Dummy variable decentralization
this is the reason for the decentralization of digital currencies such as bitcoin, Ruitai and Qianjin.
According to the data types of independent variables and regulatory variables, it can be divided into the following four situations:
< / UL > 0
For the so-called "mb layer", which is lack of biological fossils and isotopic age data in petroleum exploration, its geological age can not be determined at present, This brings many difficulties to the further study of petroleum geology. ESR (ELECRTON spin resonance) technique is used to measure the relative concentration of oxygen vacancy in quartz, and to find the correlation between the relative concentration and the total dose (which can be converted into sedimentary age) so as to determine the geological age of the "mb layer" becomes an important means. ESR technology can easily upgrade stratigraphic units to chronostratigraphic units, which is beneficial to stratigraphic correlation between various petroliferous basins or other sedimentary basins, around and inside each basin, and even to the international standard stratigraphic sections. As far as chronology is concerned, it is also helpful to open up new ideas
The principle and general situation of ESR dating of oxygen vacancies in1 quartz. Rocks exposed on the earth's surface are broken and decomposed by weathering. They are transported and deposited on land and sea by water, wind and other forces. When these materials are exposed to ionizing radiation caused by uranium, thorium, potassium and other radioactivity in themselves and the surrounding materials, some defects and free electrons are formed in the materials. When these free electrons are trapped by other impurities or defects, they will form trapped electron centers (E ', Ge, Ti centers of quartz), or hole centers (OHC, Al centers of quartz) when the original atoms lose electrons. These trapped electron centers and hole centers are magnetic because they contain uncoupled electrons. The concentration of uncoupled electrons in the material increases in direct proportion to the burial time. ESR spectrometer is the only modern analytical instrument for testing uncoupled electrons. The concentration of uncoupled electrons is detected by the microwave absorption effect of uncoupled electrons. The absorbed microwave energy is proportional to the number of spins, which can be displayed in ESR spectrum, so as to achieve the purpose of dating
ESR dating is mostly used in Quaternary geology. A.l.odom and w.j.rink (1988) reported for the first time that the ESR signal intensities of E ′ centers and peroxy radical in granite quartz are related to the radioisotope ages of samples. They are believed that these centers are caused by a recoil in quartz crystal. Therefore, they suggest that e ′ centers and peroxy radical in quartz can be used as geochronometers. They also pointed out that ring the whole geological period, oxygen vacancies in quartz were naturally accumulated and relatively stable, but they failed to propose a method to test oxygen vacancies. After its publication, this paper has received a great response and is considered as a breakthrough in ESR dating of quartz. The famous ESR expert R. GRUN (1989) gave a very high evaluation on this. He thought that the ESR technology can be used to measure the whole history of the earth with quartz samples. S. Toyoda et al. (1992) reported that the oxygen vacancy concentration of quartz in volcanic rocks is positively correlated with its radioisotope age. They used thermal activation technique to test the ESR signal of E 'center in quartz to replace the relative concentration of oxygen vacancy, which greatly simplified the experiment and made it easier to measure accurately. They think it's natural β and γ X-ray is the main reason for the increase of oxygen vacancy concentration in quartz ring the long geological period. According to this point of view, they converted the radioisotope age into the total dose received by quartz and correlated it with the oxygen vacancy concentration of quartz. As a result, the correlation coefficient was well improved. Therefore, they proposed that the oxygen vacancy concentration of quartz can be used as a geochronometer in the Ma GA range, and their research range is 12-1700ma
Fig. 1 Structure Model of oxygen vacancy and E ′ Center (modified according to w.j.rink, 1991)
the big circle represents silicon, the small circle represents oxygen, and the arrow represents electron
a-normal lattice position; B-displaced oxygen, forming oxygen vacancy; The oxygen vacancy in natural quartz is not easy to be detected, and the e ′ center is a very characteristic signal of quartz. S. The key technology of Toyoda experiment is to test the ESR signal of thermally activated e 'centers instead of the relative concentration of oxygen vacancies. Therefore, it is necessary to introce the relationship between E' centers and oxygen vacancies. The structural model of oxygen vacancy and E 'center of quartz is shown in Fig. 1
It can be seen from Fig. 1 that the E 'center is a paramagnetic center formed by an electron trapped by an oxygen vacancy. Without oxygen vacancy, there would be no e' center. There are not only deep level defect electrons such as e 'center, but also many shallow level defect electrons in quartz crystal. When heated to a certain temperature, some shallow level defect electrons can be excited and trapped by oxygen vacancies to form e 'centers until all oxygen vacancies are filled with electrons to form e' centers. On this basis, the ESR signal of E 'center can be measured to replace the relative concentration of oxygen vacancy The reports of American and Japanese scholars are of great academic significance, revealing many new ESR characteristics of quartz, and laying a theoretical foundation for ESR dating of pre quaternary quartz. The ESR dating of pre Quaternary sediments from several oil fields in China was carried out by using S. Toyoda's experimental method in order to find out the correlation between oxygen vacancy concentration of quartz in sediments and total dose (which can be converted into age)2 samples and experiments
