Background technology
Radioactive isotope is widely used in the every field such as industry, agricultural, medical science and scientific research.Current Isotope production depends on heavy water reactor, lower powered research reactor or accelerator, a domestic production part, or from an external import part, but still the source of goods is deficient, is difficult to meet growing demand.
Conventional radioactive isotope comprises cobalt-60, caesium-137, Iridium-192 source etc.For cobalt radioisotope, cobalt-59 is at reactor internal irradiation appropriate time, and cobalt-59, by absorption neutron, can obtain the cobalt-60 of high specific activity.Cobalt-60 is radioactive isotopes the most frequently used in Application of Nuclear Technology, and emitted energy is the gamma-rays of 1.17MeV and 1.33MeV or the β ray of 0.315MeV, and the half life period is 5.27 years.
Presurized water reactor is technology maturation, security of operation, economical and practical heap-type.In the world, PWR nuclear power plant installation total volume accounts for more than 60% of all kinds of reactor summation of all nuclear power plants; In the nuclear power generating sets that China has put into commercial operation at present and built, presurized water reactor heap-type accounts for more than 90%.The neutron how utilizing the nuclear reaction in nuclear power plant to produce, to produce radioactive isotope, also becomes the problem that nuclear power technology personnel pay close attention to.
Shanghai Institute of Nuclear Engineering proposed the Chinese invention patent application utilizing heavy water stack cobalt regulating rod component to produce radioactive isotope cobalt in 2008, its publication number is CN101252025A, and denomination of invention is: heavy water stack cobalt regulating rod component; To be applied in heavy water reactor due to this technology and to be bound by the regulating rod of its regulating action, therefore there is following defect:
(1) regulating rod is as the reactive a kind of control rod of adjustment reactor core, when reactor operating mode changes and needs to regulate with regulating rod, this regulating rod is inevitably made often to extract out or insert reactor core, constraint is had to the cobalt target piece in the regulating rod of cobalt, there is the phenomenon of irradiation dose instability;
(2) have the regulating rod of cobalt to substitute stainless steel regulating rod with constraint to play and regulate reactive function, have impact to reactor operation, safely etc. need carry out multinomial analysis and appropriate design to nuclear properties, thermal technology, irradiation, demonstration amount is large and complicated;
(3) in heavy water reactor, have the regulating rod of cobalt to substitute stainless steel regulating rod with constraint, need to have around the regulating rod of cobalt in constraint to arrange thick and heavy radioactive shield protective device, shielding action is played to biology;
(4) this technology is only applicable to heavy water reactor, domestic and international nuclear power plant uses the considerably less of heavy water reactor, and China only only has two at present, is of limited application, make the production quantity of cobalt radioactive source limited, be difficult to meet the demand in medical or work, agriculture widespread use market.
Presently, presurized water reactor is technology maturation, security of operation, economical and practical heap-type, and in the world, PWR nuclear power plant installation total volume accounts for more than 60% of all kinds of reactor summation of all nuclear power plants; In the nuclear power generating sets that China has put into commercial operation at present and built, presurized water reactor heap-type accounts for more than 90%.
Consider based on above-mentioned factor, the applicant wishes to produce radioactive isotope in presurized water reactor, and utilizes presurized water reactor to use feature widely, realizes radioisotopic a large amount of production, with satisfied industry, agricultural and medical demand.
Summary of the invention
Object one of the present invention is that provide a kind of absorbs neutron and produce radioisotopic high specific activity radiation source core target in nuclear reactor core.
Object two of the present invention is that provide a kind of absorbs neutron and produce radioisotopic radioactivity rod in nuclear reactor core.
Object three of the present invention is to provide one can pile Core cooling agent bypass flow by limited reactions, can produce again the radioisotopic novel choke plug assembly preparing radioactive source for presurized water reactor.
For achieving the above object, high specific activity radiation source core target provided by the invention, in nuclear reactor core, absorb neutron and produce radioactive isotope, it comprises matrix, sleeve pipe and absorb neutron and produce radioisotopic radioactive source pin, described matrix is the cylindric of hollow structure, described hollow structure forms air cavity, radial direction around described matrix is evenly offered active needle tray and is formed one deck irradiation active layer, source needle tray in same irradiation active layer is around formation circle, the center of circle of described circle is positioned on the central axis of described air cavity, the axis of described matrix has at least two-layer irradiation active layer, mutually equally spacedly between described irradiation active layer to be arranged in parallel, the source needle tray of same irradiation active layer symmetrically be inserted with described radioactive source pin, described matrix is packaged in described sleeve pipe in sealing, described air cavity is filled with helium.
