在健身房内,仅仅还是快餐式的健身,并没有系统的健身计划。不过,在调查中也发现了一个不小的问题,那就是学校里有相当一部分同学几乎还没有去过甚至不知道健身房,而能够

一百首适合一个人听的歌

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12、让我爱----阿桑 13、错过----梁咏琪 14、爱得起----梁咏琪 15、蓝天----张惠妹 16、记得----张惠妹 17、简爱----张惠妹 18、趁早----张惠妹 19、一念之间----戴佩妮 20、两难----戴佩妮 21、怎样----戴佩妮 22、一颗心的距离----范玮琪

23、我们的纪念日----范玮琪 24、启程----范玮琪 25、最初的梦想----范玮琪 26、是非题----范玮琪 27、你是答案----范玮琪 28、没那么爱他----范玮琪 29、可不可以不勇敢----范玮琪 30、一个像夏天一个像秋天----范玮琪 31、听,是谁在唱歌----刘若英 32、城里的月光----许美静 33、女人何苦为难女人----辛晓琪

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