the samples from Liaohe Oilfield, Shengli Oilfield and Bohai oilfield are taken from drilling cores, the samples from Pearl River Mouth Basin in South China Sea are taken from drilling cuttings, the samples from Kuqa River section in Tarim Basin are taken from field outcrops, and the samples are basically taken from sandstone. The samples were crushed by jaw crusher and disc crusher, and some samples were relatively loose, which were only grinded by hand. The 0.1-0.25 mm size fraction was sieved in water, the organic matter was removed by adding h < sub > 2 < / sub > o < sub > 2 < / sub > and washed clean. The carbonate was removed by soaking in 6 mol / L HCl solution for more than one day and then washed clean. Then, the samples were etched in concentrated HF for 30-60min to remove the surface layer of quartz damaged by a radiation, washed to neutral, dried at 40 ℃, and finally any magnetic minerals were removed by magnetic separator. The purity of the selected quartz was determined by X-ray diffraction technique so as to normalize the measured ESR signal. The samples treated according to S. Toyoda's method were thermally activated. The signal of E ′ center of thermally activated quartz was measured by ecs-106 ESR spectrometer of Bruker company (with high sensitivity 4103tm cavity) instead of oxygen vacancy concentration. Test conditions: room temperature, X-band, magnetic field scanning range (348 ± 5) MT, conversion time 5. 12ms (1024 points), time constant 40. 96ms, magnification 1 × 10 < sup > 5 < / sup >, microwave power 0.01mw, continuous test for 3 times. In addition, a part of the original sample was grinded for 160 mesh, and the contents of u, th and K < sub > 2 < / sub > o were measured by laser uranium analyzer, colorimetric spectrophotometry and atomic absorption spectrometry respectively to calculate the annual dose contribution of environmental substances. Figure 2 is a typical ESR spectrum of the sample
Fig. 2 typical ESR spectrogram of samples
3 geological application
3.1 Liaohe depression
samples were taken from the Zhanjin sandstone in the depression, from the top of the first member of Dongying Formation to the bottom of the third member of Shahejie formation, with the age ranging from 24.7ma to 42.4ma, and the corresponding total absorbed dose ranging from 95095gy to 212424gy. The measured normalized oxygen vacancy concentration is correlated with the corresponding total absorption, and the correlation coefficient is 0.94, showing a good linear relationship (Ye, y.g., 1998). Based on the above results, ye Yuguang et al. (1996) proposed a model for ESR dating of pre Quaternary sediments in petroliferous basins. A large number of experiments show that the ESR signals of oxygen vacancies and E ′ centers are often not observed in natural quartz samples which have not been broken and weathered. The signals observed now are formed after breaking and weathering. The sediments in Liaohe depression are generally
Fig. 3 Relationship between oxygen vacancy concentration of quartz and total dose received in the sediments of Liaohe basin
. The measured discrete data points· The regression data points are from Archaeozoic and Proterozoic around the depression. These ancient rock series can only be transported and deposited in the depression after weathering and fragmentation. The weathering time is short compared with the burial time of the sediments. Most of the observed ESR signals of quartz oxygen vacancies and E 'centers are formed after burial. On the other hand, these weathered materials only exist in the surface layer of the ancient rock series. Only after they are transported, can the weathering continue to the deep part of the rock. The core of this model is that the oxygen vacancy of quartz in sediments existed much less before deposition (ring weathering and stripping) than ring burial (Paleogene Triassic). That is to say, the oxygen vacancy concentration of quartz in the sediments of the depression we have tested is mainly affected by u, th and K in the environmental materials after deposition and burial β and γ Proced by ionizing radiation of X-rays. This model can explain the experimental results of Liaohe depression
The geological conditions of Shengli Oilfield are very complicated. Nevertheless, we have successfully established ESR dating sequences from the first member of Dongying Formation to the first member of Kongdian Formation in Dongying sag, thus for the first time putting forward the absolute age sequence of Eogene in Shengli Oilfield, which complements and perfects the Paleogene, Miocene world limit, early and late Oligocene world limit, Eocene and late Oligocene world limit The corresponding absolute age is given. These ESR ages have been accepted by Shengli Oilfield. Based on previous data and combined with ESR ages, they compiled a new Cenozoic geological age representative of Shengli Oilfield. Figure 4 shows the relationship between ESR signal and absorbed dose of oxygen vacancy in Dongying depression, with correlation coefficient of 0.983.3 Kuqa River geological section