Preferably, described high specific activity radiation source core target also comprises web member, and described web member comprises body, and described body stretches out formation connecting portion, and described connecting portion is the end of the described sleeve pipe of dismountable insertion and is sealed in described sleeve pipe by described matrix.
Preferably, described connecting portion inserts the end of described sleeve pipe is dismountable being connected with a joggle.
Preferably, described connecting portion outwards protrudes out and forms the plush copper corresponding with described air cavity, and described plush copper correspondence is inserted in described air cavity and fixed described matrix, forms gap between described matrix and described sleeve pipe.
Preferably, the source needle tray of adjacent described irradiation active layer is in staggered distribution.
Preferably, the surface of described radioactive source pin also coated one deck plated nickel film.
Preferably, the quantity of the source needle tray in every layer of described irradiation active layer is A, and wherein A is the natural number of even number and 4≤A≤12.
Preferably, the quantity of described irradiation active layer is B, and wherein B is natural number and 50≤B≤150.
Preferably, described radioactive source pin is cobalt source pin, caesium source pin, iridium source pin, molybdenum source pin, tritium source pin, carbon source pin, nickel source pin, source of iron pin, selenium source pin, antimony source pin, ytterbium source pin, thulium source pin, thallium source pin, Zhen Huobu source, polonium source pin.
Preferably, described radioactive source pin is needle-like structures.
Preferably, the diameter of described radioactive source pin is between 1.00mm-5.00mm, and length is between 1.00mm-7.00mm.
Preferably, the weight of described radioactive source pin is between 0.005g-0.1g.
Preferably, the length of described high specific activity radiation source core target is between 100.00mm-300.00mm.
Radioactivity rod provided by the invention, comprise the cladding tubes in hollow structure, it also comprises high specific activity radiation source core target described above, what described high specific activity radiation source core target docked in superposition is sealed in described cladding tubes, in dismountable connection between the described high specific activity radiation source core target of adjacent superposition docking.
Preferably, the described high specific activity of adjacent superposition docking radiates between source core target and is connected with a joggle in dismountable.
Preferably, described cladding tubes is hollow structure, and the two ends of described hollow structure arrange a space bar respectively, and the hollow structure described in two between dividing plate forms host cavity, described high specific activity radiation source core target being arranged in described host cavity in superposition docking.
Preferably, the length of described host cavity is between 1000.00mm-3500.00mm.
Preferably, the upper end of described cladding tubes seals by a upper end plug, and the lower end of described cladding tubes is by end plug sealing once.
Novel choke plug assembly provided by the invention, radioactive source is prepared for presurized water reactor, wherein, described novel choke plug assembly comprises web joint and in the nuclear reactor core of presurized water reactor, absorbs neutron and produce radioisotopic radioactivity rod, described radioactivity rod is as described above, and described web joint has the installation portion installing described radioactivity rod, and described installation portion is in dispersion distribution, described radioactivity rod is installed on described installation portion in unsettled correspondence, is parallel to each other between described radioactivity rod.
Preferably, described novel choke plug assembly also comprises centre pilot cylinder, and the upper end of described centre pilot cylinder is in sliding up and down and the flexible center being arranged in a compressing member, and the lower end of described centre pilot cylinder is fixedly connected with described web joint.
Preferably, described novel choke plug assembly also comprises pin, and the upper end of described pin is fixed on described compressing member, and described centre pilot cylinder is in vertically offering gathering sill, and the lower end of described pin is in being arranged in described gathering sill of sliding up and down.
Preferably, described novel choke plug assembly also comprises volute spring, and it is outer and between described compressing member and described web joint that described volute spring is sheathed on described centre pilot cylinder.
Preferably, described web joint runs through and offers discharge orifice.
Compared with prior art, because the existing stainless steel choked flow stopper apparatus be installed on web joint has the radioactivity rod that high specific activity radiates source core target to replace by the present invention, thus form novel choke plug assembly, wherein this high specific activity radiation source core target absorbs neutron and produces the radioactive isotope of high specific activity in nuclear reactor core, and the radioactivity rod replacing stainless steel choked flow stopper has the function of the restriction Core cooling agent bypass flow same with stainless steel choked flow stopper, this radioactivity rod is owing to having high specific activity radiation source core target simultaneously, therefore this radioactivity rod can also produce the radioactive isotope of high specific activity, therefore novel choke plug assembly of the present invention does not affect the original function of restriction Core cooling agent bypass flow, and novel choke plug assembly of the present invention, as the fixed associated component of reactor core, does not participate in the reactive adjustment of reactor core, preparing radioisotopic while, thus do not affect the safe operation of reactor, radioactive source pin (i.e. target piece) simultaneously in novel choke plug assembly of the present invention is positioned at reactor core active section, all the time reactor core irradiated site is in, irradiation dose is stablized, radioactive isotope quality is high, presurized water reactor is utilized to prepare the radioactive isotope of high specific activity, can under the prerequisite guaranteeing reactor core safety, significantly improve the utilization ratio of neutron, thus make the present invention be applicable to large quantities of PWR nuclear power plant main flow heap-type put into commercial operation and built, radioactive isotope production lot is large, remarkable in economical benefits, industry can be met greatly, agriculture and medical demand.
Embodiment
With reference now to accompanying drawing, describe embodiments of the invention, element numbers similar in accompanying drawing represents similar element.
As shown in Figure 1, radioactivity rod 1 of the present invention comprises cladding tubes 11 in hollow structure and high specific activity radiation source core target 12, this high specific activity radiation source core target 12 produces radioactive isotope for absorbing neutron in nuclear reactor core, what described high specific activity radiation source core target 12 docked in superposition is sealed in described cladding tubes 12, in dismountable connection between the described high specific activity radiation source core target 12 of adjacent superposition docking, be sealed in cladding tubes 11 by what several high specific activities radiation source core target 12 is superposed docking, thus formed multi-level, multi-facetedly produce radioisotopic radioactivity rod 1 simultaneously, and by dismountable connection between high specific activity radiation source core target 12, both ease of assembly was also for convenience detach, also be easy to the high specific activity radiation source core target 12 manufacturing applicable length simultaneously.
Because meeting in nuclear process is along with the release of neutron, and the high specific activity radiation source core target 12 of radioactivity rod 1 of the present invention has absorption (namely catching) neutron and produces radioisotopic ability, therefore radioactivity rod 1 of the present invention is used for can producing radioactive isotope in nuclear reactor core.
Continue shown in composition graphs 1, preferably, be connected with a joggle in dismountable between the described high specific activity radiation source core target 12 of adjacent superposition docking; Be connected with a joggle by screw thread between the high specific activities radiation source core targets 12 of two adjacent superposition docking, not only simple but also practical, and dismounting and assemble also very convenient.
Continue shown in composition graphs 1, preferably, described cladding tubes 11 is in hollow structure, the two ends of described hollow structure arrange a space bar 13 respectively, hollow structure described in two between dividing plate 13 forms host cavity 14, described high specific activity radiation source core target 12 being arranged in described host cavity 14 in superposition docking.
Continue shown in composition graphs 1, the length of described host cavity 14 is between 1000.00mm-3500.00mm.
Continue shown in composition graphs 1, preferably, the upper end of described cladding tubes 11 is by a upper end plug sealing 15a, and the lower end of described cladding tubes 11 seals by once end plug 15b.
Below on the basis of Fig. 1, composition graphs 2a-Fig. 5 makes a detailed description to high specific activity radiation source core target 12 of the present invention:
Shown in composition graphs 1-Fig. 3, high specific activity radiation source core target 12 of the present invention, in nuclear reactor core, absorb neutron and produce radioactive isotope, this high specific activity radiation source core target 12 comprises matrix 121, sleeve pipe 122 and absorb neutron and produce radioisotopic radioactive source pin 123, described matrix 121 is the cylindric of hollow structure, described hollow structure forms air cavity 124, radial direction around described matrix 121 is evenly offered active needle tray 125 and is formed one deck irradiation active layer 126, source needle tray 125 in same irradiation active layer 126 is around formation circle, the center of circle of described circle is positioned on the central axis O of described air cavity 124, the axis of described matrix 121 has at least two-layer irradiation active layer 126, mutually equally spacedly between described irradiation active layer 126 to be arranged in parallel, the source needle tray 125 of same irradiation active layer 126 symmetrically be inserted with described radioactive source pin 123, described matrix 121 is packaged in described sleeve pipe 122 in what seal, under the effect of sleeve pipe 122, the radioactive source pin 123 be inserted in source needle tray 125 is fixed and is limited in source needle tray 125, avoid rocking of radioactive source pin 123, improve the guarantee of safety in production, described air cavity 124 is filled with helium, thus is formed and have the air cavity 124 of certain pressure, effectively can prevent during irradiation that phenomenon that creep caves in occurs because cooling medium external pressure makes cladding tubes 11 occur, and also can improve heat transfer property.Separately, the design of whole high specific activity radiation source core target 12 can reduce the space of radioactive source pin 123 from shielding effect, thus improves radioisotopic quality.