Kuqa area is the most complete exposed area of Mesozoic and Cenozoic strata in Tarim Basin, especially Kuqa River section. We have systematically sampled the upper Permian to Neogene of this section. Due to thermal action of intrusive rocks and spontaneous combustion of coal seams in Late Triassic and Middle Jurassic, oxygen vacancies in quartz from Late Permian to Middle Jurassic were partially annealed (Ye Yuguang et al., 1998). The ESR signals of oxygen vacancies in quartz from Qigu formation of Upper Jurassic to Kangcun formation of Neogene (all in the West Bank of Kuqa) and the total dose received are plotted in Fig. 5, showing a significant linear relationship, with a correlation coefficient of 0.97
Fig. 4 the relationship between ESR signal intensity and absorbed dose in Dongying depression
Fig. 5 the relationship between ESR signal intensity and absorbed dose in Kuqa River quartz oxygen vacancy
I is the linear regression of 9 samples; II is linear regression of 10 samples
3.4 Bohai oilfield
took two samples in the oilfield, and took 59 sandstone cores to do ESR dating experiment. Bohai Petroleum Research Institute gave a higher evaluation to our experimental results, and considered that the success rate of ESR method is 70%, which is much higher than that of K-Ar method of 17% in this area. Figure 6 shows the correlation between the ESR signal of oxygen vacancy in quartz and the dose received, with a linear correlation coefficient of 0.94
Fig.6 linear relationship diagram of Bohai oilfield
3.5 Pearl River Mouth Basin
according to a large number of paleontological data, the above Pearl River Formation in Pearl River Mouth Basin is marine strata, at that time, the basin has been submerged by seawater to form a unified basin, and the sediments mainly come from the northern continent. The upper strata of Zhuhai Formation and Enping formation consist of both continental and marine strata
1. Network virtualization: for example, one virtual multi network equipment, such as Cisco's VDC and Huawei's vs technology; Multi virtual one, such as Cisco's VSS / VDC, Huawei's CSS, Huasan's IRF and other technologies, as well as network vertical virtualization, such as Cisco's Fex technology
2. Storage Virtualization: to put it bluntly, it is to combine independent storage resources to form a resource pool and jointly provide external services. Instead, as before, host a can only use storage a, and host B can only use storage B. Now host a and host B can use storage (a + b)
3. Computing virtualization: commonly known as virtual machine
the advantage of virtualization is that it can simplify operation and maintenance, provide hardware utilization, rece costs, and increase the flexibility of business deployment.
Eric Siebert, an expert in virtualization, covered various virtualization deployment processes in his article "virtualization deployment":. Next, I will expand and describe each step he described, and add some additional considerations and problems that need to be clarified
- build a virtual environment. In this step, install the server, load the selected virtualization management program (such as esxserver or Hyper-V), install the central management platform (Microsoft's scvmm or VMware's vCenter), and finally add the virtual host to the management platform
- configure the virtual environment. In this step, configure the static IP address of the server, correct the parameters of the network system, and configure VLAN if necessary
- Security of virtual environment. In this step, set a complex login password for all virtual hosts, add a group to the windows ad server, and then add the newly added and authenticated VMware administrator to the group. Next, authenticate the group as the administrator of VMware evcenter and delete the domain management account. If you have other types of users who need to manage their virtual machines (such as SQL administrator or development environment), please consider adding additional groups and new roles
- Construction of virtual environment. In this step, new virtual machines are added to the virtual architecture. By creating new virtual machines and installing new operating systems, or with the help of tools such as converter enterprise of VMware (described in the second part), the transformation from physical machines to virtual machines (P2V) is completed, and virtual applications are downloaded from them. Please select the conversion mode of your P2V migration
- monitoring of virtual environment. In this step, at least you want to be able to monitor the new virtualization host through the basic management tools, which can be realized with the help of the simple graphical interface provided in the free ESX iserver and vSphere client. Further, you may want to use some advanced performance management monitoring provided by vCenter. By setting, you can notify the designated administrator when a performance problem occurs. As you go deeper, you will probably want to use more complex performance monitoring tools, as we mentioned in "management tool selection"
- maintenance of virtual environment. In the environment of a single virtual host and a group of virtual machines, maintenance is a very simple task. However, if your system architecture is extended, maintenance tools will be used. Please do not confuse with the concept of virtual environment monitoring. The most important work in the maintenance phase is patch management. Fortunately, if you are purchasing VMware vSphere, update manager is included in all commercial versions. Through the update manager, you can manage the patch upgrade of the existing server, including the patch upgrade involving some operating systems and some applications. If you also use VMware's DRS (distributed resource scheler) function, esxserver can be upgraded without downtime
- backup of virtual environment. Just like using physical server, it is very important to build backup mechanism for virtual server. When you complete the virtualization of the physical server, an effective backup mechanism also needs to be built on the same day. Although virtual machine backup can also be realized by existing traditional backup software, it is not the best choice for virtual environment backup. By using backup software customized for virtual machines, they can know which physical host all virtual machines are on, and then they can identify when they need to migrate virtual machines to the new host. These backup software can support Microsoft's VSS (Volume Shadow Copy Service), ensure the continuous backup of applications, and provide some special additional functions, such as file level and image level backup, data plication and data replication. Typical backup software for virtualization environment includes: VMware & # 39; sDataRecovery,VeeamSoftware' Sbackup and vizioncorev Ranger
- fault diagnosis of virtual environment. We certainly hope that after the new deployment of virtualization architecture, we will not encounter any problems. But if a problem occurs, we need documentation and diagrams about the virtualization environment. And you need all the equipment - servers, sans, networks, storage and virtual software - related, after-sales support information and contact windows
- training and documentation. Although this last step is not mentioned in Siebert's article, training and documentation are also important steps for successful deployment. All good deployment plans should include training for other administrators in the company and documentation on the new virtualization architecture and daily management tasks. Although for other administrators, virtual server may not be very different from physical server. But the management and fault diagnosis of virtual machine is completely different from that of physical machine. Therefore, training courses are necessary so that the support staff and main administrators can understand the changes in the physical system architecture they are facing and how to complete the same work in the virtual machine environment
avoid the pitfalls in virtualization deployment
although we can avoid problems in virtualization deployment as long as we follow the installation plan based on the above installation steps, there are still some pitfalls that need to be paid attention to ring installation. Let's illustrate some similar problems as follows:
- underestimates the amount of memory required by the virtualization host. Although you use VMware's memory over allocation technology, it is likely that the virtualization host in the proction environment will use the total amount of memory installed. Many virtualization hosts used in the proction environment are installed with 16GB or more memory
- underestimates the storage space required for shared storage. Although the new version of VMware provides thin provisioning, which can help users rece the storage space occupied by virtualization, Virtual Opportunities quickly occupy a large amount of storage space in shared storage. If possible, use VMware's thin provisioning or SAN storage to rece the occupancy of hard disk space. You can also reclaim the over allocated storage space by using vizioncore's voptimizer Pro tool
- virtualization is much faster than training and document collection. It's easy to virtualize a physical server in a few minutes, but it takes much longer to train senior administrators and upgrade documents than virtualization itself. Therefore, we must avoid virtualization of all physical environments at the same time, and then face a long process of virtual machine fault diagnosis. And virtualization of some applications without permission of application administrator
- over allocation. When initializing the installation, it is easy to over allocate virtual machines, because the process of creating a new virtual machine seems so simple. Like the management of physical servers, we should only allocate the virtual machines needed by the business. Each new virtual opportunity takes up additional server resources and brings additional operating system license purchase costs
- missing test. It's very simple to test the application on virtual machine, just need to do the migration from physical machine to VMware Workstation virtual machine, and then verify the results in virtual machine. In my experience, 99% of the applications can work on the virtual machine, but please pay close attention to those image processing intensive applications (such as running CAD on the virtual desktop), or those applications that need to buy additional software licenses. After verifying the compatibility of the software, we also need to consider the supporting ability of the virtual machine architecture: whether it can meet the computing requirements of the application and provide the same performance as the physical server< br />
A virtual team is a team in which people are scattered in different places over a long distance but work together through remote communication technology. The virtual team's personnel are scattered in distant places, which can be in different cities, or even across countries and continents. People can span different organizations. Working hours can be staggered. Communication depends on modern communication technology. They work together to accomplish common goals and tasks
virtual teams are usually described as a loose organizational structure with little control hierarchy. Researchers mentioned that virtual team is a boundless connection, which changes constantly according to the needs of information processing
extended data:
compared with traditional team form, virtual team has obvious advantages:
1, talent advantage
2. Information advantage
3. Competitive advantage
4. Efficiency advantage
5. Cost advantage
team characteristics of ordinary team:
1. The team is goal oriented
2. The team is based on cooperation
The team needs common norms and methods Team members complement each other in technology or skills