Continue shown in composition graphs 2b, preferably, the source needle tray 125 of adjacent described irradiation active layer 126, in staggered distribution, is namely positioned at the source needle tray on upper strata and the source needle tray cross-distribution of lower floor; The source needle tray 125 of certainly adjacent described irradiation active layer 126 can be also just right setting as shown in Figure 2 a.
It should be noted that, those skilled in the art are under the prerequisite of technical scheme provided by the present invention, to the quantity of the radioactive source pin 123 that the quantity of source needle tray 125 in the quantity of irradiation active layer 126, each irradiation active layer 126 and every one deck irradiation bomb layer 126 are arranged, those skilled in the art can to make one's options use according to the demand of actual conditions without the need to any performing creative labour, and in this not go into detail.
Shown in composition graphs 4 and Fig. 5, preferably, described high specific activity radiation source core target 12 also comprises the web member for Sealed casing pipe 122, what dock due to the superposition of high specific activity radiation source core target 12 is sealed in cladding tubes 11, and therefore web member of the present invention has two kinds, for convenience of description, therefore these two kinds of web members adopt different labels, the i.e. web member 127b of the web member 127a of Fig. 4, Fig. 5, is described in detail to the two below respectively:
Shown in composition graphs 1 and Fig. 4, web member 127a shown in Fig. 4 is unidirectional male structure, this web member 127a comprises body 1271, the side of described body 1271 stretches out and forms connecting portion 1272, described connecting portion 1272 is the end 1221 of the described sleeve pipe of dismountable insertion 122 and is sealed in described sleeve pipe 122 by described matrix 121, because the body 1271 of this web member 127a only stretches out and forms connecting portion 1272 in side, the end 1221 that therefore this web member 127a is used for the sleeve pipe 122 of single high specific activity radiation source core target 12 seals; Specifically for being positioned at the upper end of the high specific activity radiation source core target 12 of the top in the radioactivity rod 1 shown in Fig. 1 and being positioned at the bottom of high specific activity radiation source core target 12 of bottom.
Particularly, the connecting portion 1272 of described web member 127a outwards protrudes out and forms the plush copper 1273 corresponding with described air cavity 124, described plush copper 1273 correspondence to be inserted in described air cavity 124 thus fixing described matrix 121, and then make to form gap between described matrix 121 and described sleeve pipe 122, under coordinate of plush copper 1273 with air cavity 124, gap between matrix 121 and sleeve pipe 122 remains unchanged, and makes high specific activity of the present invention radiation source core target 12 Stability Analysis of Structures reliable.
Shown in composition graphs 1 and Fig. 5, web member 127b shown in Fig. 5 is two-way male structure, the same with the web member 127a shown in Fig. 4, this web member 127b comprises body 1271 and connecting portion 1272 equally, relative both sides unlike described body 1271 stretch out and form connecting portion 1272, described connecting portion 1272 is the end 1221 of the described sleeve pipe of dismountable insertion 122 and is sealed in described sleeve pipe 122 by described matrix 121, body 1271 both sides due to this web member 127b all stretch out and form connecting portion 1272, therefore this web member 127b is used for superposing between two adjacent high specific activity radiation source core targets 12 achieving a butt joint, adjacent and the end 1221 of the sleeve pipe 122 of two high specific activities radiation source core targets 12 of superposition of the insertion that two connecting portions 1272 are corresponding respectively, thus this is adjacent and two high specific activities radiation source core targets 12 of superposition superpose connecting and sealing up sleeve pipe 122, docking specifically for the high specific activity radiation source core target 12 being positioned at superposition in the radioactivity rod 1 shown in Fig. 1 connects.
Equally, two connecting portions 1272 of described web member 127b all outwards protrude out and form the plush copper 1273 corresponding with described air cavity 124, described plush copper 1273 correspondence to be inserted in described air cavity 124 thus fixing described matrix 121, and then make to form gap between described matrix 121 and described sleeve pipe 122, under coordinate of plush copper 1273 with air cavity 124, gap between matrix 121 and sleeve pipe 122 remains unchanged, and makes high specific activity of the present invention radiation source core target 12 Stability Analysis of Structures reliable.
Continuing that composition graphs 4 and Fig. 5, web member 127b provided by the present invention can be understood as is that two web member 127a are symmetrical set and the integral structure that formed.
Shown in composition graphs 2a, Fig. 2 b, Fig. 4 and Fig. 5, preferably, the end 1221 that described connecting portion 1272 inserts described sleeve pipe 122 is connected with a joggle in dismountable, by arranging corresponding screw thread on the end 1221 of connecting portion 1272 and sleeve pipe 122 respectively, thus make connecting portion 1272 and sleeve pipe 122 realize dismountable being connected with a joggle, not only simple but also practical, and dismounting and assemble also very convenient.
Shown in composition graphs 1-Fig. 3, preferably, in order to prevent radioactive source pin 123 not oxidized, surface also coated one deck plated nickel film of described radioactive source pin 123.
Continue shown in composition graphs 1-Fig. 3, preferably, the quantity of the source needle tray 125 in every layer of described irradiation active layer 126 is A, and wherein A is the natural number of even number and 4≤A≤12.
Shown in composition graphs 1-Fig. 3, preferably, the quantity of described irradiation active layer 126 is B, and wherein B is natural number and 50≤B≤150; Therefore the quantity that the present invention's high specific activity radiation source core target 12 can arrange at most radioactive source pin 123 is A*B.
Preferably, described radioactive source pin 123 is cobalt source pin, caesium source pin, iridium source pin, molybdenum source pin, tritium source pin, carbon source pin, nickel source pin, source of iron pin, selenium source pin, antimony source pin, ytterbium source pin, thulium source pin, thallium source pin, Zhen Huobu source, polonium source pin; Specifically select which kind of radioactive source pin 123, those skilled in the art are according to the needs of actual conditions, and under the prerequisite of technical scheme provided by the present invention, can make one's options without the need to any performing creative labour, in this not go into detail.
Shown in composition graphs 1-Fig. 3, preferably, described radioactive source pin 123 is in needle-like structures; Radioactive source pin 123 in needle-like structures can conveniently insert in source needle tray 125.
Shown in composition graphs 1-Fig. 3, preferably, the diameter of described radioactive source pin 123 is between 1.00mm-5.00mm, and length is between 1.00mm-7.00mm.
Preferably, the weight of described radioactive source pin 123 is between 0.005g-0.1g.
Shown in composition graphs 1-Fig. 3, the length of described high specific activity radiation source core target 12 is between 100.00mm-300.00mm.
Below on the basis of Fig. 1-Fig. 5, composition graphs 6 and Fig. 7 make a detailed description to the novel choke plug assembly 100 of the present invention:
Novel choke plug assembly 100 of the present invention, radioactive source is prepared for presurized water reactor, wherein, described novel choke plug assembly 100 comprises web joint 2 and in the nuclear reactor core of presurized water reactor, absorbs neutron and produce radioisotopic radioactivity rod 1, described web joint 2 has the installation portion 21 installing described radioactivity rod 1, described installation portion 21 is in dispersion distribution, particularly, described installation portion 21 is mounting hole, described radioactivity rod 1 is installed on described installation portion 21 in unsettled correspondence, is parallel to each other between described radioactivity rod 1; The present invention is in order under maintenance original function (that is: limited reactions heap Core cooling agent bypass flow) impregnable prerequisite, also have and produce isotopic function, therefore the radioactivity rod 1 of the invention described above is devised to replace existing stainless steel choked flow stopper, and be installed on the installation portion 21 of web joint 2, thus form novel choke plug assembly 100 of the present invention.
Particularly, under normal circumstances in presurized water reactor, existing choke plug assembly all has 24 stainless steel choked flow stoppers, therefore, each novel choke plug assembly 100 of the present invention arranges 24 radioactivity rods 1 of the present invention equally, thus ensure that novel choke plug assembly 100 limited reactions heap Core cooling agent bypass flow function of the present invention is not affected; But it should be noted that, the selection of the quantity of the radioactivity rod 1 of novel choke plug assembly 100 of the present invention, those skilled in the art are under the prerequisite of technical scheme provided by the present invention, according to the radioisotopic output of production, can make decision without the need to any performing creative labour, in this not go into detail.
Continue shown in composition graphs 7, for the ease of the flowing of the heap in-core cooling medium of nuclear reaction, described web joint 2 runs through and offers discharge orifice 3.
Continue shown in composition graphs 6 and Fig. 7, novel choke plug assembly 100 of the present invention also comprises centre pilot cylinder 4, the upper end of described centre pilot cylinder 4 is in sliding up and down and the flexible center being arranged in compressing member 5, and the lower end of described centre pilot cylinder 4 is fixedly connected with described web joint 2.
Continue shown in composition graphs 6, novel choke plug assembly 100 of the present invention also comprises pin 6, the upper end of described pin 6 is fixed on described compressing member 5, and described centre pilot cylinder 4 is in vertically offering gathering sill 41, and the lower end of described pin 6 is arranged in described gathering sill 41 in what slide up and down; By guiding and the restriction of described pin 6, make compressing member 5 can centrally guide cylinder 4 further accurate in the vertical direction lower slider.
Continue shown in composition graphs 6, in order to the acting force making compressing member 5 can better apply compression to web joint 2; Novel choke plug assembly 100 of the present invention also comprises volute spring 7, and it is outer and between described compressing member 5 and described web joint 2 that described volute spring 7 is sheathed on described centre pilot cylinder 4; During use when compressing member 5 is subject to downward acting force, compressing member 5 under the guide effect of pin 6 centrally guide cylinder 4 slide straight down, thus volute spring 7 is compressed, and then make volute spring 7 compress web joint 2, along with compressing member 5 constantly slide downward, volute spring 7 decrement constantly increases, thus the downward acting force that volute spring 7 gives web joint 2 also progressively increases; Therefore make compressing member 5 give web joint 2 acting force in progressively progressive by volute spring 7, avoid the two and apply pressure by rigid contact and easily cause the situation of damage to occur, further ensure that the security of the reactor core of nuclear reactor.
Shown in composition graphs 1-Fig. 7, because the existing stainless steel choked flow stopper apparatus be installed on web joint 2 has the radioactivity rod 1 that high specific activity radiates source core target 12 to replace by the present invention, thus form novel choke plug assembly 100, wherein this high specific activity radiation source core target 12 absorbs neutron and produces the radioactive isotope of high specific activity in nuclear reactor core, and the radioactivity rod replacing stainless steel choked flow stopper has the function of the restriction Core cooling agent bypass flow same with stainless steel choked flow stopper, this radioactivity rod 1 is owing to having high specific activity radiation source core target 12 simultaneously, therefore this radioactivity rod 1 can also produce the radioactive isotope of high specific activity, therefore novel choke plug assembly 100 of the present invention does not affect the original function of restriction Core cooling agent bypass flow, and novel choke plug assembly 100 of the present invention, as the fixed associated component of reactor core, does not participate in the reactive adjustment of reactor core, preparing radioisotopic while, thus do not affect the safe operation of reactor, radioactive source pin 123 (i.e. target piece) simultaneously in novel choke plug assembly 100 of the present invention is positioned at reactor core active section, all the time reactor core irradiated site is in, irradiation dose is stablized, radioactive isotope quality is high, presurized water reactor is utilized to prepare the radioactive isotope of high specific activity, can under the prerequisite guaranteeing reactor core safety, significantly improve the utilization ratio of neutron, thus make the present invention be applicable to large quantities of PWR nuclear power plant main flow heap-type put into commercial operation and built, radioactive isotope production lot is large, remarkable in economical benefits, industry can be met greatly, agriculture and medical demand.
Separately, radioactive source pin 123 irradiation involved in the present invention forms radioisotopic principle of work, for well known to those of ordinary skill in the art, is no longer described in detail at this.
Above disclosedly be only the preferred embodiments of the present invention, certainly can not limit the interest field of the present invention with this, therefore according to the equivalent variations that the present patent application the scope of the claims is done, still belong to the scope that the present invention is contained.